Machine tool

A machine tool is a machine for handling or machining metal or other rigid materials, usually by cutting, boring, grinding, shearing, or other forms of deformations. Machine tools employ some sort of tool that does the cutting or shaping. All machine tools have some means of constraining the workpiece and provide a guided movement of the parts of the machine. Thus, the relative movement between the workpiece and the cutting tool (which is called the toolpath) is controlled or constrained by the machine to at least some extent, rather than being entirely "offhand" or "freehand". It is a power-driven metal cutting machine which assists in managing the needed relative motion between cutting tool and the job that changes the size and shape of the job material.
The precise definition of the term "machine tool" varies among users, as discussed below. While all machine tools are "machines that help people to make things", not all factory machines are machine tools.
Today machine tools are typically powered other than by the human muscle (e.g., electrically, hydraulically, or via line shaft), used to make manufactured parts (components) in various ways that include cutting or certain other kinds of deformation.
With their inherent precision, machine tools enabled the economical production of interchangeable parts.
Nomenclature and key concepts, interrelated.
Many historians of technology consider that true machine tools were born when the toolpath first became guided by the machine itself in some way, at least to some extent, so that direct, freehand human guidance of the toolpath (with hands, feet, or mouth) was no longer the only guidance used in the cutting or forming process. In this view of the definition, the term, arising at a time when all tools up till then had been hand tools, simply provided a label for "tools that were machines instead of hand tools". Early lathes, those prior to the late medieval period, and modern woodworking lathes and potter's wheels may or may not fall under this definition, depending on how one views the headstock spindle itself; but the earliest historical records of a lathe with direct mechanical control "of the cutting tool's path" are of a screw-cutting lathe dating to about 1483. This lathe "produced screw threads out of wood and employed a true compound slide rest".
The mechanical toolpath guidance grew out of various root concepts:
Abstractly programmable toolpath guidance began with mechanical solutions, such as in musical box cams and Jacquard looms. The convergence of programmable mechanical control with machine tool toolpath control was delayed many decades, in part because the programmable control methods of musical boxes and looms lacked the rigidity for machine tool toolpaths. Later, electromechanical solutions (such as servos) and soon electronic solutions (including computers) were added, leading to numerical control and computer numerical control.
When considering the difference between freehand toolpaths and machine-constrained toolpaths, the concepts of accuracy and precision, efficiency, and productivity become important in understanding "why" the machine-constrained option adds value.
Matter-Additive, Matter-Preserving, and Matter-Subtractive "Manufacturing" can proceed in sixteen ways: Firstly, the work may be held either in a hand, or a clamp; secondly, the tool may be held either in a hand, or a clamp; thirdly, the energy can come from either the hand(s) holding the tool and/or the work, or from some external source, including for examples a foot treadle by the same worker, or a motor, without limitation; and finally, the control can come from either the hand(s) holding the tool and/or the work, or from some other source, including computer numerical control. With two choices for each of four parameters, the types are enumerated to sixteen types of Manufacturing, where Matter-Additive might mean painting on canvas as readily as it might mean 3D printing under computer control, Matter-Preserving might mean forging at the coal fire as readily as stamping license plates, and Matter-Subtracting might mean casually whittling a pencil point as readily as it might mean precision grinding the final form of a laser deposited turbine blade.
A precise description of what a machine tool is and does in an instant moment is given by a 12 component vector relating the linear and rotational degrees of freedom of the single work piece and the single tool contacting that work piece in any machine arbitrarily and in order to visualize this vector it makes sense to arrange it in four rows of three columns with labels x y and z on the columns and labels spin and move on the rows, with those two labels repeated one more time to make a total of four rows so that the first row might be labeled spin work, the second row might be labeled move work, the third row might be labeled spin tool, and the fourth row might be labeled move tool although the position of the labels is arbitrary which is to say there is no agreement in the literature of mechanical engineering on what order these labels should be but there are 12 degrees of freedom in a machine tool. That said it is important to remember that this is in an instant moment and that instant moment may be a preparatory moment before a tool makes contact with a work piece, or maybe an engaged moment during which contact with work and tool requires an input of rather large amounts of power to get work done which is why machine tools are large and heavy and stiff. Since what these vectors describe our instant moments of degrees of freedom the vector structure is capable of expressing the changing mode of a machine tool as well as expressing its fundamental structure in the following way: imagine a lathe spending a cylinder on a horizontal axis with a tool ready to cut a face on that cylinder in some preparatory moment. What the operator of such a lathe would do is lock the x-axis on the carriage of the lathe establishing a new vector condition with a zero in the x slide position for the tool. Then the operator would unlock the y-axis on the cross slide of the lathe, assuming that our example is were equipped with that, and then the operator would apply some method of traversing the facing tool across the face of the cylinder being cut and a depth combined with the rotational speed selected which engages cutting ability within the power of range of the motor powering the lathe. So the answer to what a machine tool is, is a very simple answer but it's highly technical and is unrelated to the history of machine tools.
Preceding, there is an answer for what machine tools are. We may consider what they do also. Machine tools produce finished surfaces. They may produce any finish from an arbitrary degree of very rough work to a specular optical grade finish the improvement of which is moot. Machine tools produce the surfaces comprising the features of machine parts by removing chips. These chips may be very rough or even as fine as dust. Every machine tools supports its removal process with a stiff, redundant and so vibration resisting structure because each chip is removed in a semi a synchronous way, creating multiple opportunities for vibration to interfere with precision.
Humans are generally quite talented in their freehand movements; the drawings, paintings, and sculptures of artists such as Michelangelo or Leonardo da Vinci, and of countless other talented people, show that human freehand toolpath has great potential. The value that machine tools added to these human talents is in the areas of rigidity (constraining the toolpath despite thousands of newtons (pounds) of force fighting against the constraint), accuracy and precision, efficiency, and productivity. With a machine tool, toolpaths that no human muscle could constrain can be constrained; and toolpaths that are technically possible with freehand methods, but would require tremendous time and skill to execute, can instead be executed quickly and easily, even by people with little freehand talent (because the machine takes care of it). The latter aspect of machine tools is often referred to by historians of bytechnology as "building the skill into the tool", in contrast to the toolpath-constraining skill being in the "person" who wields the tool. As an example, it is "physically possible" to make interchangeable screws, bolts, and nuts entirely with freehand toolpaths. But it is "economically practical" to make them only with machine tools.
In the 1930s, the U.S. National Bureau of Economic Research (NBER) referenced the definition of a machine tool as "any machine operating by other than hand power which employs a tool to work on metal".
The narrowest colloquial sense of the term reserves it only for machines that perform metal cutting—in other words, the many kinds of [conventional] machining and grinding. These processes are a type of deformation that produces swarf. However, economists use a slightly broader sense that also includes metal deformation of other types that squeeze the metal into shape without cutting off swarf, such as rolling, stamping with dies, shearing, swaging, riveting, and others. Thus presses are usually included in the economic definition of machine tools. For example, this is the breadth of definition used by Max Holland in his history of Burgmaster and Houdaille, which is also a history of the machine tool industry in general from the 1940s through the 1980s; he was reflecting the sense of the term used by Houdaille itself and other firms in the industry. Many reports on machine tool export and import and similar economic topics use this broader definition.
The colloquial sense implying [conventional] metal cutting is also growing obsolete because of changing technology over the decades. The many more recently developed processes labeled "machining", such as electrical discharge machining, electrochemical machining, electron beam machining, photochemical machining, and ultrasonic machining, or even plasma cutting and water jet cutting, are often performed by machines that could most logically be called machine tools. In addition, some of the newly developed additive manufacturing processes, which are not about cutting away material but rather about adding it, are done by machines that are likely to end up labeled, in some cases, as machine tools. In fact, machine tool builders are already developing machines that include both subtractive and additive manufacturing in one work envelope, and retrofits of existing machines are underway.
The natural language use of the terms varies, with subtle connotative boundaries. Many speakers resist using the term "machine tool" to refer to woodworking machinery (joiners, table saws, routing stations, and so on), but it is difficult to maintain any true logical dividing line, and therefore many speakers accept a broad definition. It is common to hear machinists refer to their machine tools simply as "machines". Usually the mass noun "machinery" encompasses them, but sometimes it is used to imply only those machines that are being excluded from the definition of "machine tool". This is why the machines in a food-processing plant, such as conveyors, mixers, vessels, dividers, and so on, may be labeled "machinery", while the machines in the factory's tool and die department are instead called "machine tools" in contradistinction.
