English wheel

The English wheel, in Britain also known as a wheeling machine, is a metalworking tool that enables a craftsperson to form compound (double curvature) curves from flat sheets of metal such as aluminium or steel.
Description.
The process of using an English wheel is known as wheeling. Panels produced this way are expensive, due to the highly skilled and labour-intensive production method, but it has the key advantage that it can flexibly produce different panels using the same machine. It is a forming machine that works by surface stretching and is related in action to panel beating processes. It is used wherever low volumes of compound curved panels are required; typically in coachbuilding, car restoration, spaceframe chassis racing cars that meet regulations that require sheetmetal panels resembling mass production vehicles (NASCAR), car prototypes and aircraft skin components. English wheel production is at its highest in low-volume sports car production, particularly when more easily formed aluminium alloy is used.
Where high-volume production runs of panels are required, the wheel is replaced by a stamping press that has a much higher capital setup cost and longer development time than using an English wheel, but each panel in the production run can be produced in a matter of seconds. This cost is defrayed across a larger production run, but a stamping press is limited to only one model of panel per set of dies. The English wheel model shown is manually operated, but when used on thicker sheet metals such as for ship hulls the machine may be powered and much larger than the one shown here.
Construction.
The machine is shaped like a large, closed letter "C". At the ends of the C, there are two wheels. The wheel on the top is called the rolling wheel, while the wheel on the bottom is called the anvil wheel. (Some references refer to the wheels by their position: upper wheel and lower wheel.) The anvil wheel usually has a smaller radius than the rolling wheel. Although larger machines exist, the rolling wheel is usually wide or less, and usually in diameter, or less.
The rolling (top) wheel is flat in cross section, while the anvil (bottom) wheel is domed.
The depth of the C-shaped frame is called the throat. The largest machines have throat sizes of 120 cm (48 inches), while smaller machines have throat sizes of about 60 cm (24 inches). The C stands vertically and is supported by a frame. The throat size usually determines the largest size of metal sheet that the operator can place in the machine and work easily. On some machines, the operator can turn the top wheel and anvil 90 degrees to the frame to increase the maximum size of the work piece. Because the machine works by an amount of pressure between the wheels through the material, and because that pressure changes as the material becomes thinner, the lower jaw and cradle of the frame that holds the anvil roller is adjustable. It may move with a hydraulic jack on machines designed for steel plate, or a jackscrew on machines designed for sheet metals. As the material thins, the operator must adjust the pressure to compensate.
Frame designs are the most significant element of this simple device. For the most part wheels have changed very little since the 19th century. The early English machines (as opposed to the American versions), such as Edwards, Kendrick, Brown, Boggs, and Ranalah, etc., had cast iron frames. These wheels, made during the 19th Century, had Babbitt metal plain bearings, making them difficult to push and pull the metal through when operated at high pressures. Later, when ball bearings came into use, the machines became more suitable for hard and thick material, such as 1/8” steel. Despite the advantages of cast iron, it has less than half the stiffness (Young's modulus) of steel and sometimes must be replaced by steel when a stiffer frame is needed. Steel frames made of solid flame-cut plate, or frames built-up of cut-and-welded plates, are common designs. Steel tubing, generally of square section, has been used for wheeling machine frames during the past 30 years, in the US particularly, where sheet metal shaping has become a hobby as well as a business. Tube-framed machines are reasonably priced and are available as kit-built machines or can be built easily from plans. The stiffest tubular frames have a fully triangulated external bracing truss. They are most effective on thinner or softer materials, such as 20 ga steel or .063" aluminum. Cast frame machines, like the one pictured, are still available.
A properly equipped machine has an assortment of anvil wheels. Anvil wheels, like dollies used with hammers in panel beating (which are also known as anvils) should be used to match the desired crown or curvature of the work piece.
Operation.
The operator of the machine passes the sheet metal between the anvil wheel and the rolling wheel. This process stretches the material and causes it to become thinner. As the material stretches, it forms a convex surface over the anvil wheel. This surface is known as "crown". A high crown surface is very curved, a low crown surface is slightly curved. The rigidity and strength in the surface of a workpiece is provided by the high crown areas. The radius of the surface, after working, depends on the degree that the metal in the middle of the work piece stretches relative to the edge of the piece. If the middle stretches too much, the operator can recover the shape by wheeling the edge of the piece. Wheeling the edge has the same effect in correcting mis-shape due to over-stretching in the middle, as does shrinking directly on the overstretched area by the use of heat shrinking or Eckold-type shrinking. This is because the edge holds the shape in place. Shrinking the edge prior to wheeling aids the formation of shape during wheeling, and reduces the amount of stretching and thinning needed to reach the final shape. Shrinking processes reduce the surface area by thickening the sheet metal. Shrinking by hand is harder to do and slower than stretching using panel beating tools or wheeling, because of this it should only be used when absolutely necessary. Aluminium sheet should be annealed before wheeling because rolling at the mill during its production work hardens it.
Strength and rigidity is also provided by the edge treatment such as flanging or wiring, after the fabrication of the correct surface contour has been achieved. The flange is so important to the shape of the finished surface that it is possible to fabricate some panels by shrinking and stretching of the flange alone, without the use of surface stretching.
Adjustment.
The pressure of the contact area, which varies with the radius of the dome on the anvil wheel and the pressure of the adjusting screw, and the number of wheeling passes determines the degree to which the material stretches. Some operators prefer a foot adjuster so they can maintain constant pressure over varying sheet metal thickness for smoothing, with both hands free to manipulate the work piece. This style of adjuster is also helpful for blending the edge of high crown areas that are thinner, with low crown areas that are relatively unstretched. A drawback of the foot adjuster is that it can get in the way of very longitudinally curved panels, such as the cycle type mudguards (wings/fenders) used on motorcycles, pre-WW2 sports cars, and current open-wheeled cars like the Lotus / Caterham 7.
To address this problem, some wheeling machines have a hand adjuster close beneath the anvil yoke (also known a wheel holder) so such panels can curve underneath unobstructed. This type of machine typically has a diagonal lower 'C' shaped frame that curves lower to the floor, with a hand-operated adjuster close to the anvil wheel holder, instead of the horizontal and long vertical hand adjuster shown in the above picture. A third type of adjuster moves the top wheel up and down with the bottom anvil wheel left static.
Shaping.
At every fabrication stage, the operator must constantly reference the shape that they want to reproduce. This may involve the use of template paper, section templates (made using paper or thin sheet metal), station bucks, formers, profile gauges, profile templates and of course an original panel. Wheeling machines that feature a quick-release lever, which enables the operator to drop the anvil wheel away from the upper wheel so the work piece can be removed and inserted quickly without losing the pressure setting, are great time savers during this part of the process.
The operator must have painstaking patience to make many passes over an area on the sheet to form the area correctly. They may make additional passes with different wheels and in different directions (at 90 degrees for a simple double curvature shape, for example) to achieve the desired shape. Using the correct pressure and appropriate anvil wheel shape, and accurate close patterns of overlapping wheeling passes (or actually overlapping with low crown anvils) makes using the machine something of an art. Too much pressure produces a part that is undulating, marred, and stressed—while too little pressure makes the job take a long time.
Localised wheeling on one part of the panel is likely to cause mis-shaping in adjacent areas. Raising or stretching an area causes adjacent areas to sink, and correcting that may affect areas further away from the original panel working. This is because the tensions in the panel caused by stretching affect the panel shape further away than might be imagined. This means the operator must work over a large area of the panel, fixing these side effects while causing more side effects that must also be fixed.
Key to producing the right shape is to have the right amount of stretched metal surface over this wider area. If this is achieved, it is possible to "move" the metal with minimal extra stretching, filling the low spots with metal from the high spots. This smoothing is almost like planishing using a moderate pressure setting, but is still heavier than that used for planishing. It is a time consuming and fiddly iterative process, that is one of the most difficult and skillful parts of wheeling. As the size of the panel/section increases, the work involved and the level of difficulty increases disproportionately. This is also a reason that very large panels can be very difficult to do and are made in sections. High crown panels/sections may need to be annealed due to work-hardening of the metal, which makes it brittle unworkable and liable to fracture.
After achieving the correct basic shape with the correct amount of metal in the right places, the worker must blend the edges of high crown areas with low crown areas, so that the surface contour transitions from one to the other smoothly. After this, the final wheeling stage involves very light pressure wheeling to planish the surface to make it a smooth, cohesive shape. This stage does not stretch the metal but moves the already stretched metal around, so using the minimum anvil pressure and as wide an anvil as is possible with the panel shape, is essential.
Typically, only small high crown panels, (such as repair sections) or large low crown panels (such as roofs), are made in one piece. Large low crown panels need two skilled craftsmen to support the weight of the panel.
Limitations.
Five key limitations of the machine are:
These limitations are the reasons why large high crown panels such as wings and fenders are often made in many pieces. The pieces are then welded together usually with one of two processes. TIG welding (Tungsten Inert Gas) produces less heat distortion, but produces a harder, more brittle weld that may cause problems when planishing/smoothing by hand, or in the wheeling machine. Oxy-acetylene welding joints don't have this drawback, provided they are allowed to cool to room temperature in air, but do produce more heat distortion. Panel joints may be achieved using autogenous welding – that is welding without filler rod (Oxy-acetylene or TIG processes), this is useful when finally smoothing the welding joints as it reduces the amount filing/grinding/linishing needed or almost eliminates it altogether. It also, more importantly, reduces heat distortion of the surface contour, which must be corrected on the wheel or with hammer and dolly.
Finishing.
The final panel fabrication process, after achieving the correct surface contour, is some kind of edge treatment, such as flanging (sheet metal) or wire edging. This finishes and strengthens the edge. Typically, there is too much or too little metal in the flange, which pulls the panel out of shape after the flange is turned—so it must be stretched or shrunk to correct the surface shape. This is most easily done using Eckold shrinking and stretching, but can be done using heat shrinking or cold shrinking, by tucking and beating the tucked metal into itself, or by using a cold shrinking hammer and dolly. Stretching or shrinking the flange requires a correct profile hammer and dolly. The hammer and dolly must match the desired flange shape at the point of contact through the flange, (known as ringing the dolly) with the hammer. A lot of shrinking or stretching work hardens the flange and can cause cracks and tears. While these can be welded, it is much better to anneal the metal before this happens to restore its workability.
An English wheel is a better tool for a skilled craftsman for low-crown applications than manually hammering. Planishing manually using dollies and slapper files or planishing hammer, after hammer forming is very labour-intensive. Using a pear shaped mallet and sandbag to stretch the sheet metal (sinking), or by raising on a stake, speeds up the fabrication of higher crown sections. (A stake is a dolly, that can be much larger than hand held dollys, typically with a tapering square cross section casting underneath it. This is to mount it in a bench vice or a matching female hole in a beak anvil as used by blacksmiths and farriers.) A pneumatic hammer or power hammer is faster still. The English wheel is very effective when used for planishing, (for which it was originally patented in England), to a smooth final finish after these processes.


