Manufacturing Advisory Service

The Manufacturing Advisory Service (MAS) is a former government agency in England and Scotland.
History.
It was founded by the Department of Trade and Industry (DTI, which became BERR in 2007) in April 2002. It was split into regions and was aimed at SMEs to offer technical and strategic advice. The regional offices were titled Regional Centres of Manufacturing Excellence. There was also co-operation with trade associations, research councils and university departments. In the first year the MAS had on average improved companies productivity by 30%, reduced waste by 37%, and increased inventory turnover by 90%. It had been launched with £27 million funding for three years. (50% Government and 50% Regional) The concept for MAS was based on US model the Manufacturing Extension Programme (MEP). A DTI official who had seen the programme in US brought the model back and developed it for the UK.
In many ways it is similar to what Business Link provides for all small businesses, except that Business Link may not have the in-depth experience of manufacturing, specifically the technical know-how. From November 2011 Business Link is mostly to be disbanded, due to abolishment of regional development agencies (RDAs), and replaced with regional websites.
Much of Business Link's advice was previously via its extensive website. Like Business Link, MAS was funded through RDAs. Half of the MAS's funding came from its RDA and the other half came from BIS.
Overhaul.
On 14 October 2011 Mark Prisk, a minister at the BIS, announced an overhaul of the MAS. It will offer much of what it has done, but due to the regional development agencies being abolished, it will be a national organisation from 1 January 2012. The new national programme will be delivered by the Manufacturing Advisory Consortium comprising Grant Thornton, Pera, WM Manufacturing Consortium Ltd, and SWMAS Ltd.
On 10 December 2010 he had announced that the MAS would not be abolished, as Business Link will be, but will have a 25% cut in funding. It is costing £20 million a year, which will be reduced to £15 million. For the last financial year Business Link received £190 million.
Closure.
With no warning, on 27 November 2015, the closure of the Manufacturing Advisory Service was announced as part of the conservative government austerity programme, with the programme formally closing on 31 March 2016.
Relaunch.
In April 2017 following a high-level meeting with a consortium of Manufacturing MD's and CEO's in Birmingham led by Lord Mike Whitby and Baroness Lorely Burt, Manufacturing Advisory Service was asked to be relaunched by voices from industry. No longer reliant on government funding, MAS through its place on the All Parliamentary Manufacturing Group and its operational delivery by the Made in Brand will continue to offer the signposting service of Manufacturing Advisory Service, but not a grant funding arm.
As a result, the re-launch of the Manufacturing Advisory Service is not like the old service in any way.
In October 2016, a further programme was created to fill the void left by MAS by providing access to specialist support, free advice and grant funding to help SME Manufacturers grow and improve their businesses.
The Manufacturing Growth Programme, managed by those who ran the MAS programme for 10+ years across the West Midlands, East Midlands, Yorkshire and Humber, North West, and South regions, the new programme is also delivered by a number of previous MAS Advisors across 16 LEP regions who offer real advice and sustainable support.
The Manufacturing Growth Programme, is the new and only business support initiative to help support SME Manufacturers.
Manufacturing Growth Programme.
In October 2016, SME Manufacturers were given a major boost with a new £9.7m business support initiative to support over 3,000 companies.
Funded by ERDF and delivered by Economic Growth Solutions (EGS), the Manufacturing Growth Programme promises to fill the void left by MAS by providing access to specialist assistance to help firms grow and improve.
With an 18-strong network of experienced Manufacturing Growth Managers, the majority of which previously delivered the MAS programme, providing bespoke honest advice, MGP also provides access to industry specialists and grant funding to support improvement projects.
In July 2017, the programme had supported more than 1,000 SME Manufacturers, created more than 400 new jobs for the industry and enabled companies to make sustainable changes to support continuous growth.
Function.
It has a helpline for advice. It can conduct a free Manufacturing Review on SME manufacturers, and offers subsidised consultancy (up to 50%), and has local events.
The support offered by the Manufacturing Advisory Service covers
Level 1 (Enquiries) Provided by a small team of advisors geographically dispersed round England supported by a website offering online support.
Level 2 (Manufacturing Review) Continue to provide 1 day (2 days for more complex businesses), on-site specialist manufacturing diagnostic review. MAC will use a new diagnostic tool based on the principles of "Manufacturing Excellence" developed in conjunction with the Warwick Manufacturing Group which includes comparisons against best-in-class. In addition, a "Fast Track" over the 'phone Level 2 will be introduced for common, well understood issues.
Level 3 (Events) Continue to provide training and networking events, including best practice visits. These will be an integral part of delivering the Business Improvement actions identified at Level 2. This will be complemented by a Sustainable Improvement Community using best practice social networking tools to provide peer-led best practice examples and lower cost forms of self-help.
Level 4 (Consultancy)
Introduction of a three tier Level 4 project structure:
· MAS Foundation Service: Funding up to £1,000 (or a maximum of 50%) towards an improvement project - targeted at companies who need basic low-level help.
· MAS Step Change Service: Funding of up to £3,000 (or 50% maximum) towards a more significant improvement programme.
· MAS Transformation Service: Funding of up to £10,000 (or 50% maximum) for a strategic change to the business.
Level 5 (Referrals) MAS advisors are responsible for identifying partner organisation support but retain responsibility for referral until it is demonstrated and confirmed by the client that the partner organisation has addressed the client need.
Supply Chain Focus on helping SMEs diversify into advanced manufacturing supply
chains; helping original equipment manufacturers and their supply chains develop better relationships and greater efficiency; helping groups of SMEs in supply chains or clusters interact more effectively. It will use the tools available through Levels 1 - 5 with custom implementation packages assembled to suit client needs delivered by a team of dedicated supply chain experts.


Krones

Krones AG is a German packaging and bottling machine manufacturer. It produces lines for filling beverages in plastic and glass bottles or beverage cans. The company manufactures stretch blow-moulding machines for producing polyethylene terephthalate (PET) bottles, plus fillers, labellers, bottle washers, pasteurisers, inspectors, packers and palletisers. This product portfolio is complemented by material flow systems and process technology for producing beverages for breweries, dairies and soft-drink companies.
History.
Krones' corporate evolution is closely connected to the socioeconomic conditions prevalent in Germany following World War II. Hermann Kronseder, the father of the present-day chairman of the supervisory board, used his own designs to manufacture semi-automatic labellers starting with 1951. In the further development as from the 1960s, the firm's range of machinery was extended to include packers and filling systems. In 1980, the company was converted into a stock corporation as Krones AG.
With acquisitions of other companies the present-day range of machines for the beverage industry was reached:
Corporate data.
The headquarters of the group is situated in Neutraubling near Regensburg, Germany. In Germany in total 10,733 people are employed. Machines and systems are manufactured at the German production facilities (Neutraubling, Nittenau, Flensburg, Freising and Rosenheim). From 2019 on a fabrication site in Debrecen, Hungary, completes production facilities. The internationally focused company achieves more than 90% of its total turnover abroad and is represented worldwide through around 90 subsidiaries and shareholdings. The intralogistics business of Krones is handled by Syskron Holding GmbH since 2014.
Subsidiaries
Cover additional market segments in beverage filling.
In the year 2019 the enterprise held 5,877 patents and utility models.
Corporate structure.
Plastics engineering
Stretch blow-moulding machines for the production of PET bottles of up to a volume of 3 liters, with an output of 12,800 to 90,000 bottles/hour. The PET recycling system is based on a PET Flakes cleaning process equipped with progressive temperature controls and decontamination.
Filling and packing technology
Rinse, filling and capping lines with a rotary concept. With rotary lines, high-speed tasks of up to 72,000 bottles/hour or approximately 120,000 cans/hour are possible, including aseptic filling systems for beverages with a high pH value (> 4,5). For the disinfection of containers and closures, PES or H2O2 is used. Further steps in beverage production as bottle-washing machines, inspection and control systems for bottles and bundles, as well as labelling machines for cold and hot glue or self-adhesive labelling complete the product range. Packaging machines for bundles either one-way or returnable, sorting and grouping stations, as well as palletisation systems supplement the spectrum.
Process engineering
Breweries can be completely equipped with brewhouses, including fermenting and storage cellar equipment, along with assigned supply installations. For manufacturing plants of non-alcoholic beverages' syrup areas, mixing and carbonising equipment are supplied. Heating systems as UHT- and flash heating systems or pasteurizing systems are available for beverage preservation.
IT solutions and material handling systems
The control of production process and the integration of production data into an ERP system. Logistics systems provide production and distribution with raw, operating and auxiliary materials, as well as finished products, with either block storage or automatic warehouse systems, including commissioning equipment, forklift guidance and yard management systems for logistics process in beverage and food plants. Activities for logistics have been pooled in System Logistics, a legally independent unit.
Business figures.
Executive board
Chairman of the supervisory board: Volker Kronseder


