Tailored fiber placement

Tailored fiber placement (TFP) is a textile manufacturing technique based on the principle of sewing for a continuous placement of fibrous material for composite components. The fibrous material is fixed with an upper and lower stitching thread on a base material. Compared to other textile manufacturing processes fiber material can be placed near net-shape in curvilinear patterns upon a base material in order to create stress adapted composite parts.
History.
TFP technology was introduced in the early 1990s by the IPF Dresden. At the beginning handmade stitched reinforcement structures (preforms) were manufactured initialized by an industry inquiry about stress adapted fiber-reinforced plastic (FRP) parts with a curvilinear pattern. An adaptation of this method to industrial embroidery machines, by using the sewing capabilities of those automates, was implemented in the mid-90s. The technology was named Tailored Fiber Placement, which describes the variable axial near-net-shape fibre placement capabilities. Nowadays, the Tailored Fiber Placement is already in several companies a well-established textile technology for dry preform manufacturing applying TFP machines by the manufacturer TAJIMA.
Principle of the technology.
Based on embroidery machinery used in the garment textile industry, the machines have been adapted to deposit and stitch fiber roving material onto a base material. Roving material, mostly common carbon fibers, from about 3,000 up to 50,000 filaments can be applied. The preform is produced continuously by the placement of a single roving. The roving material pulled off a spool is guided by a pipe which is positioned in front of the stitching needle. The roving pipe and the frame, where the base material is fixed onto, move synchronized stepwise to perform a zigzag stitch relative to needle position. The stitching head equipped with roving spool, pipe and needle can rotate arbitrarily 360 degrees. During each stitch the upper thread is pulled through the base material and looped around the lower thread spool. Hence a double backstitch is performed. Currently, up to 800 stitches per minute can be achieved.
The base material can be a 2D-textile such as woven or non-woven fabric or a matrix-compatible foil material for thermoplastic composites. The stitching path can be designed in form of a pattern either with the help of classical design embroidery software or more recently by use of 2D-CAD systems. Afterwards necessary information of the stitch positions are added to the pattern with the help of so-called punch software and finally transferred to the TFP machine.
The infiltration of TFP-preforms can be done with conventional processing techniques such as resin transfer moulding, vacuum bag molding, pressing and autoclave moulding. In the case of thermoplastic composites the matrix material and the reinforcement fibers can be placed simultaneously e.g. in the form of films or fibers. The base material can then be a thermoplastic foil which melts during the consolidation process and becomes part of the matrix. This type is ideally suited for deep-drawn TFP-preforms.
Advantages of the TFP technology.
Optimizations using TFP over other laminate technologies
Optimization one: Reduce waste material
One of the leading material costs of many traditional carbon fiber composite construction techniques, includes the large amount of waste material generated. In many hand lay-up processes that use carbon fiber woven material, waste materials can easily account for 50% or more of the total weight of carbon used. This waste is generated as the fabric is initially cut before impregnation with the matrix material. Additional waste is generated after the composite has cured during the post processing steps where the shape is further refined. Tailored fiber placement is unique in its ability to reduce waste material and thereby optimize material cost. By controlling the path of the tow material as it is stitched into the desired geometry, material is only placed where it is needed in the final preform. Areas of fabric that would have to be cut out in traditional laminate design are simply left unstitched. This process reduces both the initial waste produced when cutting woven fabrics to shape and reduces post processing waste due to the ability to conform to complex geometries.
Optimization two: Hybrid carbon fiber and glass fiber composites
An additional drawback of traditional laminate processes is the inability to rapidly change materials volumetrically to benefit from their combined advantages. Tailored fiber placement is a method for quickly and effectively creating these multi-material composites. For example, when a structural analysis is performed on a part, it might be discovered that the part only requires areas of localized stiffness. In this case, carbon fiber, with its properties of high stiffness, can be placed exactly at the areas and geometries of the part requiring high stiffness. It would be cost-inefficient to fill the entire part with highly stiff carbon fiber, especially when that stiffness is not required in certain locations. Therefore, to further reduce cost, the areas around the carbon fiber stiffened geometry that do not require high stiffness can be filled in with lower cost materials such as glass fiber or even hemp fibers. Tailored fiber placement allows these material transitions to seamlessly occur.
Optimization three: Tunable fiber alignment and geometric tailor-ability
Once of the largest benefits of using tailored fiber placement to optimize a design, is the ability to precisely control where each tow of carbon fiber is placed in a design. This allows the composites designer to further optimize the materials properties, reducing the need for additional material. For example, complex tow paths of carbon fiber can be embroidered to perfectly resist the applied loads. By aligning fibers to their principal stresses, additional mechanical support is provided without using additional material. Further optimizations can occur by selectively reinforcing holes and circular drill points. In traditional laminate design, these holes can serve as areas of crack propagation due to the orthogonal nature of the woven fabric used. Tailored fiber placement can be used to selectively reinforce around these holes with curvilinear patterns reducing the effective initial crack propagation locations. This can allow for a thinner material at the hole’s location, and even potentially the removal of metal reinforcing washers.
Optimization four: Tunable localized thickness
Another interesting optimization that can occur when using tailored fiber placement in carbon fiber composites utilizes tunable thickness of the process over a given area. In traditional laminate design, carbon fiber composites are presumed to have even thickness. However, tailored fiber placement does not have such a height restriction. In combination with well-designed molding and fixtures, carbon fiber preforms can create localized thickness in highly complicated and varied geometries. In classical beam theory, the moment of inertia for a rectangular beam can be calculated by:
Where the height of the material (h) is shown to have cubic influence on the moment of inertia when compared to the base (b) length. This means that localized areas of height can be created with tailored fiber placement that significantly can help to better resist bending at that location. This optimization allows for decreased material usage to achieve the same, if not improved, bulk material properties when compared to other composite processes. ZSK offers machines that can lay fibers up to 8 mm thick. This averages out to about 8 layers of 50 K carbon fiber roving. This thickness can be uniform over the entire surface of the preform part or can be selectively placed in key structural areas for additional material conscience mechanical support.
Optimization five: Comingled fibrous materials
One of the drawbacks of traditional composite laminate manufacturing can be the long cycle times required to properly cure a thermoset resin. New materials, called comingled fibers, have been created to decease the processing time. In comingled fibers, a carbon fiber tow has additional thermoplastic matrix materials added directly into its fiber structure. These comingled materials can be stitched in the same manner as other tailored fiber placement composite materials. However, these preforms can quickly be thermocycled in a heated press to rapidly reduce the cycle processing time. Traditional thermoset composite materials using resin transfer molding can require between 30 minutes to 40 hours to properly set and cure a single piece. Tailored fiber placement of comingled materials allows for the placement of both the reinforcing fiber, and the matrix material in the same preform. As the preform is heated, the liquid matrix is distributed directly into the carbon fiber allowing proper wetting. The tailored fiber placement of comingled fibers eliminates the need for additional resins and can significantly reduce materials cost. Additionally, the desired fiber to volume fraction is created during the comingling step, increasing the uniformity of the composite material from batch to batch. Finally, these comingled fiber composites are a step towards a more sustainable carbon fiber composite due to their ability to be re-melted into new forms at the end of their lifecycle.
Optimization six: Machine versatility without retooling
Another significant process optimization that occurs with tailored fiber placement when compared with other composite processes, is the ability for the production machine to rapidly change its production from one design to a completely different design without any additional retooling of the machine. This can allow the same machine to seamlessly transfer from producing car parts in the morning shift to sporting equipment in the afternoon shift. Additionally, tailored fiber placement can allow the same machine to produce one prototype design at a time to investigate a process and troubleshoot it without wasting excess material, to creating a full production run simultaneously. This rapid prototyping to production capability, in combination with the ability for a machine to run many different types and geometries of parts in rapid succession, allows for more versatile projects to be run on the same machine. This reduces the cost of setting up a new machine each time a new design is generated. In conclusion, the six methods of optimization for carbon fiber composites briefly presented show some of the advantages of tailored fiber placement over traditional composite processes. It is hoped that the combination of these optimization methods, in conjunction with a trend of decreasing carbon fiber material costs, will allow a new class of ubiquitous and highly engineered materials to further improve consumer use cases like fuel efficiency.
Applications for structural parts.
The TFP technology allows the fabrication of preforms tailored for specific composite components or reinforcements. Applications range from highly accelerated lightweight parts for industrial robots or blades for compressors up to CFRP aircraft parts, e.g. I-beam for the NH-90 helicopter, automotive structures and bicycle parts.
TFP for self-heating tooling and components.
Using the carbon roving as an electric heating element offers the possibility to manufacture composite structures with embedded heating layers. Due to the high flexibility in the design of the heating pattern an overall nearly equal heat distribution can be achieved. In terms of applications this technology embedded in solid composite molds is very beneficial for resin consolidation and binder activation in out-of-autoclave processes. Composite molds show similar heat expansion properties as the manufactured composite parts. The lower thermal mass of composite tools compared to common metal molds help to shorten the manufacturing cycle of FRP parts and decrease the energy need for the production process. Further the TFP heating elements can be applied in CFRP wing structures of airplanes or blades of wind mills for anti- and de-icing tasks. The TFP structure embedded in elastomeric heating bags can applied to manufacturing or repairing processes of composite parts.


Toyota Trailer T10

The Toyota Trailer T10 was a trailer manufactured by Toyota that was designed to go behind the Toyota Land Cruiser or the Toyota Weapon Carrier using a ring hitch.