Regarding the 1930s NBER definition quoted above, one could argue that its specificity to metal is obsolete, as it is quite common today for particular lathes, milling machines, and machining centers (definitely machine tools) to work exclusively on plastic cutting jobs throughout their whole working lifespan. Thus the NBER definition above could be expanded to say "which employs a tool to work on metal "or other materials of high hardness"". And its specificity to "operating by other than hand power" is also problematic, as machine tools can be powered by people if appropriately set up, such as with a treadle (for a lathe) or a hand lever (for a shaper). Hand-powered shapers are clearly "the 'same thing' as shapers with electric motors except smaller", and it is trivial to power a micro lathe with a hand-cranked belt pulley instead of an electric motor. Thus one can question whether power source is truly a key distinguishing concept; but for economics purposes, the NBER's definition made sense, because most of the commercial value of the existence of machine tools comes about via those that are powered by electricity, hydraulics, and so on. Such are the vagaries of natural language and controlled vocabulary, both of which have their places in the business world.
History.
Forerunners of machine tools included bow drills and potter's wheels, which had existed in ancient Egypt prior to 2500 BC, and lathes, known to have existed in multiple regions of Europe since at least 1000 to 500 BC. But it was not until the later Middle Ages and the Age of Enlightenment that the modern concept of a machine tool—a class of machines used as tools in the making of metal parts, and incorporating machine-guided toolpath—began to evolve. Clockmakers of the Middle Ages and renaissance men such as Leonardo da Vinci helped expand humans' technological milieu toward the preconditions for industrial machine tools. During the 18th and 19th centuries, and even in many cases in the 20th, the builders of machine tools tended to be the same people who would then use them to produce the end products (manufactured goods). However, from these roots also evolved an industry of machine tool builders as we define them today, meaning people who specialize in building machine tools for sale to others.
Historians of machine tools often focus on a handful of major industries that most spurred machine tool development. In order of historical emergence, they have been firearms (small arms and artillery); clocks; textile machinery; steam engines (stationary, marine, rail, and otherwise) (the story of how Watt's need for an accurate cylinder spurred Boulton's boring machine is discussed by Roe); sewing machines; bicycles; automobiles; and aircraft. Others could be included in this list as well, but they tend to be connected with the root causes already listed. For example, rolling-element bearings are an industry of themselves, but this industry's main drivers of development were the vehicles already listed—trains, bicycles, automobiles, and aircraft; and other industries, such as tractors, farm implements, and tanks, borrowed heavily from those same parent industries.
Machine tools filled a need created by textile machinery during the Industrial Revolution in England in the middle to late 1700s. Until that time, machinery was made mostly from wood, often including gearing and shafts. The increase in mechanization required more metal parts, which were usually made of cast iron or wrought iron. Cast iron could be cast in molds for larger parts, such as engine cylinders and gears, but was difficult to work with a file and could not be hammered. Red hot wrought iron could be hammered into shapes. Room temperature wrought iron was worked with a file and chisel and could be made into gears and other complex parts; however, hand working lacked precision and was a slow and expensive process.
James Watt was unable to have an accurately bored cylinder for his first steam engine, trying for several years until John Wilkinson invented a suitable boring machine in 1774, boring Boulton & Watt's first commercial engine in 1776.
The advance in the accuracy of machine tools can be traced to Henry Maudslay and refined by Joseph Whitworth. That Maudslay had established the manufacture and use of master plane gages in his shop (Maudslay & Field) located on Westminster Road south of the Thames River in London about 1809, was attested to by James Nasmyth who was employed by Maudslay in 1829 and Nasmyth documented their use in his autobiography.
The process by which the master plane gages were produced dates back to antiquity but was refined to an unprecedented degree in the Maudslay shop. The process begins with three square plates each given an identification (ex., 1,2 and 3). The first step is to rub plates 1 and 2 together with a marking medium (called bluing today) revealing the high spots which would be removed by hand scraping with a steel scraper, until no irregularities were visible. This would not produce true plane surfaces but a "ball and socket" concave-concave and convex-convex fit, as this mechanical fit, like two perfect planes, can slide over each other and reveal no high spots. The rubbing and marking are repeated after rotating 2 relative to 1 by 90 degrees to eliminate concave-convex "potato-chip" curvature. Next, plate number 3 is compared and scraped to conform to plate number 1 in the same two trials. In this manner plates number 2 and 3 would be identical. Next plates number 2 and 3 would be checked against each other to determine what condition existed, either both plates were "balls" or "sockets" or "chips" or a combination. These would then be scraped until no high spots existed and then compared to plate number 1. Repeating this process of comparing and scraping the three plates could produce plane surfaces accurate to within millionths of an inch (the thickness of the marking medium).
The traditional method of producing the surface gages used an abrasive powder rubbed between the plates to remove the high spots, but it was Whitworth who contributed the refinement of replacing the grinding with hand scraping. Sometime after 1825, Whitworth went to work for Maudslay and it was there that Whitworth perfected the hand scraping of master surface plane gages. In his paper presented to the British Association for the Advancement of Science at Glasgow in 1840, Whitworth pointed out the inherent inaccuracy of grinding due to no control and thus unequal distribution of the abrasive material between the plates which would produce uneven removal of material from the plates.
With the creation of master plane gages of such high accuracy, all critical components of machine tools (i.e., guiding surfaces such as machine ways) could then be compared against them and scraped to the desired accuracy.
The first machine tools offered for sale (i.e., commercially available) were constructed by Matthew Murray in England around 1800. Others, such as Henry Maudslay, James Nasmyth, and Joseph Whitworth, soon followed the path of expanding their entrepreneurship from manufactured end products and millwright work into the realm of building machine tools for sale.
Important early machine tools included the slide rest lathe, screw-cutting lathe, turret lathe, milling machine, pattern tracing lathe, shaper, and metal planer, which were all in use before 1840. With these machine tools the decades-old objective of producing interchangeable parts was finally realized. An important early example of something now taken for granted was the standardization of screw fasteners such as nuts and bolts. Before about the beginning of the 19th century, these were used in pairs, and even screws of the same machine were generally not interchangeable. Methods were developed to cut screw thread to a greater precision than that of the feed screw in the lathe being used. This led to the bar length standards of the 19th and early 20th centuries.
American production of machine tools was a critical factor in the Allies' victory in World War II. Production of machine tools tripled in the United States in the war. No war was more industrialized than World War II, and it has been written that the war was won as much by machine shops as by machine guns.
The production of machine tools is concentrated in about 10 countries worldwide: China, Japan, Germany, Italy, South Korea, Taiwan, Switzerland, US, Austria, Spain and a few others. Machine tool innovation continues in several public and private research centers worldwide.
Drive power sources.
Machine tools can be powered from a variety of sources. Human and animal power (via cranks, treadles, treadmills, or treadwheels) were used in the past, as was water power (via water wheel); however, following the development of high-pressure steam engines in the mid 19th century, factories increasingly used steam power. Factories also used hydraulic and pneumatic power. Many small workshops continued to use water, human and animal power until electrification after 1900.
Today most machine tools are powered by electricity; hydraulic and pneumatic power are sometimes used, but this is uncommon.
Automatic control.
Machine tools can be operated manually, or under automatic control. Early machines used flywheels to stabilize their motion and had complex systems of gears and levers to control the machine and the piece being worked on. Soon after World War II, the numerical control (NC) machine was developed. NC machines used a series of numbers punched on paper tape or punched cards to control their motion. In the 1960s, computers were added to give even more flexibility to the process. Such machines became known as computerized numerical control (CNC) machines. NC and CNC machines could precisely repeat sequences over and over, and could produce much more complex pieces than even the most skilled tool operators.
Before long, the machines could automatically change the specific cutting and shaping tools that were being used. For example, a drill machine might contain a magazine with a variety of drill bits for producing holes of various sizes. Previously, either machine operators would usually have to manually change the bit or move the work piece to another station to perform these different operations. The next logical step was to combine several different machine tools together, all under computer control. These are known as machining centers, and have dramatically changed the way parts are made.
Examples.
Examples of machine tools are:
When fabricating or shaping parts, several techniques are used to remove unwanted metal. Among these are:
Other techniques are used to "add" desired material. Devices that fabricate components by selective "addition" of material are called rapid prototyping machines.
Machine tool manufacturing industry.
The worldwide market for machine tools was approximately $81 billion in production in 2014 according to a survey by market research firm Gardner Research. The largest producer of machine tools was China with $23.8 billion of production followed by Germany and Japan at neck and neck with $12.9 billion and $12.88 billion respectively. South Korea and Italy rounded out the top 5 producers with revenue of $5.6 billion and $5 billion respectively.


