Group technology

Group technology or TZ is a manufacturing technique in which parts having similarities in geometry, manufacturing process and/or functions are manufactured in one location using a small number of machines or processes. Group technology is based on a general principle that many problems are similar and by grouping similar problems, a single solution can be found to a set of problems, thus saving time and effort.
The group of similar parts is known as part family and the group of machineries used to process an individual part family is known as machine cell. It is not necessary for each part of a part family to be processed by every machine of corresponding machine cell. This type of manufacturing in which a part family is produced by a machine cell is known as cellular manufacturing.
The manufacturing efficiencies are generally increased by employing GT because the required operations may be confined to only a small cell and thus avoiding the need for transportation of in-process parts.
Group technology is an approach in which similar parts are identified and grouped together in order to take advantage of the similarities in design and production. Similarities among parts permit them to be classified into part families.
The advantage of GT can be divided into three groups:
Disadvantages of GT Manufacturing :


Press hardening

Hot stamping (also known as press hardening, hot press forming, or hot forming die quenching) is a relatively new technology which allows ultra-high strength steels (typically 22MnB5 boron steel) to be formed into complex shapes, which is not possible with regular cold stamping operations. This process is commonly used for the production of automotive body in white components because its advantages align with the design criteria of modern passenger vehicles.
Methods.
The unformed blank is heated in a furnace, formed in hot condition (state 2 in below figure), and quenched in the die to achieve the required properties.
The blank is formed, trimmed, and pierced in cold condition (i.e., state 1 in below figure). It is later heated and quenched in a die to get high strength properties.
Selection of the process depends on part complexity and blank coating (Zn based coatings typically require indirect process). In either method, the blank is formed in a much softer and formable state and is later hardened in the dies, which have drilled cooling channels. A typical hot stamped components has 1000 MPa (145 ksi) Yield Stress and 1500 MPa (215 ksi) Ultimate tensile strength.
Advantages.
Higher strength steels may help reducing the weight by downgaging (i.e., use of thinner sheets), while increasing the crashworthiness. However, one problem with many high strength steels is that their formability is generally lower than milder grades. In addition, springback and die wear also cause problems as the forming stresses and contact pressures are higher.


Economies of density

In microeconomics, economies of density are cost savings resulting from spatial proximity of suppliers or providers. Typically higher population densities allow synergies in service provision leading to lower unit costs. If large economies of density exist there is an incentive for firms to concentrate and agglomerate.
Typical examples are found in logistic systems where the distribution or collection of goods is needed, such as solid waste management. Delivering, for instance, mail in an area with many postboxes results in overall cost savings and thus lower delivery costs.
Different network infrastructures such as electricity or gas networks show as well economies of density.
Economies of density are not to be confused with economies of scale where unit costs are not linked to spatial properties.


Substrate (printing)

Substrate is used in a converting process such as printing or coating to generally describe the base material onto which, e.g. images, will be printed. Base materials may include:
Electronics.
Printing processes such as silk-screening and photolithography are used in electronics to produce printed circuit boards and integrated circuits. Some common substrates used are;


Electronics prototyping

In electronics, prototyping means building an actual circuit to a theoretical design to verify that it works, and to provide a physical platform for debugging it if it does not. The prototype is often constructed using techniques such as wire wrapping or using a breadboard, stripboard or perfboard, with the result being a circuit that is electrically identical to the design but not physically identical to the final product.
Open-source tools like Fritzing exist to document electronic prototypes (especially the breadboard-based ones) and move toward physical production. Prototyping platforms such as Arduino also simplify the task of programming and interacting with a microcontroller. The developer can choose to deploy their invention as-is using the prototyping platform, or replace it with only the microcontroller chip and the circuitry that is relevant to their product.
A technician can quickly build a prototype (and make additions and modifications) using these techniques, but for volume production it is much faster and usually cheaper to mass-produce custom printed circuit boards than to produce these other kinds of prototype boards. The proliferation of quick-turn PCB fabrication and assembly companies has enabled the concepts of rapid prototyping to be applied to electronic circuit design. It is now possible, even with the smallest passive components and largest fine-pitch packages, to have boards fabricated, assembled, and even tested in a matter of days.


Soft Growing Robotics

Soft Growing Robotics is a subset of soft robotics concerned with designing and building robots that use robot body expansion to move and interact with the environment.
Soft growing robots are built from compliant materials and attempt to mimic how vines, plant shoots, and other organisms reach new locations through growth. While other forms of robots use locomotion to achieve their objectives, soft growing robots elongate their body through addition of new material, or expansion of material. This gives them the ability to travel through constricted areas and form a wide range of useful 3-D formations. Currently there are two main soft growing robot designs: additive manufacturing and tip extension. Some goals of soft growing robotics development are the creation of robots that can explore constricted areas and improve surgical procedures.
Additive manufacturing design.
One way of extending the robot body is through additive manufacturing. Additive manufacturing generally refers to 3-D printing, or the fabrication of three dimensional objects through the conjoining of many layers of material. Additive manufacturing design of a soft growing robot utilizes a modified 3-D printer at the tip of the robot to deposit thermoplastics (material that is rigid when cooled and flexible when heated) to extend the robot in the desired orientation.
Design characteristics.
The body of the robot consists of:
The additive manufacturing process involves polylactic acid filament (a thermoplastic) being pulled through the tubular body of the robot by a motor in the tip. At the tip, the filament passes through a heating element, making it pliable. The filament is then turned perpendicular to the direction of robot growth and deposited onto the outer edge of a rotating disk facing the base of the robot. As the disk (known as the deposition head) rotates, new filament is deposited in spiraling layers. This filament solidifies in front of the previous layer of filament, pushing the tip of the robot forward. The interactions between the temperature of the heating element, the rotation of the deposition head, and the speed the filament is fed through the heating element is precisely controlled to ensure the robot grows in the desired manner.
Movement control.
The speed of the robot is controlled by changing the temperature of the heating element, the speed at which filament is fed through the heating element, and the speed the deposition head is spun. Speed can be defined as the function:
formula_1
Where formula_2 is the thickness of the deposited layer of filament, and formula_3 is the angle of the helix in which the filament material is deposited.
Controlling the direction of growth (and thus the direction of robot "movement") can be done in two ways:
Capabilities.
One of the major advantages of soft growing robots is that minimal friction exists between the outside environment and the robot. This is because only the robot tip moves relative to the environment. Multiple robots using additive manufacturing for growth were designed for burrowing into the soil, as less friction with the environment reduces energy required to move through the environment
Tip extension design.
A second form of soft growing robot design is tip extension. This design is characterized by a tube of material (common materials include nylon fabric, low density polyethylene, and silicone coated nylon) pressurized with air or water that is folded into itself. By letting out the folded material, the robot extends from the tip as the pressurized tube pushes out the inner folded material.
Design characteristics.
In contrast with additive manufacturing where new material is deposited behind the tip of the robot to push the tip forward, tip extension utilizes the internal pressure within the robot body to push out new material at the tip of the robot. Often, the tubing inside the robot body is stored on a reel to make it easier to control the release of tubing and thus robot growth.
Multiple methods of turning a tip extension robot have been developed. They include:
Robots utilizing the tip extension design are retractable. Current designs use a wire attached to the tip of the robot that is used to pull the tip of the robot back into the robot body.
Mathematical analysis.
The theoretical force the tip grows under can be modelled as:
formula_4
Where formula_5 represents the force the tip grows under, formula_6 represents internal pressure, and formula_7 represents cross sectional area of the robot tip. However, the experimental force the tip expands under has been found to be less than this largely due to axial tension in the robot body. A model that approximates formula_5 more accurately is:
formula_9
Here, formula_10 is an experimentally determined constant and formula_11 is yield pressure when no growth occurs. formula_12, formula_13, and formula_14, are force terms dependent on velocity, length, and curvature or the robot respectively.
Additionally, multiple mathematical models for various forms of turning, twisting, and retracting have been developed.
Methods of robot operation.
Soft growing robots can be controlled in various ways depending on how well the objective and growth path are defined. Without a clearly defined goal or robot growth path, teleoperation is used. When a clearly defined goal exists (such as a light source), computer vision can be used to find a path to the goal and grow a robot along that path. If the desired path of robot growth is known before the robot is deployed, pre-planned turning positions can be used to control the robot.
Applications.
Possible applications of soft growing robots focus on their low friction/interaction with the environment, their simple method of growth, and their ability to grow through cramped environments.