Reticulation (metalwork)

In metalwork, reticulation refers to a decorative surface finishing technique involving the application of localised heat to the surface of a metal object. Reticulation is typically performed on alloys of silver and copper or of gold and copper.
Reticulation exploits the difference between the melting temperature of an unalloyed metal and that of an alloy of the metal; by depleting the base metal content in the surface layer, a piece can be heated in such a manner so as to render the interior of the piece molten while leaving the surface of the piece intact. The reticulated surface is formed by the thermal expansion and contraction of the interior metal which is effected by deliberate variation in the application of localised heat.
In the late 19th century, reticulation was used as a decorative technique by Russian goldsmiths such as Fabergé, where the process was referred to as "samorodok" (lit. "born by itself"). Use of the technique spread to the Nordic and Scandinavian countries where it was applied in the creation of objects such as cigarette boxes, card cases, eyeglass cases, and flasks.


Fill and finish

In the pharmaceutical industry, fill and finish (also referred to as fill finish, fill-finish or fill/finish) is the process of filling vials with vaccine, biological and pharmaceutical Drug Substances (DS) and finishing the process of packaging the medicine for distribution. Many vaccine manufacturers use third parties to fill and finish their vaccines.
The fill/finish process is a common bottleneck in the manufacturing and deployment of vaccines.
To address this problem, in 2013 the U.S. federal government created the Fill Finish Manufacturing Network, a network of third-party provider contracts intended to perform fill and finish operations for vaccines against future infectious diseases. As part of its response to the COVID-19 pandemic, the UK government has provided financial support for fill and finish operations.


Induction brazing

Induction brazing is a process in which two or more materials are joined together by a filler metal that has a lower melting point than the base materials using induction heating. In induction heating, usually ferrous materials are heated rapidly from the electromagnetic field that is created by the alternating current from an induction coil.
Materials and applications.
"Induction brazing is suitable for many metallic materials, with magnetic materials being heated more readily. Where ceramic materials are involved, heating will most likely occur by conduction from surrounding metallic parts, or the use of a susceptor" (Sue Dunkerton, 1).
According to Ambrell Group Application Labs talking about filler metals: Silver is frequently used for induction brazing because of its low melting point. Silver-copper eutectic brazes have melting temperatures between 1100°F and 1650°F. Aluminum braze, the least common, has a melting temperature of 1050°F to 1140°F. Copper braze, the least expensive, has a melting temperature of 1300°F to 2150°F. (p1)
The filler can be manually applied but because of the more common semiautomatic production a preloaded joint is more commonly used to speed the operation and help to keep a more uniform bond.
Benefits.
There are specific reasons to use induction heating for industrial brazing. These include selective heating, better joint quality, reduced oxidation and acid cleaning, faster heating cycles, more consistent results and suitability for large volume production.
Selective heating.
Induction heating can be targeted to provide heat to very small areas within tight production tolerances. Only those areas of the part in close proximity to the joint are heated; the rest of the part is not affected. Since there is no direct contact with the part, there is no opportunity for breakage. The life of the fixturing is substantially increased because problems due to repeated exposure to heat (such as distortion and metal fatigue) are eliminated. This advantage becomes particularly important with high-temperature brazing processes.
With efficient coil design, careful fixturing and consistent part placement, it is possible to simultaneously provide heat in different areas of the same part
Better quality joints.
Induction heating produces clean, leak proof joints by preventing the filler from flowing in areas that it shouldn't flow. This ability to create clean and controllable joints is one of the reasons that induction brazing is being used extensively for high-precision, high-reliability applications.
Reduced oxidation and cleaning.
Flame heating in a normal atmosphere causes oxidation, scaling and carbon build up on the parts. To clean the parts, applications of joint-weakening flux and expensive acid cleaning baths have traditionally been required. Batch vacuum furnaces solve these problems, but have significant limitations of their own because of their large size, poor efficiency and lack of quality control. Brazing with induction reduces both oxidation and costly cleaning requirements, especially when a rapid cool-down cycle is used.
Fast heating cycles.
Because the induction heating cycle is very short in comparison to flame brazing, more parts can be processed in the same amount of time, and less heat is released to the surrounding environment.
“An induction brazing system quickly delivers highly localized heat to minimize part warpage and distortion. Brazing in a controlled vacuum or in an inert protective atmosphere can significantly improve overall part quality and eliminate costly part cleaning procedures” (Induction Atmospheres, 1).
Consistent results.
Induction brazing is a very repeatable process because variables such as time, temperature, alloy, fixturing, and part positioning are very controllable. The internal power supply of the RF power supply can be used to control cycle time, and temperature control can be accomplished with pyrometers, visual temperature sensors or thermocouples.
For processes, which involve medium to high production runs of the same parts, an automated part handling system is often utilized to further improve consistency and maximize productivity.
For the most part, induction brazing and soldering is done in an open-air environment but it can also be done in a controlled atmosphere when necessary to keep the parts completely clean and free of oxidation.
Induction brazing generally works best with two pieces of similar metal. Dissimilar metals can also be joined by induction heating but they require special attention and techniques. This is due to differences in the materials' resistivity, relative magnetic permeability and coefficients of thermal expansion. (p1)
General temperatures and times.
Source:


Sustainable packaging

Sustainable packaging is the development and use of packaging which results in improved sustainability. This involves increased use of life cycle inventory (LCI) and life cycle assessment (LCA) to help guide the use of packaging which reduces the environmental impact and ecological footprint. It includes a look at the whole of the supply chain: from basic function, to marketing, and then through to end of life (LCA) and rebirth. Additionally, an eco-cost to value ratio can be useful
The goals are to improve the long term viability and quality of life for humans and the longevity of natural ecosystems. Sustainable packaging must meet the functional and economic needs of the present without compromising the ability of future generations to meet their own needs. Sustainability is not necessarily an end state but is a continuing process of improvement.
Sustainable packaging is a relatively new addition to the environmental considerations for packaging (see Packaging and labeling). It requires more analysis and documentation to look at the package design, choice of materials, processing, and life-cycle. This is not just the vague "green movement" that many businesses and companies have been trying to include over the past years. Companies implementing eco-friendly actions are reducing their carbon footprint, using more recycled materials and reusing more package components. They often encourage suppliers, contract packagers, and distributors to do likewise.
Environmental marketing claims on packages need to be made (and read) with caution. Ambiguous greenwashing titles such as "green packaging" and "environmentally friendly" can be confusing without specific definition. Some regulators, such as the US Federal Trade Commission, are providing guidance to packagers
Companies have long been reusing and recycling packaging when economically viable. Using minimal packaging has also been a common goal to help reduce costs. Recent years have accelerated these efforts based on social movements, consumer pressure, and regulation. All phases of packaging, distribution, and logistics are included.
Sustainable packaging is not focused on just recycling. Just as packaging is not the only eco target, although it is still top of mind for many. Right or wrong, the packaging is frequently scrutinized and used as the measure of a company's overall sustainability, even though it may contribute only a small percentage to the total eco-impact compared to other things, such as transportation, and water and energy use.
Environmental Impacts.
Impacts of packaging originate from three main stages including feedstock sourcing, production of polymers and packaging, and the end of life treatment of the packaging. Emissions from each stage contribute to climate change, air pollution, acidification, and other environmental issues. Food waste is another prominent issue as one third of food meant for human consumption is lost. Sustainable packaging aims to address properties of food, for example chemical and microbiological properties, in order to limit packaging and food waste.
Criteria.
The criteria for ranking and comparing packaging based on their sustainability is an active area of development. General guidance, metrics, checklists, and scorecards are being published by several groups.
Government, standards organizations, consumers, retailers, and packagers are considering several types of criteria.
Each organization words the goals and targets a little differently. In general, the broad goals of sustainable packaging are:
Specific factors for sustainable design of packaging may include:
The chosen criteria are often used best as a basis of comparison for two or more similar packaging designs; not as an absolute success or failure. Such a multi-variable comparison is often presented as a radar chart (spider chart, star chart, etc.).
Benefits.
Some aspects of environmentally sound packaging are required by regulators while others are decisions made by individual packagers. Investors, employees, management, and customers can influence corporate decisions and help set policies. When investors seek to purchase stock, companies known for their positive environmental policy can be attractive. Potential stockholders and investors see this as a solid decision: lower environmental risks lead to more capital at cheaper rates. Companies that highlight their environmental status to consumers can boost sales as well as product reputation. Going green is often a sound investment that can pay off.
Alongside the environmental benefits of adopting sustainable packaging, eco-friendly packaging can increase sales, reduce packaging cost, and increase the image of a company's brand alongside the rising awareness spread regarding environmental impact. There has also been found a direct correlation between a company's implementation of sustainable packaging and a more sustainable supply chain management. Alternatives such as bio-based plastics that are abundant, low cost, and biodegradable, offer a possibility of reducing use of petroleum resources and carbon dioxide emissions.
Alternatives to conventional plastics.
Plastic packages or plastic components are sometimes part of a valid environmental solution. Other times, alternatives to petroleum and natural gas based plastic are desirable.
Materials have been developed or used for packaging without plastics, especially for use-cases in which packaging can't be phased-out – such as with policies for national grocery store requirements – for being needed for preserving food products or other purposes.
A plant proteins-based biodegradable packaging alternative to plastic was developed based on research about spider silk which is known for its high strength and similar on the molecular level.
Researchers at the Agricultural Research Service are looking into using dairy-based films as an alternative to petroleum-based packaging. Instead of being made of synthetic polymers, these dairy-based films would be composed of proteins such as casein and whey, which are found in milk. The films would be biodegradable and offer better oxygen barriers than synthetic, chemical-based films. More research must be done to improve the water barrier quality of the dairy-based film, but advances in sustainable packaging are actively being pursued.
Sustainable packaging policy cannot be individualized by a specific product. Effective legislation would need to include alternatives to many products, not just a select few; otherwise, the positive impacts of sustainable packing will not be as effective as they need in order to propel a significant reduction of plastic packaging. Finding alternatives can reduce greenhouse gas emissions from unsustainable packaging production and reduce dangerous chemical by-products of unsustainable packaging practices.
Another alternative to commonly used petroleum plastics are bio-based plastics. Examples of bio-based plastics include natural biopolymers and polymers synthesized from natural feedstock monomers, which can be extracted from plants, animals, or microorganisms. A polymer that is bio-based and used to make plastic materials is not necessarily compostable or bio-degradable. Natural biopolymers can be often biodegraded in the natural environment while only a few bio-based monomer bio-based plastics can be. Bio-based plastics are a more sustainable option in comparison to their petroleum based counterparts, yet they only account for 1% of plastics produced annually as of 2020.
Costs.
The process of engineering more environmentally acceptable packages can include consideration of the costs. Some companies claim that their environmental packaging program is cost effective. Some alternative materials that are recycled/recyclable and/or less damaging to the environment can lead to companies incurring increased costs. Though this is common when any product begins to carry the true cost of its production (producer pays, producer responsibility laws, take-back laws). There may be an expensive and lengthy process before the new forms of packaging are deemed safe to the public, and approval may take up to two years. It is important to note here, that for most of the developed world, tightening legislation, and changes in major retailer demand (Walmart's Sustainable Packaging Scorecard for example) the question is no longer "if" products and packaging should become more sustainable, but how-to and how-soon to do it.
ISO standards.
The ISO's series of standards relating to packaging and the environment were published in 2013:
Criticism.
Efforts toward “greener” packaging are supported in the sustainability community; however, these are often viewed only as incremental steps and not as an end. Some people foresee a true sustainable steady state economy that may be very different from today's: greatly reduced energy usage, minimal ecological footprint, fewer consumer packaged goods, local purchasing with short food supply chains, little processed foods, etc.
Less packaging would be needed in a sustainable carbon neutral economy, which means that fewer packaging options would exist and simpler packaging forms may be necessary.