Computer-aided process planning

Computer-aided process planning.
As the design process is supported by many computer-aided tools, computer-aided process planning (CAPP) has evolved to simplify and improve process planning and achieve more effective use of manufacturing resources.
Process Planning is of two types:
Routings that specify operations, operation sequences, work centers, standards, tooling, and fixtures. This routing becomes a major input to the manufacturing resource planning system to define operations for production activity control purposes and define required resources for capacity requirements planning purposes.
Computer-aided process planning initially evolved as a means to electronically store a process plan once it was created, retrieve it, modify it for a new part and print the plan.
Other capabilities were table-driven cost and standard estimating systems, for sales representatives to create customer quotations and estimate delivery time.
Future development.
Generative or dynamic CAPP is the main focus of development, the ability to automatically generate production plans for new products, or dynamically update production plans on the basis of resource availability. Generative CAPP will probably use iterative methods, where simple production plans are applied to automatic CAD/CAM development to refine the initial production plan.
A Generative CAPP system was developed at Beijing No. 1 Machine Tool Plant (BYJC) in Beijing, China as part of a UNDP project (DG/CRP/87/027) from 1989 to 1995. The project was reported in "Machine Design Magazine; New Trends" May 9, 1994, P.22-23. The system was demonstrated to the CASA/SME Leadership in Excellence for Applications Development (LEAD) Award committee in July 1995. The committee awarded BYJC the LEAD Award in 1995 for this achievement. In order to accomplish Generative CAPP, modifications were made to the CAD, PDM, ERP, and CAM systems. In addition, a Manufacturing Execution System (MES) was built to handle the scheduling of tools, personnel, supply, and logistics, as well as maintain shop floor production capabilities.
Generative CAPP systems are built on a factory's production capabilities and capacities. In Discrete Manufacturing, Art-to-Part validations have been performed often, but when considering highly volatile engineering designs, and multiple manufacturing operations with multiple tooling options, the decisions tables become longer and the vector matrices more complex. BYJC builds CNC machine tools and Flexible Manufacturing Systems (FMS) to customer specifications. Few are duplicates. The Generative CAPP System is based on the unique capabilities and capacities needed to produce those specific products at BYJC. Unlike a Variant Process Planning system that modifies existing plans, each process plan could be defined automatically, independent of past routings. As improvements are made to production efficiencies, the improvements are automatically incorporated into the current production mix. This generative system is a key component of the CAPP system for the Agile Manufacturing environment.
In order to achieve the Generative CAPP system, components were built to meet needed capabilities:
The parameters are used to produce multidimensional differential equations. Solving the partial differential equations will produce the optimum process and production planning at the time when the solution was generated. Solutions had the flexibility to change over time based on the ability to satisfy agile manufacturing criteria. Execution planning can be dynamic and accommodate changing conditions.
The system allows new products to be brought on line quickly based on their manufacturability. The more sophisticated CAD/CAM, PDM and ERP systems have the base work already incorporated into them for Generative Computer Aided Process Planning. The task of building and implementing the MES system still requires identifying the capabilities that exist within a given establishment, and exploiting them to the fullest potential. The system created is highly specific, the concepts can be extrapolated to other enterprises.
Traditional CAPP methods that optimize plans in a linear manner have not been able to satisfy the need for flexible planning, so new dynamic systems will explore all possible combinations of production processes, and then generate plans according to available machining resources. For example, K.S. Lee et al. states that "By considering the multi-selection tasks simultaneously, a specially designed genetic algorithm searches through the entire solution space to identify the optimal plan".


Flats Sequencing System

 Flats Sequencing System (FSS) is an automated system used by the US Postal Service. It uses a dual pass sort technique to sort flats all the way to delivery sequence order. Prior to the deployment of FSS machines, flats were machine sorted to the route level only. Carriers had to manually sort all the flats they were to deliver into proper delivery order before they could embark on their routes. With FSS, when the carrier receives them they are ready to be delivered without need for any further manual sorting.
FSS machines are manufactured by Northrop Grumman. Deployment began in 2008.


Multilayered packaging

Multi-layered packaging are multilayer or composite materials using innovative technologies aimed to give barrier properties, strength and storage stability to food items, new materials as well as hazardous materials.
Multiple layers are formed by coextrusion, lamination
, or various coating technologies. The material of construction of multilayered packaging ranges from paper to plastics to metals. Most multilayered packages are not readily recyclable. Basf company and Uflex recently developed multilayered food packaging from 100% recyclable materials.
History of multilayered packaging dates back to the late 1950s when Procter & Gamble first designed multilayered collapsible tubes for toothpastes.
Amine group containing products deforms HDPE on storage, and are incapable of arresting amine odours. Multilayered CO-EX bottles are the best packaging solution for such products.
Types.
Multiwall paper sacks.
These are made of multiple layers of extensible kraft paper of differing grammages. These are gaining popularity in the cement industry, drug and fertilizer industry where the inner or outer layer of the sacks are made of polyethylene to protect the product from moisture.
Laminated-cartons and plastic bottles.
These find use in paint industry, tetra packs containing milk, fruit juice, syrups and pharmaceutical industry. The typical combinations are as follows:
Apart from these nylon, EVOH, EAA, PA, EVA, SiO2 plasma coatings are also used in laminates to give various functional properties. The layer combinations are selected by the engineer depending on the product characteristic, shelf life and extent of vapour transmission rate. Precooked food are packed in PS/EVOH/PE bags with PVE/PDVC/PE closures.
Coextrusion.
Coextrusion is the plastic extrusion of multiple layers of material simultaneously. Such products are popularly known as CO-EX.


CFSMC

CFSMC, or Carbon Fiber Sheet Molding Compound (also known as CSMC or CF-SMC), is a ready to mold carbon fiber reinforced polymer composite material used in compression molding. While traditional SMC utilizes chopped glass fibers in a polymer resin, CFSMC utilizes chopped carbon fibers. The length and distribution of the carbon fibers is more regular, homogeneous, and constant than the standard glass SMC. CFSMC offers much higher stiffness and usually higher strength than standard SMC, but at a higher cost.
Manufacturing.
CF-SMC are made up of carbon tow chunks, spread between two layers of uncured thermosetting resin. The carbon fibre tows are cut from prepreg UD tape. The originating tape can be made up of a certain number of fibres (filaments), thus affecting the properties of the final composite: values can vary from 3 to 50 thousand filaments, while typical tow lengths are within 10 to 50 mm. As for the resin, thermosetting resins are used: possible choices are polyester, vinyl ester or epoxy, with the former being the cheapest and the latter being the most performant. Despite not being as strong nor stiff as epoxy, vinyl ester is often used for its properties like corrosion and higher temperature resistance. The constituents are combined in sheets of prepreg material. The tows usually fall from the cutter onto one of the two layers of resin, and are then covered by the second layer. The prepreg sheets of SMC are made after the viscous assembly is compacted via rollers. In this phase, any control over the orientation of the fibres is generally impossible, and the fibres can be considered to have an equiprobable orientation in all directions.
Once the prepreg sheets are made, the material can be compression moulded into the final desired shape. Compression moulding is a manufacturing technique that requires a two part mould: the first one hosts the moulding material (charge), while the second one is mounted on a press to close the cavity while applying high pressure. Due to complex geometry, it may be necessary to cut the sheets to place them more easily in the lower mould. Then, while the upper mould cavity is closing, the material is pushed throughout the mould until closed. Pressure is maintained, together with elevated temperature, to allow the curing of the resin and low porosity. This stage has a heavy influence on the mechanical performances of the final product, as the viscous flow into the mold cavity tends to orient the fibers along the direction of the flow. By controlling the amount and direction of the flow, it is thus possible to influence the fibre orientation, having a quasi-isotropic material (low-flow moulding) or higher performances in a desired direction (high-flow moulding).
During the manufacturing phase, it is also important to avoid, when possible, defects like weld-
lines. Weld lines occur when two flow fronts of material meet during the filling of a mold cavity. This can sometimes result in air entrapment, inhibited crosslinking in the polymer matrix, or the clumping or absence of fibers. For these reasons weld-lines can be as weak or weaker than the neat polymer resin.
Material Properties.
Due to their heterogeneous and anisotropic microstructure, mechanical properties of CF-SMC can vary significantly within broad ranges. Parameters having profound impact on these materials performances are mainly related to the fibres and matrix neat mechanical and geometrical properties (especially those of the fibres) and the orientation and content of the reinforcement. Modulus can vary from less than 20 GPa to 60 GPa, while strength values are within 60-500 MPa.
CF-SMC can also be engineered, to some extent, to have better performances in a specific direction, in a similar fashion as continuous fibres composites. This can be achieved by carefully controlling the compression moulding stage to influence fibre orientation. When the fibres are mainly aligned with the loading direction, the material behaviour is mainly dominated by that of the fibres, thus resulting in stronger and stiffer, but also more brittle response. In the opposite case, if fibres tend to dispose perpendicular to the loading direction, the resin contributes more to the load bearing, and the overall composite will be less stiff, less strong and more ductile. Being based on hydrodynamic transport phenomena, however, the control over fibre orientation in CF-SMC is much more limited than in the continuous composites case, where orientation is often directly determined accurately by the manufacturer. In addition, while continuous fibres composites have a specific orientation, short fibre reinforced plastics can have a preferential orientation, meaning that, considering a generic system of axis, the majority of fibres can have a higher component along a direction and a lower component along the other two axis.
The discontinuous tow-based microstructure of these materials makes is even more heterogeneous than standard composites: fibre ends themselves acts as stress concentration areas for both the resin and the neighbouring tows; moreover, especially for complex shaped parts, it is impossible to prevent some local spots with badly aligned tows (e.g. perpendicular to the direction of axial stress) or with low fibre volume content, like resin pockets. Although making the material weaker and the structural design more complex, this feature makes these materials quite notch-insensitive.
When moulded, CFSMC has a very different appearance than traditional carbon fibre fabric composites, which traditionally appear with a woven checkerboard pattern. CFSMC has the appearance of black and grey marble or burl.
Industrial use.
CF SMC combines the lightweight properties of carbon composites with a manufacturing process, as compression moulding, that allows fast manufacturing and thus is suitable for high volume industrial applications. For these reasons, the automotive industry is one of the best candidates for this technology.
Car manufacturers have used standard glass SMC for over 30 years as a material for body panels in select sport cars such as the Chevrolet Corvette. Substituting glass fibres with carbon is a recent development, having been used for significant structural components of the 2003 Dodge Viper, the multifunctional spare wheel pan of Mercedes-AMG E-Class, the Mercedes-Benz SLR McLaren, the 2009 Lexus LFA, 2015 Lamborghini Huracán, the 2017 BMW 7 series and 2017 McLaren chassis. Lamborghini (together with Callaway Golf Company) patented an advanced version of CF-SMC called Forged Composite. They first introduced it in the Sesto Elemento concept car, and since then, Forged Composite has been a distinctive mark for Lamborghini cars, used both in structural and aesthetical purposes. CF-SMC use is recently spreading also to the much broader non-high performance automotive sector as for the 2017 Toyota Prius PHV.
CF-SMC has also been used in the aeronautic industry by Boeing, for the 787 Dreamliner window frames, while producers suggest that the use of these materials will grow in this sector as well.