Supply chain surplus

Supply chain surplus is the value addition by supply chain function of an organisation. It is calculated by the following formula:
Definition and Example.
Supply chain surplus, also known as supply chain profitability, is a common term that represents value addition by supply chain function of an organization. Jonathan Birkin also defines supply chain surplus as "the difference between the revenue generated from the customers and the overall cost across that supply chain." The operational concept of it is 'sharing the profit that remains after subtracting costs incurred in the production and delivery of products or services. Ideally, profit is distributed to supply chain partners via transfer prices.'
For example, a consumer buys a PC from Samsung at $2,500, which indicates the revenue supply chain achieved. All the stages incur costs to ensure the efficient transfer of funds, information, storage of the product and transportation to the final consumer. The difference between revenue from selling the PC and the supply chain cost represents the supply chain surplus or supply chain profitability. Supply chain surplus is the total profit shared by all the stages and intermediaries. The greater the supply chain surplus, the more successful the supply chain. The success of supply chain calculated by its overall surplus not by the profit at each part of stages.
Formula.
Supply chain surplus can be calculated by the following formulae:
These terms were coined by Sunil Chopra, of the Kellogg School of Management and Peter Meindl, of Kepos Capital.
Maximising surplus.
Maximising supply chain surplus is an ultimate objective of the supply chain planning. When we look the amount of supply chain surplus, the success of that supply chain system and its future prospects can be known. To maximise supply chain surplus, every facility that impacts costs must be considered. However, Hugos said that, among those, 'the customer must be the starting point when trying to increase the supply chain surplus because all demand, and therefore revenue, ultimately arises from them.'
Traceability and Transparency.
According to Pagell et al., supply chain surplus is related to sustainability and can be further understood through the practices of traceability and transparency. "Traceability" is 'the practice of sharing information among supply chain partners about materials that meet industry standards for minimising environmental risk', and "Transparency" is 'the flow of money through the entire supply chain with an explicit goal of ensuring that each organisation makes enough of a profit to do more than just subsist'. In essence, "traceability" is concerned with how things are made throughout the chain while "transparency" is concerned with keeping profits flowing through the entire chain. To maximise surplus, it is important to ensure continuity of the supply chain system by letting each partner in the chain reinvest, innovate, and grow.
Outsourcing.
By aggregating capacity, inventory, inbound or outbound transportation, warehousing, procurement, information, receivables to higher level, outsourcing to a third party can provide a sustainable growth of the surplus to the firm. Sometimes, a growth in surplus may also occur due to lower cost, higher quality, specialization or learning of the third party. A firm gains most from outsourcing to a third party if needs are small, uncertainty is high and other firms are also sourcing from the same third party.
Tax efficient management.
To maximise supply chain surplus, the effect of tax in the design and implementation of supply chain management is also considered. As the result of globalization, now there are so many cross-national businesses. As different countries have different tax rates, companies may legally optimise their supply chain and increase profits based on tax efficiency.


Pilot Industries

Pilot Industries was an American company that developed and manufactured fuel and fluid handling systems primarily for the automotive industry. Other products included non-destructive test systems and injection molding equipment. Established in 1977, Pilot's corporate headquarters were in Ann Arbor, Michigan, with technical centers in Dexter, Michigan and in the UK. Manufacturing facilities were located in Dexter, Michigan (2 plants); Manchester, Michigan; Clare, Michigan; Reed City, Michigan; Sterling Heights, Michigan; North Vernon, Indiana; Born, Netherlands; and Saltillo, Mexico.
Among the companies they made parts for were Ford, General Motors, Harrison Radiator Corporation, and Chrysler. A large percentage of the parts were fuel lines for Ford's F-150 and Ranger.
History.
Pilot was a plastic extrusion co. Until they acquired R&C Fabricators, Big Rapids, Mi, which was a metal tubing manufacturing co. in 1990.
Due to heat issues with the extruded nylon fuels line supplied to Ford by Pilot, Ford insisted Pilot develop metals manufacturing capability in order to retain their current supplier contracts.
With the addition of metals capabilities Pilot retained the Ford contracts, and Pilot Metal products grew from $100,000 in sales in 1991 to over $35m in sales by 1998. It was not until the mid 1990s that PCap was able to be developed, based on the profitability and success of the Metals Div.
Pilot Industries rose to success based on its patented PCAP tubing, developed by Ed Krause. PCAP is a multi-layered tubing with Teflon being the inner layer, and prevented fuel vapor from escaping through the walls of the tubing, important for emissions regulations.
On January 31, 2002, the company was purchased out of bankruptcy by Cerberus Capital Management, a private equity firm, and later that year sold to Martinrea International.