Automobile safety rating

An automobile safety rating is a grade given by a testing organisation to a motor vehicle indicating the safety of occupants in the event of a motor vehicle crash, like with the New Car Assessment Program.
Australia.
In Australia, vehicle safety ratings are provided by ANCAP whose procedures are similar to Euro NCAP.
ANCAP took in 1999 some part of Euro NCAP procedures.
In 2018, ANCAP adopted the Euro NCAP protocols, with the scoring tweaked to the local conditions.
Europe.
In Europe, vehicle safety ratings are provided by Euro NCAP.
Euro NCAP provides motoring consumers with a realistic and independent assessment of the safety performance of some of the most popular cars sold in Europe.
Established in 1997 and now backed by seven European Governments, the European Commission and motoring and consumer organisations in every EU country, Euro NCAP has rapidly become a catalyst for encouraging significant safety improvements to new car design.
Global.
In the world, there are nine New Car Assessment Programs.
Eight out of the nine test programs makes their vehicle safety ratings with a count of stars included in the range (1 to 5 stars).
One test program, IIHS, makes a four level rating: Good, Acceptable, Marginal and Poor.
The differences between those various test programs include the range of tests and test configurations, the final rating computation, and the specification of models available in different markets.
Latin America.
Since 2010, Latin NCAP has been rating new cars for Latin America and the Caribbean with procedures similar to the ones used by Euro NCAP.
Latin NCAP results cannot be compared to Euro NCAP results:
Euro NCAP has 5 ratings: Frontal off-set, side, pole, whiplash and pedestrian tests, while Latin NCAP has 2: frontal off-set crash test and side impact test. Latin NCAP 2020-2022 is similar to Euro NCAP 2014.
The frontal crash test of Latin NCAP is similar to the frontal crash test of Euro NCAP.
United States.
In the U.S., an NCAP which provides vehicle safety ratings is run by the National Highway Traffic Safety Administration.


Collegium of Manufacturing

The Collegium of Manufacturing ("Manufaktur-kollegia"; also College) was an executive body in the Russian Empire from 1722, when the Collegium of Mining and Manufacturing split into two.


Projected tolerance zone

In geometric dimensioning and tolerancing, a projected tolerance zone is defined to predict the final dimensions and locations of features on a component or assembly subject to tolerance stack-up.


Leidolf

Leidolf was a manufacturer of optical equipment situated in Wetzlar, Germany. It was founded by Rudolf Leidolf in 1921, initially producing lenses for microscopes. In 1948 camera production was started and in 1962 the factory ceased operations. Leidolf is in no way related to Leitz (the manufacturer of Leica), even though Wetzlar has been the historical location for both companies. The company would later be acquired by Adams, producing the Adams model 351 and 352 sold by Montgomery Ward, before going bankrupt.


Virtual product development

Virtual product development (VPD) is the practice of developing and prototyping products in a completely digital 2D/3D environment. VPD has four main components:
VPD typically takes place in a collaborative, web-based environment that brings together designers, customers/consumers, and value chain partners around a single source of real-time product "truth". VPD enables practitioners to arrive at the right idea more quickly, and to accurately predict its performance in both manufacturing and retail settings, ultimately minimizing time to value, market failure potential, and product development costs.
Virtual process planning is a relatively new concept for manufacturing companies, although the concept has been in use for the construction industry for several years. BIM (building information modeling) is the system used by many construction, architectural and contracting firms. The detail and scheduling aspects are some of the more valuable aspects of the system. By utilizing virtual process planning, the entire production process can be designed to both maximize efficiency and avoid the trial and error method employed by most manufacturers.
Various software exists with differing levels of information. The placement of work stations, inventory, personnel and equipment can be valuable for space planning. The interaction of the previously mentioned can also be investigated, allowing the user to identify potential issues from safety, quality and ergonomic standpoints.
VPD is a result of constant efforts in a direction to overcome the limitations of conventional testing procedures. VPD allows a designer to take important design decisions at early stages based on test results, giving control over cost. ‘Virtual product development’ is a strategy for coordinating technology, processes and people to enhance the established product development process. It is a gradual process that efficiently builds up a product virtually. Thus any changes to be made in its design can be reflected into its physical properties, supply chain, distribution channel and ultimately into the customer view; without physically manufacturing the product.
VPD encompasses a wide variety of software tools to cover a product from the conception to the final design and even manufacturing. This path consists of various processes to be carried out at manufacturing level, testing procedures and the final design which is modified automatically based on the test results. One of the major advantages of VPD is its computer brain capability, which can simulate various complex load conditions at a time. Non-linear load conditions are not always possible to create at the testing centre where the prototypes are being tested in conventional testing methods. These complex conditions, if accommodated during testing, can yield more reliable product form.


Shell molding

Shell molding, also known as shell-mold casting, is an expendable mold casting process that uses resin covered sand to form the mold. As compared to sand casting, this process has better dimensional accuracy, a higher productivity rate, and lower labour requirements. It is used for small to medium parts that require high precision. Shell molding was developed as a manufacturing process during the mid-20th century in Germany. It was invented by German engineer Johannes Croning. Shell mold casting is a metal casting process similar to sand casting, in that molten metal is poured into an expendable mold. However, in shell mold casting, the mold is a thin-walled shell created from applying a sand-resin mixture around a pattern. The pattern, a metal piece in the shape of the desired part, is reused to form multiple shell molds. A reusable pattern allows for higher production rates, while the disposable molds enable complex geometries to be cast. Shell mold casting requires the use of a metal pattern, oven, sand-resin mixture, dump box, and molten metal.
Shell mold casting allows the use of both ferrous and non-ferrous metals, most commonly using cast iron, carbon steel, alloy steel, stainless steel, aluminium alloys, and copper alloys. Typical parts are small-to-medium in size and require high accuracy, such as gear housings, cylinder heads, connecting rods, and lever arms.
The shell mold casting process consists of the following steps:
Pattern creation - A two-piece metal pattern is created in the shape of the desired part, typically from iron or steel. Other materials are sometimes used, such as aluminium for low volume production or graphite for casting reactive materials.
Mold creation - First, each pattern half is heated to 175-370 °C (350-700 °F) and coated with a lubricant to facilitate removal. Next, the heated pattern is clamped to a dump box, which contains a mixture of sand and a resin binder. The dump box is inverted, allowing this sand-resin mixture to coat the pattern. The heated pattern partially cures the mixture, which now forms a shell around the pattern. Each pattern half and surrounding shell is cured to completion in an oven and then the shell is ejected from the pattern.
mold assembly - The two shell halves are joined together and securely clamped to form the complete shell mold. If any cores are required, they are inserted prior to closing the mold. The shell mold is then placed into a flask and supported by a backing material.
Pouring - The mold is securely clamped together while the molten metal is poured from a ladle into the gating system and fills the mold cavity.
Cooling - After the mold has been filled, the molten metal is allowed to cool and solidify into the shape of the final casting.
Casting removal - After the molten metal has cooled, the mold can be broken and the casting removed. Trimming and cleaning processes are required to remove any excess metal from the feed system and any sand from the mold.
Examples of shell molded items include gear housings, cylinder heads and connecting rods. It is also used to make high-precision molding cores.
Process.
The process of creating a shell mold consists of six steps:
The machine that is used for this process is called a "shell molding machine". It heats the pattern, applies the sand mixture, and bakes the shell.
Details.
Setup and production of shell mold patterns takes weeks, after which an output of 5–50 pieces/hr-mold is attainable. Common materials include cast iron, aluminum and copper alloys. Aluminum and magnesium products average about as a normal limit, but it is possible to cast items in the range. The small end of the limit is . Depending on the material, the thinnest cross-section castable is . The minimum draft is 0.25 to 0.5 degrees.
Typical tolerances are 0.005 mm/mm or in/in because the sand compound is designed to barely shrink and a metal pattern is used. The cast surface finish is 0.3–4.0 micrometers (50–150 μin) because a finer sand is used. The resin also assists in forming a very smooth surface. The process, in general, produces very consistent castings from one casting to the next.
The sand-resin mix can be recycled by burning off the resin at high temperatures.
Advantages and disadvantages.
Advantages
Disadvantages
Applications.
Cylinder head, connecting rod, Engine blocks and manifolds, machine bases.