Job production

Job production, sometimes called jobbing or one-off production, involves producing custom work, such as a one-off product for a specific customer or a small batch of work in quantities usually less than those of mass-market products. Job production consists of an operator or group of operators to work on a single job and complete it before proceeding to the next similar or different job. Together with batch production and mass production (flow production) it is one of the three main production methods.
Job production can be classical craft production by small firms (making railings for a specific house, building/repairing a computer for a specific customer, making flower arrangements for a specific wedding etc.), but large firms use job production, too, and the products of job production are often interchangeable, such as machined parts made by a job shop. Examples include:
Fabrication shops and machine shops whose work is primarily of the job production type are often called job shops. The associated people or corporations are sometimes called jobbers.
Job production is, in essence, manufacturing on a contract basis, and thus it forms a subset of the larger field of contract manufacturing. But the latter field also includes, in addition to jobbing, a higher level of outsourcing in which a product-line-owning company entrusts its entire production to a contractor, rather than just outsourcing parts of it.
Benefits and disadvantages.
Key benefits of job production include:
Disadvantages include:
Essential features.
There are a number of features that should be implemented in a job production environment, they include:


Motion system

Motion system in engineering and systems, is a component of a test and measurement system that provides motion to a load or loads in a one or many directions. Generally a motion system is made up of a set (or stack) of linear and rotational stages. A linear stage moves in a straight line, while a rotation stage moves in a partial or full circle. A stage can either be manually controlled with a knob control, or automated with a motion controller.
A motion system generally is computer controlled and can perform fast, reliable, repeatable, and accurate positioning of loads. Most systems will support motion in X and Y directions, which is referred to as an XY stack. Often either a Z axis (up/down motion) or R axis (rotational motion) is placed on top of the XY stack.
For automated stages, a scale can be attached to the internals of the stage and an encoder used to measure the position on the scale and report this to the controller, thereby determining the precise position of the stage. This allows for a motion controller to reliably and repeatably move to set positions with the linear stage.
External links.
Motion Basics and Standards


Draw plate

A draw plate is type of die consisting of a hardened steel plate with one or more tapered holes through which wire is drawn to make it thinner. A typical plate will have twenty to thirty holes, so a wide range of diameters can be drawn.
Drawing wire.
Before drawing, the draw plate is held securely in a vise or other fixture. The plate is oriented so that the wider end of a tapered opening can receive a metal wire which is to be pulled through it.
Annealed soft, ductile wire is filed at one end to give it an initial taper. The tapered end is inserted into a tapered hole with a final diameter just smaller than its current width. Special pliers, called draw tongs are used to hold the tip of the wire and pull it through, sometimes with the aid of grease or wax as a lubricant. Small-diameter wire may be drawn manually, while very thick wire may require a drawing bench with a crank to produce enough force.
Typically, a wire can be drawn three times in sequence before it needs to be re-annealed. This must be done because drawing wire hardens it, which causes the wire to become brittle. Brittle wire that has not been annealed may snap during the drawing process (or develop microscopic or macroscopic cracks, which may weaken the piece or "grow" with further working).
Draw plates reduce the thickness of wire by reshaping the metal; increasing its length while decreasing diameter. As such, a piece of wire will become considerably lengthened during the drawing process.
With a mandrel, a draw plate can be used to draw tubes of metal. Plates are available in many different sizes and shapes for drawing different shapes of wire, including round, square, oval, half-round, and hexagonal.


Canon Tokki

Canon Tokki Corporation is a Japanese manufacturer of material deposition equipment for making OLED displays. It is a wholly owned subsidiary of Canon Inc. and has a near-monopoly in its main business field.
History.
The company began producing Factory Automation systems, machine tools and production tools. In 1983 it began to produce vacuum thin film deposition equipment. In 1986, Tsugami Specialty Machine, Nagaoka Precision, Tsugami Robotics, and UPR Co., Ltd. merged to form Tokki Corporation Ltd. It began OLED material deposition equipment research in 1993, and in 1996, it started to sell its OLED material deposition equipment.
In 1999, Tokki developed the first OLED mass production system that processes both OLED and electrode material deposition as well as encapsulation by one system. The company also produces commercial encapsulation tools for laboratory and mass manufacturing. Canon Tokki and Sunic of Korea are the only two major manufacturers of production-scale OLED thin-film deposition equipment of G6 and above.
In 2001 it purchased the Niigata Factory from Niigata Keiso Co., Ltd., which became Tokki's main production base. In 2004, Tokki spun off its Factory Automation division forming the subsidiary Tokki Industries Co., Ltd. In 2009, Tokki moved its headquarters from Tokyo to its factory in Niigata. In 2010, Tokki sold Tokki Industries Co., Ltd to Marubeni Corporation. In 2010, Tokki was bought by Canon Inc., and in 2012 it changed its name to Canon Tokki.
An increase in orders enabled the company to double production capacity in 2016, but in 2018 the demand went down as a recovery in the equipment market had been lagged behind that of the display market.