Microstructures in 3D printing

The use of microstructures in 3D printing, where the thickness of each strut scale of tens of microns ranges from 0.2mm to 0.5mm, has the capabilities necessary to change the physical properties of objects (metamaterials) such as: elasticity, resistance, and hardness. In other words, these capabilities allow physical objects to become lighter or more flexible. The pattern has to adhere to geometric constraints (shape regulations), and thickness constraints (minimum thickness control), or can be enforced using optimization methods (microstructure shape and topological optimization). Innovations in this field are being discovered in addition to 3D printers being built and researched with the intent to specialize in building structures needing altered physical properties.
Microstructure parameters.
Elastic deformation materials are described by two major parameters: Poisson's ratio and Young's modulus. However, the alternative elastic constants, Bulk modulus and Shear modulus can also be used. Poisson's ratio defines the ratio between the transversal and axial strain when the object is compressed. Materials with negative Poisson's ratio expand laterally when stretched, in contrast with ordinary materials. In comparing a material's resistance to distort under mechanical load rather than a change in volume, Poisson's ratio offers the fundamental metric by which to compare the performance of any material when strained elastically. The numerical limits are set by 1/2 and -1, between which all stable isotropic materials are found. Young's modulus is a property that measures how rigid or soft an object is. It relates stress (per unit area) to strain (proportional deformation) along an axis or line.
Microstructure process chain.
The microstructures are designed synthetically, given the input parameters correlated with the desired deformation behavior. Parameters space sampling allows the creation of a family of related structures able to satisfy the feasibility range of material parameters. The corresponding microstructure of the cell is computed by interpolation. Using microstructure optimization and parameter space sampling, several families of related structures that together satisfy the feasible range of material parameters can be defined. Using these candidates, the best fit is chosen to ensure that neighboring structures are properly connected.
Steps for additive manufacturing.
Additive manufacturing design can be divided into two general steps: the pre-processing planning and the process chain. During the pre-processing planning a microstructure design (3D geometric modelling by the use of CAD modelling system) and properties are modelled (factors and parameters).
The process chain of additive manufacturing can be synthesized in the following five steps:
Depending on the quality of the model and results of steps 3 through 5 respectively, the process may be iterated until a satisfactory model or part is achieved.
Microstructures optimization.
Pattern optimization.
To create a microstructure, first, a kind of tile has to be designed which provides isotropy, for example, a cube. By assigning nodes to the vertices, the edges, the surfaces, and one node to the interior of the shape of the tile, it is possible to connect these nodes. These connections are the parts which will be printed, and the choice of which nodes will be connected with other nodes determines the properties and stability of the microstructure. Therefore, maximizing the edge space and the vertex space is important to achieve an optimized microstructure. However, the following two attributes have to be met to be able to print the structure:
Printability.
Printability can be achieved by ensuring that for every set of connected nodes on one level, there is at least one node which is connected to another node located lower in the structure. This criterion obviously does not have to be met for the lowest level. In addition to that, the edges between the nodes have to be sufficiently thick.
Tileability.
In order to be connectable, the set of nodes which are on the surface of the tile must be the same on every side. This means if two tiles are put together, the respective nodes must connect. The actual microstructure consists of these tiles which are connected through the nodes on the tile-surface.
Shape optimization.
Geometry complexity in 3D printing requires the control of the material parameters and therefore their properties to produce microstructures which can achieve different behaviors. Shape optimization can perfectly improve stress concentration. Based on the assumption that curvature variation and negatively curved regions generated high stress regions, introduces a low dimensional parametric shape model to eliminate sharp concave corners, which supports minimization of maximal stress and an efficient implementation of printability constraint. Shape optimization is based on the thickness of the deposited material to reduce the stress concentration by first accurately representing shells in the shape of conic by the use of the CAD, and then derived by sensitivity analysis the stress required.
Topology optimization.
Bendsøe and Kikuchi can be considered as the pioneers in the microstructure topology optimization domain, which was originally intended for the design of mechanical structures. In additive manufacturing, topology optimization is considered an efficient method to find the right topologies by running optimization algorithms targeting the prescribed properties. The effective properties of the material structures are found using a numerical homogenization method, and then the topology optimization is applied to find the best distribution of material phases that extremizes the objective function. The Inverse homogenization method has been introduced to achieve specific macro-scale behaviors with desired Poisson’s ratio. The inverse homogenization method plus constraint approach has been extended to design mechanical properties. A proposed data-driven approach encodes the variability in properties into a viable finite-dimensional stochastic model with prescribed constraints and optimized to obtain the target properties. One of the problems in topology optimization is the increasing number of parameters due to the linear number of cells in the object. Two approaches have been investigated to resolve this complexity. First, working with microstructures corresponding to blocks of voxels instead of individual voxels directly. Second, ignoring the microstructure geometry and considering only the macroscopic behavior.
Printing methods used for microstructures.
Additive manufacturing is used for the realization of complex material composition in 3D printing. Different techniques can be used to create microstructures, but they need to be able to print thin and complex structures.
Microstructures applications.
Possible applications of microstructures are the fabrication of plastic toys using metamaterials to give them an elastic behavior. The design of microstructures brings possibilities of realizing novel properties beyond traditional materials, and the use in different domains such as mechanical engineering, aeronautics, astronomy, and electronics, based on their deformation, compression, light, sound, thermal and mechanical properties. In the medical domain, applications have been demonstrated with the ability to synthesize tissue, or to fabricate prosthetics or manufacturing bone with biomaterial. Other examples of applications of microstructures are the creation of sound absorbing material, using them as a catalyst, to create custom structures or just for design purposes.


RAVON

RAVON (Robust Autonomous Vehicle for Off-road Navigation) is a robot being developed at the Robotics Research Lab at University of Kaiserslautern, Germany. The vehicle is used as a testbed to investigate behaviour-based strategies on motion adaptation, localization and navigation in rough outdoor terrain. The basis vehicle was produced by Robosoft.
Description.
The vehicle uses a 3D laser scanner.
The vehicle is an example of using behavior-based components on two layers of a multi-layer control system. It also uses a form of short-term memory to prevent collisions with obstacles that it observed some time ago.
The vehicle was experimentally tested at the 2nd Military European Land Robot Trial 2008.


Pullapart

PullApart was a UK-based, independent packaging recycling classification system. Applied at the kerbside, it combined environmental and consumer packaging surveys to provide customers with a measurement of the ease with which specific types of packaging could be locally recycled. The process was invented by Michael Butler of Dawlish in 2005, and operated for free.
Methodology.
As PullApart was applied to existing local authority-installed recycling bin refuse collection systems, its scoring scheme was dependent on individual local authorities’ own packaging disassembly practices. Sample packaging was disassembled, according to the Local Authority’s process, rearranged and its components graded for ease of recycling. The raw information from this exercise was also made available to the public.
A final, consumer-oriented "PAC" (PullApart Code) score was achieved by measuring what proportion of a product's components was recyclable from the kerbside. The PAC score is represented by 13 stages of ‘traffic light’ grading.
Broader aims.
PullApart’s stated aims are to encourage, manufactures, retailers, food and agricultural producers to give greater weight to the ease of disposal and recycling in their packaging designs. Weighting the consumers point of view equally to that of packaging manufactures, retailers and recyclers, in the handling of domestic waste products for kerbside collections. To provide consumers with information enabling product choice (ethical consumerism), that's easy, local and totally kerbside recyclable. Furnishing an unambiguous tool, that measures the differences between those mentioned above, assisting in the optimisation of products for the goal of near Zero waste.
According to PullApart’s then current Teignbridge (2011) survey of over 2000 products, 2.84% were ideally suited for kerbside recycling and a further 29.32% were good, whilst the rest failed. The sample area, Teignbridge, and therefore Teignbridge District Council, had a current recycling rate of 57% (2008/2009), (by weight). Quoting from their periodical, “Teignbridge Life” explaining to local people how PullApart worked: “The online packaging recycling guide features a free search function which classifies ordinary consumer products, like cereal boxes, with a 'PullApart' rating. The rating breaks the product down into its components, explaining which parts can be recycled in Teignbridge.”
Awards for the scheme.
PullApart is considered to be of “Environmental Best Practice” by The Green Organisation.
Comparison with other efforts.
Worldwide there are broader packaging scoring systems that address the full environmental impact of packaging. Recycling being one factor, other vital considerations include the use of recycled materials in the package, avoidance of toxic substances, minimization of packaging, effects on atmosphere (greenhouse gas, VOC, etc.), use of renewable resources, etc. Efforts involve methodologies such as life cycle assessment to inventory the all environmental impacts and factors.
There are many Sustainability metrics and indices, some specifically for packaging.


Lockout chip

In a general sense, a lockout chip is a chip within an electronic device to prevent other manufacturers from using a company's device to perform certain functions.
A notable example is the lockout chip found in Nintendo's Nintendo Entertainment System (called 10NES), designed to prevent "unlicensed" manufacturers from creating games for the console. The presence of the chip forced unlicensed companies to raise the price of each cartridge (due to a bypass chip having to be added to the cartridge), and allowed Nintendo a foothold for a lawsuit.
Lockout functions are commonly used in printers to prevent the manufacture of third-party ink or toner cartridges.