RoboDK

RoboDK is an offline programming and simulation software for industrial robots. The simulation software can be used for many manufacturing projects including milling, welding, pick and place, packaging and labelling, palletizing, painting, robot calibration and more.
Main Features.
Robot Brand Independence.
RoboDK has a library of over 500 robots from more than 50 different manufacturers including ABB, Fanuc, Kuka, Motoman, Hwashi Robots and Universal Robots.
User Interface.
The user interface enables easy simulation and doesn't require any previous programming knowledge.
File Format.
Different types of files can be imported including step and iges files. RoboDK post processors allow for programs to be exported to an actual robot including, ABB Rapid (mod/prg), Fanuc LS (LS/TP), Kuka KRC/IIWA (SRC/java), Motoman Inform (JBI), Universal Robots (urscript), Hwashi (C＋＋), Kawasaki (Python and C＋＋) and more.


Machinability

Machinability is the ease with which a metal can be cut (machined) permitting the removal of the material with a satisfactory finish at low cost. Materials with good machinability (free machining materials) require little power to cut, can be cut quickly, easily obtain a good finish, and do not cause significant wear on the tooling. Factors that typically improve a material's performance often degrade its machinability, presenting a significant engineering challenge.
Machinability can be difficult to predict due to the large number of variables involved in the machining process. Two sets of factors are the condition of work materials and the physical properties of work materials. The condition of the work material includes at least eight factors: microstructure, grain size, heat treatment, chemical composition, fabrication, hardness, yield strength, and tensile strength. Physical properties are those of the individual material groups, such as the modulus of elasticity, thermal conductivity, thermal expansion, and work hardening. Other important factors are operating conditions, cutting tool material and geometry, and the parameters of the specific machining process being performed.
Machinability of steels.
Steels are among the most important and commonly used materials in engineering. Free machining steels are alloys that include elements like sulfur and lead that reduce the size of chips produced by the machining process. Free machining steels are more expensive than standard steels, but their cost is offset by savings on manufacturing costs.
Quantifying machinability.
There are many factors affecting machinability, but no widely accepted way to quantify it. Instead, machinability is often assessed on a case-by-case basis, and tests are tailored to the needs of a specific manufacturing process. Common metrics for comparison include tool life, surface finish quality, cutting temperature, tool forces, and power consumption.
Tool life method.
Machinability can be based on the measure of how long a tool lasts. This can be useful when comparing materials that have similar properties and power consumptions, but one is more abrasive and thus decreases the tool life. The major downfall with this approach is that tool life is dependent on more than just the material it is machining; other factors include cutting tool material, cutting tool geometry, machine condition, cutting tool clamping, cutting speed, feed, and depth of cut. Also, the machinability for one tool type cannot be compared to another tool type (i.e. HSS tool to a carbide tool).
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Tool forces and power consumption method.
The forces required for a tool to cut through a material is directly related to the power consumed. Therefore, tool forces are often given in units of specific energy. This leads to a rating method where higher specific energies equal lower machinability. The advantage of this method is that outside factors have little effect on the rating.
Surface finish method.
The surface finish is sometimes used to measure the machinability of a material. Soft, ductile materials tend to form a built up edge. Stainless steel and other materials with a high strain hardening ability also want to form a built up edge. Aluminium alloys, cold worked steels, and free machining steels, as well as materials with a high shear zone don't tend to form built up edges, so these materials would rank as more machinable.
The advantage of this method is that it is easily measured with the appropriate equipment. The disadvantage of this criterion is that it is often irrelevant. For instance when making a rough cut, the surface finish is of no importance. Also, finish cuts often require a certain accuracy that naturally achieves a good surface finish. This rating method also doesn't always agree with other methods. For instance titanium alloys would rate well by the surface finish method, low by the tool life method, and intermediate by the power consumption method.
Machinability rating.
The machinability rating of a material attempts to quantify the machinability of various materials. It is expressed as a percentage or a normalized value. The American Iron and Steel Institute (AISI) determined machinability ratings for a wide variety of materials by running turning tests at 180 surface feet per minute (sfpm). It then arbitrarily assigned 160 Brinell B1112 steel a machinability rating of 100%. The machinability rating is determined by measuring the weighted averages of the normal cutting speed, surface finish, and tool life for each material. Note that a material with a machinability rating less than 100% would be more difficult to machine than B1112 and material with a value more than 100% would be easier.
Machinability Rating= (Speed of Machining the workpiece giving 60min tool life)/( Speed of machining the standard metal)
Machinability ratings can be used in conjunction with the Taylor tool life equation, formula_2, in order to determine cutting speeds or tool life. It is known that B1112 has a tool life of 60 minutes at a cutting speed of 100 sfpm. If a material has a machinability rating of 70%, it can be determined, with the above knowns, that in order to maintain the same tool life (60 minutes) the cutting speed must be 70 sfpm (assuming the same tooling is used).
Steels.
The carbon content of steel greatly affects its machinability. High-carbon steels are difficult to machine because they are strong and because they may contain carbides that abrade the cutting tool. On the other end of the spectrum, low-carbon steels are troublesome because they are too soft. Low-carbon steels are "gummy" and stick to the cutting tool, resulting in a built up edge that shortens tool life. Therefore, steel has the best machinability with medium amounts of carbon, about 0.20%.
Chromium, molybdenum and other alloying metals are often added to steel to improve its strength. However, most of these metals also decrease machinability.
Inclusions in steel, especially oxides, may abrade the cutting tool. Machinable steel should be free of these oxides.
Additives.
There are a variety of chemicals, both metal and non-metal, that can be added to steel to make it easier to cut. These additives may work by lubricating the tool-chip interface, decreasing the shear strength of the material, or increasing the brittleness of the chip. Historically, sulfur and lead have been the most common additives, but bismuth and tin are increasingly popular for environmental reasons.
Lead can improve the machinability of steel because it acts as an internal lubricant in the cutting zone. Since lead has poor shear strength, it allows the chip to slide more freely past the cutting edge. When it is added in small quantities to steel, it can greatly improve its machinability while not significantly affecting the steel's strength.
Sulfur improves the machinability of steel by forming low shear strength inclusions in the cutting zone. These inclusions are stress risers that weaken the steel, allowing it to deform more easily.
Stainless steel.
Stainless steels have poor machinability compared to regular carbon steel because they are tougher, gummier and tend to work harden very rapidly. Slightly hardening the steel may decrease its gumminess and make it easier to cut. AISI grades 303 and 416 are easier to machine because of the addition of sulfur and phosphorus.
Aluminium.
Aluminium is a much softer metal than steel, and the techniques to improve its machinability usually rely on making it more brittle. Alloys 2007, 2011 and 6020 have very good machinability.
Other materials.
Thermoplastics are difficult to machine because they have poor thermal conductivity. This creates heat that builds up in the cutting zone, which degrades the tool life and locally melts the plastic. Once the plastic melts, it just flows around the cutting edge instead of being removed by it. Machinability can be improved by using high lubricity coolant and keeping the cutting area free of chip build up.
Composites often have the worst machinability because they combine the poor thermal conductivity of a plastic resin with the tough or abrasive qualities of the fiber (glass, carbon etc.) material.
The machinability of rubber and other soft materials improves by using a very low temperature coolant, such as liquid carbon dioxide. The low temperatures chill the material prior to cutting so that it cannot deform or stick to the cutting edge. This means less wear on the tools and easier machining.