List of number-one digital tracks of 2008 (Australia)

The ARIA Digital Track Chart ranks the best-performing digital tracks of Australia. It is published by Australian Recording Industry Association (ARIA), an organisation who collects music data for the weekly ARIA Charts.
To be eligible to appear on the chart, the recording must be a single not an EP and only paid downloads counted from downloadable outlets.


List of number-one digital tracks of 2009 (Australia)


Manufacturing process management

Manufacturing process management (MPM) is a collection of technologies and methods used to define how products are to be manufactured. MPM differs from ERP/MRP which is used to plan the ordering of materials and other resources, set manufacturing schedules, and compile cost data.
A cornerstone of MPM is the central repository for the integration of all these tools and activities aids in the exploration of alternative production line scenarios; making assembly lines more efficient with the aim of reduced lead time to product launch, shorter product times and reduced work in progress (WIP) inventories as well as allowing rapid response to product or product changes.


Gray Tools

Gray Tools is a Canadian professional tool company based in Brampton, Ontario. Founded in 1912 by Alex Gray (1883-1969), Gray Tools is Canada's largest professional tool manufacturing company, with 4000 industrial products available.
History.
Gray Tools Canada was founded in 1912 by Alex Gray as a machinery equipment supplier. As the automobile industry was starting up, Gray began making automobile manufacturing tools and tool kits specific to the automobile companies in nearby Detroit.
In May 2012, President and owner Alex Gray III sold the company to Garry Nuttall and Frank Dominguez. Alex Gray III remains with the company as chairman.
As of 2013, the company employed 60 people at its head office in Brampton, Ontario, where all manufacturing is done. Company warehouses are located in Brampton and Edmonton, Alberta.
Gray Tools celebrated its 100th birthday by making a large donation of tools and equipment to local schools and by initiating the Gray Tools Canada Highest Standard Achievement Award, presented to a student with exceptional success in vocational education.
Products.
The main focus at Gray tools is the professional hand tool line. Tool storage and organization is a subsidiary product line. A cheaper line of foreign-made tools sold as Dynamic are made to compete with the middle range tool marketplace.


Jewelry model

A jewelry model is a master design that is copied to make many similar pieces of jewelry. The model may either be a piece of actual finished jewelry or a low-cost blank fashioned from base metal. In either case, the model is used to create the casting mold from which all subsequent pieces are made.
Prefabricated models are available from a number of sources to supply the hobby and high-volume jewelry manufacture trade.


Voestalpine Böhler Welding

voestalpine Böhler Welding is a manufacturer of welding consumables (joint welding, maintenance, repair and overlay welding and brazing), welding equipment and accessories with headquarters in Düsseldorf. The company owns over 50 subsidiaries in more than 25 countries, 2,300 employees, customers in approximately 150 countries and more than 1,000 distribution partners.
The company is a business segment of the voestalpine AG Metal Engineering Division.
The company offers extensive technical consultation and individual solutions for industrial welding and soldering applications. It has three specialized and dedicated brands for joint welding, maintenance and cladding, and brazing and soldering.
Products.
Alloys


Displacer beast

A displacer beast is a fictional evil feline creature created for the "Dungeons & Dragons" role-playing game in 1975; it has subsequently been included in every edition of the game to the present day.
Description.
A displacer beast is a magical six-legged black panther-like feline with a pair of tentacles growing from its shoulders; the beast has an innate "displacement" ability, causing it appear to be several feet away from its actual location. "These mighty predators are typically found in the Feywild", "an alternate plane of existence" home to "D&D"'s version of fairies.
Publication history.
"Dungeons & Dragons" (1974–1976).
The displacer beast was created for "Dungeons & Dragons", first introduced in the game's supplement, "Greyhawk" (1975), as "a puma-like creature with six legs and a pair of tentacles which grow from its shoulders." The concept of the creature was borrowed from A. E. van Vogt's 1939 science fiction story "Black Destroyer", which described a feline-like creature called a coeurl. Van Vogt later incorporated the coeurl into the novel "The Voyage of the Space Beagle" (1950).
"Advanced Dungeons & Dragons" 1st edition (1977–1988).
The displacer beast appears in the first edition "Monster Manual" (1977), where it is described as a vaguely puma-like beast that always appears to be three feet away from its actual position. David M. Ewalt, in his book "Of Dice and Men", discussed several monsters appearing in the original "Monster Manual", describing displacer beasts as looking like "pumas with thorn-covered tentacles growing out of their shoulders".
The displacer beast was detailed in "Dragon" #109 (May 1986), in the "Ecology of the Displacer Beast".
"Dungeons & Dragons" (1977–1999).
This edition of the "D&D" game included its own version of the displacer beast, in the "Dungeons & Dragons Basic Set" (1977), and "Expert Set" (1981 & 1983), and was also later featured in the "Dungeons & Dragons Game" set (1991), the "Dungeons & Dragons Rules Cyclopedia" (1991), the "Classic Dungeons & Dragons Game" set (1994), and the "Dungeons & Dragons Adventure Game" set (1999).
"Advanced Dungeons & Dragons" 2nd edition (1989–1999).
The displacer beast appears in the "Monstrous Compendium Volume One" (1989), and is reprinted in the "Monstrous Manual" (1993).
"Dungeons & Dragons" 3.0 & 3.5 editions (2000–2007).
The displacer beast appears in the 3rd edition "Monster Manual" (2000) and then in the 3.5 edition "Monster Manual" (2003). This edition also described the displacer beast pack lord. For this edition, Wizards of the Coast considered the displacer beast to be an original product of "D&D" and was therefore categorized as a "Product Identity"; as such it was not released under its Open Game License.
"Dungeons & Dragons" 4th edition (2008–2013).
The displacer beast appears in the 4th edition "Monster Manual" (2008), and again a description is included for the displacer beast packlord.
"Dungeons & Dragons" 5th edition (2014).
The displacer beast appears in the 5th edition "Monster Manual" (2014). It is considered a copyrighted original creation for the "Dungeons & Dragons" game.
Other media.
A displacer beast appears in the film '. A displacer beast kitten is a ' card created as part of the "" crossover.
Reception.
Rob Bricken from io9 named the displacer beast as the 2nd most memorable "D&D" monster. Reviewers also counted it among the "most iconic" and "fan-favorite" monsters of the game. It was considered an "old-school" and "most enduring" monster, having been part of the game from its earliest stages. Author Ben Riggs remarked on the movie version of the displacer beast: "The design of the creature is just so fantastic. It's creepy. Even though it's a panther with a couple tentacles, at first you're creeped out". David M. Marshall remarked that the displacer beast is one of the elements "which disrupts the roughly period [medieval] atmosphere of the game".