Medisize

Medisize AG Switzerland is a Swiss plastics processing company, owned by the Dutch Philips-Medisize Corporation. The Medisize Switzerland was original created as Createch AG.
History.
Werner Dubach founded the company Createch in Nürensdorf, which produced various bottles and closures for the medical, cosmetics and food sector in the injection blow, injection blow stretching molding and injection molding process. It was planned to build a building consisting of several parts, with office, production and storage space. On the one hand, granting problems, which led to massive changes in the construction project, led to financial problems. In addition, copyright complaints were filed for the production of food-grade food packaging for Danone yoghurts and quarks by the toy manufacturer Lego. This leads to the bankruptcy of the company Createch and the main building was not completely finished. A part is still in the shell and is used as a warehouse. The Createch was passed on by the Credit Suisse Bank until the Dutch Medisize Group took over the company. The Createch was then renamed to Medisize Switzerland AG.
In the meantime Werner Dubach had founded the company Terxo AG Switzerland in Wetzikon with some former Createch employees and the financial commitment of Markus Schellenberg. Werner Dubach had designed and patented a number of closures, some of which are still produced today by Medisize, Terxo and the German Terxo partner company Bericap. Werner Dubach retired some years ago.
Products.
Branch of industry: Plastic industry and packaging industry, food and medical packaging
Medisize Switzerland produces mainly closures for food packaging and cosmetics by means of injection molding machines and injection blowmachines, injection stretch blow molding machines as well as with assembly machines for further processing, but primarily packaging for medical products such as, for example, Eyedrops as well as bottles for drinks.
The Actifit bottles (polyethylene) for the milk processor Emmi, which produces medisize, have a great competitive pressure. This is because the company Terxo manufactures these bottles for Emmi too. In addition, the injection molding and injection blow molding machine manufacturer Ganahl, who has produced the corresponding tools for Terxo and Medisize, also manufactures such bottles by themselves. This means that there are three companies in the canton of Zurich, which all supply the same customer with the same product.
Equipment.
Medisize uses injection molding machines of Japanese and German origin. Three Italian machines are available for the injection blow-molding machines, but the majority of injection-molding machines are Jomar machines with vertical plasticizing cylinders, which come from the US. Medisize Switzerland is the first production company to use a fully electric injection blow molding machine. This was developed by a German toolmaking company.


Automated truck loading systems

Automated Truck Loading Systems - ATLS has been commonly used in the material handling industry to refer to the automation of loading or unloading trucks and trailers with product either on or without pallets, slip sheets, racks, containers, using several different types of automated guided vehicle systems (AGV) or engineered conveyor belt systems that are integrated into vehicles, automating the shipping / receiving and logistics operations.
These conveyor systems are commonly referred to as
Some of these systems are used to handle bulk products such as garbage, agriculture products, recycled tires, cotton, bark or sawdust. Manufacturing industries such as automotive, food & beverage, paper, consumer products, appliance manufacturers and uses ATLS systems for incoming materials and outgoing product to increase throughput and streamline production. The transportation industry relies heavily on ATLS material handling systems to rapidly move product via land, sea, and air.
The major advantages of ATLS are:
ATLS vehicle loading technologies significantly reduce the manpower required on the shipping and receiving docks, eliminate product damage, accidents, and ergonomic injuries related to lift-truck operation. Generally, products can be loaded quicker and product density is increased resulting in more payload per shipment which reduces shipping cost, using a loading automation system. Loading automation is often the key component to achieve complete plant automation.


Compression molding

Compression molding is a method of molding in which the molding material, generally preheated, is first placed in an open, heated mold cavity. The mold is closed with a top force or plug member, pressure is applied to force the material into contact with all mold areas, while heat and pressure are maintained until the molding material has cured; this process is known as compression molding method and in case of rubber it is also known as 'Vulcanisation'. The process employs thermosetting resins in a partially cured stage, either in the form of granules, putty-like masses, or preforms.
Compression molding is a high-volume, high-pressure method suitable for molding complex, high-strength fiberglass reinforcements. Advanced composite thermoplastics can also be compression molded with unidirectional tapes, woven fabrics, randomly oriented fiber mat or chopped strand. The advantage of compression molding is its ability to mold large, fairly intricate parts. Also, it is one of the lowest cost molding methods compared with other methods such as transfer molding and injection molding; moreover it wastes relatively little material, giving it an advantage when working with expensive compounds.
However, compression molding often provides poor product consistency and difficulty in controlling flashing, and it is not suitable for some types of parts. Fewer knit lines are produced and a smaller amount of fiber-length degradation is noticeable when compared to injection molding. Compression-molding is also suitable for ultra-large basic shape production in sizes beyond the capacity of extrusion techniques. Materials that are typically manufactured through compression molding include: Polyester fiberglass resin systems (SMC/BMC), Torlon, Vespel, Poly(p-phenylene sulfide) (PPS), and many grades of PEEK.
Compression molding is commonly utilized by product development engineers seeking cost effective rubber and silicone parts. Manufacturers of low volume compression molded components include PrintForm, 3D, STYS, and Aero MFG.
Compression molding was first developed to manufacture composite parts for metal replacement applications, compression molding is typically used to make larger flat or moderately curved parts. This method of molding is greatly used in manufacturing automotive parts such as hoods, fenders, scoops, spoilers, as well as smaller more intricate parts.
The material to be molded is positioned in the mold cavity and the heated platens are closed by a hydraulic ram. Bulk molding compound (BMC) or sheet molding compound (SMC), are conformed to the mold form by the applied pressure and heated until the curing reaction occurs. SMC feed material usually is cut to conform to the surface area of the mold. The mold is then cooled and the part removed.
Materials may be loaded into the mold either in the form of pellets or sheet, or the mold may be loaded from a plasticating extruder. Materials are heated above their melting points, formed and cooled. The more evenly the feed material is distributed over the mold surface, the less flow orientation occurs during the compression stage.
Compression molding is also widely used to produce sandwich structures that incorporate a core material such as a honeycomb or polymer foam.
Thermoplastic matrices are commonplace in mass production industries. One significant example are automotive applications where the leading technologies are long fibre reinforced thermoplastics (LFT) and glass fiber mat reinforced thermoplastics (GMT).
In compression molding there are six important considerations that an engineer should bear in mind:
Process definition.
Compression molding is a forming process in which a plastic material is placed directly into a heated metal mold then is softened by the heat and therefore forced to conform to the shape of the mold, as the mold closes. Once molding is completed excess Flash may be removed. Typically, compression molding machines open along a vertical axis.
Process characteristics.
The use of thermoset plastic compounds characterizes this molding process from many of the other molding processes. These thermosets can be in either preform or granule shapes. Unlike some of the other processes we find that the materials are usually preheated and measured before molding. This helps to reduce excess flash. Inserts, usually metallic, can also be molded with the plastic. As a side note, remember not to allow any undercuts on the shape, it will make ejection especially difficult. Thermoplastic matrices with an inherent indefinite shelf-life and shorter cycle molding times are widely used and examples are shown in Ref 3.
Process schematic.
Compression molding is one of the oldest manufacturing techniques for rubber molding. The process parameters include molding time, temperature, and pressure. Usually, a 300-400 ton clamp pressure is used. The typical mold is shaped like a clam shell with the bottom being the mold cavity. The molding press looked a lot like a ladle filled vertical press used for casting aluminum. Compression molding uses preforms made by an extruder and wink cutter (in which two blades meet at the center to cut the extrudate to length) or a roller die and die cutter.
Compression molded water bottles are made from die-cut 3 inch by 6 inch sheets. One sheet is placed below a core and one sheet of equal size is placed above the core, and then the top of the mold is lowered by hand or by hoist to near shut. The mold is then pushed into the press, and the press is hydraulically closed to full pressure. The mold temperature is about 350 degrees. When the cycle ends (after about 3.5-4.0 minutes), the press opens and the mold is pulled out toward the operator. The operator opens the clam shell mold top and leans the top of the mold back against the press. Exposed is the bottle with the core still inside. While the bottle is still hot, the operator inserts prongs in between the bottle and the steel core and stretches the bottle at the neck to free it from the core.
The preforms for compression molded golf ball centers are extruded. The preform has a 1 inch by 1 inch round slug that stands up in the mold cavity. During the cycle, the operator loads the jig with slugs and places the jig over the mold. The preforms are released into the cavity of the mold when the slide tray is pulled. When the mold is opened, the lower platen lowers and the mold is hydraulically pushed out to the operator. The heat sheet (all molded parts from that cycle joined together by a parting line rind (flash)) is then placed in a transfer cart to be die cut.
Typical tools and geometry produced.
Three types of molds used are the flash plunger-type, straight plunger-type, and the "landed" plunger-type molds. The flash type mold must have an accurate charge of plastic and produces a horizontal flash (excess material protruding from the mold). The straight plunger-type mold allows for some inaccuracy in the charge of plastic and produces a vertical flash. The landed plunger type mold must have an accurate charge of plastic, and no flash is produced. Further details are explained in Ref 3.