Machinist

A machinist is a tradesperson or trained professional who operates machine tools, and has the ability to set up tools such as milling machines, grinders, lathes, and drilling machines.
A competent machinist should have a well-developed mechanical aptitude, the ability to correctly use precision measuring instruments, interpret blueprints, and a working knowledge of the proper parameters required for successfully utilizing the various tools commonly used in machining operations.
Nature of work.
The machine trade is an extremely broad field with a wide variety of workplaces, job duties, and types of work. Most Machinists work in machine shops and factories where they operate machinery that produce precision component parts. In general, the occupation is exacting, and requires extensive knowledge of the tools and processes in order to achieve the tight tolerances and surface finishes that these parts specify.
Many machinists make Mass-produced parts using highly automated computer numerical control machines which are common today, but still require such professionals to set up and calibrate the machines. Other more specialized machinists produce custom-made parts for prototyping, repair, or research. A machinist may work on manufacturing something relatively simple like a bracket, or a shaft, or something extraordinarily complex, such as aerospace components accurate to .0002 of an inch.
Good machinists are highly sought after and respected skilled trades persons and are generally well-paid. In utility, medical, and military use companies, experienced machinists can earn over $100,000 per year.
Related occupational titles.
Some titles reflect further development of machinist skills such as tool and die maker, patternmaker, mold maker, programmer, and operator. A machinist is one who is called on to fix a problem with a part or to create a new one using metals, plastics, or rarely, wood. Depending on the company, a machinist can be any or all of the titles listed above.
other related fields include Millwrights, quality assurance, and mechanical engineers.
In Australia, a related profession is a fitter and turner. A fitter and turner is the tradesperson who fits, assembles, grinds and shapes metal parts and subassemblies to fabricate production machines and other equipment.
Under the machinist title are other specialty titles that refer to specific skills that may be more highly developed to meet the needs of a particular job position, such as fitter (assembles parts), turning hand, mill hand, and grinder.
Role in manufacturing.
A machinist is usually called upon when a part needs to be produced from a stock material by cutting. Such a part may be unique or may be needed in the thousands. The part could be anything made from metal or plastic, though machined parts are usually ones that require high precision and cannot be produced by other means. Machinists generally start with a saw cut length of stock or a casting. Producing a part will often require several steps and more than one machine tool. Each machine tool plays a specific role in cutting away excess material. When large numbers of parts are needed, production planning is required to plan the most logical workflow through a series of machines. Computer numerical controlled (CNC) machines are computer-driven tools that can machine a large variety of shapes, and whose use in the workflow depends on the part to be machined.
CNC machines are becoming the standard due to their speed, precision, flexibility, repeatability, and reduced downtime while changing jobs. Production runs consisting of large numbers of parts are more cost effective and commonly referred to as production work in the trade. Conversely, small production runs are sometimes referred to as prototype or jobbing work.
Production engineers use blueprints and engineering drawings to produce detailed specifications of the part, especially its geometry (shape), then decide on a strategy to make it. Machine tools are then configured by the machinist and production commences. The machinist works with the quality department to ensure the specifications are maintained in the finished product.
Large commercial organizations often staff machinists on site in a maintenance mode to ensure continuing operations of the production machinery. Such machinists can often make replacement parts the same day. Because of this, the labor cost for this role are significantly lower than costs involved with production shutdowns.
Additive machining.
Additive machining means 3D printing to create industrial components, prototypes, tooling, and end-use production parts. Additive machining comes into its own in the manufacturing of very small intricate parts, which could not be produced through any other manufacturing process. There are several processes in additive manufacturing which include direct metal deposition: electron beam melting, fused filament fabrication, select laser sintering, and variations of them.
Materials commonly encountered by machinists.
The most common materials that machinists make parts from are steel, aluminium, brass, copper, and various alloys of these materials. Other less common materials such as vanadium, zinc, lead, or manganese are often used as alloying elements for the most common materials. Materials that machinists work with occasionally are plastics, rubber, glass, and wood products. Rarely, machinists also work with exotic and refractory metals. The term exotic metals is a general term describing out of the ordinary, rare or special purpose metals. A synonym might be space-age. A list of exotic metals might include, but is not limited to, titanium, beryllium, vanadium, chromium, molybdenum and tungsten, as well as special high-temperature metal alloys like Inconel or Hastelloy (superalloys). Very often the meaning of the term suggests the need for specialized handling and/or tooling to machine them effectively.
While the foregoing were primarily the materials that a machinist would be cutting, the cutters that the machinist uses must be harder and tougher than the materials to be cut. The materials in the cutters a machinist uses are most commonly high-speed steel, tungsten carbide, ceramics, Borazon, and diamond.
Machinists usually work to very small tolerances, usually within 0.010" or 0.25 mm (more commonly expressed as ±0.005" (Plus or minus five thousandths of an inch) or ±0.13 mm), and sometimes at tolerances as low as +/-0.0001" (plus or minus one tenth of a thousandth of an inch – or 0.0025 mm) for specialty operations. A machinist deals with all facets of shaping, cutting and some aspects of forming metal, although forming is typically a separate trade. The operations most commonly performed by machinists are milling, drilling, turning, and grinding. There are other more specialized operations that a machinist will less frequently be called upon to perform such as honing, keyseating, lapping, and polishing, to name a few.
Tools of the machinist.
The tools that a machinist is expected to be proficient with fall into broad categories:


Preventive maintenance checks and services (PMCS) in the United States Army or preventive maintenance inspections (PMI) in the United States Air Force are the checks, services, and maintenance performed before, during, and after any type of movement or before the use of all types of military equipment.
Description.
Most pieces of military equipment have PMCS charts used to go over every detail needed or noted to ensure the proper function of every mechanical item or non-mechanical surface. A PMCS check is required before, during, and after a piece of equipment or vehicle is used. Checks are also done at weekly, monthly, semi-annual, annual, or bi-annual intervals, depending on the specific part.
Doing a PMCS check every time equipment is used may reduce the number of failures. This reduces the number of injuries during training exercises, improve effectiveness in combat, and increase the operator's ability to implement their equipment.
A PMCS is required before a vehicle can be dispatched and before a piece of equipment, such as a weapon, can be issued. A PMCS sheet, as listed above, for vehicles is called a DA 5988E. This sheet is used to write down any deficiency found during the PMCS procedure. The steps taken to perform the PMCS are explained in a Technical Manual and performed by the operator. A PMCS is also used at the unit level.


Angle plate

An angle plate is a work holding device used as a fixture in metalworking.
Angle plates are used to hold workpieces square to the table during marking out operations. Adjustable angle plates are also available for workpieces that need to be inclined, usually towards a milling cutter. Angle plates are made from high quality material (generally spheroidal cast iron) that has been stabilized to prevent further movement or distortion. Slotted holes or "T" bolt slots are machined into the surfaces to enable the secure attachment or clamping of workpieces to the plate, and the plate to the worktable.


Indexing head

An indexing head, also known as a dividing head or spiral head, is a specialized tool that allows a workpiece to be circularly indexed; that is, easily and precisely rotated to preset angles or circular divisions. Indexing heads are usually used on the tables of milling machines, but may be used on many other machine tools including drill presses, grinders, and boring machines. Common jobs for a dividing head include machining the flutes of a milling cutter, cutting the teeth of a gear, milling curved slots, or drilling a bolt hole circle around the circumference of a part.
The tool is similar to a rotary table except that it is designed to be tilted as well as rotated and often allows positive locking at finer gradations of rotation, including through differential indexing. Most adjustable designs allow the head to be tilted from 10° below horizontal to 90° vertical, at which point the head is parallel with the machine table.
The workpiece is held in the indexing head in the same manner as a metalworking lathe. This is most commonly a chuck but can include a collet fitted directly into the spindle on the indexing head, faceplate, or between centers. If the part is long then it may be supported with the help of an accompanying tailstock.
Manual indexing heads.
Indexing is an operation of dividing a periphery of a cylindrical workpiece into equal number of divisions by the help of index crank and index plate.
A manual indexing head includes a hand crank. Rotating the hand crank in turn rotates the spindle and therefore the workpiece. The hand crank uses a worm gear drive to provide precise control of the rotation of the work. The work may be rotated and then locked into place before the cutter is applied, or it may be rotated during cutting depending on the type of machining being done.
Most dividing heads operate at a 40:1 ratio; that is 40 turns of the hand crank generates 1 revolution of the spindle or workpiece. In other words, 1 turn of the hand crank rotates the spindle by 9 degrees. Because the operator of the machine may want to rotate the part to an arbitrary angle indexing plates are used to ensure the part is accurately positioned.
Direct indexing plate: Most dividing heads have an indexing plate permanently attached to the spindle. This plate is located at the end of the spindle, very close to where the work would be mounted. It is fixed to the spindle and rotates with it. This plate is usually equipped with a series of holes that enables rapid indexing to common angles, such as 30, 45, or 90 degrees. A pin in the base of the dividing head can be extended into the direct indexing plate to lock the head quickly into one of these angles. The advantage of the direct indexing plate is that it is fast and simple and no calculations are required to use it. The disadvantage is that it can only be used for a limited number of angles.
Interchangeable indexing plates are used when the work must be rotated to an angle not available on the direct indexing plate. Because the hand crank is fixed to the spindle at a known ratio (commonly 40:1) the dividing plates mounted at the handwheel can be used to create finer divisions for precise orientation at irregular angles. These dividing plates are provided in sets of several plates. Each plate has rings of holes with different divisions. For example, an indexing plate might have three rows of holes with 24, 30, and 36 holes in each row. A pin on the hand crank engages these holes. Index plates with up to 400 holes are available. Only one such plate can be mounted to the dividing head at a time. The plate is selected by the machinist based on exactly what angle he wishes to index to.
For example, if a machinist wanted to index (rotate) his workpiece by 22.5 degrees then he would turn the hand crank two full revolutions plus one-half of a turn. Since each full revolution is 9 degrees and a half-revolution is 4.5 degrees, the total is 22.5 (9 + 9 + 4.5 = 22.5). The one-half turn can easily be done precisely using any indexing plate with an even number of holes and rotating to the halfway point (Hole #8 on the 16-hole ring).
Brown and Sharpe indexing heads include a set of 3 indexing plates. The plates are marked #1, #2 and #3, or "A", "B" and "C". Each plate contains 6 rows of holes. Plate #1 or "A" has 15, 16, 17, 18, 19, and 20 holes. Plate #2 or "B" has 21, 23, 27, 29, 31, and 33 holes. Plate #3 or "C" has 37, 39, 41, 43, 47, and 49 holes.
Universal Dividing heads: some manual indexing heads are equipped with a power drive provision. This allows the rotation of the dividing head to be connected to the table feed of the milling machine instead of using a hand crank. A set of change gears is provided to select the ratio between the table feed and rotation. This setup allows the machining of spiral or helical features such as spiral gears, worms, or screw type parts because the part is simultaneously rotated at the same time it is moved in the horizontal direction. This setup is called a "PTO dividing head".
CNC indexing heads.
CNC indexing heads are similar in design to the manual variety except that they have a servo motor coupled to the spindle instead of a hand crank and indexing plates. The servo motor is electronically controlled to index the work to the required position. The control can either be a simple keypad for the operator or it may be fully CNC controlled.
CNC indexing heads may be controlled in two different modes. The most basic method of operation uses simple control functions built into the dividing head. It does not require a CNC machine. The operator enters the desired angle into a control box attached to the indexing head and it automatically rotates to the desired position and locks into place for machining. Changing angles is as simple as typing a new angle value onto the control pad. This is simpler than setting up a manual indexing head because there is no need to interchange indexing plates or to calculate which hole positions to use. It is also faster for repetitive operations because the work can be indexed by simply pressing a button, eliminating the need to count rotations of the hand crank or specific hole positions on the indexing plate. A CNC dividing head may be used in this manner on either manual or CNC machinery.
Most CNC dividing heads are also able to function as a full CNC axis and may be wired into the control of a CNC machine. This enables the machine's main CNC controller to control the indexing head just like it would control the other axes of the machine. This can be used to machine complex 3D shapes, helices with a non-constant pitch, and similar exotic parts. This mode of operation cannot be used on a manual machine tool because it requires a full CNC controller to operate.