Abrasive machining

Abrasive machining is a machining process where material is removed from a workpiece using a multitude of small abrasive particles. Common examples include grinding, honing, and polishing. Abrasive processes are usually expensive, but capable of tighter tolerances and better surface finish than other machining processes
Mechanics of abrasive machining.
Abrasive machining works by forcing the abrasive particles, or grains, into the surface of the workpiece so that each particle cuts away a small bit of material. Abrasive machining is similar to conventional machining, such as milling or turning, because each of the abrasive particles acts like a miniature cutting tool. However, unlike conventional machining the grains are much smaller than a cutting tool, and the geometry and orientation of individual grains are not well defined. As a result, abrasive machining is less power efficient and generates more heat.
The grain size may be different based on the machining. For rough grinding, coarse abrasives are used. For fine grinding, fine grains (abrasives) are used.
Abrasive machining processes.
Abrasive machining processes can be divided into two categories based on how the grains are applied to the workpiece.
In bonded abrasive processes, the particles are held together within a matrix, and their combined shape determines the geometry of the finished workpiece. For example, in grinding the particles are bonded together in a wheel. As the grinding wheel is fed into the part, its shape is transferred onto the workpiece.
In loose abrasive processes, there is no structure connecting the grains. They may be applied without lubrication as dry powder, or they may be mixed with a lubricant to form a slurry. Since the grains can move independently, they must be forced into the workpiece with another object like a polishing cloth or a lapping plate.
Common abrasive processes are listed below.
Abrasives.
The most important property of an abrasive is its hardness. For abrasive grains to effectively cut, they must be significantly harder than the workpiece material. They can be grouped based on their hardness into two categories: conventional abrasives and superabrasives.
Conventional abrasive materials have been used since the advent of machining. They are made of materials that exist naturally on Earth, and they are abundant and cheap. Conventional abrasives can suitably machine most materials.
Superabrasives are much harder than conventional abrasives. Since they are much more expensive, they are used when conventional abrasives will not suffice.
Common abrasives are listed below.


Electrofusion

Electrofusion is a method of joining MDPE, HDPE and other plastic pipes using special fittings that have built-in electric heating elements which are used to weld the joint together.
The pipes to be joined are cleaned, inserted into the electrofusion fitting (with a temporary clamp if required) and a voltage (typically 40V) is applied for a fixed time depending on the fitting in use. The built in heater coils then melt the inside of the fitting and the outside of the pipe wall, which weld together producing a very strong homogeneous joint. The assembly is then left to cool for a specified time.
Electrofusion welding is beneficial because it does not require the operator to use dangerous or sophisticated equipment. After some preparation, the Electrofusion Welder will guide the operator through the steps to take. Welding Heat and Time is dependent on the type and size of the fitting. All Electrofusion Fittings are not created equal - Precise positioning of the energising coils of wire in each fitting ensures uniform melting for a strong joint and the minimisation of welding and cooling time.
The operator must be qualified according to the local and national laws. In Australia, an Electrofusion Course can be done within 8 hours. Electrofusion welding training focuses on the importance of accurately fusing EF fittings. Both manual and automatic methods of calculating electrofusion time gives operators the skills they need in the field. There is much to learn about the importance of preparation, timing, pressure, temperature, cool down time and handling, etc.
Training and certification are very important in this field of welding, as the product can become dangerous under certain circumstances. There has been cases of major harm and death, including when molten polyethylene spurts out of the edge of a mis-aligned weld, causing skin burns. Another case was due to a tapping saddle being incorrectly installed on a gas line, causing the death of the two welders in the trench due to gas inhalation. There are many critical parts to Electrofusion welding that can cause weld failures, most of which can be greatly reduced by using welding clamps, and correct scraping equipment.
To keep their qualification current, a trained operator can get their fitting tested, which involves cutting open the fitting and examining the integrity of the weld.


Selective soldering

Selective soldering is the process of selectively soldering components to printed circuit boards and molded modules that could be damaged by the heat of a reflow oven or wave soldering in a traditional surface-mount technology (SMT) or through-hole technology assembly processes. This usually follows an SMT oven reflow process; parts to be selectively soldered are usually surrounded by parts that have been previously soldered in a surface-mount reflow process, and the selective-solder process must be sufficiently precise to avoid damaging them.
Processes.
Assembly processes used in selective soldering include:
Less-common selective soldering processes include:
Other selective soldering applications are non-electronic, such as lead-frame attachment to ceramic substrates, coil-lead attachment, SMT attachment (such as LEDs to PCBs) and fire sprinklers (where the fuse is low-temperature solder alloys).
Regardless of the selective soldering equipment used, there are two types of selective flux applicators: spray and dropjet fluxers. The spray fluxer applies atomized flux to a specific area, while the dropjet fluxer is more precise; the choice depends on the circumstances surrounding the soldering application.
Miniature wave selective solder fountain.
The miniature wave selective solder fountain type is widely used, yielding good results if the PCB design and manufacturing process are optimized. Key requirements for selective fountain type soldering are:
Drop-Jet.
The Drop-Jet is an Electromechanical device which is capable of depositing a droplet of flux on demand onto a surface such as a Printed Circuit Board and or component pin.
Thermal Profiling.
The thermal profile of the selective process is critical as with other common automated soldering techniques.
Topside temperature measurements within the pre-heat stage must be verified as with conventional flow solder machine, additionally flux activation must be verified as sufficient.
As number of miniature profiling dataloggers are now available to make the process more simple such as the Solderstar Pro units.
Selective Solder Optimization.
A number of fixtures are available to allow daily checking of the selective solder process, these instruments allow the verification of machine parameters to be performed on a periodic basis.
Parameters such as contact time, X/Y speeds, nozzle wave height and profile temperature can all be measured.
Use of Nitrogen Atmosphere.
Selective soldering is normally undertaken in a nitrogen atmosphere. This prevents oxidation of the fountain surface and results in better wetting. Less flux is needed with less left-over residue. The use of nitrogen results in clean, shiny joints without the need for PCB cleaning or brushing.


System in a package

A system in a package (SiP) or system-in-package is a number of integrated circuits (ICs) enclosed in one chip carrier package or encompassing an IC package substrate that may include passive components and perform the functions of an entire system. The ICs may be stacked using package on package, placed side by side, and/or embedded in the substrate. The SiP performs all or most of the functions of an electronic system, and is typically used when designing components for mobile phones, digital music players, etc. Dies containing integrated circuits may be stacked vertically on a substrate. They are internally connected by fine wires that are bonded to the package. Alternatively, with a flip chip technology, solder bumps are used to join stacked chips together. SiPs are like systems on a chip (SoCs) but less tightly integrated and not on a single semiconductor die.
Technology.
SiP dies can be stacked vertically or tiled horizontally, with techniques like chiplets or quilt packaging, unlike less dense multi-chip modules, which place dies horizontally on a carrier. SiPs connect the dies with standard off-chip wire bonds or solder bumps, unlike slightly denser three-dimensional integrated circuits which connect stacked silicon dies with conductors running through the die. Many different 3D packaging techniques have been developed for stacking many fairly standard chip dies into a compact area.
SiPs can contain several chips—such as a specialized processor, DRAM, flash memory—combined with passive components—resistors and capacitors—all mounted on the same substrate. This means that a complete functional unit can be built in a multi-chip package, so that few external components need to be added to make it work. This is particularly valuable in space constrained environments like MP3 players and mobile phones as it reduces the complexity of the printed circuit board and overall design. Despite its benefits, this technique decreases the yield of fabrication since any defective chip in the package will result in a non-functional packaged integrated circuit, even if all other modules in that same package are functional.
SiPs are in contrast to the common system on a chip (SoC) integrated circuit architecture which integrates components based on function into a single circuit die. An SoC will typically integrate a CPU, graphics and memory interfaces, hard-disk and USB connectivity, random-access and read-only memories, and secondary storage and/or their controllers on a single die. In comparison an SiP would connect these modules as discrete components in one or more chip carrier packages. An SiP resembles the common traditional motherboard-based PC architecture, which separates components based on function and connects them through a central interfacing circuit board. An SiP has a lower grade of integration in comparison to an SoC. Hybrid integrated circuits are somewhat similar to SiPs, however they tend to use older or less advanced technology (tend to use single layer circuit boards or substrates, not use die stacking, use wire bonding for connecting dies/devices or Small outline integrated circuit packages instead of flip chip or BGA, use Dual in-line packages, or Single in-line packages for interfacing outside the Hybrid IC instead of BGA, etc.)
SiP technology is primarily being driven by early market trends in wearables, mobile devices and the internet of things which do not demand the high numbers of produced units as in the established consumer and business SoC market. As the internet of things becomes more of a reality and less of a vision, there is innovation going on at the system on a chip and SiP level so that microelectromechanical (MEMS) sensors can be integrated on a separate die and control the connectivity.
SiP solutions may require multiple packaging technologies, such as flip chip, wire bonding, wafer-level packaging and more.