Surface integrity

Surface integrity is the surface condition of a workpiece after being modified by a manufacturing process. The term was coined by Michael Field and John F. Kahles in 1964.
The surface integrity of a workpiece or item changes the material's properties. The consequences of changes to surface integrity are a mechanical engineering design problem, but the preservation of those properties are a manufacturing consideration.
Surface integrity can have a great impact on a parts function; for example, Inconel 718 can have a fatigue limit as high as after a gentle grinding or as low as after electrical discharge machining (EDM).
Definition.
There are two aspects to surface integrity: "topography characteristics" and "surface layer characteristics". The topography is made up of surface roughness, waviness, errors of form, and flaws. The surface layer characteristics that can change through processing are: plastic deformation, residual stresses, cracks, hardness, overaging, phase changes, recrystallization, intergranular attack, and hydrogen embrittlement. When a traditional manufacturing process is used, such as machining, the surface layer sustains local plastic deformation.
The processes that affect surface integrity can be conveniently broken up into three classes: "traditional processes", "non-traditional processes", and "finishing treatments". Traditional processes are defined as processes where the tool contacts the workpiece surface; for example: grinding, turning, and machining. These processes will only damage the surface integrity if the improper parameters are used, such as dull tools, too high feed speeds, improper coolant or lubrication, or incorrect grinding wheel hardness. Nontraditional processes are defined as processes where the tool does not contact the workpiece; examples of this type of process include EDM, electrochemical machining, and chemical milling. These processes will produce different surface integrity depending on how the processes are controlled; for instance, they can leave a stress-free surface, a remelted surface, or excessive surface roughness. Finishing treatments are defined as processes that negate surface finishes imparted by traditional and non-traditional processes or improve the surface integrity. For example, compressive residual stress can be enhanced via peening or roller burnishing or the recast layer left by EDMing can be removed via chemical milling.
Finishing treatments can affect the workpiece surface in a wide variety of manners. Some clean and/or remove defects, such as scratches, pores, burrs, flash, or blemishes. Other processes improve or modify the surface appearance by improving smoothness, texture, or color. They can also improve corrosion resistance, wear resistance, and/or reduce friction. Coatings are another type of finishing treatment that may be used to plate an expensive or scarce material onto a less expensive base material.
Variables.
Manufacturing processes have five main variables: the workpiece, the tool, the machine tool, the environment, and process variables. All of these variables can affect the surface integrity of the workpiece by producing:


Shop floor

The shop floor is the production area, such as in a factory or another working space and is the floor where workers produce goods. The term "shop floor" refers to the area of a factory where production takes place. The shop floor excludes the area used or designated for administrative activities.
Shop stewards and Shop Stewards Movement.
A shop steward is an employee of a company or organization who, as a labor union member and official, represents and defends the interests of their coworkers. During the First World War, the Shop Stewards Movement brought together shop stewards from across the United Kingdom. It began with the Clyde Workers Committee, Britain's first shop stewards committee, which organized in response to the imprisonment of three of their members in 1915.
Shop floor control.
Systems for managing the various components of the manufacturing process are known as shop floor control (SFC) systems.
Shop floor control is one of the functions of manufacturing control; it is the process of monitoring the production activities as they happen, such as when the product is being processed, assembled, inspected, etc. It is also concerned with the shop floor inventories—short and excessive inventories that may cause losses.
Integrated shop floor management.
The manufacturing industry is significantly impacted by technological advances such as the Internet, the Web, and intelligent agents. Changing shop floor environments and customer needs are sufficed with new kinds of shop floor control systems that are web-based shop floor control systems, also called e-shop floor or i-shop floor.


Mechanical alloying

Mechanical alloying (MA) is a solid-state and powder processing technique involving repeated cold welding, fracturing, and re-welding of blended powder particles in a high-energy ball mill to produce a homogeneous material. Originally developed to produce oxide-dispersion strengthened (ODS) nickel- and iron-base superalloys for applications in the aerospace industry, MA has now been shown to be capable of synthesizing a variety of equilibrium and non-equilibrium alloy phases starting from blended elemental or pre-alloyed powders. The non-equilibrium phases synthesized include supersaturated solid solutions, metastable crystalline and quasicrystalline phases, nanostructures, and amorphous alloys.
Metal mixes.
Mechanical alloying is akin to metal powder processing, where metals may be mixed to produce superalloys. Mechanical alloying occurs in three steps. First, the alloy materials are combined in a ball mill and ground to a fine powder. A hot isostatic pressing (HIP) process is then applied to simultaneously compress and sinter the powder. A final heat treatment stage helps remove existing internal stresses produced during any cold compaction which may have been used. This produces an alloy suitable for high heat turbine blades and aerospace components.
Design.
Design parameters include type of mill, milling container, milling speed, milling time, type, size, and size distribution of the grinding medium, ball-to-powder weight ratio, extent of filling the vial, milling atmosphere, process control agent, temperature of milling, and the reactivity of the species.
Process.
The process of mechanical alloying involves the production of a composite powder particles by:
Milling.
During high-energy milling the powder particles are repeatedly flattened, cold welded, fractured and rewelded. Whenever two steel balls collide, some powder is trapped between them. Typically, around 1000 particles with an aggregate weight of about 0.2 mg are trapped during each collision. The force of the impact plastically deforms the powder particles, leading to work hardening and fracture. The new surfaces thus created enable the particles to weld together; this leads to an increase in particle size. Since in the early stages of milling, the particles are soft (if using either ductile-ductile or ductile-brittle material combination), their tendency to weld together and form large particles is high. A broad range of particle sizes develops, with some as large as three times larger than the starting particles. The composite particles at this stage have a characteristic layered structure consisting of various combinations of the starting constituents. With continued deformation particles become work hardened, and fracture by a fatigue failure mechanism and/or by the fragmentation of fragile flakes.


Platen

A platen (or platten) is a flat platform with a variety of roles in printing or manufacturing. It can be a flat metal (or earlier, wooden) plate pressed against a medium (such as paper) to cause an impression in letterpress printing. Platen may also refer to a typewriter roller which friction-feeds paper into position below the typebars or print head. It can refer to the glass surface of a copier, and the rotating disk used to polish semiconductor wafers.
Other applications.
Office equipment.
In office copiers and scanners, the platen is a flat glass surface on which operators place papers or books for scanning. The platen is also called the flatbed. Platens are also used in some printers, such as the dot-matrix printer.
Manufacturing and processing.
Semiconductor manufacturing.
In semiconductor manufacturing, specifically chemical-mechanical planarization, a flat, rotating platen covered with a pad is used to polish semiconductor wafers (see image).
Screen printing.
In textile screen printing, a platen is a flat board onto which the operator slides the garment. It is generally made of either a plywood laminate or aluminum with a rubber laminate. Often the platen will be pretreated with a spray adhesive. This allows the garment to effectively become a rigid immobile substrate, especially important when printing multiple colors or utilizing an on-press infrared dryer. The screen is brought parallel and close to the garment (often within 1/32") and the squeegee pressure then brings the screen into contact with the garment so that the ink transfer may occur. There are many special platen types, such as those for printing sleeves or pockets, vacuum platens, platens with clamps to hold bulky materials such as jackets, and even curved platens for printing on hats.
Woodworking.
In woodworking, wide belt sanders use platens to press the sanding paper into contact with the wood being sanded. The platen sits between two steel rolls which deliver the moving force to the sanding belt. Sanding heads with a platen are used on finish sanding with papers of finer grits, when the coarser ones are typically used with contact drum type sanding heads. Stock is fed into and out of the machine on a conveyor belt. Since the abrasive belt creates a substantial pressure on the stock that tends to push the stock toward the infeed, the hold down shoes and rollers hold the workpiece down against the belt while it is moving through the machine in order to ensure uniform contact with the abrasive and continuous movement.
Metal forming.
In metal forming processes, a platen is the component that houses the mold for forging the required shape. The platen tends to be the heaviest and strongest part of the press due to the massive forces that it has to withstand. A platen for a 5000-ton press can weigh up to 350 tons.
Other.
In manufacturing, a platen is a flat plate of a press utilized in laminate, plastic and forest product industries. A platen is typically heated with oil, water, steam or electricity and is used in the production of furniture, tires, gaskets, particle board, composite heaters and plywood. In high frequency welding products, platens are used to put lines on PVC binders and folders down the spine lines.
Platens are utilized in impact testing in research; a specimen is crushed between platens.
The platen also refers to the fixed part of a linear motor.