Bolted joint

A bolted joint is one of the most common elements in construction and machine design. It consists of a male threaded fastener (e. g., a bolt) that captures and joins other parts, secured with a matching female screw thread. There are two main types of bolted joint designs: tension joints and shear joints.
Joint types.
In a tension joint, the bolt and clamped components of the joint are designed to transfer an applied tension load through the joint by way of the clamped components by the design of a proper balance of joint and bolt stiffness. The joint should be designed such that the clamp load is never overcome by the external tension forces acting to separate the joint. If the external tension forces overcome the clamp load (bolt preload) the clamped joint components will separate, allowing relative motion of the components.
The second type of bolted joint transfers the applied load in shear of the bolt shank and relies on the shear strength of the bolt. Tension loads on such a joint are only incidental. A preload is still applied but consideration of joint flexibility is not as critical as in the case where loads are transmitted through the joint in tension. Other such shear joints do not employ a preload on the bolt as they are designed to allow rotation of the joint about the bolt but use other methods of maintaining bolt/joint integrity. Joints that allow rotation include clevis linkages, and rely on a locking mechanism (like lock washers, thread adhesives, and lock nuts).
Proper joint design and bolt preload provides useful properties:
In both the tension and shear joint design cases, some level of tension preload in the bolt and resulting compression preload in the clamped components is essential to the joint integrity. The preload target can be achieved by a variety of methods: applying a measured torque to the bolt, measuring bolt extension, heating to expand the bolt then turning the nut down, torquing the bolt to the yield point, testing ultrasonically, or by applying a certain number of degrees of relative rotation of the threaded components. Each method has a range of uncertainties associated with it, some of which are very substantial.
Theory.
Typically, a bolt is tensioned (preloaded) by the application of a torque to either the bolt head or the nut. The applied torque causes the bolt to "climb" the thread causing a tensioning of the bolt and an equivalent compression in the components being fastened by the bolt. The preload developed in a bolt is due to the applied torque and is a function of the bolt diameter, the geometry of the threads, and the coefficients of friction that exist in the threads and under the torqued bolt head or nut. The stiffness of the components clamped by the bolt has no relation to the preload that is developed by the torque. The relative stiffness of the bolt and the clamped joint components do, however, determine the fraction of the external tension load that the bolt will carry and that in turn determines preload needed to prevent joint separation and by that means to reduce the range of stress the bolt experiences as the tension load is repeatedly applied. This determines the durability of the bolt when subjected to repeated tension loads. Maintaining a sufficient joint preload also prevents relative slippage of the joint components that would produce fretting wear that could result in a fatigue failure of those parts.
The clamp load, also called preload of a fastener, is created when a torque is applied, and so develops a tensile preload that is generally a substantial percentage of the fastener's proof strength. Fasteners are manufactured to various standards that define, among other things, their strength. "Torque charts" are available to specify the required torque for a given fastener based on its "property class" (fineness of manufacture and fit) and "grade" (tensile strength).
When a fastener is torqued, a tension preload develops in the bolt and an equal compressive preload develops in the parts being fastened. This can be modeled as a spring-like assembly that has some assumed distribution of compressive strain in the clamped joint components. When an external tension load is applied, it relieves the compressive strains induced by the preload in the clamped components, hence the preload acting on the compressed joint components provides the external tension load with a path (through the joint) other than through the bolt. In a well designed joint, perhaps 80-90% of the externally applied tension load will pass through the joint and the remainder through the bolt. This reduces the fatigue loading of the bolt.
When the fastened parts are less stiff than the fastener (those that use soft, compressed gaskets for example), this model breaks down and the fastener is subjected to a tension load that is the sum of the tension preload and the external tension load.
In some applications, joints are designed so that the fastener eventually fails before more expensive components. In this case, replacing an existing fastener with a higher strength fastener can result in equipment damage. Thus, it is generally good practice to replace old fasteners with new fasteners of the same grade.
Calculating the torque.
Engineered joints require the torque to be chosen to provide the correct tension preload. Applying the torque to fasteners is commonly achieved using a torque wrench. The required torque value for a particular fastener application may be quoted in the published standard document, defined by the manufacturer or calculated. The side of the threaded fastening having the least friction should receive torque while the other side is counter-held or otherwise prevented from turning.
A common relationship used to calculate the torque for a desired preload takes into account the thread geometry and friction in the threads and under the bolt head or nut. The following assumes standard ISO or National Standard bolts and threads are used:
where
The nut factor K accounts for the thread geometry, friction, pitch. When ISO and Unified National Standard threads are used the nut factor is:
where
When formula_10 = formula_12 = 0.15, the dimensions used correspond to any size coarse or fine bolt, and the nut factor is K ≈ 0.20, the torque/preload relationship becomes:
A study of the effect of torquing two samples, one lubricated and the other unlubricated, 1/2 in.- 20 UNF bolts to 800 lb-in, produced the same mean preload of 7700 lbf. The preloads for the unlubricated bolt sample had a standard deviation from the mean value of 1100 lbf, whereas the lubricated sample had a standard deviation of 680 lbf. If the preload value and torques are used in the above relation to solve for the nut factor it is found to be K = 0.208, which is very close to the recommended value of 0.20
The preferred bolt preload for structural applications should be at least 75% of the fastener's proof load for the higher strength fasteners and as high as 90% of the proof load for permanent fasteners. To achieve the benefits of the preloading, the clamping force must be higher than the joint separation load. For some joints, multiple fasteners are required to secure the joint; these are all hand tightened before the final torque is applied to ensure an even joint seating.
The preload achieved by torquing a bolt is caused by the part of the torque that is effective. Friction in the threads and under the nut or bolt head uses up some fraction of the applied torque. Much of the torque applied is lost overcoming friction under the torqued bolt head or nut (50%) and in the threads (40%). The remaining 10% of the applied torque does useful work in stretching the bolt and providing the preload. Initially, as the torque is applied, it must overcome static friction under the head of the bolt or nut (depending on which end is being torqued) and also in the threads. Finally, dynamic friction prevails and the torque is distributed in a 50/40/10 % manner as the bolt is tensioned. The torque value is dependent on the friction produced in the threads and under the torqued bolt head or nut and the fastened material or washer if used. This friction can be affected by the application of a lubricant or any plating (e.g. cadmium or zinc) applied to the threads, and the fastener's standard defines whether the torque value is for dry or lubricated threading, as lubrication can reduce the torque value by 15% to 25%; lubricating a fastener designed to be torqued dry could over-tighten it, which may damage threading or stretch the fastener beyond its elastic limit, thereby reducing its clamping ability.
Either the bolt head or the nut can be torqued. If one has a larger bearing area or coefficient of friction it will require more torque to provide the same target preload. Fasteners should only be torqued if they are fitted in clearance holes.
Torque wrenches do not give a direct measurement of the preload in the bolt.
More accurate methods for determining the preload rely on defining or measuring the "screw extension" from the nut. Alternatively, measurement of the angular rotation of the nut can serve as the basis for defining screw extension based on the fastener's thread pitch. Measuring the screw extension directly allows the clamping force to be very accurately calculated. This can be achieved using a dial test indicator, reading deflection at the fastener tail, using a strain gauge, or ultrasonic length measurement.
Bolt preload can also be controlled by torquing the bolt to the point of yielding. Under some circumstances, a skilled operator can feel the drop off of the work required to turn the torque wrench as the material of the bolt begins to yield. At that point the bolt has a preload determined by the bolt area and the yield strength of the bolt material. This technique can be more accurately executed by specially built machines. Because this method only works for very high preloads and requires comparatively expensive tooling, it is only commonly used for specific applications, primarily in high performance engines.
There is no (as yet) simple method to measure the tension of a fastener in situ. All methods, from the least to most accurate, involve first relaxing the fastener, then applying force to it and quantifying the resultant amount of elongation achieved. This is known as 're-torqueing' or 're-tensioning' depending on which technology is employed.
Technologies employed in this process can be:
An electronic torque wrench is used on the fastener in question, so that the torque applied can be measured as it is increased in magnitude.
Recent technological developments have enabled tensions to be established (± 1%) by using ultrasonic testing. This provides the same accuracy to that of strain gauging without having to set strain gauges on each fastener.
Another method that indicates tension (mainly in erecting steel) involves the use of crush-washers. These are washers that have been drilled and filled with orange RTV. When a given force has been applied (± 10%), orange rubber strands appear.
Large-volume users (such as auto makers) frequently use computer-controlled nut drivers. With such machines, the computer is in control of shutting off the torque mechanism when a predetermined value has been reached. Such machines are often used to fit and tighten wheel nuts on an assembly line, and have also been developed for use in mobile plant tire fitting bays on mine sites.
Thread engagement.
"Thread engagement" is the length or number of threads that are engaged between the screw and the female threads. Bolted joints are designed so that the bolt shank fails in tension before the threads fail in shear, but for this to hold true, a minimum thread engagement must be achieved. The following equation defines this minimum thread engagement:
Where Le is the thread engagement length, At is the tensile stress area, D is the major diameter of the screw, and p is the pitch. This equation only holds true if the screw and female thread materials are the same. If they are not the same, then the following equations can be used to determine the additional thread length that is required:
Where Le2 is the new required thread engagement.
While these formulas give absolute minimum thread engagement, many industries specify that bolted connections be at least fully engaged. For instance, the FAA has determined that in general cases, at least one thread must be protruding from any bolted connection.
Failure modes.
When doing a failure mode analysis for bolts that have broken, come loose or corroded, careful consideration must be given to the below Failure Modes:
Bolted joints may be used intentionally as sacrificial parts, which are intended to fail before other parts, as in a shear pin.
Locking mechanisms.
Locking mechanisms keep bolted joints from coming loose. They are required when vibration or joint movement will cause loss of clamp load and joint failure, and in equipment where the security of bolted joints is essential. A prevalent test for the self-loosening behaviour is the Junker test.
Bolt banging.
"Bolt banging" occurs in buildings when bolted joints slip into "bearing under load", thus causing a loud and potentially frightening noise resembling a rifle shot that is not, however, of structural significance and does not pose any threat to occupants.
A bolted joint between two elements may act as a bearing-type joint, or a friction joint. In the friction joint, the elements are clamped together with enough force that the resultant friction between the clamped surfaces prevents them from slipping laterally over each other.
In the bearing joint, the bolt itself limits lateral movement of the elements by the shank of the bolt bearing upon the sides of the holes in the clamped elements. Such joints require less clamping force, because a high level of friction between the clamped surfaces is not required. The clearance between the bolt and the holes means that some lateral movement may occur before the bolt bears against the sides of the holes.
Even when designed as a bearing joint, the surface friction between the clamped elements may be sufficient to resist movement for some time, especially when the building may not yet be fully loaded – thus it operates initially as a friction joint. When the lateral force becomes sufficient to overcome this friction, the clamped elements move until the sides of the holes bear against the shank of the bolt. This movement – "slip into bearing" – usually starts and stops very suddenly, often releasing elastic energy in the associated elements, resulting in a loud but harmless bang.