Reverse logistics network modelling

Reverse logistics is for all operations related to the reuse of products and materials. It is "the process of moving goods from their typical final destination for the purpose of capturing value, or proper disposal. Remanufacturing and refurbishing activities also may be included in the definition of reverse logistics."
In order to model reverse logistics network from an economics point of view, the following simplified reverse logistics system has to be set.
In this model the products are gathered from the consumers and transferred back to the producers, hence the direction of the flow in the distribution supply chain is reversed and the model is expanded with the recovery center. First of all the used products are collected from the consumers and moved to the recovery center, where the condition of the products are examined according to their end of life cycle. If there is still recapture value, then the product is disassembled as preparation for further reprocessing, which means physical transformation to new customer. Otherwise the used product is disposed and transferred to the landfill site. According to the introduced model the main differences between forward and reverse logistics can be identified:
Modeling techniques for optimizing in reverse logistics network.
In case of a reverse logistics network the nodes represent the different kind of facilities such as the manufacturers, distribution centers, recovery centers, ware houses. The opening of a facility is marked with a binary integer number. The links are acted for flow between facilities and the weights are continuous variables showing the quantity of flow. The two common way of designing reverse logistics network are the Mixed Integer Linear Programing (MILP) and Mixed Integer Non-Linear Programing (MINLP) methods, where the objective function, decision variables and constraint have to be defined
Mixed Integer Linear Programing (MILP).
Remanufacturing model.
This model is a two-level location problem with three type of facilities, integrated forward and reverse flow of goods. It means that the used items are gathered from consumers, transported back to plants and after remanufacturing get into the logistics network of new products.
Objective function:
Decision variables:
Constraints:
Refurbishment model.
This model take into account just reverse flow of goods.
Objective function:
Decision variables:
Constraints:
Generic reverse logistics network model.
Objective function:
Decision variables:
Constraints:
This model can be further developed by introducing penalty cost for not collecting returned items and a compulsory minimal disposal fraction as a feasibility technical constraints of reuse. Moreover, the static approach can be partly eliminated by multi-period programming, as a result trade-off between investment and operational cost and long run effect can be analyzed.
Mixed Integer Non-Linear Programing (MINLP).
The most severe drawback of MILP is the static aspect, hence MINLP try to relieve these restriction and develop further the existing model with dynamic elements, such as integrating cycle time, time and inventory positions. By this way uncertainty appears stronger in the model. The main objective is to maximize profit by determining the optimal number of facilities in order to:
Solution techniques of reverse logistics network models.
Genetic algorithm.
It is applicable for large size complex problems
Main steps of the algorithm:
Tabu search.
The algorithm pursues local search and if it finds a local optimum it is prevented to get back formerly visited solution, which were recorded in the so-called tabu list


RePack

RePack is a packaging service which enables the return and reuse of delivery packaging for online retailers and their users. The service and packaging is designed by Original RePack Oy, a Finnish company focused on sustainable products and business model solutions.
Business.
On supported e-commerce sites, the customer can select to use RePack as the online order's delivery packaging. The customer will then receive the goods in RePack's recyclable packaging. This packaging can be returned to RePack by dropping it into a local letterbox, and can be reused up to 20 times.
The return rate of RePack's products has reached 95%.
RePack is used by over 200 online retailers in Europe and the US.
Awards.
In October 2013, RePack was awarded the Pactec 2013 innovation prize by the Finnish packaging association.
In January 2014, RePack was awarded the Fennia Prize.
In September 2014, RePack won the Green Alley startup competition in Germany.
In November 2014, RePack finished fourth in Slush 100’s pitching competition for startups.
In November 2017, the company was awarded the Nordic Council Environment Prize.


Exchange spring media

Exchange spring media (also exchange coupled composite media or ECC) is a magnetic storage technology for hard disk drives that allows to increase the storage density in magnetic recording. The idea, proposed in 2004 by Suess et al., is that the recording media consists of exchange coupled soft and hard magnetic layers. Exchange spring media allows a good writeability due to the write-assist nature of the soft layer. Hence, hard magnetic layers such as FePt, CoCrPt-alloys or hard magnetic multilayer structures can be written with conventional write heads. Due to the high anisotropy these grains are thermally stable even for small grain sizes. Small grain sizes are required for high density recording. The introduction of the soft layer does not decrease the thermal stability of the entire structure if the hard layer is sufficiently thick. The required thickness of the hard layer for best thermal stability is the exchange length of the hard layer material.
The first experimental realization of exchange spring media was done on Co-PdSiO multilayers as the hard layer which was coupled via a PdSi interlayer to a FeSiO soft layer.
Besides the improved writeability, another advantage of exchange spring media is, that the switching field distribution of the grains, which has to be as small as possible to allow for high storage densities, can be decreased. This effect was predicted theoretically and experimentally verified on Co/Pd multilayers as hard layer coupled to Co/Ni multilayers as soft layer.
In commercial hard disks exchange spring media is used since about 2007.


BTU International

BTU International, Inc. was set up in 1950 and now is based in North Billerica, Massachusetts. The company focuses on thermal processing equipment for alternative energy and electronics, such as semiconductor packaging, solar cell manufacturing, printed circuit board assembly, and nuclear fuel processing. The Company completes its assembly, systems integration and testing at the facilities in North Billerica, Massachusetts and Shanghai, China.
History.
BTU International, Inc. was founded in 1950 in Cambridge, Massachusetts, producing small ovens for hospital, laboratory and daily use. The company entered the semiconductor market making alloying furnaces in late 1950s. In 1972, BTU moved to Billerica, Massachusetts. The company entered photovoltaics market and shipped its first furnace for solar cells in 1985. In 1989, BTU became a publicly traded company on the NASDAQ. In the early 1990s, BTU began to produce solder reflow related products and convections. It also produced the industry's first lead-free reflow furnace. In 1995, BTU hired its first direct employees in mainland China. The Intellectual Property portfolio of BTU includes over 200 patents and patent applications. In 2003, the Company acquired Sagarus Robotics Corporation of Tempe, Ariz, a provider of advanced, automated systems for the semiconductor packaging, MEMS and sensor markets. In 2006, BTU acquired AtmoPlas Technology and research team from Data Corporation. In the same year the company acquired the product line, trademarks and other related assets of Radiant Technology Corporation (RTC).
Products and services.
In the alternative energy market, BTU offers processing equipment for silicon and thin film photovoltaics, MERIDIAN In-line Diffusion system, spray-coating systems, rapid thermal processing furnaces (supported by near infrared heating technology), and walking beam and pusher systems for sintering nuclear fuel.
In the electronics market, the Company's products are used in solder reflow and curing stages for surface mount applications, such as connecting and sealing integrated circuits in wafer and dies level packaging, such as the PYRAMAX family of convection reflow systems, Flip-chip reflow.
Awards.
In November 2013, BTU International, Inc. won the 2013 Global Technology Award in the category of Soldering Equipment for its new DYNAMO. The product also win the 2013 EM Asia Innovation Award during the NEPCON China event.
In June, 2009, BTU International won the 'Industry Choice' International Solar Technology Award.