Integrated circuit packaging

In electronics manufacturing, integrated circuit packaging is the final stage of semiconductor device fabrication, in which the block of semiconductor material is encapsulated in a supporting case that prevents physical damage and corrosion. The case, known as a "package", supports the electrical contacts which connect the device to a circuit board.
In the integrated circuit industry, the process is often referred to as packaging. Other names include semiconductor device assembly, assembly, encapsulation or sealing.
The packaging stage is followed by testing of the integrated circuit.
The term is sometimes confused with electronic packaging, which is the mounting and interconnecting of integrated circuits (and other components) onto printed-circuit boards.
Design considerations.
Electrical.
The current-carrying traces that run out of the die, through the package, and into the printed circuit board (PCB) have very different electrical properties compared to on-chip signals. They require special design techniques and need much more electric power than signals confined to the chip itself. Therefore, it is important that the materials used as electrical contacts exhibit characteristics like low resistance, low capacitance and low inductance. Both the structure and materials must prioritize signal transmission properties, while minimizing any parasitic elements that could negatively affect the signal.
Controlling these characteristics is becoming increasingly important as the rest of technology begins to speed up. Packaging delays have the potential to make up almost half of a high-performance computer's delay, and this bottleneck on speed is expected to increase.
Mechanical and thermal.
The integrated circuit package must resist physical breakage, keep out moisture, and also provide effective heat dissipation from the chip. Moreover, for RF applications, the package is commonly required to shield electromagnetic interference, that may either degrade the circuit performance or adversely affect neighboring circuits. Finally, the package must permit interconnecting the chip to a PCB. The materials of the package are either plastic (thermoset or thermoplastic), metal (commonly Kovar) or ceramic. A common plastic used for this is epoxy-cresol-novolak (ECN). All three material types offer usable mechanical strength, moisture and heat resistance. Nevertheless, for higher-end devices, metallic and ceramic packages are commonly preferred due to their higher strength (which also supports higher pin-count designs), heat dissipation, hermetic performance, or other reasons. Generally, ceramic packages are more expensive than similar plastic packages.
Some packages have metallic fins to enhance heat transfer, but these take up space. Larger packages also allow for more interconnecting pins.
Economic.
Cost is a factor in selection of integrated circuit packaging. Typically, an inexpensive plastic package can dissipate heat up to 2W, which is sufficient for many simple applications, though a similar ceramic package can dissipate up to 50W in the same scenario. As the chips inside the package get smaller and faster, they also tend to get hotter. As the subsequent need for more effective heat dissipation increases, the cost of packaging rises along with it. Generally, the smaller and more complex the package needs to be, the more expensive it is to manufacture.
History.
Early integrated circuits were packaged in ceramic flat packs, which the military used for many years for their reliability and small size. The other type of packaging used in the 1970s, called the ICP (Integrated Circuit Package), was a ceramic package (sometime round as the transistor package), with the leads on one side, co-axially with the package axis.
Commercial circuit packaging quickly moved to the dual in-line package (DIP), first in ceramic and later in plastic. In the 1980s VLSI pin counts exceeded the practical limit for DIP packaging, leading to pin grid array (PGA) and leadless chip carrier (LCC) packages. Surface mount packaging appeared in the early 1980s and became popular in the late 1980s, using finer lead pitch with leads formed as either gull-wing or J-lead, as exemplified by small-outline integrated circuit—a carrier which occupies an area about 30–50% less than an equivalent DIP, with a typical thickness that is 70% less.The next big innovation was the "area array package", which places the interconnection terminals throughout the surface area of the package, providing a greater number of connections than previous package types where only the outer perimeter is used. The first area array package was a ceramic pin grid array package. Not long after, the plastic ball grid array (BGA), another type of area array package, became one of the most commonly used packaging techniques.
In the late 1990s, plastic quad flat pack (PQFP) and thin small-outline packages (TSOP) replaced PGA packages as the most common for high pin count devices, though PGA packages are still often used for microprocessors. However, industry leaders Intel and AMD transitioned in the 2000s from PGA packages to land grid array (LGA) packages.
Ball grid array (BGA) packages have existed since the 1970s, but evolved into flip-chip ball grid array (FCBGA) packages in the 1990s. FCBGA packages allow for much higher pin count than any existing package types. In an FCBGA package, the die is mounted upside-down (flipped) and connects to the package balls via a substrate that is similar to a printed-circuit board rather than by wires. FCBGA packages allow an array of input-output signals (called Area-I/O) to be distributed over the entire die rather than being confined to the die periphery.
Traces out of the die, through the package, and into the printed circuit board have very different electrical properties, compared to on-chip signals. They require special design techniques and need much more electric power than signals confined to the chip itself.
Recent developments consist of stacking multiple dies in single package called SiP, for "System In Package", or three-dimensional integrated circuit. Combining multiple dies on a small substrate, often ceramic, is called an MCM, or Multi-Chip Module. The boundary between a big MCM and a small printed circuit board is sometimes blurry.
Operations.
"Die attachment" is the step during which a die is mounted and fixed to the package or support structure (header). For high-powered applications, the die is usually eutectic bonded onto the package, using e.g. gold-tin or gold-silicon solder (for good heat conduction). For low-cost, low-powered applications, the die is often glued directly onto a substrate (such as a printed wiring board) using an epoxy adhesive.
The following operations are performed at the packaging stage, as broken down into bonding, encapsulation, and wafer bonding steps. Note that this list is not all-inclusive and not all of these operations are performed for every package, as the process is highly dependent on the package type.


Computer-aided industrial design

Computer Aided Industrial Design (CAID) is a subset of computer-aided design (CAD) software that can assist in creating the look-and-feel or industrial design aspects of a product in development.
CAID programs tend to provide designers with improved freedom of creativity compared to typical CAD tools. However a typical workflow may follow a simple design methodology as follows:
The end result is generally a 3D model that represents the main intent of the designer had in mind for the physical product. Such models can then be saved in formats for more convenient exchange with others (such as OBJ for virtual viewing in 3D graphics programs) or manufacturing (such a STL to create a real-life model via a rapid prototyping machine). CAID helps the designer focus on the technical aspect of the design methodology rather than the sketching and modelling aspects, contributing to the selection of a better product proposal in less time. When product pre-requisites and parameters have been more completely defined, output from the CAID software can be imported into a CAD program for pre-production testing, adjustment, and generation of technical drawings and manufacturing data such as CNC tool-paths.
CAID is far more conceptual and less technically focused than CAD. CAID programs tend to offer more tools that allow a designer to freely express themselves with more organic shapes and complex curves, whilst CAD software tends to be more focused on tools for the simple curves and straight lines more suitable for easy manufacturing.
CAD implementations have evolved dramatically since initial 3D offerings in the 1970s, which were typically limited to producing drawings similar to hand-drafted output. Advances in programming and computer hardware,[21][22] notably solid modelling in the 1980s, have allowed more versatile applications of computers in design activities.