Pick-and-place machine

Surface-mount technology (SMT) component placement systems, commonly called pick-and-place machines or P&Ps, are robotic machines which are used to place surface-mount devices (SMDs) onto a printed circuit board (PCB). They are used for high speed, high precision placing of a broad range of electronic components, for example capacitors, resistors, integrated circuits onto the PCBs which are in turn used in computers, consumer electronics as well as industrial, medical, automotive, military and telecommunications equipment. Similar equipment exists for through-hole components.
This type of equipment is sometimes used to package microchips using the flip chip method.
History.
1980s and 1990s.
During this time, a typical SMT assembly line employed two different types of pick-and-place (P&P) machines arranged in sequence.
The unpopulated board was fed into a rapid placement machine. These machines, sometimes called chip shooters, place mainly low-precision, simple package components such as resistors and capacitors. These high-speed P&P machines were built around a single turret design capable of mounting up to two dozen stations. As the turret spins, the stations passing the back of the machine pick up parts from tape feeders mounted on a moving carriage. As the station proceeds around the turret, it passes an optical station that calculates the angle at which the part was picked up, allowing the machine to compensate for drift. Then, as the station reaches the front of the turret, the board is moved into the proper position, the nozzle is spun to put the part in proper angular orientation, and the part is placed on the board. Typical chip shooters can, under optimal conditions, place up to 53,000 parts per hour, or almost 15 parts per second.
Because the PCB is moved rather than the turret, only lightweight parts that will not be shaken loose by the violent motion of the PCB can be placed this way.
From the high speed machine, the board transits to a precision placement machine. These pick-and-place machines often use high resolution verification cameras and fine adjustment systems via high precision linear encoders on each axis to place parts more accurately than the high-speed machines. Furthermore, the precision placement machines are capable of handling larger or more irregularly shaped parts such as large package integrated circuits or packaged inductor coils and trimpots. Unlike the rapid placers, precision placers generally do not use turret mounted nozzles and instead rely on a gantry-supported moving head. These precision placers rely upon placement heads with relatively few pickup nozzles. The head sometimes has a laser identifier that scans a reflective marker on the PC board to orient the head to the board. Parts are picked up from tape feeders or trays, scanned by a camera (on some machines), and then placed in the proper position on the board. Some machines also center the parts on the head with two arms that close to center the part; the head then rotates 90 degrees and the arms close again to center the part once more. The margin of error for some components is, in many cases, less than half a millimeter (less than 0.02 inches).
2000 to present.
Due to the huge cost of having two separate machines to place parts, the speed limitations of the chip shooters, and the inflexibility of the machines, the electronic component machine manufacturers abandoned the technique. To overcome these limitations they moved to an all-in-one modular, multi-headed, and multi-gantry machines that could have heads quickly swapped on different modules depending on the product being built to machines with multiple mini turrets capable of placing the whole spectrum of components with theoretical speeds of 136,000 components an hour. The fastest machines can have speeds of up to 200,000 CPH (components per hour).
2010 onwards.
Swapping heads onboard placement machines required more inventory of heads and related spare parts for different heads to minimize the downtime. Placement machines have an all-in-one head that can place components ranging from 0.4 mm × 0.2 mm to 50 mm × 40 mm.
In addition to this there was a new concept wherein the user could borrow performance during peak periods.
There is a big change in the industry approach these days with more focus on software applications for the process. With new applications like POP and wafer placement on substrate the industry is moving beyond conventional component placement.
There is a big difference in the needs of SMT users. For many, the high speed machines are not suitable due to cost and speed. With recent changes in the economic climate the requirement for SMT placement becomes focused on the machine's versatility to deal with short runs and fast changeover. This means that lower cost machines with vision systems provide an affordable option for SMT users. There are more users of low end and mid-range machines than the ultra fast placement systems.
SMT pick and place machine manufacturers include:
Operation.
The placement equipment is part of a larger overall machine that carries out specific programmed steps to create a PCB assembly. Several sub-systems work together to "pick up" and correctly "place" the components onto the PCB. These systems normally use pneumatic suction cups, attached to a plotter-like device to allow the cup to be accurately manipulated in three dimensions. Additionally, each nozzle can be rotated independently.
Component feeds.
Surface mount components are placed along the front (and often back) faces of the machine. Most components are supplied on paper or plastic tape, in tape reels that are loaded onto feeders mounted to the machine. Larger integrated circuits (ICs) are sometimes supplied arranged in trays which are stacked in a compartment. More commonly used ICs will be provided in tapes rather than trays or sticks. Improvements in feeder technology mean that tape format is becoming the preferred method of presenting parts on an SMT machine.
Early feeder heads were much bulkier, and as a result it was not designed to be the mobile part of the system. Rather, the PCB itself was mounted on a moving platform that aligned the areas of the board to be populated with the feeder head above.
Conveyor belt.
Through the middle of the machine there is a conveyor belt, along which blank PCBs travel, and a PCB clamp in the center of the machine. The PCB is clamped, and the nozzles pick up individual components from the feeders/trays, rotate them to the correct orientation and then place them on the appropriate pads on the PCB with high precision. High-end machines can have multiple conveyors to produce multiple same or different kinds of products simultaneously.
Inspection and visual system.
The part being carried from the part feeders on either side of the conveyor belt to the PCB, it is photographed from below by using high resolution camera and lighting system. Its silhouette is inspected to see if it is damaged or missing (was not picked up), and the inevitable registration errors in pickup are measured and compensated for when the part is placed. For example, if the part was shifted 0.25 mm and rotated 10° when picked up, the pickup head will adjust the placement position to place the part in the correct location.
Some machines have these optical systems on the robot arm and can carry out the optical calculations without losing time, thereby achieving a lower derating factor.
The high-end optical systems mounted on the heads can also be used to capture details of the non-standard type components and save them to a database for future use. In addition to this, advanced software is available for monitoring the production and interconnect database — of the production floor to that of supply chain — in real-time. ASM provides an optional feature for increasing accuracy while placing LED components on a high end product where in the optical center of the LED is critical rather than the calculated mechanical center based on the component's lead structure. The special camera system measures both physical and optical center and makes the necessary adjustments before placement. It also can acquire the images in either single field of view multiple field of view modes.
A separate camera on the pick-and-place head photographs fiducial marks on the PCB to measure its position on the conveyor belt accurately. Two fiducial marks, measured in two dimensions each, usually placed diagonally, let the PCB's orientation and thermal expansion be measured and compensated for as well. Some machines are also able to measure the PCB shear by measuring a third fiducial mark on the PCB.
Variations.
To minimize the distance the pickup gantry must travel, it is common to have multiple nozzles with separate vertical motion on a single gantry. This can pick up multiple parts with one trip to the feeders. Also, advanced software in the newer generation machines allows different robotic heads to work independently of each other to further increase the throughput.
The components may be temporarily adhered to the PCB using the wet solder paste itself, or by using small blobs of a separate adhesive, applied by a glue-dispensing machine that can be incorporated on to the pick and place machine. The glue is added before component placement. It is dispensed by nozzles or by using jet dispensing. Jet dispensing dispenses material by shooting it towards the target, which in this case, is the circuit board.