Ecomechatronics

Ecomechatronics is an engineering approach to developing and applying mechatronical technology in order to reduce the ecological impact and total cost of ownership of machines. It builds upon the integrative approach of mechatronics, but not with the aim of only improving the functionality of a machine. Mechatronics is the multidisciplinary field of science and engineering that merges mechanics, electronics, control theory, and computer science to improve and optimize product design and manufacturing. In ecomechatronics, additionally, functionality should go hand in hand with an efficient use and limited impact on resources. Machine improvements are targeted in 3 key areas: energy efficiency, performance and user comfort (noise & vibrations).
Description.
Among policy makers and manufacturing industries there is a growing awareness of the scarcity of resources and the need for sustainable development. This results in new regulations with respect to the design of machines (e.g. European Ecodesign Directive 2009/125/EC) and to a paradigm shift in the global machines market: "instead of maximum profit from minimum capital, maximum added value must be generated from minimal resources". Manufacturing industries increasingly require high performance machines that use resources (energy, consumables) economically in a human-centered production. Machine building companies and original equipment manufacturers are thus urged to respond to this market demand with a new generation of high performance machines with higher energy efficiency and user comfort.
A reduction of the energy consumption lowers energy costs and reduces environmental impact. Typically more than 80% of the total-life-cycle impact of a machine is attributed to its energy consumption during the use phase. Therefore, improving a machine's energy efficiency is the most effective way of reducing its environmental impact.
Performance quantifies how well a machine executes its function and is typically related to productivity, precision and availability. User comfort is related to the exposure of operators and the environment to noise & vibrations due to machine operation.
Since energy efficiency, performance and noise & vibrations are coupled in a machine they need to be addressed in an integrated way in the design phase. Example of the interrelation between the 3 key areas: with increasing machine speed typically the machine’s productivity increases, but energy consumption will increase as well and machine vibrations may grow such that machine accuracy (e.g. positioning accuracy) and availability (due to downtime and maintenance) decrease. Ecomechatronical design deals with the trade-off between these key areas.
Approach.
Ecomechatronics impacts the way mechatronical systems and machines are being designed and implemented. Therefore, the transformation to a new generation of machines concerns knowledge institutes, original equipment manufacturers, CAE software suppliers, machine builders and industrial machine owners. The fact that about 80% of the environmental impact of a machine is determined by its design puts emphasis on making the right technological design choices. A model-based, multidisciplinary design approach is required in order to address the energy efficiency, performance and user comfort of a machine in an integrated way.
The key enabling technologies can be categorized in machine components, machine design methods & tools, and machine control. A few examples are listed below per category.
Machine components
Design methods & tools
Machine control
Applications.
Some examples of ecomechatronical system applications are:


Theegarten-Pactec

Theegarten-Pactec is a German manufacturer in the packaging technology sector. The company develops and produces packaging machines and complete packaging systems for bite-sized confectionery products and other foodstuffs, such as bouillon cubes, as well as for non-food items, e.g. dishwasher detergent. The packaging machines are developed and manufactured exclusively in Germany and are distributed worldwide.


Logistics automation

Logistics automation is the application of computer software or automated machinery to improve the efficiency of logistics operations. Typically this refers to operations within a warehouse or distribution center, with broader tasks undertaken by supply chain engineering systems and enterprise resource planning systems.
Logistics automation systems can powerfully complement the facilities provided by these higher level computer systems. The focus on an individual node within a wider logistics network allows systems to be highly tailored to the requirements of that node.
Components.
Logistics automation systems comprise a variety of hardware and software components:
Benefits of logistics automation.
A typical warehouse or distribution center will receive stock of a variety of products from suppliers and store these until the receipt of orders from customers, whether individual buyers (e.g. mail order), retail branches (e.g. chain stores), or other companies (e.g. wholesalers). A logistics automation system may provide the following:
A complete warehouse automation system can drastically reduce the workforce required to run a facility, with human input required only for a few tasks, such as picking units of product from a bulk packed case. Even here, assistance can be provided with equipment such as pick-to-light units. Smaller systems may only be required to handle part of the process. Examples include automated storage and retrieval systems, which simply use cranes to store and retrieve identified cases or pallets, typically into a high-bay storage system which would be unfeasible to access using fork-lift trucks or any other means. The use of Automatic Guided Vehicles maximizes the output compared to humans since they can do repetitive tasks for long hours and with least to no supervision. An AGV is built and programmed for precision and accuracy thereby reducing the chances of errors in a warehouse, especially when dealing with fragile goods.
Automation software.
Software or cloud-based SaaS solutions are used for logistics automation which helps the supply chain industry in automating the workflow as well as management of the system. There are few generalized software available in the new market in the said topology. This is because there is no rule to generalize the system as well as work flow even though the practice is more or less the same. Most of the commercial companies do use one or the other of the custom solutions.
But there are various software solutions that are being used within the departments of logistics. There are a few departments in Logistics, namely: Conventional Department, Container Department, Warehouse, Marine Engineering, Heavy Haulage, etc.


C-K theory

C-K design theory or concept-knowledge theory is both a design theory and a theory of reasoning in design. It defines design reasoning as a logic of expansion processes, "i.e." a logic that organizes the generation of unknown objects. The theory builds on several traditions of design theory, including systematic design, axiomatic design, creativity theories, general and formal design theories.
Background.
Claims made for C-K design theory include that it is the first design theory that:
The name of the theory is based on its central premises: the distinction between two spaces:
The process of design is defined as a "double expansion" of the C and K spaces through the application of four types of operators: C→C, C→K, K→C, K→K.
The first draft of C-K theory was sketched by Armand Hatchuel, and then developed by Hatchuel and his colleague, Benoît Weil. Recent publications explain C-K theory and its practical application in different industries.
Genesis of C-K theory.
C-K theory was a response to three perceived limitations of existing design theories:
C-K theory uses an approach which is domain-independent and which allows acting on unknown objects, and changes of the definitions of known objects during the process ("revision of objects' identities"). C-K theory was shown by Hatchuel and Weil to be closely related to Braha's Formal Design Theory and its clarification by Braha and Reich's Coupled Design Theory, which are both based on topological structures for design modeling.
Structure of C-K theory.
The core idea behind C-K theory is to define rigorously a design situation. A brief is an incomplete description of objects that do not exist yet and are still partly unknown. The first step in C-K theory is to define a brief as a concept, through the introduction of a formal distinction between concept and knowledge spaces; the second step is to characterize the operators that are needed between these two spaces.
Knowledge.
The knowledge space is defined as a set of propositions with a logical status, according to the knowledge available to the designer or the group of designers. The knowledge space (i.e. K-Space) describes all objects and truths that are established from the point of view of the designer. Then K-Space is expandable as new truths may appear in it as an effect of the design process. Conversely, the structure and properties of the K-Space have a major influence on the process.
Concept.
A concept is defined as a proposition without a logical status in the K-Space. A central finding of C-K theory is that concepts are the necessary departure point of a design process. Without concepts, design reduces to standard optimization or problem-solving. Concepts assert the existence of an unknown object that presents some properties desired by the designer. Concepts can be partitioned or included, but not searched nor explored.
C-K operators.
Building on these premises, C-K theory shows the design process as the result of four operators: C→K, K→C, C→C, K→K.
The process can be synthesized through a design square. One design solution for a first concept C0 will be a path in the C-space that forms a new proposition in K. There may exist several design paths for the same C0.
Central findings.
The following graphical representation summarises the design process using C-K theory.
Crazy concepts are concepts that seem absurd as an exploration path in a design process. Both C-K theory and practical applications have shown that crazy concepts can benefit the global design process by adding extra knowledge, not to be used to pursue that "crazy concept" design path, but to be used to further define a more "sensible concept" and lead to its eventual conjunction. The following image is a graphical representation of this process.
The creative aspect of Design results from two distinct expansions: C-expansions which may be seen as "new ideas", and K-expansions which are necessary to validate these ideas or to expand them towards successful designs.
Domain dependent design theories are built on some specific structure of the K-space, either by assuming that some objects have invariant definitions and properties (like in all engineering fields), or by assuming that the K-space presents some stable structure (e.g. that the functions of an object can be defined independently from its technical realization, as in systematic design theory).
At The Design Society's 2009 International Conference on Engineering Design, an awarded-paper links scientific discovery and design process using C-K theory as a formal framework. It is suggested that a science of design is possible, and complementary to the more traditional bounded rationality.
Mathematical approaches to design have been developed since the 1960s by scholars such as Christopher Alexander, Hiroyuki Yoshikawa, Dan Braha and Yoram Reich. They tended to model the dynamic co-evolution between design solutions and requirements. Within the field of engineering design, C-K theory opens new modelling directions that explore connections with basic issues in logic and mathematics; these are different from the classic use of scientific models in design. It has been argued that C-K theory has analogies with forcing in set theory, and with intuitionistic mathematics.
C-K theory has been applied in several industrial contexts since 1998, mainly in France, Sweden and Germany. It is generally used as a method that increases the innovative capacity of design and R&D departments. C-K theory has also inspired new management principles for collaborative innovation, with the aim of overcoming the limitations of standard design management methods.