Plastic extrusion

Plastics extrusion is a high-volume manufacturing process in which raw plastic is melted and formed into a continuous profile. Extrusion produces items such as pipe/tubing, weatherstripping, fencing, deck railings, window frames, plastic films and sheeting, thermoplastic coatings, and wire insulation.
This process starts by feeding plastic material (pellets, granules, flakes or powders) from a hopper into the barrel of the extruder. The material is gradually melted by the mechanical energy generated by turning screws and by heaters arranged along the barrel. The molten polymer is then forced into a die, which shapes the polymer into a shape that hardens during cooling.
History.
The first precursors to the modern extruder were developed in the early 19th century. In 1820, Thomas Hancock invented a rubber "masticator" designed to reclaim processed rubber scraps, and in 1836 Edwin Chaffee developed a two-roller machine to mix additives into rubber. The first thermoplastic extrusion was in 1935 by Paul Troester and his wife Ashley Gershoff in Hamburg, Germany. Shortly after, Roberto Colombo of LMP developed the first twin screw extruders in Italy.
Process.
In the extrusion of plastics, the raw compound material is commonly in the form of nurdles (small beads, often called resin) that are gravity fed from a top mounted hopper into the barrel of the extruder. Additives such as colorants and UV inhibitors (in either liquid or pellet form) are often used and can be mixed into the resin prior to arriving at the hopper. The process has much in common with plastic injection molding from the point of the extruder technology, although it differs in that it is usually a continuous process. While pultrusion can offer many similar profiles in continuous lengths, usually with added reinforcing, this is achieved by pulling the finished product out of a die instead of extruding the polymer melt through a die.
The material enters through the feed throat (an opening near the rear of the barrel) and comes into contact with the screw. The rotating screw (normally turning at e.g. 120 rpm) forces the plastic beads forward into the heated barrel. The desired extrusion temperature is rarely equal to the set temperature of the barrel due to viscous heating and other effects. In most processes, a heating profile is set for the barrel in which three or more independent PID-controlled heater zones gradually increase the temperature of the barrel from the rear (where the plastic enters) to the front. This allows the plastic beads to melt gradually as they are pushed through the barrel and lowers the risk of overheating which may cause polymer degradation.
Extra heat is contributed by the intense pressure and friction taking place inside the barrel. In fact, if an extrusion line is running certain materials fast enough, the heaters can be shut off and the melt temperature maintained by pressure and friction alone inside the barrel. In most extruders, cooling fans are present to keep the temperature below a set value if too much heat is generated. If forced air cooling proves insufficient then cast-in cooling jackets are employed.
At the front of the barrel, the molten plastic leaves the screw and travels through a screen pack to remove any contaminants in the melt. The screens are reinforced by a breaker plate (a thick metal puck with many holes drilled through it) since the pressure at this point can exceed 5,000 psi (34 MPa). The screen pack/breaker plate assembly also serves to create back pressure in the barrel. Back pressure is required for uniform melting and proper mixing of the polymer, and how much pressure is generated can be "tweaked" by varying screen pack composition (the number of screens, their wire weave size, and other parameters). This breaker plate and screen pack combination also eliminates the "rotational memory" of the molten plastic and creates instead, "longitudinal memory".
After passing through the breaker plate molten plastic enters the die. The die is what gives the final product its profile and must be designed so that the molten plastic evenly flows from a cylindrical profile, to the product's profile shape. Uneven flow at this stage can produce a product with unwanted residual stresses at certain points in the profile which can cause warping upon cooling. A wide variety of shapes can be created, restricted to continuous profiles.
The product must now be cooled and this is usually achieved by pulling the extrudate through a water bath. Plastics are very good thermal insulators and are therefore difficult to cool quickly. Compared to steel, plastic conducts its heat away 2,000 times more slowly. In a tube or pipe extrusion line, a sealed water bath is acted upon by a carefully controlled vacuum to keep the newly formed and still molten tube or pipe from collapsing. For products such as plastic sheeting, the cooling is achieved by pulling through a set of cooling rolls. For films and very thin sheeting, air cooling can be effective as an initial cooling stage, as in blown film extrusion.
Plastic extruders are also extensively used to reprocess recycled plastic waste or other raw materials after cleaning, sorting and/or blending. This material is commonly extruded into filaments suitable for chopping into the bead or pellet stock to use as a precursor for further processing.
Screw design.
There are five possible zones in a thermoplastic screw. Since terminology is not standardized in the industry, different names may refer to these zones. Different types of polymer will have differing screw designs, some not incorporating all of the possible zones.
Most screws have these three zones:
In addition, a vented (two-stage) screw has:
Often screw length is referenced to its diameter as L:D ratio. For instance, a diameter screw at 24:1 will be 144 inches (12 ft) long, and at 32:1 it is 192 inches (16 ft) long. An L:D ratio of 25:1 is common, but some machines go up to 40:1 for more mixing and more output at the same screw diameter. Two-stage (vented) screws are typically 36:1 to account for the two extra zones.
Each zone is equipped with one or more thermocouples or RTDs in the barrel wall for temperature control. The "temperature profile" i.e., the temperature of each zone is very important to the quality and characteristics of the final extrudate.
Typical extrusion materials.
Typical plastic materials that are used in extrusion include but are not limited to: polyethylene (PE), polypropylene, polyacetal, acrylic, nylon (polyamides), polystyrene, polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS) and polycarbonate.
Die types.
There are a variety of dies used in plastics extrusion. While there can be significant differences between die types and complexity, all dies allow for the continuous extrusion of polymer melt, as opposed to non-continuous processing such as injection molding.
Blown film extrusion.
The manufacture of plastic film for products such as food packages, shopping bags, and continuous sheeting is achieved using a blown film line.
This process is the same as a regular extrusion process up until the die. There are three main types of dies used in this process: annular (or crosshead), spider, and spiral. Annular dies are the simplest, and rely on the polymer melt channeling around the entire cross section of the die before exiting the die; this can result in uneven flow. Spider dies consist of a central mandrel attached to the outer die ring via a number of "legs"; while flow is more symmetrical than in annular dies, a number of weld lines are produced which weaken the film. Spiral dies remove the issue of weld lines and asymmetrical flow, but are by far the most complex.
The melt is cooled somewhat before leaving the die to yield a weak semi-solid tube. This tube's diameter is rapidly expanded via air pressure, and the tube is drawn upwards with rollers, stretching the plastic in both the transverse and draw directions. The drawing and blowing cause the film to be thinner than the extruded tube, and also preferentially aligns the polymer molecular chains in the direction that sees the most plastic strain. If the film is drawn more than it is blown (the final tube diameter is close to the extruded diameter) the polymer molecules will be highly aligned with the draw direction, making a film that is strong in that direction, but weak in the transverse direction. A film that has significantly larger diameter than the extruded diameter will have more strength in the transverse direction, but less in the draw direction.
In the case of polyethylene and other semi-crystalline polymers, as the film cools it crystallizes at what is known as the frost line. As the film continues to cool, it is drawn through several sets of nip rollers to flatten it into lay-flat tubing, which can then be spooled or slit into two or more rolls of sheeting.
Sheet/film extrusion.
Sheet/film extrusion is used to extrude plastic sheets or films that are too thick to be blown. There are two types of dies used: T-shaped and coat hanger. The purpose of these dies is to reorient and guide the flow of polymer melt from a single round output from the extruder to a thin, flat planar flow. In both die types ensure constant, uniform flow across the entire cross sectional area of the die. Cooling is typically by pulling through a set of cooling rolls (calender or "chill" rolls). In sheet extrusion, these rolls not only deliver the necessary cooling but also determine sheet thickness and surface texture. Often co-extrusion is used to apply one or more layers on top of a base material to obtain specific properties such as UV-absorption, texture, oxygen permeation resistance, or energy reflection.
A common post-extrusion process for plastic sheet stock is thermoforming, where the sheet is heated until soft (plastic), and formed via a mold into a new shape. When vacuum is used, this is often described as vacuum forming. Orientation (i.e. ability/ available density of the sheet to be drawn to the mold which can vary in depths from 1 to 36 inches typically) is highly important and greatly affects forming cycle times for most plastics.
Tubing extrusion.
Extruded tubing, such as PVC pipes, is manufactured using very similar dies as used in blown film extrusion. Positive pressure can be applied to the internal cavities through the pin, or negative pressure can be applied to the outside diameter using a vacuum sizer to ensure correct final dimensions. Additional lumens or holes may be introduced by adding the appropriate inner mandrels to the die.
Multi-layer tubing applications are also ever present within the automotive industry, plumbing & heating industry and packaging industry.
Over jacketing extrusion.
Over jacketing extrusion allows for the application of an outer layer of plastic onto an existing wire or cable. This is the typical process for insulating wires.
There are two different types of die tooling used for coating over a wire, tubing (or jacketing) and pressure. In jacketing tooling, the polymer melt does not touch the inner wire until immediately before the die lips. In pressure tooling, the melt contacts the inner wire long before it reaches the die lips; this is done at a high pressure to ensure good adhesion of the melt. If intimate contact or adhesion is required between the new layer and existing wire, pressure tooling is used. If adhesion is not desired/necessary, jacketing tooling is used instead.
Coextrusion.
Coextrusion is the extrusion of multiple layers of material simultaneously. This type of extrusion utilizes two or more extruders to melt and deliver a steady volumetric throughput of different viscous plastics to a single extrusion head (die) which will extrude the materials in the desired form. This technology is used on any of the processes described above (blown film, overjacketing, tubing, sheet). The layer thicknesses are controlled by the relative speeds and sizes of the individual extruders delivering the materials.
In many real-world scenarios, a single polymer cannot meet all the demands of an application. Compound extrusion allows a blended material to be extruded, but coextrusion retains the separate materials as different layers in the extruded product, allowing appropriate placement of materials with differing properties such as oxygen permeability, strength, stiffness, and wear resistance.
Extrusion coating.
Extrusion coating is using a blown or cast film process to coat an additional layer onto an existing rollstock of paper, foil or film. For example, this process can be used to improve the characteristics of paper by coating it with polyethylene to make it more resistant to water. The extruded layer can also be used as an adhesive to bring two other materials together. Tetrapak is a commercial example of this process.
Compound extrusions.
Compounding extrusion is a process that mixes one or more polymers with additives to give plastic compounds. The feeds may be pellets, powder and/or liquids, but the product is usually in pellet form, to be used in other plastic-forming processes such as extrusion and injection molding. As with traditional extrusion, there is a wide range in machine sizes depending on application and desired throughput. While either single- or double-screw extruders may be used in traditional extrusion, the necessity of adequate mixing in compounding extrusion makes twin-screw extruders all but mandatory.
Types of extruder.
There are two sub-types of twin screw extruders: co-rotating and counter-rotating. This nomenclature refers to the relative direction each screw spins compared to the other. In co-rotation mode, both screws spin either clockwise or counter clockwise; in counter-rotation, one screw spins clockwise while the other spins counter clockwise. It has been shown that, for a given cross sectional area and degree of overlap (intermeshing), axial velocity and degree of mixing is higher in co-rotating twin extruders. However, pressure buildup is higher in counter-rotating extruders. The screw design is commonly modular in that various conveying and mixing elements are arranged on the shafts to allow for rapid reconfiguration for a process change or replacement of individual components due to wear or corrosive damage. The machine sizes range from as small as 12 mm to as large as 380mm [12- Polymer Mixing by James White, pages 129-140]
Advantages.
A great advantage of extrusion is that profiles such as pipes can be made to any length. If the material is sufficiently flexible, pipes can be made at long lengths even coiling on a reel. Another advantage is the extrusion of pipes with integrated coupler including rubber seal.