Phantom inventory

Phantom inventory is a common expression for goods that an inventory accounting system considers to be on-hand at a storage location but are not available. This could be due to the items being moved without recording the change in the inventory accounting system, breakage, theft, data entry errors or deliberate fraud. The resulting discrepancy between the online inventory balance and physical availability can delay automated reordering and lead to out-of-stock incidents.
If not addressed, phantom inventory can result in:
A number of techniques have been used to correct phantom inventory problems, including physical cycle counts, RFID tagging of items and statistical modelling of phantom inventory conditions.


Industrial estates in Malta

Many factories in Malta are located in one of the several industrial estates throughout the archipelago. Malta Industrial Parks is a company which was created to manage industrial estates in Malta.
Major Industrial Areas.
The industrial estates include:
Bulebel Industrial Estate.
Bulebel Industrial Estate is one of the major industrial estates in Malta. Its namesake comes from milk production. Among the factories located here are:
The estate is found on the outskirts of Żejtun, near the localities of Tarxien and Fgura, and is not far from Malta International Airport.


Thermocompression bonding

Thermocompression bonding describes a wafer bonding technique and is also referred to as diffusion bonding, pressure joining, thermocompression welding or solid-state welding. Two metals, e.g. gold-gold (Au), are brought into atomic contact applying force and heat simultaneously. The diffusion requires atomic contact between the surfaces due to the atomic motion. The atoms migrate from one crystal lattice to the other one based on crystal lattice vibration. This atomic interaction sticks the interface together.
The diffusion process is described by the following three processes:
This method enables internal structure protecting device packages and direct electrical interconnect structures without additional steps beside the surface mounting process.
Overview.
The most established materials for thermocompression bonding are copper (Cu), gold (Au) and aluminium (Al) because of their high diffusion rates. In addition, aluminium and copper are relatively soft metals with good ductility.
Bonding with Al or Cu requires temperatures ≥ 400 °C to ensure sufficient hermetical sealing. Furthermore, "aluminium" needs extensive deposition and requires a high applied force to penetrate the surface oxide, as it is not able to penetrate through the oxide.
When using "gold" for diffusion, a temperature around 300 °C is needed to achieve a successful bond. Compared to Al or Cu, it does not form an oxide. This allows to skip a surface cleaning procedure before bonding.
"Copper" has the disadvantage that the damascene process is very extensive. It also immediately forms a surface oxide which can, however, be removed by formic acid vapor cleaning. Oxide removal doubles as surface passivation.
The diffusion of these metals requires good knowledge of the CTE differences between the two wafers to prevent resulting stress. Therefore, the temperature of both heaters needs to be matched and center-to-edge uniform for synchronized wafer expansion.
Procedural steps.
Pre-conditioning.
Oxidation and impurities in the metal films affect the diffusion reactions by reducing the diffusion rates. Therefore, clean deposition practices and bonding with oxide removal and re-oxidation prevention steps are applied. The oxide layer removal can be realized by various oxide etch chemistry methods. Dry etching processes, i.e. formic acid vapor cleaning, are preferred based on the minimization of the immersion in fluids and the resulting etching of the passivation or the adhesion layer. Using the CMP process, which is especially for Cu and Al required, creates a planarized surface with micro roughness around several nanometres and enables the achievement of void-free diffusion bonds. Further, a surface treatment for organic removal, e.g. UV-ozone exposure, is possible.
Methods, i.e. plasma surface pretreatment, provide an accelerated diffusion rate based on an increased surface contact. Also the use of an ultra planarization step is considered to improve the bonding due to a reduction of material transport required for the diffusion. This improvement is based on a defined height Cu, Au and Sn.
Deposition.
The metal films can be deposited by evaporation, sputtering or electroplating. Evaporation and sputtering, producing high quality films with limited impurities, are slow and hence used for micrometre and sub-micrometre layer thicknesses. The electroplating is commonly used for thicker films and needs careful monitoring and control of the film roughness and the layer purity.
The gold film can also be deposited on a diffusion barrier film, i.e. oxide or nitride. Also, an additional nano crystalline metal film, e.g. Ta, Cr, W, or Ti, can enhance the adhesion strength of the diffusion bond at decreased applied pressure and bonding temperature.
Bonding.
The factors of the chosen temperature and applied pressure depend on the diffusion rate. The diffusion occurs between the crystal lattices by lattice vibration. Atoms can not leap over free space, i.e. contamination or vacancies. Beside the most rapid diffusion process (surface diffusion), the grain boundary and the bulk diffusion exist.
"Surface diffusion", also referred to as atomic diffusion, describes the process along the surface interface, when atoms move from surface to surface to free energy.
The "grain boundary diffusion" terms the free migration of atoms in free atomic lattice spaces. This is based on polycrystalline layers and its boundaries of incomplete matching of the atomic lattice and grains.
The "diffusion through bulk crystal" is the exchange of atoms or vacancies within the lattice that enables the mixing. The bulk diffusion starts at 30 to 50% of the materials melting point increasing exponentially with the temperature.
To enable the diffusion process, a high force is applied to plastically deform the surface asperities in the film, i.e. reducing bow and warp of the metal. Further, the applied force and its uniformity is important and depends on the wafer diameter and the metal density features. The high degree of force uniformity diminish the total force needed and alleviate the stress gradients and sensitivity to fragility. The bonding temperature can be lowered using a higher applied pressure and vice versa, considering that high pressure increases the chances of damage to the structural material or the films.
The bonding process itself takes place in a vacuum or forming gas environment, e.g. N2. The pressure atmosphere supports the heat conduction and prevents thermal gradients vertically across the wafer and re-oxidation. Based on the difficult control of thermal expansion differences between the two wafers, precision alignment and high quality fixtures are used.
The bonding settings for the most established metals are following (for 200 mm wafers):
Examples.
1. Thermocompression bonding is well established in the CMOS industry and realizes vertical integrated devices and production of wafer level packages with smaller form factors. This bonding procedure is used to produce pressure sensors, accelerometers, gyroscopes and RF MEMS.
2. Typically, thermocompression bonds are made with delivering heat and pressure to the mating surface by a hard faced bonding tool. Compliant bonding is a unique method of forming this type of solid state bond between a gold lead and a gold surface since heat and pressure is transmitted through a compliant or deformable media. The use of the compliant medium ensures the physical integrity of the lead by controlling the extent of wire deformation. The process also allows one to bond a multiple number of gold wires of various dimensions simultaneously since the compliant media ensures contacting and deforming all the lead wires.


The International Journal of Advanced Manufacturing Technology is a peer-reviewed scientific journal published by Springer Science+Business Media in 18 issues per year. It covers all aspects of advanced manufacturing technology, such as robotics, artificial intelligence (including speech technology), vision and tactile sensing, grippers, programmable controllers, lasers and other advanced processes, programmable assembly, flexible manufacturing systems, computer integrated manufacturing, inspection, automatic test equipment, simulation, motors, controls and drives, local area networking, production planning and control, logistics and supply chain management, human factors, and economics. The editor-in-chief is A.Y.C. Nee (National University of Singapore).
Abstracting and indexing.
The journal is abstracted and indexed in EBSCO databases, Science Citation Index Expanded, and Scopus. According to the "Journal Citation Reports", the journal has a 2017 impact factor of 2.601.