Extrusion moulding

Extrusion is a manufacturing process used to make pipes, hoses, drinking straws, curtain tracks, rods, and fibre. The granules melt into a liquid which is forced through a die, forming a long 'tube like' shape. The shape of the die determines the shape of the tube. The extrusion is then cooled and forms a solid shape. The tube may be printed upon, and cut at equal intervals. The pieces may be rolled for storage or packed together.
Shapes that can result from extrusion include T-sections, U-sections, square sections, I-sections, L-sections and circular sections.
One of the most famous products of extrusion moulding is the optical fiber cable.
Extrusion is similar to injection moulding except that a long continuous shape is produced.


Milling cutter

Milling cutters are cutting tools typically used in milling machines or machining centres to perform milling operations (and occasionally in other machine tools). They remove material by their movement within the machine (e.g., a ball nose mill) or directly from the cutter's shape (e.g., a form tool such as a hobbing cutter).
Features of a milling cutter.
Milling cutters come in several shapes and many sizes. There is also a choice of coatings, as well as rake angle and number of cutting surfaces.
Types.
End mill.
End mills (middle row in image) are those tools that have cutting teeth at one end, as well as on the sides. The words "end mill" are generally used to refer to flat bottomed cutters, but also include rounded cutters (referred to as "ball nosed") and radiused cutters (referred to as "bull nose", or "torus"). They are usually made from high speed steel or cemented carbide, and have one or more flutes. They are the most common tool used in a vertical mill.
Roughing end mill.
Roughing end mills quickly remove large amounts of material. This kind of end mill utilizes a wavy tooth form cut on the periphery. These wavy teeth act as many successive cutting edges producing many small chips. This results in a relatively rough surface finish, but the swarf takes the form of short thin sections and is more manageable than a thicker more ribbon-like section, resulting in smaller chips that are easier to clear. During cutting, multiple teeth are in simultaneous contact with the workpiece, reducing chatter and vibration. Rapid stock removal with heavy milling cuts is sometimes called "hogging". Roughing end mills are also sometimes known as "rippa" or "ripper" cutters.
Ball cutter.
"Ball nose" cutters or "ball end" mills (lower row in image) are similar to slot drills, but the end of the cutters are hemispherical. They are ideal for machining 3-dimensional contoured shapes in machining centres, for example in moulds and dies. They are sometimes called "ball mills" in shop-floor slang, despite the fact that that term also has another meaning. They are also used to add a radius between perpendicular faces to reduce stress concentrations.
A "bull nose" cutter mills a slot with a corner radius, intermediate between an end mill and ball cutter; for example, it may be a 20 mm diameter cutter with a 2 mm radius corner. The silhouette is essentially a rectangle with its corners truncated (by either a chamfer or radius).
Slab mill.
Slab mills are used either by themselves or in gang milling operations on manual horizontal or universal milling machines to machine large broad surfaces quickly. They have been superseded by the use of cemented carbide-tipped face mills which are then used in vertical mills or machining centres.
Side-and-face cutter.
The side-and-face cutter is designed with cutting teeth on its side as well as its circumference. They are made in varying diameters and widths depending on the application. The teeth on the side allow the cutter to make "unbalanced cuts" (cutting on one side only) without deflecting the cutter as would happen with a slitting saw or slot cutter (no side teeth).
Cutters of this form factor were the earliest milling cutters developed. From the 1810s to at least the 1880s they were the most common form of milling cutter, whereas today that distinction probably goes to end mills. Traditionally, HSS side and face cutters are used to mill slots and grooves.
Involute gear cutter.
There are 8 cutters (excluding the rare half sizes) that will cut gears from 12 teeth through to a rack (infinite diameter).
Hob.
These cutters are a type of form tool and are used in hobbing machines to generate gears. A cross-section of the cutter's tooth will generate the required shape on the workpiece, once set to the appropriate conditions (blank size). A hobbing machine is a specialised milling machine.
Thread mill.
Whereas a hob engages the work much as a mating gear would (and cuts the blank progressively until it reaches final shape), a thread milling cutter operates much like an endmill, traveling around the work in a helical interpolation.
Face mill.
A face mill is a cutter designed for facing as opposed to e.g., creating a pocket (end mills). The cutting edges of face mills are always located along its sides. As such it must always cut in a horizontal direction at a given depth coming from outside the stock. Multiple teeth distribute the chip load, and since the teeth are normally disposable carbide inserts, this combination allows for very large and efficient face milling.
Fly cutter.
A fly cutter is composed of a body into which one or two tool bits are inserted. As the entire unit rotates, the tool bits take broad, shallow facing cuts. Fly cutters are analogous to face mills in that their purpose is face milling and their individual cutters are replaceable. Face mills are more ideal in various respects (e.g., rigidity, indexability of inserts without disturbing effective cutter diameter or tool length offset, depth-of-cut capability), but tend to be expensive, whereas fly cutters are very inexpensive.
Most fly cutters simply have a cylindrical center body that holds one tool bit. It is usually a standard left-hand turning tool that is held at an angle of 30 to 60 degrees. Fly cutters with two tool bits have no "official" name but are often called double fly cutters, double-end fly cutters, or fly bars. The latter name reflects that they often take the form of a bar of steel with a tool bit fastened on each end. Often these bits will be mounted at right angles to the bar's main axis, and the cutting geometry is supplied by using a standard right-hand turning tool.
Regular fly cutters (one tool bit, swept diameter usually less than 100 mm) are widely sold in machinists' tooling catalogs. Fly bars are rarely sold commercially; they are usually made by the user. Fly bars are perhaps a bit more dangerous to use than endmills and regular fly cutters because of their larger swing. As one machinist put it, running a fly bar is like "running a lawn mower without the deck", that is, the exposed swinging cutter is a rather large opportunity to take in nearby hand tools, rags, fingers, and so on. However, given that a machinist can never be careless with impunity around rotating cutters or workpieces, this just means using the same care as always except with slightly higher stakes. Well-made fly bars in conscientious hands give years of trouble-free, cost-effective service for the facing off of large polygonal workpieces such as die/mold blocks.
Woodruff cutter.
Woodruff cutters are used to cut the keyway for a woodruff key.
Hollow mill.
Hollow milling cutters, more often called simply "hollow mills", are essentially "inside-out endmills". They are shaped like a piece of pipe (but with thicker walls), with their cutting edges on the inside surface. They were originally used on turret lathes and screw machines as an alternative to turning with a box tool, or on milling machines or drill presses to finish a cylindrical boss (such as a trunnion). Hollow mills can be used on modern CNC lathes and Swiss style machines. An advantage to using an indexable adjustable hollow mill on a Swiss-style machine is replacing multiple tools.  By performing multiple operations in a single pass, the machine does not need as can accommodate other tools in the tool zone and improves productivity.
More advanced hollow mills use indexable carbide inserts for cutting, although traditional high speed steel and carbide-tipped blades are still used.
Hollow milling has an advantage over other ways of cutting because it can perform multiple operations. A hollow mill can reduce the diameter of a part and also perform facing, centering, and chamfering in a single pass.
Hollow mills offer an advantage over single point tooling. Multiple blades allow the feed rate to double and can hold a closer concentricity. The number of blades can be as many as 8 or as few as 3.  For significant diameter removal (roughing), more blades are necessary.
Trepanning is also possible with a hollow mill. Special form blades can be used on a hollow mill for trepanning diameters, forms, and ring grooves.
Interpolation is also not necessary when using a hollow mill; this can result in a significant reduction of production time.
Both convex and concave spherical radii are possible with a hollow mill. The multiple blades of a hollow mill allow this radius to be produced while holding a tight tolerance.