Design for assembly

Design for assembly (DFA) is a process by which products are designed with ease of assembly in mind. If a product contains fewer parts it will take less time to assemble, thereby reducing assembly costs. In addition, if the parts are provided with features which make it easier to grasp, move, orient and insert them, this will also reduce assembly time and assembly costs. The reduction of the number of parts in an assembly has the added benefit of generally reducing the total cost of parts in the assembly. This is usually where the major cost benefits of the application of design for assembly occur. Critics of DFA from within industry argue that DFA/DFM is simply a new term for something that has existed as long as manufacturing itself, and is otherwise known as engineering design.
Approaches.
Design for assembly can take different forms. In the 1960s and 1970s various rules and recommendations were proposed in order to help designers consider assembly problems during the design process. Many of these rules and recommendations were presented together with practical examples showing how assembly difficulty could be improved. However, it was not until the 1970s that numerical evaluation methods were developed to allow design for assembly studies to be carried out on existing and proposed designs.
The first evaluation method was developed at Hitachi and was called the Assembly Evaluation Method (AEM). This method is based on the principle of "one motion for one part." For more complicated motions, a point-loss standard is used and the ease of assembly of the whole product is evaluated by subtracting points lost. The method was originally developed in order to rate assemblies for ease of automatic assembly.
Starting in 1977, Geoff Boothroyd, supported by an NSF grant at the University of Massachusetts Amherst, developed the Design for Assembly method (DFA), which could be used to estimate the time for manual assembly of a product and the cost of assembling the product on an automatic assembly machine. Recognizing that the most important factor in reducing assembly costs was the minimization of the number of separate parts in a product, he introduced three simple criteria which could be used to determine theoretically whether any of the parts in the product could be eliminated or combined with other parts. These criteria, together with tables relating assembly time to various design factors influencing part grasping, orientation and insertion, could be used to estimate total assembly time and to rate the quality of a product design from an assembly viewpoint. For automatic assembly, tables of factors could be used to estimate the cost of automatic feeding and orienting and automatic insertion of the parts on an assembly machine.
In the 1980s and 1990s, variations of the AEM and DFA methods have been proposed, namely: the GE Hitachi method which is based on the AEM and DFA; the Lucas method, the Westinghouse method and several others which were based on the original DFA method. All methods are now referred to as "design for assembly" methods.
Implementation.
Most products are assembled manually and the original DFA method for manual assembly is the most widely used method and has had the greatest industrial impact throughout the world.
The DFA method, like the AEM method, was originally made available in the form of a handbook where the user would enter data on worksheets to obtain a rating for the ease of assembly of a product. Starting in 1981, Geoffrey Boothroyd and Peter Dewhurst developed a computerized version of the DFA method which allowed its implementation in a broad range of companies. For this work they were presented with many awards including the National Medal of Technology. There are many published examples of significant savings obtained through the application of DFA. For example, in 1981, Sidney Liebson, manager of manufacturing engineering for Xerox, estimated that his company would save hundreds of millions of dollars through the application of DFA. In 1988, Ford Motor Company credited the software with overall savings approaching $1 billion. In many companies DFA is a corporate requirement and DFA software is continually being adopted by companies attempting to obtain greater control over their manufacturing costs. There are many key principles in design for assembly.
Notable examples.
Two notable examples of good design for assembly are the Sony Walkman and the Swatch watch. Both were designed for fully automated assembly. The Walkman line was designed for "vertical assembly", in which parts are inserted in straight-down moves only. The Sony SMART assembly system, used to assemble Walkman-type products, is a robotic system for assembling small devices designed for vertical assembly.
The IBM Proprinter used design for automated assembly (DFAA) rules. These DFAA rules help design a product that can be assembled automatically by robots, but they are useful even with products assembled by manual assembly.
Further information.
For more information on Design for Assembly and the subject of Design for Manufacture and Assembly see:


Rack rail

A rack rail, or rack strip, is used to mount rackable electronic hardware and 19-inch rack mount accessories within a 19-inch rack. Within a rack a minimum of two rack rails are required to mount equipment. The height of rack rail is determined by the number of rack units required for mounting the equipment.
The design of racks and rack rails is specified in ECIA - EIA/ECA-310.
Each rack unit (U) is equivalent to . Most rack rail is in sizes from 2 units high  to 54 units high .
Types.
Rack Rail comes in two different commonly used forms. Tapped/threaded rack rail has round holes tapped for 10-32 UNF or 10-24 UNC screws. The other common form of rack rail is square hole rack strip which has square holes for captive nuts, available tapped for various different screw threads, that are clipped into the holes as needed to mount equipment.
In both cases, rack screws and washers are required to mount rack mount equipment to the rack rail. The size and strength of rack rail is determined by its application. Increased thickness of steel results in stronger rack rail and varieties of rack rail can be found such as double angle and single angle rack rail.


Hugon, The Mighty

Hugon, The Mighty is a lost 1918 silent film Northwoods drama directed by Rollin S. Sturgeon and starring Monroe Salisbury. It was produced by Bluebird Photoplays and released through Universal Film Manufacturing Company.


Autobike

An autobike or automatically geared bicycle is a bicycle with an automatic transmission that shifts gears without intervention from the rider.
History.
In 2011 the company Autobike was founded by Mark Simpson. In the company applied for a patent on a system which automatically changes gears on a bicycle, and they started selling their Voyage line of bicycles. The original Autobike was equipped with a system of centrifugal weights on the rear wheel with a rear derailleur attached to them. When the rider started pedaling it would cause the weights to spin outwards, which shifted the derailleur to a higher gear. When the rider stops pedaling and the bike comes to a stop, the weights would return to the centre position, shifting the bike into its lowest gear so it is easier to get started again. Autobike went bankrupt.
The current Autobike uses three main components in its automatic transmission. In order to provide the system with power, the front wheel uses a hub dynamo to generate electricity. Wires connect the dynamo through the frame to the bottom bracket area where it joins a small onboard computer with sensors that detect the rider's speed and cadence. The computer uses this information to actuate a motorised shifter mounted on the rear wheel's hub gear to change the gear ratio. The rear hub used is the Nuvinci N360 CVP which is a continuously variable transmission using a planetary gear system that can be shifted smoothly at any time, under any load.


Bugatti EB 218

The Bugatti EB 218 saloon is the second concept car presented by Bugatti under the ownership of the Volkswagen Auto Group. The EB 218 was designed by Giorgetto Giugiaro, who also designed the EB 112, the car's predecessor and the EB 118, the car's 2-door variant. The EB 218 can be considered as an update of the EB 112, a concept saloon introduced by Bugatti Automobili SpA in 1993. The EB 218 features Volkswagen's unconventional W18 engine and permanent four-wheel drive borrowed from the Lamborghini Diablo VT.
Design.
Bugatti commissioned Giorgetto Giugiaro of Italdesign to update the EB 112 concept that he designed for Bugatti Automobili SpA in 1993. The EB218's wheelbase measures and it has a total length of . This makes the EB 218 longer that the EB 112 by . The most notable visual differences between the EB 218 and the EB 112 is a redesigned hood, bumpers and lights. The overall design is far less controversial than the EB 112's "Droopy hatchback-saloon" design and has a much more of a typical saloon shape rather than the EB 112's hatchback shape. The interior design is very simple yet extremely luxurious, with beige leather seats and a large wooden dashboard which manages to keep all the instruments and vents "composed". The EB 218 draws inspiration from the classic Type 101 Guillore.
Debut.
Bugatti introduced the EB 218 at the 1999 Geneva Motor Show, one year after its 2-door counterpart was introduced at the 1998 Paris Auto Show.
Powertrain.
The EB 218 uses the same W18 engine and permanent four wheel drive powertrain that debuted in the 1998 EB 118. The same technology was used in the 1999 18/3 Chiron concept car.
Power comes from a Volkswagen-designed, and , W18 engine. This engine design was extremely unconventional due to the unusual firing order of the engine. The EB 218 W18 engine is composed of three banks of six cylinders with a sixty degree offset between each cylinder bank. In contrast, the W16 engine in Bugatti's (Under Volkswagen ownership) first production car, the 2005 Veyron EB 16.4 features four banks of four cylinders. The EB 218 has the permanent all-wheel drive taken from the Lamborghini Diablo VT sports car.