Inventory theory

Material theory (or more formally the mathematical theory of inventory and production) is the sub-specialty within operations research and operations management that is concerned with the design of production/inventory systems to minimize costs: it studies the decisions faced by firms and the military in connection with manufacturing, warehousing, supply chains, spare part allocation and so on and provides the mathematical foundation for logistics. The inventory control problem is the problem faced by a firm that must decide how much to order in each time period to meet demand for its products. The problem can be modeled using mathematical techniques of optimal control, dynamic programming and network optimization. The study of such models is part of inventory theory.
Issues.
One issue is infrequent large orders vs. frequent small orders. Large orders will increase the amount of inventory on hand, which is costly, but may benefit from volume discounts. Frequent orders are costly to process, and the resulting small inventory levels may increase the probability of stockouts, leading to loss of customers. In principle all these factors can be calculated mathematically and the optimum found.
A second issue is related to changes in demand (predictable or random) for the product. For example, having the needed merchandise on hand in order to make sales during the appropriate buying season(s). A classic example is a toy store before Christmas: if the items are not on the shelves, they cannot be sold. And the wholesale market is not perfect; there can be considerable delays, particularly with the most popular toys. So, the entrepreneur or business manager will buy speculatively. Another example is a furniture store. If there is a six-week, or more, delay for customers to receive merchandise, some sales will be lost. A further example is a restaurant, where a considerable percentage of the sales are the value-added aspects of food preparation and presentation, and so it is rational to buy and store somewhat more to reduce the chances of running out of key ingredients. The situation often comes down to two key questions: confidence in the merchandise selling, and the benefits accruing if it does?
A third issue comes from the view that inventory also serves the function of decoupling two separate operations. For example, work in process inventory often accumulates between two departments because the consuming and the producing department do not coordinate their work. With improved coordination this buffer inventory could be eliminated. This leads to the whole philosophy of Just In Time, which argues that the costs of carrying inventory have typically been underestimated, including both the direct, obvious costs of storage space and insurance, but also the harder-to-measure costs of increased variables and complexity, and thus decreased flexibility, for the business enterprise.
Inventory models.
The mathematical approach is typically formulated as follows:
a store has, at time formula_1, formula_2 items in stock. It then orders (and receives) formula_3 items, and sells formula_4 items, where formula_5 follows a given probability distribution. Thus:
Whether formula_2 is allowed to go negative, corresponding to back-ordered items, will depend on the specific situation; if allowed there will usually be a penalty for back orders. The store has costs that are related to the number of items in store and the number of items ordered:
The store wants to select formula_3 in an optimal way, i.e. to minimize
Many other features can be added to the model, including multiple products (denoted formula_13), upper bounds on inventory and so on. Inventory models can be based on different assumptions:
Classic models.
Although the number of models described in the literature is immense, the following is a list of classics:
Further reading.
Classic books that established the field are:
Many university courses in inventory theory use one or more of the following current textbooks:


Ball screw

A ball screw (or ballscrew) is a mechanical linear actuator that translates rotational motion to linear motion with little friction. A threaded shaft provides a helical raceway for ball bearings which act as a precision screw. As well as being able to apply or withstand high thrust loads, they can do so with minimum internal friction. They are made to close tolerances and are therefore suitable for use in situations in which high precision is necessary. The ball assembly acts as the nut while the threaded shaft is the screw.
In contrast to conventional leadscrews, ball screws tend to be rather bulky, due to the need to have a mechanism to recirculate the balls.
History.
The ball screw was invented independently by H.M. Stevenson and D. Glenn who were issued in 1898 patents 601,451 and 610,044 respectively.
Early precise screwshafts were produced by starting with a low-precision screwshaft, and then lapping the shaft with several spring-loaded nut laps. By rearranging and inverting the nut laps, the lengthwise errors of the nuts and shaft were averaged. Then, the very repeatable shaft's pitch is measured against a distance standard. A similar process is sometimes used today to produce reference standard screw shafts, or master manufacturing screw shafts.
Design.
Low friction in ball screws yields high mechanical efficiency compared to alternatives. A typical ball screw may be 90 percent efficient, versus 20 to 25 percent efficiency of an Acme lead screw of equal size. Lack of sliding friction between the nut and screw lends itself to extended lifespan of the screw assembly (especially in no-backlash systems), reducing downtime for maintenance and parts replacement, while also decreasing demand for lubrication. This, combined with their overall performance benefits and reduced power requirements, may offset the initial costs of using ball screws.
Ball screws may also reduce or eliminate backlash common in lead screw and nut combinations. The balls may be preloaded so that there is no "wiggle" between the ball screw and ball nut. This is particularly desirable in applications where the load on the screw varies quickly, such as machine tools.
Because of their very high mechanical efficiency, especially compared to traditional lead screws, ball screws can potentially be back-driven (i.e., a linear force applied directly to the nut can induce a rotation of the shaft, an effect counterproductive to most uses). While this is usually of limited consequence to motorized applications, and potentially even provides a mild protective effect in some cases, it makes them generally unsuitable for application in manually actuated systems, such as hand-fed machine tools. The static torque and digital control of an appropriate servomotor can be made to resist and compensate, but hand cranked mechanisms would require additional mechanisms to prevent undesirable behaviors. Such undesirable behavior could range from simple loss of control of the machine, such as self-feeding (the tool of the machine causing motion of the axes without the control input of the operator), to potentially dangerous cases where unexpected force could be transmitted all the way to an operator's limbs and pose a risk of injury. Because an ordinary lead screw resists or even prohibits such reverse operation, they are inherently safer and more reliable for manual use. The magnitude of force needed to consequentially back-drive an Acme lead screw would usually be sufficient to destroy the mechanism, immobilizing the machine and absorbing any dangerous force before it could pose a risk to an operator.
The circulating balls travel inside the thread form of the screw and nut, and balls are recirculated through various types of return mechanisms. If the ball nut did not have a return mechanism the balls would fall out of the end of the ball nut when they reached the end of the nut. For this reason several different recirculation methods have been developed. An external ballnut employs a stamped tube which picks up balls from the raceway by use of a small pick-up finger. Balls travel inside the tube and are then replaced back into the thread raceway. An internal button ballnut employs a machined or cast button style return which allows balls to exit the raceway track and move one thread then reenter the raceway. An endcap return ball nut employs a cap on the end of the ball nut. The cap is machined to pick up balls coming out of the end of the nut and direct them down holes which are bored transversely down the ballnut. The complement cap on the other side of the nut directs balls back into the raceway. The returning balls are not under significant mechanical load and the return path may incorporate injection moulded low-friction plastic parts.
A ball screw involves significantly more parts and surface interactions than many similar systems. While a basic lead screw is composed of only a solid shaft and a solid nut with simple mating geometries, a ball screw requires precisely formed curved contours and multi-part assemblies to facilitate the action of the bearing balls. This makes them more expensive to manufacture and sometimes to maintain, and provides more potential avenues for failure if the apparatus is not properly cared for.
Equations.
with the rotary input driving in the conventional way, or
if the linear force is backdriving the system
Where formula_3 is torque applied to screw or nut, formula_4 is linear force applied, formula_5 is ball screw lead, and formula_6 is ball screw efficiency. Selection of the standard to be used is an agreement between the supplier and the user and has some significance in the design of the screw. In the United States, ASME has developed the B5.48-1977 Standard entitled "Ball Screws".
The correct evaluation of the curvatures of ball screw grooves allows to accurately design the constructive parameters of this mechanism and to enhance its performance. The formulation commonly used in literature refers to the ball bearings geometry, ignoring the shape of the section’s profile and the helix angle. In particular, the first principal curvature is calculated asformula_7for the screw shaft groove, and asformula_8for the nut groove, where φ is the contact angle, formula_9 is the pitch circle radius and formula_10 is the ball radius.
The second principal curvature is simplyformula_11for the screw shaft groove and formula_12for the nut groove, in which formula_13 and formula_14 are, respectively, the conformity factors of the groove profiles of the screw shaft and nut.
These formulations do not take into account the shape of the groove profiles and the presence of the helix angle: more recent publications found the exact solution for the curvature of the grooves of screw shaft and nut. A new research proposes a new formulation which approximates the real curvature values with a maximum relative error of approximately 0.5%. Therefore, a much more precise formula for the first principal curvature of the screw shaft groove isformula_15andformula_16for the nut groove, where formula_17 is the helix angle.
Operation.
To maintain their inherent accuracy and ensure long life, great care is needed to avoid contamination with dirt and abrasive particles. This may be achieved by using rubber or leather bellows to completely or partially enclose the working surfaces. Another solution is to use a positive pressure of filtered air when they are used in a semi-sealed or open enclosure.
While reducing friction, ball screws can operate with some preload, effectively eliminating backlash (slop) between input (rotation) and output (linear motion). This feature is essential when they are used in computer-controlled motion-control systems, e.g., CNC machine tools and high precision motion applications (e.g., wire bonding).
To obtain proper rolling action of the balls, as in a standard ball bearing, it is necessary that, when loaded in one direction, the ball makes contact at one point with the nut, and one point with the screw. In practice, most ball screws are designed to be lightly preloaded, so that there is at least a slight load on the ball at four points, two in contact with the nut and two in contact with the screw. This is accomplished by using a thread profile that has a slightly larger radius than the ball, the difference in radii being kept small (e.g. a simple V thread with flat faces is unsuitable) so that elastic deformation around the point of contact allows a small, but non-zero contact area to be obtained, like any other rolling element bearing. To this end, the threads are usually machined as a "gothic arch" profile. If a simple semicircular thread profile were used, contact would only be at two points, on the outer and inner edges, which would not resist axial loading.
To remove backlash and obtain the optimum stiffness and wear characteristics for a given application, a controlled amount of preload is usually applied. This is accomplished in some cases by machining the components such that the balls are a "tight" fit when assembled, however this gives poor control of the preload, and cannot be adjusted to allow for wear. It is more common to design the ball nut as effectively two separate nuts which are tightly coupled mechanically, with adjustment by either rotating one nut with respect to the other, so creating a relative axial displacement, or by retaining both nuts tightly together axially and rotating one with respect to the other, so that its set of balls is displaced axially to create the preload.
Manufacture.
Ball screw shafts may be fabricated by rolling, yielding a less precise, but inexpensive and mechanically efficient product. Rolled ball screws have a positional precision of several thousandths of an inch per foot.
Ball screw are classified using "accuracy grades" from C0 (most precise) to C10. High-precision screw shafts are typically precise to one thousandth of an inch per foot (830 nanometers per centimeter) or better. They have historically been machined to gross shape, case-hardened, and then ground. The three step process is needed because high temperature machining distorts the work-piece. Hard whirling is a recent (2008) precision machining technique that minimizes heating of the work, and can produce precision screws from case-hardened bar stock. Instrument quality screw shafts are typically precise to 250 nanometers per centimeter. They are produced on precision milling machines with optical distance measuring equipment and special tooling. Similar machines are used to produce optical lenses and mirrors. Instrument screw shafts are generally made of Invar, to prevent temperature from changing tolerances too much.
Applications.
Ball screws are used in aircraft and missiles to move control surfaces, especially for electric fly by wire, and in automobile power steering to translate rotary motion from an electric motor to axial motion of the steering rack. They are also used in machine tools, robots, and precision assembly equipment. High precision ball screws are used in steppers for semiconductor manufacturing.
A ball screw is used to expand the Deployable Tower Assembly (DTA) structure on the James Webb Space Telescope.
Similar systems.
Another form of linear actuator based on a rotating rod is the threadless ballscrew, a.k.a. "rolling ring drive". In this design, three (or more) rolling-ring bearings are arranged symmetrically in a housing surrounding a smooth (threadless) actuator rod or shaft. The bearings are set at an angle to the rod, and this angle determines the direction and rate of linear motion per revolution of the rod. An advantage of this design over the conventional ballscrew or leadscrew is the practical elimination of backlash and loading caused by preload nuts.