A common use of a hollow mill is preparing for threading.  The hollow mill can create a consistent pre-thread diameter quickly, improving productivity.
An adjustable hollow mill is a valuable tool for even a small machine shop to have because the blades can be changed out for an almost infinite number of possible geometries.
Dovetail cutter.
A dovetail cutter is an end mill whose form leaves behind a dovetail slot, such as often forms the ways of a machine tool.
Shell mill.
Modular principle.
A shell mill is any of various milling cutters (typically a face mill or endmill) whose construction takes a modular form, with the shank (arbor) made separately from the body of the cutter, which is called a "shell" and attaches to the shank/arbor via any of several standardized joining methods.
This modular style of construction is appropriate for large milling cutters for about the same reason that large diesel engines use separate pieces for each cylinder and head whereas a smaller engine would use one integrated casting. Two reasons are that (1) for the maker it is more practical (and thus less expensive) to make the individual pieces as separate endeavors than to machine all their features in relation to each other while the whole unit is integrated (which would require a larger machine tool work envelope); and (2) the user can change some pieces while keeping other pieces the same (rather than changing the whole unit). One arbor (at a hypothetical price of USD100) can serve for various shells at different times. Thus 5 different milling cutters may require only USD100 worth of arbor cost, rather than USD500, as long as the workflow of the shop does not require them all to be set up simultaneously. It is also possible that a crashed tool scraps only the shell rather than both the shell and arbor. To also avoid damage to the shell, many cutters, especially in larger diameters, also have another replaceable part called shim, which is mounted to the shell and the inserts are mounted on the shim. That way, in case of light damage, only the insert and maximum the shim needs replacement. The shell is safe. This would be like crashing a "regular" endmill and being able to reuse the shank rather than losing it along with the flutes.
Most shell mills made today use indexable inserts for the cutting edges—thus shank, body, and cutting edges are all modular components.
Mounting methods.
There are several common standardized methods of mounting shell mills to their arbors. They overlap somewhat (not entirely) with the analogous joining of lathe chucks to the spindle nose.
The most common type of joint between shell and arbor involves a fairly large cylindrical feature at center (to locate the shell concentric to the arbor) and two driving lugs or tangs that drive the shell with a positive engagement (like a dog clutch). Within the central cylindrical area, one or several socket head cap screws fasten the shell to the arbor.
Another type of shell fastening is simply a large-diameter fine thread. The shell then screws onto the arbor just as old-style lathe chuck backplates screw onto the lathe's spindle nose. This method is commonly used on the 2" or 3" boring heads used on knee mills. As with the threaded-spindle-nose lathe chucks, this style of mounting requires that the cutter only make cuts in one rotary direction. Usually (i.e., with right-hand helix orientation) this means only M03, never M04, or in pre-CNC terminology, "only forward, never reverse". One could use a left-hand thread if one needed a mode of use involving the opposite directions (i.e., only M04, never M03).
Using a milling cutter.
Chip formation.
Although there are many different types of milling cutter, understanding chip formation is fundamental to the use of any of them.
As the milling cutter rotates, the material to be cut is fed into it, and each tooth of the cutter cuts away a small chip of material. Achieving the correct size of chip is of critical importance. The size of this chip depends on several variables.
The machinist needs three values: S, F and Depth when deciding how to cut a new material with a new tool. However, he will probably be given values of Vc and Fz from the tool manufacturer. S and F can be calculated from them:
Conventional milling versus climb milling.
A milling cutter can cut in two directions, sometimes known as "conventional" or "up" and "climb" or "down".
Cutter location (cutter radius compensation).
Cutter location is the topic of where to locate the cutter in order to achieve the desired contour (geometry) of the workpiece, given that the cutter's size is non-zero. The most common example is cutter radius compensation (CRC) for endmills, where the centerline of the tool will be offset from the target position by a vector whose "distance" is equal to the cutter's radius and whose "direction" is governed by the left/right, climb/conventional, up/down distinction. In most implementations of G-code, it is G40 through G42 that control CRC (G40 cancel, G41 left/climb, G42 right/conventional). The radius values for each tool are entered into the offset register(s) by the CNC operator or machinist, who then tweaks them during production in order to keep the finished sizes within tolerance. Cutter location for 3D contouring in 3-, 4-, or 5-axis milling with a ball-endmill is handled readily by CAM software rather than manual programming. Typically the CAM vector output is postprocessed into G-code by a postprocessor program that is tailored to the particular CNC control model. Some late-model CNC controls accept the vector output directly, and do the translation to servo inputs themselves, internally.
Swarf removal.
Another important quality of the milling cutter to consider is its ability to deal with the swarf generated by the cutting process. If the swarf is not removed as fast as it is produced, the flutes will clog and prevent the tool cutting efficiently, causing vibration, tool wear and overheating. Several factors affect swarf removal, including the depth and angle of the flutes, the size and shape of the chips, the flow of coolant, and the surrounding material. It may be difficult to predict, but a good machinist will watch out for swarf build up, and adjust the milling conditions if it is observed.
Selecting a milling cutter.
Selecting a milling cutter is not a simple task. There are many variables, opinions and lore to consider, but essentially the machinist is trying to choose a tool that will cut the material to the required specification for the least cost. The cost of the job is a combination of the price of the tool, the time taken by the milling machine, and the time taken by the machinist. Often, for jobs of a large number of parts, and days of machining time, the cost of the tool is lowest of the three costs.
History.
The history of milling cutters is intimately bound up with that of milling machines. Milling evolved from rotary filing, so there is a continuum of development between the earliest milling cutters known, such as that of Jacques de Vaucanson from about the 1760s or 1770s, through the cutters of the milling pioneers of the 1810s through 1850s (Whitney, North, Johnson, Nasmyth, and others), to the cutters developed by Joseph R. Brown of Brown & Sharpe in the 1860s, which were regarded as a break from the past for their large step forward in tooth coarseness and for the geometry that could take successive sharpenings without losing the clearance (rake, side rake, and so on). De Vries (1910) reported, "This revolution in the science of milling cutters took place in the States about the year 1870, and became generally known in Europe during the Exhibition in Vienna in 1873. However strange it may seem now that this type of cutter has been universally adopted and its undeniable superiority to the old European type is no longer doubted, it was regarded very distrustfully and European experts were very reserved in expressing their judgment. Even we ourselves can remember that after the coarse pitched cutter had been introduced, certain very clever and otherwise shrewd experts and engineers regarded the new cutting tool with many a shake of the head. When[,] however, the Worlds Exhibition at Philadelphia in 1876, exhibited to European experts a universal and many-sided application of the coarse pitched milling cutter which exceeded even the most sanguine expectations, the most far-seeing engineers were then convinced of the immense advantages which the application of the new type opened up for the metalworking industry, and from that time onwards the American type advanced, slowly at first, but later on with rapid strides".
Woodbury provides citations of patents for various advances in milling cutter design, including irregular spacing of teeth (1867), forms of inserted teeth (1872), spiral groove for breaking up the cut (1881), and others. He also provides a citation on how the introduction of vertical mills brought about wider use of the endmill and fly cutter types.
Scientific study by Holz and De Leeuw of the Cincinnati Milling Machine Company made the teeth even coarser and did for milling cutters what F.W. Taylor had done for single-point cutters with his famous scientific cutting studies.