Desoldering

In electronics, desoldering is the removal of solder and components from a circuit board for troubleshooting, repair, replacement, and salvage.
Tools.
Desoldering tools and materials include the following:
Terminology is not totally standardised. Anything with a base unit with provision to maintain a stable temperature, pump air in either direction, etc., is often called a "station" (preceded by rework, soldering, desoldering, hot air); one, or sometimes more, tools may be connected to a station, e.g., a rework station may accommodate a soldering iron and hot air head. A soldering iron with a hollow tip and a spring-, bulb-, or electrically-operated suction pump may be called a . Terms such as "suction pen" may be used; the meaning is usually clear from the context.
Pumps.
Electrically operated pumps are used for several purposes in conjunction with a hand-held head connected by a tube.
Suction pumps are used to suck away molten solder, leaving previously joined terminals disconnected. They are primarily used to release through-hole connections from a PCB. The desoldering head must be designed so that the extracted solder does not solidify so as to obstruct it, or enter the pump, and can be removed and discarded easily. It is not possible to remove a multi-pin part by melting solder on the pins sequentially, as one joint will solidify as the next is melted; pumps and solder wick are among methods to remove solder from all joints, leaving the part free to be removed.
Suction pumps are also used with a suction head appropriate for each part to pick up and remove tiny surface mount devices once solder has melted, and to place parts.
Hot air pumps blow air hot enough to melt all the solder around a small surface mounted part, and can be used for soldering parts in place, and for desoldering followed by removal before the solder solidifies by a vacuum pump or with tweezers. Hot air has a tendency to oxidise metals; a non-oxidising gas, usually nitrogen, can be used instead of air, at increased cost of equipment and consumables.
Desoldering pump.
A desoldering pump, colloquially known as a solder sucker, is a manually-operated device which is used to remove solder from a printed circuit board. There are two types: the "plunger" style and "bulb" style. (An electrically-operated pump for this purpose would usually be called a vacuum pump.)
The plunger type has a cylinder with a spring-loaded piston which is pushed down and locks into place. When triggered by pressing a button, the piston springs up, creating suction that sucks the solder off the soldered connection. The bulb type creates suction by squeezing and releasing a rubber bulb.
The pump is applied to a heated solder connection, then operated to suck the solder away.
Desoldering braid.
Desoldering braid, also known as desoldering wick or solder wick, is finely braided 18 to 42 AWG copper wire coated with rosin flux, usually supplied on a roll.
The end of a length of braid is placed over the soldered connections of a component being removed. The connections are heated with a soldering iron until the solder melts and is wicked into the braid by capillary action. The braid is removed while the solder is still molten, its used section cut off and discarded when cool. Short lengths of cut braid will prevent heat being carried away by the braid instead of heating the joint.
Technique.
Desoldering requires application of heat to the solder joint and removing the molten solder so that the joint may be separated. Desoldering may be required to replace a defective component, to alter an existing circuit, or to salvage components for re-use. Use of too high a temperature or heating for too long may damage components or destroy the bond between a printed circuit trace and the board substrate. Techniques are different for through-hole and surface-mounted components.
Through-hole.
A component with one or two connections to the PCB can usually be removed by heating one joint, pulling out an end of the component while the solder is molten (bending the other lead to do so), and repeating for the second joint. Solder filling the hole can be removed with a pump or with a pointed object made of a material which solder does not wet, such as stainless steel or wood.
If a multi-pin component need not be salvaged, it is often possible to cut the pins, then remove the residual ends one by one.
Components with more connections cannot be removed intact in the way described above unless the wire leads are long and flexible enough to be pulled out one by one. For a component such as a Dual-Inline Package (DIP), the pins are too short to pull out, and solder melted on one joint will solidify before another can be melted. A technique sometimes used is the use of a large soldering-iron tip designed to melt the solder on all pins at once; different tips are required for different packages. The component is removed while the solder is molten, most easily by a spring-loaded puller attached to it before heating.
Otherwise all joints must be freed from solder before the component can be removed. Each joint must be heated and the solder removed from it while molten using a vacuum pump, manual desoldering pump, or desoldering braid.
For through-hole mounted devices on double-sided or multi-layer boards, special care must be taken not to remove the via connecting the layers, as this will ruin the entire board. Hard pulling on a lead which is not entirely free of solder (or with solder not thoroughly molten in the case of a soldering iron tip heating all pins) may pull out a via.
To remove and recover all components, both through-hole and surface-mount, from a board which itself is usually no longer needed, a flame or hot air gun can be used to rapidly heat all parts so they can be pulled off. Parts may be damaged, and toxic fumes emitted, if excessive temperature or prolonged heating is used.
Surface mount.
If they do not need to be re-used, some surface-mount components can be removed by cutting their leads and desoldering the remnants with a soldering iron.
Otherwise, surface-mount components must be removed by heating the entire component to a temperature sufficient to melt the solder used, but not high or prolonged enough to damage the component. For most purposes, a temperature not exceeding for a time not exceeding 10 seconds is acceptable.
The entire board may be preheated to a temperature that all components can withstand indefinitely. Then localised heat is applied to the component to remove, with less heating required than from cold. Most frequently, a hot air (or hot gas) gun, with a nozzle of appropriate size and shape, is used to heat the component, with nearby components shielded from the heat if necessary, followed by removal with tweezers or a vacuum tool. Removal of multi-pin components with a soldering iron and solder removal tools is impractical, as the solder between the component and the pads remains in place, unlike solder which can be removed from a hole.
Hot air (or gas) may be applied with tools ranging from some portable gas soldering irons such as the Weller Portasol Professional which can be fitted with a narrow hot-air nozzle, set to a temperature not controlled but approximately correct, to an industrial rework station with many facilities including hot-gas blowing, vacuum part holding, soldering iron head, and nozzles and fitting specific to particular component packages.
Quad flat packages.
Quad Flat Package (QFP) chips have thin leads closely packed together protruding from the four sides of the integrated circuit (IC); usually a square IC. Removal of these chips can be problematic as it is impossible to heat all of the leads at once with a standard soldering iron. It is possible to remove them with the use of a razor blade or a high-rpm craft tool, simply by cutting off the leads. The stubs are then easy to melt off and clean with a soldering iron. Obviously this technique entails the destruction of the IC. Another method is to use a heat gun or pencil butane torch and heat up a corner, and gently pry it off, working the torch down the leads. This method often leads to traces getting lifted off the PCB where a lead did not get heated enough to cause the solder to flow.
Several vendors offer systems that use heat shields to concentrate hot air where it needs to be, protecting nearby components and avoiding damage to the board or the QFP. The extractor uses a spring system that gently pulls the IC upward when the liquid stage of solder has been reached. The IC is held by a vacuum nozzle similar to the ones used in pick & place machines. This system prevents damage to the pads on the PCB, the IC, avoids overheating surrounding components and blowing them off and also reduces the risk of operator error when using tweezers or other tools that can damage the PCB or IC.
Another way to remove these devices is to use Field's metal, an alloy which melts at around 140 °F (62 °C), lower than the boiling point of water. The metal is melted into the solder joints of the device, where it remains liquid even once cooled down to room temperature, and the chip can simply be lifted off the board. This has the advantage of not damaging the PCB or the IC, although the solder joints must be carefully cleaned of any remaining Field's metal to maintain solder joint strength after resoldering.


Supply chain responsiveness matrix

A supply chain responsiveness matrix is a tool that is used to analyze inventory and lead time within an organization. The matrix is one of a number of value stream mapping tools. The matrix is represented by showing lead time along the x-axis and inventory along the y-axis. The result shows where slow moving stock resides.


Antiwear additive

AW additives, or antiwear additives, are additives for lubricants to prevent metal-to-metal contact between parts of gears.
EP additives are used in applications such as gearboxes, while AW additives are used with lighter loads such as bushings.
Details.
Some popular AW additives are:
Some formulations use colloidal PTFE (Teflon), but its efficiency is controversial.
Many AW additives function as EP additives, for example organophosphates or sulfur compounds. The mechanism of function of TCP and ZDDP is explained in EP additives.
Under extreme pressure conditions, the performance of AW additives becomes insufficient and designated EP additives are required.