Product structure modeling

Product structure is a hierarchical decomposition of a product, typically known as the bill of materials (BOM).
As business becomes more responsive to unique consumer tastes and derivative products grow to meet the unique configurations, BOM management can become unmanageable. For manufacturers, a bill of materials (BOM) is a critical product information record that lists the raw materials, assemblies, components, parts and the quantities of each needed to manufacture a product.
Advanced modeling techniques are necessary to cope with configurable products where changing a small part of a product can have multiple impacts on other product structure models. Concepts within this entry are in capital letters in order to indicate these concepts.
Several concepts are related to the subject of product structure modeling. All these concepts are discussed in this section. These concepts are divided into two main aspects. First the product breakdown is discussed which involves all the physical aspects of a product. Second, different views at the product structure are indicated.
Product breakdown.
Figure 1 illustrates the concepts that are important to the structure of a product. This is a meta-data model, which can be used for modeling the instances in a specific case of product structuring.
The core of the product structure is illustrated by the product components ("items") and their "relationships". Thus, this involves the linking between items related to the product.
The "assembly" can consist of "subassemblies and "parts", whereas "subassemblies" can also consist of other subassemblies or part. Thus, this is typically hierarchically ordered. These concepts are generalized into the concept of item. This classification is overlapping, because a subassembly could be a part in another assembly configuration.
Due to differentiation and variation of items several concepts must be indicated into the product breakdown structure. Three concepts are involved in this differentiation, namely "alternatives", variants and "revisions". An alternative of an item is considered as a substitute for that particular item, whereas a variant is another option of an item which the consumer can choose. When an error occurs at a part or subassembly, it needs to be revised. This revision indicates the change history of the item.
Product structure views.
Product structure views are made upon several activity domains within the company. Due to the fact not everyone in the company has to have a detailed overview of the product several components with their attributes can be extracted.
When the "Master Structure" is made out of the several items of the product assembly, multiple views can be made upon this "Master Structure". Thus this "Master Structure" contains every item in detail, which is important to the "Assembly" of the product.
The modeling process.
The process of constructing the product model consists of six main activities, which can be decomposed in several sub-activities. The next table describes these activities and the sub-activities within them provided with a description about this activity.
Process-data model.
When combining the activities with the concepts of the product structure model it will result in a process-data diagram. This diagram displays the steps which need to be taken within the process of product structure modeling together with the deliverables, at the right side, which are outcomes of these activities.
Example.
This example discusses the product structure modeling within car manufacturing. This will be discussed through the main activities which are identified within the process of product structure modeling.
Define product components.
First, all components are identified and indicated. In the area of car manufacturing, the product components are as follows. A car (ASSEMBLY) consists of several SUBASSEMBLIES such as the body and the engine of the car. The engine for example is assembled in several parts such as screws and small pipes.
Define product assortment.
In case of car manufacturing instances of these concepts can be made. For example an engine has several alternatives. For example a car manufacturer can choose between an engine made in America or Japan.
Within these different engines, variants exist. Initially an engine can be made as a 1.6 engine, but a variant, such as a 1.8 engine, can be made of this engine. Thus the 1.6 engine is used as base concept for the new 1.8 engine.
Product structuring.
An example of a correlation between items within car manufacturing can be indicated as follows. The engine is connected to the body with several screws. Thus, these two items must be linked by the concept of a relationship.
Create master structure.
After structuring the product with all the listed items and relationship between them this must be combined into one MASTER STRUCTURE which contains all of the details of the product. In case of the car, all items from engine to screw must be documented in one MASTER STRUCTURE.
Documenting.
When the MASTER STRUCTURE of the car is created one must link this structure with documents which contains the product definition of this specific car. Primarily, this consists of an extensive description of the car which is linked to the MASTER STRUCTURE of this product.
Define product structure views.
In case of the car manufacturer multiple views can be derived from the car assembly. For example a structure from a sales point of view will need more detail about the functions and characteristics of the car rather than detailed information about the body. Thus a sales manager needs information about the color of the car or the type of gear (automatic of manual).
From a purchasing view more information is needed about the mixing of the paint instead of the general color, which is only needed for the customer. Purchasing department also needs more information about the suppliers of the used components within the manufacturing of the car, so they can easily overview where which component is used and which supplier it comes from.


Scribing (cartography)

Scribing was used to produce lines for cartographic map compilations before the use of computer-based geographic information systems. Lines produced by manual scribing are sharp, clear and even.
An impression of the corrected compilation sheet is photographed onto scribe sheet material or drawn using pencil. While working over a light table, lines on the scribe sheet are traced with a metal or sapphire-tipped scribe tool to remove thin lines of translucent coating to produce a handmade negative image. This compares with drafting, where an ink image is made on tracing paper by depositing ink using a pen to produce a positive image. Scribing produces a result superior to drafting, but is more time-consuming. A separate stylus is required for each thickness of line required. For example, a contour line might require a 0.15mm stylus whereas a major road might require a 0.5mm stylus.
The scribe sheet is made of a stable plastic base material and coated with a material which is designed for easy removal using a scribing tool to produce a cleanly cut line. Various colours are used, and orange is said to produce the least eye-strain for the cartographer.
One scribe sheet is produced for each map colour. Corrections can be made by "duffing" (re-coating) the scribe sheet with special duffing liquid. The detail can then be re-scribed. Printing plates are produced from the finished scribe sheets, one for each colour of the map.
Scribe tools.
A tripod or trolley arrangement is used to hold the scribe stylus. A stylus of required thickness is set in the trolley and the surface material is removed by applying light pressure as the trolley is moved over the image. Care must be taken to ensure the base material is not gouged or distorted.
Either a round point or chisel point stylus may be used. Chisel points must be set at right angles to the direction of movement. As well as single line gravers, double and triple lines can be produced with double and triple graver stylus. Small circles can be produced using motorised versions of scribing tools, and symbols, figures etc., can be produced using plastic or metal templates.
Area symbols.
‘Peelcoat’ is used to produce a negative of an area of detail such as a lake or forest. The border of the area is cut or scribed on the peelcoat and the coat of the sheet within the area is peeled off to produce a negative image.
A stipple pattern can be used to produce an area symbol over the peeled surface. A stipple sheet with a simple repeating symbol (such as that for swamp or sand) is combined with the area by photographing the stipple onto the peelcoat.