Occam process

The Occam process is a solder-free, Restriction of Hazardous Substances Directive (RoHS)-compliant method for use in the manufacturing of electronic circuit boards developed by Verdant Electronics. It combines the usual two steps of the construction of printed circuit boards (PCBs) followed by the population process of placing various leaded and non-leaded electronic components into one process. The name "Occam" comes from a quotation by William of Ockham.
Overview.
Electronic components are first positioned onto an adhesive layer of a temporary or permanent substrate, according to the design parameters. Then, the pre-tested, burned-in components are held firm in their positions by encapsulating them in insulating material, and the entire assembly is then inverted. The adhesive layer is then cut (after removing the temporary substrate if it exists) or drilled out over the component leads, mechanically or by laser ablation. These holes are then plated with a conductive, copper connection (a via) from the top of the layer to the component leads. If needed, other encapsulation layers of components or vias can be placed on top of each other to make multi-level circuit connections. This construction is then coated with copper where needed to provide traces. Thus, this finished circuit board can now receive a conformal coating to protect against the environment, and then be placed into an assembly housing or sent through another process for mechanical and/or electrical connections with other PCBs.
Advantages.
In 2006, European, RoHS regulations prompted the research needed to move from traditional lead-based solder connection processes to a more environmentally friendly approach. Much manufacturing is currently being done with tin-based solder to address this issue. Using tin requires much higher reflow temperatures and can result in rework stages due to electric shorts caused by tin-whiskers (electrically conductive structures formed in this process) and other issues in the manufacturing process which are avoided by the Occam process.
PCBs themselves are usually created by use of a phenolic resin, itself a corrosive, toxic substance completely removed from the Occam process. Also, the nitric acid or ferric chloride used to etch traces into the boards is also removed from the process.
Since the PCB and parts population stages happen in the same process in the same plant, a company would no longer need to wait for the delivery of ordered PCBs to begin manufacturing.
The high temperatures usually seen by PCBs inside of a reflow soldering oven are avoided by use of this process. This means that any issue of moisture sensitivity (MSL) in components by outgassing of moisture is completely avoided. This also then removes the storage equipment and processes needed to keep the moisture levels low in more intricate and expensive chips.
Disadvantages.
Currently, though the process is set, it has not yet been implemented. It is defined as a “disruptive technology” requiring a complete change in current manufacturing processes. Therefore, cost concerns for manufacturers needing new equipment, labour concerns for current PCB manufactures and others will need to be solved or addressed before the widespread adoption of this process.
Although many toxic chemicals are removed from the traditional process, Occam's increased use of encapsulation by epoxy could mean more of that sort of waste. The usual additives in epoxy have been shown to mimic estrogen, possibly resulting in adverse hormonal responses in humans.


Vacuum packing

Vacuum packing is a method of packaging that removes air from the package prior to sealing. This method involves placing items in a plastic film package, removing air from inside and sealing the package. Shrink film is sometimes used to have a tight fit to the contents. The intent of vacuum packing is usually to remove oxygen from the container to extend the shelf life of foods and, with flexible package forms, to reduce the volume of the contents and package.
Vacuum packing reduces atmospheric oxygen, limiting the growth of aerobic bacteria or fungi, and preventing the evaporation of volatile components. It is also commonly used to store dry foods over a long period of time, such as cereals, nuts, cured meats, cheese, smoked fish, coffee, and potato chips (crisps). On a more short-term basis, vacuum packing can also be used to store fresh foods, such as vegetables, meats, and liquids, because it inhibits bacterial growth.
Vacuum packing greatly reduces the bulk of non-food items. For example, clothing and bedding can be stored in bags evacuated with a domestic vacuum cleaner or a dedicated vacuum sealer. This technique is sometimes used to compact household waste, for example where a charge is made for each full bag collected.
Vacuum packaging products, using plastic bags, canisters, bottles, or mason jars, are available for home use.
For delicate food items that might be crushed by the vacuum packing process (such as potato chips), an alternative is to replace the interior gas with nitrogen. This has the same effect of inhibiting deterioration due to the removal of oxygen.
Type of Vacuum Sealers or Vacuum Packaging Machines.
Edge, Suction, and External Vacuum Sealers.
External vacuum sealers involve a bag being attached to the vacuum-sealing machine externally. The machine will remove the air and seal the bag, which is all done outside the machine. A heat sealer is often used to seal the pack. Typically these units use a dry piston vacuum pump which is often considered a "maintenance-free" pump. If you are sealing dry goods only, this is the perfect solution. Moist foods are known to cause internal corrosion on these dry piston pumps.
Single Chamber Vacuum Sealers.
Single chamber sealers require the entire product to be placed within the machine. Like external sealers, a plastic bag is typically used for packaging. Once the product is placed in the machine, the lid is closed and air is removed. Then, there is a heat seal inside the chamber that will seal the bag, after sealing the bag the chamber is refilled with air by the automatic opening of a vent to the outside. This oncoming pressure squeezes all remaining air in the bag. The lid is then opened and the product removed. Chamber sealers are typically used for low-to-medium-volume packaging. This style of vacuum machine is also capable of sealing liquids due to equal pressure in the chamber and the bag eliminating the risk of the liquid being sucked out of the open edge of the bag.
Double Chamber Vacuum Sealers.
Double chamber sealers require the entire product to be placed in a plastic bag within the machine. Once the product is placed in the machine on the seal bar, the lid is closed and air is removed. Then a seal bar inside the chamber seals the product in the bag, after sealing the bag the chamber is refilled with air by the automatic opening of a vent to the outside. This oncoming pressure squeezes all remaining air in the bag. The lid is then opened and the product removed. Double chamber sealers are typically used for medium-volume packaging, and also have the capability to vacuum seal liquids. The lid generally swings from one side to another, increasing production speed over a single chamber model. Double chamber vacuum packaging machines generally have either spring-weighted lids or fully automatic lids.
Double chamber vacuum packaging machines are commonly used for:
Rotary belt type vacuum sealer (rolling vacuum sealer).
Rotary belt type vacuum packaging machine or vacuum sealer features the same function as the double chamber vacuum packaging machine as a 'vacuum bag sealer'. But the rotary belt vacuum packaging machine is more convenient, as the belt rotates automatically while the bags are placed to the sealing bar and vacuum sealing process completed. The vacuumed and sealed bags are automatically unloaded, which obviously is more convenient.
The packaging plate of the machine is adjustable to 4 degrees, which allows the vacuum packaging of food with soup and liquid.
Rotary belt type packaging machines are commonly used for:
Automatic belt vacuum chamber machines.
Automatic belt chamber sealers require the entire product to be placed in a plastic bag or flow wrapped pouch within the machine. The product travels on the conveyor belt, it is automatically positioned in the machine on the seal bar, the lid is closed and air is removed. Then a seal bar inside the chamber seals the product in the bag. After sealing the bag, the chamber is refilled with air by the automatic opening of a vent to the outside. This oncoming pressure squeezes all remaining air in the bag. The lid is then opened and the product removed. Automatic belt vacuum chamber machines are typically used for high-speed packaging of large items, and also have the capability to vacuum seal liquids. The lid generally travels straight up and down.
Automatic belt vacuum chamber packaging machines are commonly used for:
Thermoforming (rollstock) HFFS vacuum packaging machines.
Vacuum Packaging in large production facilities can be done with thermoforming machines. These are Form-Fill-Seal style machines that form the package from rolls of packaging film (webbing). Products are loaded into the thermoformed pockets, the top web is laid and sealed under a vacuum, MAP (modified atmosphere), or skin packaging producing rapidly packaged products. Thermoforming can greatly increase packaging production speed.
Thermoformed plastics can be customized for size, color, clarity, and shape to fit products perfectly, creating a consistent appearance. One of the most commonly used thermoformed plastics is PET, known for a high-strength barrier resistant to outside tampering and an ease of molding into designated designs and shapes. Some common uses for Thermoforming in vacuum packaging include:
Types of Food Storage.
Food safety.
In an oxygen-depleted environment, anaerobic bacteria can proliferate, potentially causing food-safety issues. Some pathogens of concern in vacuum packed foods are spore-forming non-proteolytic "Clostridium botulinum", "Yersenia enterocolitica", and "Listeria monocytogenes". Vacuum packing is often used in combination with other food processing techniques, such as retorting or refrigeration, to inhibit the growth of anaerobic organisms.
Shelf life.
Depending on the product, atmosphere, temperature, and the barrier properties of the package, vacuum packaging extends the shelf life of many foods. The shelf life of meats can be extended by vacuum packaging, particularly when used with modified atmosphere packaging.
High Barrier - Chamber Vacuum Shrink Bags.
The amount of shelf life enhanced by a vacuum bag is dependent on the structure in the material. A standard vacuum bag is composed of a PA/PE structure where PA is for puncture resistance and PE is for sealing. The high barrier category includes the usage of more layers focused on the prevention of oxygen permeability, and therefore shelf life protection. There are two materials used in high barrier structures, polyvinylidene chloride (PVDC) and ethylene vinyl alcohol (EVOH). Shelf life indication can be effectively measured by how many cubic centimeters of oxygen can permeate through 1 square meter of material over a 24-hour period. A standard PA/PE bag allows on average 100 cubic centimeters, PVDC allows on average over 10, and EVOH on average 1 cubic centimeter. Multi-layer structures allow the ability to use strong oxygen-barrier materials for enhanced shelf life protection. The PremiumPack structure is a good example of EVOH based high barrier shrink material.
Eliminate freezer burn.
When foods are frozen without preparation, freezer burn can occur. It happens when the surface of the food is dehydrated, and this leads to a dried and leathery appearance. Freezer burn also changes the flavor and texture of foods. Vacuum packing reduces freezer burn by preventing the food from exposure to the cold, dry air.
Typical Uses.
Sous vide cooking.
Vacuum packaging also allows for a special cooking method, sous-vide. Sous-vide, French for "under vacuum", involves poaching food that is vacuum sealed in a plastic bag.
Dry Goods.
Stock up on lentils, beans, legumes, ground or whole bean coffee, rice, noodles, oatmeal, spices, cereal, powdered milk/juice, chips, potato flakes, and flour.
Vacuum Sealing Meats.
Preserve the freshness of steak, brisket, venison, ground beef, chicken, turkey, frozen fish, moose, bear, bison, jerky, and more!
Preservation of Vegetables.
Vacuum seal corn-on-the-cob, whole carrots, asparagus, radishes, onions, tomatoes, bell peppers, cucumbers, and other commonly used vegetables are fresh for longer.