Quad flat package

A quad flat package (QFP) is a surface-mounted integrated circuit package with "gull wing" leads extending from each of the four sides. Socketing such packages is rare and through-hole mounting is not possible. Versions ranging from 32 to 304 pins with a pitch ranging from 0.4 to 1.0 mm are common. Other special variants include low-profile QFP (LQFP) and thin QFP (TQFP).
The QFP component package type became common in Europe and United States during the early nineties, even though it has been used in Japanese consumer electronics since the seventies. It is often mixed with hole mounted, and sometimes socketed, components on the same printed circuit board (PCB).
A package related to QFP is plastic leaded chip carrier (PLCC) which is similar but has pins with larger pitch, 1.27 mm (or 1/20 inch), curved up underneath a thicker body to simplify socketing (soldering is also possible). It is commonly used for NOR flash memories and other programmable components.
Limitations.
The quad flat-pack has connections only around the periphery of the package. To increase the number of pins, the spacing was decreased from 50 mil (as found on small outline packages) to 20 and later 12 (1.27 mm, 0.51 mm and 0.30 mm respectively). However, this close lead spacing made solder bridges more likely and put higher demands on the soldering process and alignment of parts during assembly. The later pin grid array (PGA) and ball grid array (BGA) packages, by allowing connections to be made over the area of the package and not just around the edges, allowed for higher pin counts with similar package sizes, and reduced the problems with close lead spacing.
Variants.
The basic form is a flat rectangular (often square) body with leads on four sides but with numerous variation in the design. These differ usually only in lead number, pitch, dimensions, and materials used (usually to improve thermal characteristics). A clear variation is bumpered quad flat package (BQFP) with extensions at the four corners to protect the leads against mechanical damage before the unit is soldered.
Heat sink quad flat package, "heatsink very thin quad flat-pack no-leads" ("HVQFN") is a package with no component leads extending from the IC. Pads are spaced along the sides of the IC with an exposed die that can be used as ground. Spacing between pins can vary.
A thin quad flat pack (TQFP) provides the same benefits as the metric QFP, but is thinner. Regular QFP are 2.0 to 3.8 mm thick depending on size. TQFP packages range from 32 pins with a 0.8 mm lead pitch, in a package 5 mm by 5 mm by 1 mm thick, to 256 pins, 28 mm square, 1.4 mm thick and a lead pitch of 0.4 mm.
TQFPs help solve issues such as increasing board density, die shrink programs, thin end-product profile and portability. Lead counts range from 32 to 176. Body sizes range from 5 mm x 5 mm to 20  x 20 mm. Copper lead-frames are used in TQFPs. Lead pitches available for TQFPs are 0.4 mm, 0.5 mm, 0.65 mm, 0.8 mm, and 1.0 mm. "PQFP", or plastic quad flat pack, is a type of QFP, as is the thinner TQFP package. PQFP packages can vary in thickness from 2.0 mm to 3.8 mm. A low-profile quad flat package (LQFP) is a surface mount integrated circuit package format with component leads extending from each of the four sides. Pins are numbered counter-clockwise from the index dot. Spacing between pins can vary; common spacings are 0.4, 0.5, 0.65 and 0.80 mm intervals.
Some QFP packages have an exposed pad. The exposed pad is an extra pad underneath or on top of the QFP that may act as a ground connection and/or as a heat sink for the package. The pad is typically 10 or more mm², and with the pad soldered down onto the ground plane, heat is passed into the PCB. This exposed pad also gives a solid ground connection. These type of QFP packages often have a -EP suffix (e.g. a LQFP-EP 64), or they have an odd number of leads, (e.g. a TQFP-101).
Ceramic QFP package.
Ceramic QFP packages come in two variants, CERQUAD and CQFP:
CERQUAD packages.
Hereby the leadframe is attached between two ceramic layers of the package. The leadframe is attached using glass. This package is a variant of the CERDIP package. CERQUAD packages are the "low cost" alternative for CQFP packages, and are mainly used for terrestrial applications.
Main ceramic package manufacturers are Kyocera, NTK... and offer the full pincount range
CQFP packages.
Hereby the leads are soldered on top of the package. The package is a multilayer package, and is offered as HTCC (high temperature co-fired ceramic). The number of bonding decks can be one, two or three. Package is finished with a nickel plus a "thick" gold layer, except where the leads are soldered and decoupling capacitors are soldered on top of the package. These packages are hermetic. Two methods are used in order to make the hermetic sealing: eutectic gold-tin alloy (melting point 280°C) or seam welding. Seam welding gives rise to significantly less temperature rise in the internal of the package (e.g., the die attach). This package is the main package used for Space projects.
Due to the large body size of CQFP packages, parasitics are important for this package. Power supply decoupling is improved by having the decoupling capacitors mounted on top of this package. E.g. TI offers 256-pin CQFP packages where decoupling capacitors can be soldered on top of the package E.g. Test-expert 256-pin CQFP packages where decoupling capacitors can be soldered on top of the package.
The main ceramic package manufacturers are Kyocera (Japan), NTK (Japan), Test-Expert (Russia), etc. and offer the full pincount range. Maximum pin count is 352 pins.


Economic order quantity

Economic Order Quantity (EOQ), also known as Financial Purchase Quantity or Economic Buying Quantity (EPQ), is the order quantity that minimizes the total holding costs and ordering costs in inventory management. It is one of the oldest classical production scheduling models. The model was developed by Ford W. Harris in 1913, but R. H. Wilson, a consultant who applied it extensively, and K. Andler are given credit for their in-depth analysis.
Overview.
EOQ applies only when demand for a product is constant over the year and each new order is delivered in full when inventory reaches zero. There is a fixed cost for each order placed, regardless of the number of units ordered; an order is assumed to contain only 1 unit. There is also a cost for each unit held in storage, commonly known as holding cost, sometimes expressed as a percentage of the purchase cost of the item. While the EOQ formulation is straightforward there are factors such as transportation rates and quantity discounts to consider in actual application.
We want to determine the optimal number of units to order so that we minimize the total cost associated with the purchase, delivery, and storage of the product.
The required parameters to the solution are the total demand for the year, the purchase cost for each item, the fixed cost to place the order for a single item and the storage cost for each item per year. Note that the number of times an order is placed will also affect the total cost, though this number can be determined from the other parameters.
The total cost function and derivation of EOQ formula.
The single-item EOQ formula finds the minimum point of the following cost function:
Total Cost = purchase cost or production cost + ordering cost + holding cost
Where:
To determine the minimum point of the total cost curve, calculate the derivative of the total cost with respect to Q (assume all other variables are constant) and set it equal to 0:
Solving for Q gives Q* (the optimal order quantity):
Therefore:

Q* is independent of P; it is a function of only K, D, h.
The optimal value Q* may also be found by recognizing that
where the non-negative quadratic term disappears for formula_12 which provides the cost minimum formula_13
Example.
Economic order quantity = formula_14 formula_15 = 400 units
Number of orders per year (based on EOQ) formula_16
Total cost formula_17
Total cost formula_18
If we check the total cost for any order quantity other than 400(=EOQ), we will see that the cost is higher. For instance, supposing 500 units per order, then
Total cost formula_19
Similarly, if we choose 300 for the order quantity, then
Total cost formula_20
This illustrates that the economic order quantity is always in the best interests of the firm.
Extensions of the EOQ model.
Quantity discounts.
An important extension to the EOQ model is to accommodate quantity discounts. There are two main types of quantity discounts: (1) all-units and (2) incremental. Here is a numerical example:
In order to find the optimal order quantity under different quantity discount schemes, one should use algorithms; these algorithms are developed under the assumption that the EOQ policy is still optimal with quantity discounts. Perera et al. (2017) establish this optimality and fully characterize the (s,S) optimality within the EOQ setting under general cost structures.
Design of optimal quantity discount schedules.
In presence of a strategic customer, who responds optimally to discount schedules, the design of an optimal quantity discount scheme by the supplier is complex and has to be done carefully. This is particularly so when the demand at the customer is itself uncertain. An interesting effect called the "reverse bullwhip" takes place where an increase in consumer demand uncertainty actually reduces order quantity uncertainty at the supplier.
Backordering costs and multiple items.
Several extensions can be made to the EOQ model, including backordering costs and multiple items. In the case backorders are permitted, the inventory carrying costs per cycle are:
where s is the number of backorders when order quantity Q is delivered and formula_22 is the rate of demand. The backorder cost per cycle is:
where formula_24 and formula_25 are backorder costs, formula_26, T being the cycle length and formula_27. The average annual variable cost is the sum of order costs, holding inventory costs and backorder costs:
To minimize formula_29 impose the partial derivatives equal to zero:
Substituting the second equation into the first gives the following quadratic equation:
If formula_33 either s=0 or formula_34 is optimal. In the first case the optimal lot is given by the classic EOQ formula, in the second case an order is never placed and minimum yearly cost is given by formula_35. If formula_36 or formula_37 formula_38 is optimal, if formula_39 then there shouldn't be any inventory system. If formula_40 solving the preceding quadratic equation yields:
If there are backorders the reorder point is: formula_43; with m being the largest integer formula_44 and μ the lead time demand.
Additionally, the economic order interval can be determined from the EOQ and the economic production quantity model (which determines the optimal production quantity) can be determined in a similar fashion.
A version of the model, the Baumol-Tobin model, has also been used to determine the money demand function, where a person's holdings of money balances can be seen in a way parallel to a firm's holdings of inventory.
Malakooti (2013) has introduced the multi-criteria EOQ models where the criteria could be minimizing the total cost, Order quantity (inventory), and Shortages.
A version taking the time-value of money into account was developed by Trippi and Lewin.
Imperfect quality.
Another important extension of the EOQ model is to consider items with imperfect quality. Salameh and Jaber (2000) are the first to study the imperfect items in an EOQ model very thoroughly. They consider an inventory problem in which the demand is deterministic and there is a fraction of imperfect items in the lot and are screened by the buyer and sold by them at the end of the circle at discount price.