Almen round

An Almen round is a thin round disk used to quantify the intensity of a shot peening process. Developed in 1994 by Rudolf Bosshard in Switzerland, it is a modification of the Almen strip method, which is used worldwide as a surface treatment testing method in the field of shot peening. The basic principle is the same, but due to the simple shape and minimized size, the Almen round is more suitable for automated processing and installation on dummy rigs. Also instead of the Almen block according SAE J442, here a matching device is used and if connected to electronic processing unit, the Almen value according AMS-S-13165 (predecessor MIL-S-13165 Rev.C) can be evaluated in one run.
Test specimen.
The Almen round is a circular cutting from an original Almen strip normally in material SAE 1070. It can be either of a "A", "C" or "N" type offered in various quality grades. The standard strip allows the splitting into four pieces rounds, which have a diameter of 18.7 mm, by either waterjet or laser technique. Therefore, the spaces are maintained in respect of material and thickness. The flatness test to follow is simple and imprecise pieces can be eliminated.
Specimen holder.
In the endeavor to standardize the parameters, the clamping down of the Almen rounds follows a strict geometry. The clamping head fixes the Almen round in correct manner, thus important for all related procedure. When working with the monitoring sensor, the specimen is preloaded to increase overall accuracy.
Measuring technique.
Other than the Almen strip method with the two steps: 1. Processing with holder and 2. Measuring with gage, the Almen round technique combines those activities. The specimen holder is complemented with a measuring system, e.g. a distance sensor system of various kinds to complete the monitoring sensor. While bombarded by shot, the captured Almen round gets bent towards the direction of the attack. The linear transformation gets converted into an electric signal sent to a processing unit. With calibration discs, errors will be minimalized. For the offline measuring of an individual round, the online monitoring sensor or an appropriate device will also be used.
Signal processing.
Thus the equipment is designed for direct exposure to the shot stream, the deformation of the round can be monitored online and directly converted into the Almen standard arc high definition (SAE J443) either in mm or inches. Such a process time will be in the range of less than 5 to 40 seconds. If on screen, the graph shows the basis for the calculation algorithm, also the essential point in mm or inches that is the output information equivalent to the original Almen round definition.
Advanced application.
Many so called "critical parts" require a test run with dummy parts. Therefore the Almen round is captured in a special mount that can be screwed or glued onto the dummy or even on a real part. In such a case an online monitoring is not possible, the specimens must get removed and then measured separately with the monitoring sensor. In this case, only the arc height can be traced. So this application should be in combination with a parallel running online process.
Field of application.
The Almen round can be utilized in aircraft and automotive industry, research and subcontracting peening enterprises.
Application restriction.
As the Almen strip principle has been established in 1942 and international standardization has reached a top-level. The strip work routine is a fixed procedure in practical peening technology. The Almen round principle is more accurate and offers a considerable working time reduction. But as there is no international approved standardization, this technique will be used for special applications only.


Terex THS15 Motorscraper

The Terex THS15 Motorscraper was a concept machine scraper displayed for the first time at Minexpo 2000. This machine features some unusual design concepts, including an adjustable cutting edge on the bowl to reduce friction when loading. Other notable features were the rear-mounted drivetrain (there was no engine on the front module) and a hydrostatic transmission, which featured hydraulic wheel motors. At least two prototypes were made, and these featured noticeable differences in front end styling. A digital copy of the brochure for this machine is available through ozebooks. Both the THS15 scrapers were spotted for sale in used machinery dealers by 2011 and their fate is unknown. Terex never went ahead with production and subsequently abandoned motor scraper manufacture altogether.
Transmission.
Hydrostatic transmissions have many benefits; however, they are not usually suited to machines that travel at higher speeds over longer distances. The hydrostatic drive may have been a contributing factor in abandoning the project. Changes in the way earthmoving is done, including the use of excavators and dumptrucks, has also eroded the market for scrapers. Therefore, this machine exhibited many revolutionary design concepts but was probably too costly to put into production in a declining market sector.


Cartoning machine

A cartoning machine or cartoner, is a packaging machine that forms cartons: erect, close, folded, side seamed and sealed cartons.
Packaging machines which form a carton board blank into a carton filled with a product or bag of products or number of products say into single carton, after the filling, the machine engages its tabs / slots to apply adhesive and close both the ends of carton completely sealing the carton.
Cartoning machines can be divided into two types:
A cartoning machine which picks a single piece from stack of folded carton and erects it, fills with a product or bag of products or number of products horizontally through an open end and closes by tucking the end flaps of the carton or applying glue or adhesive. The product might be pushed in the carton either through the mechanical sleeve or by pressurized air. For many applications however, the products are inserted into the carton manually. This type of Cartoning machine is widely used for packaging foodstuffs, confectionery, medicine, cosmetics, sundry goods, etc.
A cartoning machine which erects a folded carton, fills with a product or number of products vertically through an open end and closes by either tucking the end flaps of the carton or applying glue or adhesive, is called an end load cartoning machine. Cartoning machines are widely used for packaging bottled foodstuffs, confectionery, medicine, cosmetics, etc., and can vary based on the scale of business.