Autonomation

Autonomation describes a feature of machine design to effect the principle of （じどうか jidouka), used in the Toyota Production System (TPS) and lean manufacturing. It may be described as "intelligent automation" or "automation with a human touch". This type of automation implements some supervisory functions rather than production functions. At Toyota, this usually means that if an abnormal situation arises, the machine stops and the worker will stop the production line. It is a quality control process that applies the following four principles:
Autonomation aims to prevent the production of defective products, eliminate overproduction and focus attention on understanding the problems and ensuring that they do not reoccur.
Purpose and implementation.
Shigeo Shingo calls autonomation "pre-automation". It separates workers from machines through mechanisms that detect production abnormalities (many machines in Toyota have these). He says there are twenty-three stages between purely manual and fully automated work. To be fully automated machines must be able to detect "and" correct their own operating problems which is currently not cost-effective. However, ninety percent of the benefits of full automation can be gained by Autonomation.
The purpose of autonomation is that it makes possible the rapid or immediate address, identification and correction of mistakes that occur in a process. Autonomation relieves the worker of the need to continuously judge whether the operation of the machine is normal; their efforts are now only engaged when there is a problem alerted by the machine. As well as making the work more interesting this is a necessary step if the worker is to be asked later to supervise several machines. The first example of this at Toyota was the auto-activated loom of Sakichi Toyoda that automatically and immediately stopped the loom if the vertical or lateral threads broke or ran out.
For instance rather than waiting until the end of a production line to inspect a finished product, autonomation may be employed at early steps in the process to reduce the amount of work that is added to a defective product. A worker who is self-inspecting their own work, or source-inspecting the work produced immediately before their work station is encouraged to stop the line when a defect is found. This detection is the first step in Jidoka. A machine performing the same defect detection process is engaged in autonomation.
Once the line is stopped a supervisor or person designated to help correct problems gives immediate attention to the problem the worker or machine has discovered. To complete Jidoka, not only is the defect corrected in the product where discovered, but the process is evaluated and changed to remove the possibility of making the same mistake again. One solution to the problems can be to insert a "mistake-proofing" device somewhere in the production line. Such a device is known as poka-yoke.
Relationship with just-in-time.
Taiichi Ohno and Sakichi Toyoda, originators of the TPS and practices in the manufacturing of textiles, machinery and automobiles considered just-in-time manufacturing and Autonomation as the pillars upon which TPS is built. Jeffrey Liker and David Meier indicate that Jidoka or "the decision to stop and fix problems as they occur rather than pushing them down the line to be resolved later" is a large part of the difference between the effectiveness of Toyota and other companies who have tried to adopt lean manufacturing. Automation, therefore can be said to be a key element in successful Lean Manufacturing implementations.
For just-in-time (JIT) systems, it is absolutely vital to produce with zero defects, or else these defects can disrupt the production process - or the orderly flow of work.
JIT and Lean Manufacturing are always searching for targets for continuous improvement in its quest for quality improvements, finding and eliminating the causes of problems so they do not continually crop up.
Jidoka involves the automatic detection of errors or defects during production. When a defect is detected the halting of the production forces immediate attention to the problem.
The halting causes slowed production but it is believed that this helps to detect a problem earlier and avoids the spread of bad practices.
Etymology.
The word "autonomation" 自働化, a loan word from the Sino-Japanese vocabulary, is a portmanteau of "autonomous" and "automation" 自動化, which is written using three kanji characters: 自（じ ji） "self", 動（どう dou）movement, and 化（か ka）"-ization". In the Toyota Production System, the second character is replaced with 働（どう dou） "work", which is a character derived by adding a radical representing "human" to the original 動.
Zenjidoka.
"Zenjidoka" (全自働化) is described as "taking "jidoka" all the way to the customer" and refers to extended practices in which sales, service and technical staff also have power to interrupt production to correct faults.


MEMS thermal actuator

A MEMS thermal actuator is a microelectromechanical device that typically generates motion by thermal expansion amplification. A small amount of thermal expansion of one part of the device translates to a large amount of deflection of the overall device. Usually fabricated out of doped single crystal silicon or polysilicon as a complex compliant member, the increase in temperature can be achieved internally by electrical resistive heating or by a heat source capable of locally introducing heat. Microfabricated thermal actuators can be integrated into micromotors.


Design prototyping

Design prototyping in its broader definition comprises the actions to make, test and analyse a prototype, a model or a mockup according to one or various purposes in different stages of the design process. Other definitions consider "prototyping" as the methods or techniques for making a prototype (e.g., rapid prototyping techniques), or a stage in the design process (prototype development, prototype or prototyping). The concept of "prototyping" in design disciplines' literature is also related to the concepts of "experimentation" (i.e., an iterative problem-solving process of trying, failing and improving), and "Research through Design (RtD)" (i.e., designers make a prototype with the purpose of conducting research and generating knowledge while trying it, rather than aiming to improving it to become a final product).
Background.
Initial references to the concept of prototyping in design could be traced to the proceedings of the "Conference on Design Methods" in 1962:
In 1968, Bruce Archer, a relevant figure in the "Design Methods Movement" describes the design process. One of the stages of the process is called "Prototype development" and it indicates activities to build and test a prototype. Thus, it would be possible to say that from a design methods' perspective, "prototyping" recalls a process in which a prototype is built, tried out and tested. In the same line, additional references to prototyping can be found in later editions of the Design Research Society's Conferences. For example, referring to build models and use them to consult people out of the design team, review the model and make decisions on how to modify the design proposal; or describing modelling (creating a model) and model simulation.
However, one of the first documented uses of the term "prototyping" linked to a design process appears in 1983 in "A systematic look at prototyping" in the field of information systems and software development. The work of Floyd was inspired by the discussions among the scholars who were preparing the "Working Conference on Prototyping." It focuses on "prototype" as a process, rather than the artefact and how prototyping could be applied to the full solution (or product) or parts of it seeking to improve the final output. Although this work was not developed within the design discipline, it provides a comprehensive characterisation of prototyping by defining its steps, purposes and strategies. Moreover, it serves as a referent to further studies of design prototyping.
Later, around the year of 1990, the availability of methods for rapidly manufacturing models and prototypes stimulated the publication of a great body of literature dedicated to rapid prototyping techniques and technologies (e.g., 3D printing). Technologies for additive manufacturing (i.e., adding material) or substractive manufacturing (i.e., removing material) together with the use of software for computer-aided design (CAD), leveraged prototype building but also the fabrication of products in limited numbers.
Along the years, further efforts have been dedicated to characterising prototyping in design disciplines in the fields of interaction design, experience design, product design and service design, as well as in product-design-related fields such as engineering/mechanical design. In 2000, designers from IDEO described "experience prototyping," introducing types of design representations and methods that allow to simulate aspects of an interaction that people experience by themselves. Experience prototyping can combine various types of prototypes such as spaces, products and interfaces to resemble what the real experience could be like. Around the year of 2010, studies were developed to examine the prototyping of services theorising from the growing practice of service design, which later in 2018 were also used as a reference for service design practitioners.
Prototyping cycle.
Prototyping is developed in an iterative cycle of making, testing and analysing which allows to examine dimensions of a solution before its future implementation, anticipating to possible issues and improving them earlier in the process. This cycle can be portrayed the following steps:
One example of this cycle could be the design of a digital interface in the early stages of the process applying paper prototyping. In this case, prototyping may seek to explore and evaluate multiple alternatives of ideas with the users as fast and cheap as possible, before investing time to program it. Thus, the prototypes will represent the structure of the interface by using simple forms and text to indicate the elements (1). A common technique for creating prototypes of digital interfaces would be to sketch wireframes in paper (2). The team will meet with a potential user and the wireframes will be presented by the design researcher. The user will simulate to click the elements and explain the actions that intends to do while moving to other sheets that represent other screens in the navigation flow (3). The feedback gathered will be used to make decisions on the aspects that need to be modified and the layout of the interface will be updated (4).
Characteristics of prototyping.
To prepare for prototyping, some aspects need to be decided. For this purpose, it is useful to individualise and consider various characteristics that will allow identifying how prototyping should be developed according to the design needs. In this regard, the prototyping framework proposed by Blomkvist and Holmid could provide some guidelines. As a result of a literature review, they identify a set of characteristics which are:
Position in the process.
Whilst for some scholars prototyping was happening in a particular stage of the design process, the importance of prototyping has been gaining relevance as a continuous activity since the early stages of the process. Considering in which moment of the process prototyping is going to be developed will guide decisions on its purpose and further characteristics of prototyping.
Purpose.
Prototyping can be developed according to different aims of the design process that influence decisions such as what variables of the prototype are going to be examined and who is going to be involved in the testing session. For example, in the early stages of the process, the need could be to explore various ideas within the design team and prototypes may be created fast and with little resources, while at the end of the process the functionality of the solution may be evaluated with future users so the prototype would largely resemble its final version.
Some of the purposes of prototyping identified by different authors are:
Stakeholder.
A prototyping session can involve a variety of people related to the solution. Internal to the organisation, the participants could range from the members of the design team to colleagues from other departments and managers. External to the organisation, prototyping could involve future users and clients, and representatives from other organisations. The selection of the participants would depend on the purposes of prototyping. For instance, a prototyping session for exploration could be developed internally with colleagues in order to get quick feedback about initial design proposals. Another example would be to involve users in co-design prototyping sessions in order to explore proposals directly with future users.
Activity.
The activity refers to the method that would be used for testing a prototype, the context in which it is going to occur, and the strategies for testing in relation to what would be the real conditions of use of the solution.
Prototype.
Prototypes can represent one component of a future solution such as "(Inter)actions, service processes, experiences, physical objects, environments, spaces, architecture, digital artifacts and software, ecosystems, [or] (business) value" or comprise various of these components.
Moreover, a prototype can reflect one or multiple dimensions of the future solution and a variety of aspects could be considered. A simple approach would be to think on the "fidelity," meaning how close the prototype resembles to the final solution (blom)(stick). More comprehensive approaches can be considered through multiple dimensions. For instance, Houde and Hill describe the “role” (i.e., functionality for the user), “look and feel” (i.e., sensory, and experiential aspects), “implementation” (i.e., performance of the solution). Lim, Stolterman and Tenenberg propose a classification of prototypes according to “filtering dimensions: functionality, interactivity, and spatial structure"; and “manifestation dimensions:materials, resolution, and scope". They suggest these dimensions can be pondered in order to decide how the prototype should be.