EnvisionTEC

EnvisionTEC is a privately held global company that develops, manufactures and sells more than 40 configurations of desktop and production 3D printers based on seven several distinct process technologies that build objects from digital design files. Founded in 2002, the company now has a corporate headquarters for North America, located in Dearborn, Mich., and International headquarters in Gladbeck, Germany. It also has a production facility in the Greater Los Angeles area, as well as additional facilities in Montreal, for materials research, in Kiev, Ukraine, for software development, and in Woburn, Mass, for robotic 3D printing research and development. Today, the company's 3D Printers are used for mass customized production and to manufacture finished goods, investment casting patterns, tooling, prototypes and more. EnvisionTEC serves a variety of medical, professional and industrial customers. EnvisionTEC has developed large customer niches in the jewelry, dental, hearing aid, medical device, biofabrication and animation industries. EnvisionTEC is one of the few 3D printer companies globally whose products are being used for real production of final end-use parts.
Technology.
Since it filed its first patent in 1999, EnvisionTEC has developed and brought to market several new additive manufacturing technologies used for 3D printing.
Three of those technologies are based on harnessing light as a tool to cure liquid resin into a three-dimensional object based on a digital design files.
EnvisionTEC has also been developing and expanding its process technology beyond DLP and light-based curing technologies, too.
The company's 3D-Bioplotter series now includes a Starter, Developer and Manufacturing model that extrude materials in three dimensions using pressure. Materials range from a viscous paste to a liquid, and are inserted using syringes moving in three dimensions. Air or mechanical pressure is applied to the syringe, which then deposits a strand of material for the length of movement and time the pressure is applied. Parallel strands are plotted in one layer. For the following layer, the direction of the strands is turned over the center of the object, creating a fine mesh with good mechanical properties and mathematically well-defined porosity. The 3D-Bioplotter is frequently used in biofabrication and is being used in a wide range of medical research. Scientists from Northwestern University, for example, have created 3D printed ovary implants using an EnvisionTEC 3D-Bioplotter that may be used one day to treat women experiencing infertility.
Products.
EnvisionTEC sells more than 40 configurations of 3D Printers that sell for between $6,299 and $1 million. The company's printers are organized into several families of printers: Desktops (Aria, Micro, Vida, Aureus, etc.); Perfactory; cDLM; 3SP; 3D-Bioplotter; and the SLCOM. EnvisionTEC also markets and sells the Viridis3D RAM123 under an "exclusive strategic partnership."
In early 2016, EnvisionTEC demonstrated a shift in its strategic direction with the launch of several new models of printers, including the 3D-Bioplotter Starter Series, the SLCOM 1 and RAM123. "Previously known as pioneers in the 3D printing technology of digital light processing (DLP), the U.S.-German company has managed to redefine itself once again by announcing three new platforms at the event: a new bioprinter, a 3D printer for sandcasting and, perhaps its most substantial unveil, a massive industrial 3D printer dedicated to composite manufacturing," according to Engineering.com.
Founder.
EnvisionTEC was founded by Hendrik John a German inventor and later managed by John and its current owner, Al Siblani, a Lebanese immigrant who came to the United States to complete his higher education. After earning a bachelor's degree in engineering at Lawrence Technological University and a master's degree in electrical and computer engineering from Wayne State University, both located in Metro Detroit, Siblani entered a 3D printing market still in its infancy. He began working in 1993, for an early 3D printing company, Helisys, that used Laminated Object Manufacturing (LOM) technology to create prototypes for automakers and other commercial customers. Shortly thereafter, he founded Sibco Inc., which provided 3D printing services and materials. In 1996, after mastering the 3D printing technologies and materials at the time, Siblani decided to make his own 3D printing machines using a then-novel idea to cure resins into objects. His first patent submission, which laid the foundation for EnvisionTEC, was filed in 1999. In 2015, Siblani was honored as a finalist for the Ernst & Young Entrepreneur of the Year program for the Michigan and Northwest Ohio region.


Solderability

The solderability of a substrate is a measure of the ease with which a soldered joint can be made to that material. Good solderability requires wetting (low contact angle) of the substrate by the solder.
Of metals.
Solderability varies depending on the type of solder alloy under discussion. The discussion that follows applies only to unspecified electronic solders (which may include solders that contain lead, now banned for use in nearly all electronic equipment made or sold in the EU). Solderability when using lead-free alloys can differ significantly from solderability when using lead based alloys.
Noble metals may be easy to solder but they have brittle joints. The metals in the good category require a large amount of heat therefore oxidation is an issue. To overcome this a flux is required. For carbon steel, low alloy steel, zinc, and nickel the presence of sulfur creates a brittle joint; lower temperatures are used to minimize this problem. The oxides on the surface of aluminium cause wetting issues and special solders must be used to prevent galvanic corrosion issues. Stainless steel and high alloy steel have a low solderability because the chromium alloying element creates oxides that require aggressive fluxes. The only way that the final category of metals can be soldered is by pre-plating them in a metal that is solderable.
Testing solderability.
Both quantitative and qualitative tests for solderability exist.
The two most common testing methods are the 'dip and look' method and wetting balance analysis. In both of these tests, the soldered pieces undergo an accelerated aging process before being tested for solderability, to take into consideration the time a component was in storage prior to mounting to final assembly. The dip and look method is a qualitative test. One form of it is specified as Mil-Std-883 Method 2003. On the other hand, the wetting balance analysis is a quantitative test that measures the wetting forces between molten solder and the test surface as a function of time.


Polygonal turning

Polygonal turning (or polygon turning) is a machining process which allows non-circular forms (polygons) to be machine turned without interrupting the rotation of the raw material.
Technical details.
Polygonally turned parts may have several points, teeth, or other forms at the ends or along their circumference. The technique requires synchronisation of the movement of the polygonal turning mill and the part being machined. Polygonal turning allows rapid production and clean machining of advanced geometries.
The polygon turning unit has a multitude of inserts, and is synchronized so that when an insert cuts the turning bar stock, it cuts the bar at the same radial position each time the workpiece rotates. This enables geometries such as hexes, squares and flats to be machined at faster speeds than by milling.
Historical notes.
The Polygonal Turning Corporation of Marquette, Michigan manufactured shaped joinery products for domestic use during the 1890s.


Spring Back Compensation

Due to the plastic-elastic characteristic of a metal, it is typical that any deformation of sheet metal at room temperature will have both elastic and plastic deformation. After the metal workpiece is removed from the tool or deformation implement, the elastic deformation will be released and only the plastic deformation will remain. When a metal forming tool is planned and designed to deform a workpiece, the shape imparted by the tool will be a combination of elastic and plastic deformation. The release of the elastic deformation is the spring back often observed at the end of a metal forming process.
The spring back has to be compensated to achieve an accurate result.
Usually, that is realized by overbending the material corresponding to the magnitude of the spring back. That means for the practical side of the bending process; the bending former, enters deeper into the bending prism.
For other sheet metal forming operations like drawing, it entails deforming the sheet metal past the planned net shape of the part, so that when the spring back is released from the part, the plastic deformation in that part delivers the desired shape of the part. In the case of complex tools, the spring back has to be already considered in the engineering and construction phases. Therefore, complex software simulations are used. Frequently this is not enough to deliver the desired results. In such cases practical experiments are done, using the trial-and-error plus experience method to correct the tool. However, the results (work pieces) are only stable, if all influencing factors are the same.
This mainly includes:
The list of factors may be continued. Spring back assessment of final formed products is a difficult problem and is affected by the complexity of the formed shape. The NUMISHEET 93 conference benchmark problem involves the draw bending of a U-channel using three measured parameters. Parameter less approaches have been proposed for more complex geometries but need validation.
Practical example: electronic bending tools with spring-back compensation.
Manufactures of electrical assembly's produce components that are flat, using copper and aluminum. The mechanical properties of copper and aluminum are very different and require different programmable inputs in order to achieve the same dimensional characteristics. This variation in inputs is due to spring-back compensation.
Bending technology for flat material which measures each bend angle and provides spring back compensation is required. This gives the bend angle of flat materials true accuracy. This is attained by using bending prisms with electronic angular measurement technology. While bending two flat bolds supporting the material turn around. The bolds are directly connected to the angular sensors. A computer or rather the machine control then calculates the required final stroke. The spring back of every bend is compensated regardless of material type.
If the measuring accuracy is 0.1º, a high angle accuracy of +/- 0.2º is achieved instantly with the first workpiece without any rework. Because no adjustments are required, material waste amounts and setup times drop considerably. Even inconsistencies within a single piece of material are automatically adjusted.


CR-5000

CR-5000 is Zuken's EDA design suite for electronics systems and printed circuit boards aimed at the enterprise market. It was developed to tackle complex design needs that involve managing the complete development and manufacturing preparation process on an enterprise-wide scale. CR-5000 offers relevant functionality for the design of complex and high-speed boards, addressing design challenges such as signal integrity and electromagnetic compatibility.
CR-5000 is the fourth generation successor of CREATE1000 that was originally developed for PDP-11 by Zukei-Gijutsu-Kenkyusho (Japanese for "Graphic Technology and Research Laboratory"). The main CR-5000 software is developed at Zuken Inc. headquarters in Yokohama, Japan. Other modules are developed in Zuken's EMC Technology Center in Paderborn, Germany which is renowned for its research in EMC and SI simulation tools, and Zuken Technology Center in Bristol, England which focuses on routing tools. The latest version as of June 2012 is CR-5000 version 14.


Menlo Logistics

Menlo Logistics was a global supply chain company operating in 20 countries on five continents. Its core business offerings included third-party logistics and supply chain management, and the company specialized in the integration of all functions across the supply chain. The company operated 210 locations worldwide and had of warehouse capacity.
It was a business unit of Con-way, which was acquired in 2015 by XPO Logistics. Sister companies included Con-way Freight, Con-way Truckload, and Con-way Multimodal.
History.
The idea for Menlo Logistics was developed in the late 1980s. At that time, CF Inc.’s director of marketing, John Williford, presented the idea for the company's creation — an organization that offered warehouse, inventory, and transportation management as well as full integration of supply chain links through customized systems and software — to upper management. The initial business plan was to create, implement, and manage logistics projects for its customers.
On October 26, 1990, Menlo Logistics Inc. was formed. The name was a deliberate choice to prompt an association with California’s Menlo Park, which was well known as the home of venture capitalists and high-tech industries.
Menlo Logistics established itself as a third-party logistics provider in the 1990s, and rode the popularity of the outsourcing trend by notching double-digit growth every year during that era. One of Menlo’s early success stories was its successful bid on a $100 million distribution contract with Sears. The department store wanted to close its internal distribution system, which cost Sears about twice as much as its competitors at 7 percent of its sales.
In December 2000, Menlo Logistics collaborated with General Motors to create Vector SCM, a new global supply chain management company serving the automotive industry.
Effective January 1, 2002, Con-Way formed Menlo Worldwide Logistics in its current form by combining Menlo Logistics (renamed Menlo Worldwide Logistics), Vector SCM and Emery Worldwide Forwarding (later renamed Menlo Worldwide Forwarding). Menlo Worldwide Logistics absorbed the operations of Emery’s logistics unit, Emery Global Logistics (EGL). The EGL operations gave Menlo Worldwide Logistics presence in Asia and South America, and expanded its European scope. The company began leveraging these operations to pursue organic growth outside of North America and grow its European footprint.
In December 2004, Con-Way sold Menlo Worldwide Forwarding to United Parcel Service, and Con-Way streamlined its operating units by merging Con-Way Transportation Service’s logistics unit, Con-way Logistics, into Menlo Worldwide Logistics. This completed the rationalization of three logistics entities into a single business unit.
In 2006, GM exercised its right to purchase Menlo Logistics' interest in Vector SCM, and the sale was completed in December.
In seeking to grow its business in the Asian logistics market, Menlo purchased two Asian logistics companies, Cougar Holdings Pte, Ltd. and Chic Holdings, Ltd. in 2007. Singapore-based Cougar enlarged Menlo's operational scope in southeastern Asia, and Shanghai-based Chic significantly expanded Menlo's presence in China.
In October 2015 Menlo Logistics and its parent Con-Way were acquired by XPO Logistics.