Demand chain

The term demand chain has been used in a business and management context as contrasting terminology alongside, or in place of, "supply chain". Madhani suggests that the demand chain "comprises all the demand processes necessary to understand, create, and stimulate customer demand". Cranfield School of Management academic Martin Christopher has suggested that "ideally the supply chain should become a demand chain", explaining that ideally all product logistics and processing should occur "in response to a known customer requirement".
Concept.
Analysing the firm's activities as a linked chain is a tried and tested way of revealing value creation opportunities. The business economist Michael Porter of Harvard Business School pioneered a value chain approach: "the value chain disaggregates the firm into its strategically relevant activities in order to understand the costs and existing potential sources of differentiation". It is the micro mechanism at the level of the firm that equalizes supply and demand at the macro market level.
Early applications in distribution, manufacturing and purchasing collectively gave rise to a subject known as supply chain management. Old supply chains have been transformed into faster, cheaper and more reliable modern supply chains as a result of investment in information technology, cost-analysis and process-analysis.
Marketing, sales and service are the other half of the value-chain, which collectively drive and sustain demand, and are known as the Demand Chain. Progress in transforming the demand side of business is behind the supply side, but there is growing interest today in transforming demand chains.
Without marketing / supply chain management (SCM) cross-functional collaboration, firms cannot be expected to respond optimally and promptly to customers' requirements.
Challenges.
At present, there appear to be four main challenges to progress in transforming demand chains and making them faster, leaner and better:
Linking supply chains to demand – "demand driven" v "forecast push".
The challenge of improving the link between demand and supply has occupied many supply chain specialists in recent years; and concepts such as "demand-driven supply chains" (Demand Driven MRP), and customer-driven supply chains have attracted attention and have become the subject of conferences and seminars.
The fundamental attribute of a "demand driven" supply chain is that material movements (or replenishment execution) are directly triggered by demand itself. Those parts of a supply chain that directly respond to orders, such as "make to order" or "assemble to order" are, therefore, "demand driven".
"Make to stock" supply chains can also be "demand driven" if individual echelon replenishment quantities are determined by the need to simply replace stock that has been consumed by the immediate downstream activity (i.e.. sold to a customer, used by a manufacturing process or moved to another distribution location). This is in contrast to "forecast push" supply chains in which the customer facing echelon replenishment quantity is calculated using a forecast of future requirements and a minimum stock balance (i.e. safety stock) while all upstream activities are coupled directly to the forecast using MRP calculations.
Due to inevitable forecast inaccuracy, "forecast push" supply chains suffer excessive and unbalanced stock levels and, despite a great deal of expediting (and associated costs) are prone to service issues. Such supply chains also experience the bullwhip effect. This occurs due to forecast error being amplified as it cascades up the supply chain and it has the unintended consequence of driving up supply chain costs and service issues, due to supply capacity being unable to meet the spiky demand pattern and the entire chain becoming unstable as a consequence. By contrast, "demand driven" supply chains are protected from the need to be buffered from variability and bullwhip by the impact of "process decoupling' and are thus able to meet planned service levels with significantly lower inventory levels and capacity costs.
"Demand driven" supply chains do use forecasts for the purposes of planning – but not replenishment execution. Forecasts are used for capacity and financial planning which are the main components of "Sales and Operations Planning". The accuracy and strategic value of S&OP is actually enhanced when supply chains are "demand driven" because they are less prone to unplanned capacity utilisation, "fire fighting" and focusing upon resolving current performance issues (i.e.. inventory and service). "Demand driven" supply chains also use forecasts for Event Management (e.g., stock build for anticipated events) when postponement strategies are not an option.
Despite academics having, for many years, written a great deal about the benefits of driving supply chains with demand (e.g.. Forrester 1958, 1961 - "Industrial Dynamics"; Burbidge 1983 - "5 Golden Rules for Avoiding Bankruptcy"; Christopher & Towill 1995), only since 2002 have 'demand driven' concepts begun to be adopted by supply chain management software providers and industry. (e.g..Lean Planning, Demand Flow Technology, Demand Driven MRP
Information systems.
Information about activities and costs is an essential resource for improving value chain performance. Such information is nowadays readily available for the supply chain, due to the widespread implementation of ERP technology (systems such as SAP), and these systems have been instrumental in the transformation of supply chain performance.
Demand chain IT development has focused on database marketing and CRM systems. Demand driving activities and associated costs are still recorded in an inconsistent manner, mostly on spreadsheets and even then the quality of the information tends to be incomplete and inaccurate.
Recently, however, marketing resource management systems have become available to plan, track and measure activities and costs as an embedded part of marketing workflows.
Implementation of MRM systems often reveals process issues that must be tackled, as Gartner have observed
Process improvement.
Processes in a demand chain are often less well-organised and disciplined than their supply side equivalents, partly due to the absence of an agreed framework for analysing the demand chain process. In 2009, Philip Kotler and Robert Shaw proposed such a framework. Describing it as the "Idea to Demand Chain" they say:
Budget segmentation, targeting and optimization.
Demand chain budgets for marketing, sales and service expenditure are substantial. Maximising their impact on shareholder value has become an important financial goal for decision makers. Developing a shared language across marketing and finance is one of the challenges to achieving this goal.
Segmentation is the initial thing to decide. From a strategic finance perspective "segments are responsibility centers for which a separate measure of revenues and costs is obtained". From a marketing perspective "segmentation is the act of dividing the market into distinct groups of buyers who might require separate products and/or marketing mixes". An important challenge for decision makers is how to align these two marketing and finance perspectives on segmentation.
Targeting of the budget is the final thing to decide. From the marketing perspective the challenge is how "to optimally allocate a given marketing budget to various target markets". From a finance perspective the problem is one of resource and budget allocation "determining the right quantity of resources to implement the value maximising strategy".
Optimization provides the technical basis for targeting decisions. Whilst mathematical optimization theory has been in existence since the 1950s, its application to marketing only began in the 1970s, and lack of data and computer power were limiting factors until the 1990s.
Since 2000, applying maths to budget segmentation, targeting and optimization has become more commonplace. In the UK the IPA Awards have documented over 1000 cases of modelling over 15 years, as part of their award process. The judging criteria are rigorous and not a matter of taste or fashion. Entrants must prove beyond all reasonable doubt that the marketing is profitable. It enables marketing to be brought centre stage in four important ways:
First, it translates the language of marketing and sales into the language of the boardroom. Finance and profits are the preferred language of the modern executive suite. Marketing and sales strategies have to be justified in terms of their ability to increase the financial value of the business. It provides a bridge between marketing and the other functions.
Second, it strengthens demand chain accountability. In Marketing Departments awareness, preference and satisfaction are often tracked as alternative objectives to shareholder value. In Sales Departments, sales promotion spending is often used to boost volumes, even when the result is unprofitable. Optimization modelling can assess these practices and support more rigorous accountability methods.
Third, it provides a counter-argument to the arbitrary cutting of demand chain budgets. Return on marketing investment models can help demonstrate where financial impact of demand driving activities is positive and negative, and so help support fact-based budgeting.
Finally, demand-chain profitability modelling encourages a strategic debate. Because long-term cashflow and NPV calculations can show the shareholder value effect of marketing, sales and service, strong arguments can be made for putting the demand chain on an equal footing to the supply chain.


Uniform-machines scheduling

Uniform machine scheduling (also called uniformly-related machine scheduling or related machine scheduling) is an optimization problem in computer science and operations research. It is a variant of optimal job scheduling. We are given "n" jobs "J"1, "J"2, ..., "Jn" of varying processing times, which need to be scheduled on "m" different machines. The goal is to minimize the makespan - the total time required to execute the schedule. The time that machine "i" needs in order to process job j is denoted by "pi,j". In the general case, the times "pi,j" are unrelated, and any matrix of positive processing times is possible. In the specific variant called "uniform machine scheduling", some machines are "uniformly" faster than others. This means that, for each machine "i", there is a speed factor "si", and the run-time of job "j" on machine "i" is "pi,j" = "pj" / "si".
In the standard three-field notation for optimal job scheduling problems, the uniform-machine variant is denoted by Q in the first field. For example, the problem denoted by " Q||formula_1" is a uniform machine scheduling problem with no constraints, where the goal is to minimize the maximum completion time. A special case of uniform machine scheduling is identical machine scheduling, in which all machines have the same speed. This variant is denoted by P in the first field.
In some variants of the problem, instead of minimizing the "maximum" completion time, it is desired to minimize the "average" completion time (averaged over all "n" jobs); it is denoted by Q||formula_2. More generally, when some jobs are more important than others, it may be desired to minimize a "weighted average" of the completion time, where each job has a different weight. This is denoted by Q||formula_3.
Algorithms.
Minimizing the average completion time.
Minimizing the "average" completion time can be done in polynomial time:
Minimizing the weighted-average completion time.
Minimizing the "weighted average" completion time is NP-hard even on "identical" machines, by reduction from the knapsack problem. It is NP-hard even if the number of machines is fixed and at least 2, by reduction from the partition problem.
Sahni presents an exponential-time algorithm and a polynomial-time approximation algorithm for "identical" machines.
Horowitz and Sahni presented:
Minimizing the maximum completion time (makespan).
Minimizing the "maximum" completion time is NP-hard even for "identical" machines, by reduction from the partition problem.
A constant-factor approximation is attained by the Longest-processing-time-first algorithm (LPT).
Horowitz and Sahni presented:
Hochbaum and Shmoys presented several approximation algorithms for any number of "identical" machines. Later, they developed a PTAS for "uniform" machines.
Epstein and Sgall generalized the PTAS for uniform machines to handle more general objective functions. Let "Ci" (for "i" between 1 and "m") be the makespan of machine "i" in a given schedule. Instead of minimizing the objective function max("Ci"), one can minimize the objective function max("f"("Ci")), where "f" is any fixed function. Similarly, one can minimize the objective function sum("f"("Ci")).
Monotonicity and Truthfulness.
In some settings, the machine speed is the machine's private information, and we want to incentivize machines to reveal their true speed, that is, we want a truthful mechanism. An important consideration for attaining truthfulness is "monotonicity". It means that, if a machine reports a higher speed, and all other inputs remain the same, then the total processing time allocated to the machine weakly increases. For this problem:
Extensions.
Dependent jobs: In some cases, the jobs may be dependent. For example, take the case of reading user credentials from console, then use it to authenticate, then if authentication is successful display some data on the console. Clearly one task is dependent upon another. This is a clear case of where some kind of ordering exists between the tasks. In fact it is clear that it can be modelled with partial ordering. Then, by definition, the set of tasks constitute a lattice structure. This adds further complication to the multiprocessor scheduling problem.
Static versus Dynamic: Machine scheduling algorithms are static or dynamic. A scheduling algorithm is static if the scheduling decisions as to what computational tasks will be allocated to what processors are made before running the program. An algorithm is dynamic if it is taken at run time. For static scheduling algorithms, a typical approach is to rank the tasks according to their precedence relationships and use a list scheduling technique to schedule them onto the processors.
Multi-stage jobs: In various settings, each job might have several operations that must be executed in parallel. Some such settings are handled by open shop scheduling, flow shop scheduling and job shop scheduling.


List of former automotive manufacturing plants. The table below lists former automotive industry manufacturing factories and facilities.


Horizontal pitch

Horizontal pitch (HP) is a unit of length defined by the Eurocard printed circuit board standard used to measure the horizontal width of rack mounted electronic equipment, similar to the rack unit (U) used to measure vertical heights of rack mounted equipment. One HP is wide. A standard 19-inch rack is 95 HP wide of which 84 HP is typically usable. A standard 23-inch rack is 115 HP wide of which 104HP is typically usable.