2021–22 UEFA Europa Conference League qualifying phase and play-off round (Main Path)

This page summarises the Main Path matches of the 2021–22 UEFA Europa Conference League qualifying phase and play-off round.
Times are CEST , as listed by UEFA (local times, if different, are in parentheses).
First qualifying round.
Summary.

Matches.
"FCI Levadia won 4–2 on aggregate."
"Puskás Akadémia won 3–1 on aggregate."
"Drita won 3–1 on aggregate."
"Sūduva won 2–1 on aggregate."
"Birkirkara won 2–1 on aggregate."
"FC Santa Coloma won 5–1 on aggregate."
"Velež Mostar won 4–2 on aggregate."
"Domžale won 2–1 on aggregate."
"Shkupi won 3–1 on aggregate."
"Dinamo Batumi won 7–0 on aggregate."
"Partizani won 8–4 on aggregate."
"Maribor won 2–0 on aggregate."
"Laçi won 3–1 on aggregate."
"Milsami Orhei won 1–0 on aggregate."
"KuPS won 5–1 on aggregate."
"Žilina won 6–3 on aggregate."
"FH won 3–1 on aggregate."
"Śląsk Wrocław won 4–1 on aggregate."
"RFS won 6–5 on aggregate."
"Larne won 2–0 on aggregate."
"Ararat Yerevan won 3–1 on aggregate."
"Sutjeska won 2–1 on aggregate."
"Petrocub Hîncești won 2–1 on aggregate."
"Vllaznia won 4–3 on aggregate."
"Bohemians won 4–1 on aggregate."
"The New Saints won 3–1 on aggregate."
"1–1 on aggregate. Gżira United won 5–3 on penalties."
"Kauno Žalgiris won 2–0 on aggregate."
"Dundalk won 5–0 on aggregate."
"Spartak Trnava won 4–3 on aggregate."
"Liepāja won 5–2 on aggregate."
"Breiðablik won 5–2 on aggregate."
"Honka won 3–1 on aggregate."
Second qualifying round.
Summary.

Matches.
"KuPS won 5–4 on aggregate."
"2–2 on aggregate. Shakhter Karagandy won 5–3 on penalties."
"Hapoel Be'er Sheva won 6–0 on aggregate."
"Žilina won 5–3 on aggregate."
"Čukarički won 2–0 on aggregate."
"Maccabi Tel Aviv won 3–1 on aggregate."
"Astana won 3–2 on aggregate."
"Sivasspor won 2–0 on aggregate."
"AEL Limassol won 2–0 on aggregate."
"Sochi won 7–2 on aggregate."
"Elfsborg won 9–0 on aggregate."
"RFS won 5–0 on aggregate."
"Dinamo Batumi won 4–2 on aggregate."
"Partizan won 3–0 on aggregate."
"Dundalk won 4–3 on aggregate."
"Rijeka won 3–0 on aggregate."
"Viktoria Plzeň won 4–2 on aggregate."
"The New Saints won 10–1 on aggregate."
"Domžale won 2–1 on aggregate."
"0–0 on aggregate. CSKA Sofia won 3–1 on penalties."
"Santa Clara won 5–0 on aggregate."
"Hibernian won 5–1 on aggregate."
"Larne won 3–2 on aggregate."
"Gent won 4–2 on aggregate."
"Bohemians won 4–0 on aggregate."
"2–2 on aggregate. Velež Mostar won 3–2 on penalties."
"Qarabağ won 1–0 on aggregate."
"1–1 on aggregate. Lokomotiv Plovdiv won 3–2 on penalties."
"Śląsk Wrocław won 7–5 on aggregate."
"Laçi won 1–0 on aggregate."
"Feyenoord won 3–2 on aggregate."
"Basel won 5–0 on aggregate."
"Osijek won 1–0 on aggregate."
"Breiðablik won 3–2 on aggregate."
"1–1 on aggregate. Olimpija Ljubljana won 5–4 on penalties."
"Hammarby won 4–1 on aggregate."
"Molde won 3–2 on aggregate."
"Újpest won 5–2 on aggregate."
"0–0 on aggregate. Raków Częstochowa won 4–3 on penalties."
"1–1 on aggregate. Spartak Trnava won 4–3 on penalties."
"Rosenborg won 6–1 on aggregate."
"Copenhagen won 9–1 on aggregate."
"Vojvodina won 2–0 on aggregate."
"Tobol won 4–3 on aggregate."
"Aberdeen won 5–3 on aggregate."
Third qualifying round.
Summary.

Matches.
"Sivasspor won 3–2 on aggregate."
"KuPS won 5–4 on aggregate."
"3–3 on aggregate. Partizan won 4–2 on penalties."
"Hapoel Be'er Sheva won 5–2 on aggregate."
"Santa Clara won 3–0 on aggregate."
"Basel won 6–1 on aggregate."
"IF Elfsborg won 5–2 on aggregate."
"0–0 on aggregate. Shakhter Karagandy won 3–1 on penalties."
"Paços de Ferreira won 4–1 on aggregate."
"Feyenoord won 6–0 on aggregate."
"Gent won 3–2 on aggregate."
"Rijeka won 5–2 on aggregate."
"Aberdeen won 5–3 on aggregate."
"4–4 on aggregate. Trabzonspor won 4–3 on penalties."
"PAOK won 3–2 on aggregate."
"5–5 on aggregate. Viktoria Plzeň won 4–1 on penalties."
"Raków Częstochowa won 1–0 on aggregate."
"Copenhagen won 5–3 on aggregate."
"Hammarby IF won 6–4 on aggregate."
"Žilina won 6–0 on aggregate."
"CSKA Sofia won 5–3 on aggregate."
"LASK won 7–1 on aggregate."
"Qarabağ won 2–1 on aggregate."
"Maccabi Tel Aviv won 1–0 on aggregate."
"Rosenborg won 8–2 on aggregate."
"Anderlecht won 5–1 on aggregate."
"Vitesse won 4–3 on aggregate."
Play-off round.
Summary.

Matches.
"Qarabağ won 4–1 on aggregate."
"4–4 on aggregate. Basel won 4–3 on penalties."
"CSKA Sofia won 3–2 on aggregate."
"Tottenham Hotspur won 3–1 on aggregate."
"Rennes won 5–1 on aggregate."
"Vitesse won 5–4 on aggregate."
"LASK won 3–1 on aggregate."
"Maccabi Tel Aviv won 4–1 on aggregate."
"PAOK won 3–1 on aggregate."
"Union Berlin won 4–0 on aggregate."
"Feyenoord won 6–3 on aggregate."
"Gent won 3–1 on aggregate."
"Copenhagen won 7–1 on aggregate."
"Partizan won 3–2 on aggregate."
"Roma won 5–1 on aggregate."
"Anorthosis Famagusta won 3–1 on aggregate."
"Jablonec won 8–1 on aggregate."


Brandt (brand)

Brandt is a French brandname producing various home equipment, created in 1924 by Edgar Brandt as a part of Hotchkiss-Brandt. Today, the company currently is owned by Cevital.
Manufacturing facilities.
current :
former :


Ford MA

The Ford MA Concept concept car was a 2002 minimalist design exercise drawn by Jose Paris and championed by Ford's VP of design J. Mays. It was exhibited as an art object in museums as well as a traditional concept car in auto shows. It received an IDSA Silver Industrial Design Excellence Award in 2003.
The MA displayed many unusual automotive practices. It had the shape of a low slung two seat roadster with no top, but it was powered by an electric motor. The design was flexible enough, though, to accommodate a small internal combustion engine.
Very few of the parts were painted and there were none of the usual hydraulic fluids or industrial adhesives common in most cars, making it 96% recyclable.
It was designed to be assembled and disassembled easily with a minimal amount of equipment. There were no welds holding it together: Instead, its 500 or so pieces of bamboo, aluminum and carbon fibre were held together with 364 titanium bolts. The total weight was said to be .
Some automotive columnists have presented the Ford MA as the forerunner to a small series kit car, much like the Lotus Seven. Others have called it an IKEA-mobile.