Build-on-demand

Build-on-demand or manufacturing on demand (MOD) refers to a manufacturing process where goods are produced only when or as they are required. This allows scalability and adjustable assemblies depending on the current needs of the part requestor or client.
Manufacturing on demand has the potential to markedly affect the manufacturing industry by shortening lead times and reducing costs. Manufacturing previously relied on Request for quotes (RfQs) that were not digitally obtainable.


Mass finishing

Mass finishing is a group of manufacturing processes that allow large quantities of parts to be simultaneously finished. The goal of this type of finishing is to burnish, deburr, clean, radius, de-flash, descale, remove rust, polish, brighten, surface harden, prepare parts for further finishing, or break off die cast runners. The two main types of mass finishing are tumble finishing, also known as barrel finishing, and vibratory finishing. Both involve the use of a cyclical action to create grinding contact between surfaces. Sometimes the workpieces are finished against each other; however, usually a finishing medium is used. Mass finishing can be performed dry or wet; wet processes have liquid lubricants, cleaners, or abrasives, while dry processes do not. Cycle times can be as short as 10 minutes for nonferrous workpieces or as long as 2 hours for hardened steel.
Mass finishing processes can be configured as either batch systems, in which batches of workpieces are added, run, and removed before the next batch is run, or as continuous systems, in which the workpieces enter at one end and leave at the other end in the finished state. They may also be sequenced, which involves running the workpieces through multiple different mass finishing processes; usually, the finish becomes progressively finer. Due to the random action of the processes, mass finishing is as much an art as it is a science.
Media.
Functions of Media.
Media are designed for four things:
Compounds.
Compounds are added to mass finishing processes to assist in deburring, burnishing, cutting, cleaning, descaling, and inhibiting corrosion. They may be liquids or dry powders. They are usually broken up into four types: deburring and finishing, burnishing, cleaning, and water stabilizing.
References.
Notes.
"Mass Finishing Handbook" by LaRoux Gillespie, Society of Manufacturing Engineers, 2007


Lean Six Sigma

Lean Six Sigma is a process improvement approach that uses a collaborative team effort to improve performance by systematically removing operational waste and reducing process variation. It combines Lean Management and Six Sigma to increase the velocity of value creation in business processes.
History.
1980s–2000s.
Lean Six Sigma's predecessor, Six Sigma, originated from the Motorola company in the United States in 1986. Six Sigma was developed within Motorola to compete with the "kaizen" (or lean manufacturing) business model in Japan.
In the 1990s, Allied Signal hired Larry Bossidy and introduced Six Sigma in heavy manufacturing. A few years later, General Electric's Jack Welch consulted Bossidy and implemented Six Sigma at the conglomerate.
During the 2000s, Lean Six Sigma forked from Six Sigma and became its own unique process. While Lean Six Sigma developed as a specific process of Six Sigma, it also incorporates ideas from lean manufacturing, which was developed as a part of the Toyota Production System in the 1950s.
2000s–2010s.
The first concept of Lean Six Sigma was created in Chuck Mills, Barbara Wheat, and Mike Carnell's 2001 book, "Leaning into Six Sigma: The Path to Integration of Lean Enterprise and Six Sigma". It was developed as a guide for managers of manufacturing plants on how to combine lean manufacturing and Six Sigma to improve quality and cycle time in the plant.
In the early 2000s Six Sigma principles expanded into other sectors of the economy, such as healthcare, finance, and supply chains.
Description.
Lean Six Sigma is a synergized managerial concept of Lean and Six Sigma. Lean traditionally focuses on eliminating the eight kinds of waste (""muda")", and Six Sigma focuses on improving process output quality by identifying and removing the causes of defects (errors) and minimizing variability in (manufacturing and business) processes.
Lean Six Sigma uses the "Define, Measure, Analyze, Improve and Control (DMAIC)" phases similar to that of Six Sigma. The five phases used in Lean Six Sigma aim to identify the root cause of inefficiencies and work with any process, product, or service that has a large amount of data or measurable characteristics available.
The different levels of certifications are divided into belt colors. The highest level of certification is a black belt, signifying a deep knowledge of Lean Six Sigma principles. Below the black belt are the green and yellow belts. For each of these belts, level skill sets that describe which of the overall Lean Six Sigma tools are expected to be part at a certain belt level are available. The skill sets reflect elements from Six Sigma, Lean and other process improvement methods like the theory of constraints and total productive maintenance. In order to achieve any of the certification levels, a proctored exam must be passed that asks questions about Lean Six Sigma and its applications.
Waste.
Waste ("muda") is defined by Fujio Cho as "anything other than the minimum amount of equipment, materials, parts, space, and workers time, which are absolutely essential to add value to the product".
Different types of waste have been defined in the form of a mnemonic of "downtime":


Pneumatic valve springs

Pneumatic valve springs are metal bellows filled with compressed air used as an alternative to the metal wire springs used to close valves in high-speed internal combustion engines. This system was introduced in Formula One in 1986 with the Renault EF-Type.
Concept.
Racing engines often fail at high rotational speeds because mechanical springs are unable to retract the valves quickly enough to provide clearance for the piston. Renault's pneumatic valve technology replaced steel springs with light weight compressed air bellows. These could retract valves more quickly and reduce the possibility of piston-valve interference, as long as pressure could be maintained. Additionally, the amount of seat tension required to keep a coil sprung valve under control results in greater peak lift loading. This results in added stress to the entire valvetrain. Pneumatic systems, sharing a common reservoir of pressure retain a more static level of force, controlling the valve effectively, without any attendant peak lift load increase.
The actuation mechanism is simply a piston and cylinder, similar to a small pneumatic ram. The "tappet bore" where a hydraulic tappet would normally reside, becomes the cylinder, and the retainer assembly becomes the piston. Pressurized air (nitrogen) is pumped into this cylinder which then causes the piston/retainer to rise to the top of cylinder, causing the valve to form an airtight seal with the seat. The compressed gas then becomes the spring, so to speak, but does not have the same traits as springs do at elevated rpm. A small light spring is sometimes fitted between the piston and retainer so that when the system is switched off the spring forces the piston down against the bottom of the bore, thus forcing the retainer upwards. This ensures that no crown-to-valve contact occurs when shut down.
Pneumatic valve technology in racing.
Pneumatic valve springs gave Renault an advantage with its turbocharged engines, often said to be one of the most powerful. However, reliability and poor handling of their chassis kept the cars from success until 1989, when Renault provided Williams with a new V10 engine that began a winning streak.
Pneumatic valve springs are also found in several Moto GP motorcycle engines, debuting in 2002 with the Aprilia RS Cube. In 2005, Team Roberts was the first to use pneumatic valves full-time in their uncompetitive KTM powered bike. Today, almost all of the MotoGP teams use pneumatic valve technology on their bikes, including Yamaha, Suzuki and Honda. Ducati uses a desmodromic design.
Future valve technology.
While pneumatic valve springs have become standard in Formula One engines, a number of manufacturers have been researching computer-controlled electromagnetic valve actuation (EVA) using no camshaft, to reduce moving parts while improving valve control. In particular, Renault and Freevalve (under supervision of Koenigsegg) are two companies interested in developing the technology for production road vehicles.


Tool wear

In machining, tool wear is the gradual failure of cutting tools due to regular operation. Tools affected include tipped tools, tool bits, and drill bits that are used with machine tools.
Types of wear include:
Effects of tool wear.
Some general effects of tool wear include:
Reduction in tool wear can be accomplished by using lubricants and coolants while machining. These reduce friction and temperature, thus reducing the tool wear.
A more general form of the equation is
where
Temperature considerations.
At high temperature zones crater wear occurs.
The highest temperature of the tool can exceed 700 °C and occurs at the rake face whereas the lowest temperature can be 500 °C or lower depending on the tool...
Energy considerations.
Energy comes in the form of heat from tool friction. It is a reasonable assumption that 80% of energy from cutting is carried away in the chip. If not for this the workpiece and the tool would be much hotter than what is experienced. The tool and the workpiece each carry approximately 10% of the energy. The percent of energy carried away in the chip increases as the speed of the cutting operation increases. This somewhat offsets the tool wear from increased cutting speeds. In fact, if not for the energy taken away in the chip increasing as cutting speed is increased; the tool would wear more quickly than is found.
Multi-criteria of machining operation.
Malakooti and Deviprasad (1989) introduced the multi-criteria metal cutting problem where the criteria could be cost per part, production time per part, and quality of surface. Also, Malakooti et al. (1990) proposed a method to rank the materials in terms of machinability. Malakooti (2013) presents a comprehensive discussion about tool life and its multi-criteria problem. As an example objectives can be minimizing of Total cost (which can be measured by the total cost of replacing all tools during a production period), maximizing of Productivity (which can be measured by the total number of parts produced per period), and maximizing of quality of cutting.