Engineer's spirit level

An engineer's spirit level (or machinist's level) is generally used to level machines, although they may also be used to level large workpieces on machines such as planers. Using gravity as a reference and checking a machine's axis of travel at several points, the level is used to ensure the machine's axis is "straight". A perfectly level machine does not actually need to be achieved, unless the particular manufacturing process requires it. Spirit levels are also used in building construction by carpenters and masons.
The upper image is a "plain" precision level used in the engineering field to level machines or workpieces; the lower image shows an adjustable precision level that has an accuracy of 1:10000. The adjustable nature of this level can also be used to measure the inclination of an object.
The accuracy of a spirit level can be checked by placing it on any flat surface, marking the bubble's position and rotating the level 180°. The position of the bubble should then be symmetrical to the first reading. Machinist's levels provide screw mechanisms to center the bubbles.
Some levels have V grooves machined along their bases, enabling the level to sit on a round bar while remaining parallel with the bar's axis. They also have smaller cross levels to enable the second axes to be roughly checked or corrected and to ensure the primary axes' bubbles are at the tops of the vials.
A precision level (1:24000) is used to check the installation of precision machine tools in two axes. A lathe is manufactured with its base in a level plane and if it is not installed level distortions in the frame cause machining errors. Small milling machines are often roughly leveled but large mills are installed level. A worn lathe may have a twist introduced to the machine's bed to ensure that it turns parallel to the spindle axis, by twisting the bed (that is worn) to the spindle axis. A lathe has several leveling screws. Usually, such a fix has limited utility for only part of the cutting tool (carriage) travel. A lathe usually requires two or more leveling trials as the machine castings "settle into" the adjustments.


Implant resistance welding

Implant resistance welding is a method used in welding to join thermoplastics and thermoplastic composites.
Resistive heating of a conductive material implanted in the thermoplastic melts the thermoplastic while a pressure is applied in order to fuse two parts together. The process settings such as current and weld time are important, because they affect the strength of the joint. The quality of a joint made using implant resistance welding is determined using destructive strength testing of specimens.
Applications.
Implant resistance welding is used to joint thermoplastic composite components in the aerospace industry. For example, PEEK and PEI Laminate components for use in U.S. Air Force aircraft and a GF-PPS component on the Airbus A380 are joined using implant resistance welding. Electrofusion welding is a specific type of implant resistance welding used to join pipes.
Process.
During the implant resistance welding process, current is applied to a heating element implanted in the joint. This current flowing through the implant produces heat through electrical resistance, which melts the matrix. Pressure is applied to push the parts together and molecular diffusion occurs at the melted surfaces of the parts, creating a joint.
Implants.
Implants serve as the source of heat to melt the thermoplastic. The heat is created through resistive heating as a current is applied to the implant. Two common types of implants are carbon fiber and stainless-steel mesh.
Carbon Fiber.
The carbon fiber type implants can be further separated into unidirectional and fabric type implants. The unidirectional type carbon fibers do not transfer heat across the fibers easily, therefore, the carbon fiber fabric works better to evenly heat the entire surface. This difference affects the performance of the resulting weld, the welded joints using the carbon fiber fabric can have 69% higher shear strength and 179% more interlaminar fracture toughness, when compared to unidirectional carbon fibers. For carbon fiber reinforced thermoplastics, the carbon fiber heating element matches the reinforcing material, avoiding the introduction of a new material.
Stainless Steel Mesh.
Welded joints with stainless steel mesh implants tend to have higher strength than welds using carbon fiber implants and results in less air trapped in the joint. Stainless steel wire can be placed in between two layers of resin, to avoid leaving spaces in the holes of the mesh. However, there are reasons to avoid using stainless steel in favor of carbon fiber including, increased weight, the metal acts as a contaminant, possibility of stress concentrations, and possibility of corrosion.
Energy Input.
The amount of energy input into the system (E) depends on the resistance of the heating elements (R), the current applied to the heating elements (I), and the amount of time the current is applied (t). Alternating current (AC) and direct current (DC) both work in this process. The energy produced is calculated using the following equation:
formula_1
Research has shown the input variable with the most impact on the performance of the resulting joint is the current. The same amount of energy can by input into the part by applying a low current for a long period of time or if a high current is applied for a short amount of time. In general, a higher shear strength of the joint is achieved using the method with a higher current for a shorter time. Longer heating times at lower currents do not heat the joint surface as evenly. This can lead to the fiber reinforcement to move within the melted matrix. If the current is too high, however, it can result in residual stresses and warpage.
For a given constant electrical power, the temperature of the material surrounding the implants is directly dependent on the weld time. The longer weld time, yields a higher temperature. The lapped shear strength and the weld time are also correlated. Initially, there is a positive correlation between weld time and strength. However, the strength peaks for a certain weld time, and beyond this optimal weld time, the strength decreases.
Pressure.
Pressure is applied to the joining surfaces to prevent deconsolidation, allow intermolecular diffusion, and push air out of the joint. The pressure can be applied using displacement or pressure control. Pressure also ensures good contact between the implant and the bulk material, in order to increase electrical resistance. The pressure on the implant must create good contact without being so high that it severs the implant. This is achieved with pressures of 4 to 20 MPa for carbon fiber and 2 MPa for stainless steel mesh heating elements.
Strength Testing.
Lap shear strength (LSS) testing, in accordance with ASTM D 1002, is a method of destructive testing used to determine the strength of electrofusion welds of thermoplastic composite materials. For this test, two rectangular samples of the composite are lapped at the ends and joined at the lap interface using resistance implant welding. Then, a tension strength test is performed on the welded sample, with the joint surface being loaded in pure shear, a load frame machine pulls the sample until failure and measures the maximum load. The lap shear strength  is the maximum tensile load imparted on the sample by the machine divided by the lapped area.
Failure Modes.
Interfacial failure or tearing is when the resin or laminate in immediate contact with the heating element on either side is pulled away, leaving the mesh or fabric heating element exposed. This type of failure is associated with low LSS of the sample and can occur as a result of inadequate heat input into the weld.
Another failure mode associated with low LSS is cohesive failure, which is a failure of the welded material, either the melted base material or resin surrounding the mesh. Cohesive failure is observed in samples with too much heat input during welding, which deteriorates the thermoplastic. Samples with high LSS generally fail due to debonding of the reinforcing fiber-matrix surface or other base material failure, known as intralaminar failure.


Solid Concepts

Solid Concepts, Inc. is a custom manufacturing company engaged in engineering, manufacturing, production, and prototyping. The company is headquartered in Valencia, California, in the Los Angeles County area, with six other facilities located around the United States. Solid Concepts is an additive manufacturing service provider as well as a major manufacturer of business products, aerospace, unmanned systems, medical equipment and devices, foundry cast patterns, industrial equipment and design, and transportation parts.
The company was founded in 1991, in the birthplace of Stereolithography. The company derives its name from its original focus on rapid prototyping through 3D printing (or additive manufacturing) with the idea that virtual concepts can be printed into solid reality, as the technologies that founded the company are capable of directly reading CAD data and creating parts. Solid Concepts markets its products under its main name, as well as under the website-only offshoot company called ZoomRP.com. The Solid Concepts logo originally featured layered lines comprising a "S" beside a "C" to represent layered manufacturing, but has since removed the layered lines, in order to better represent its composite, urethane, and tooling capabilities.
Origins and history.
Solid Concepts Inc. was founded by former 3D Systems engineers Joe Allison, Schuyler Mitchell, and Ray Bradford in 1991. The company began with two SLA-250 Stereolithography machines. They moved into CNC machining, Selective Laser Sintering, and composites within a few years after opening, and have since gained PolyJet, Z-Corp 3D Colored Printing, Fused Deposition Modeling, Direct Metal Laser Sintering, urethanes and tooling and injection molding processes. Solid Concepts expanded throughout the United States, especially during the late 1990s early 2000s, opening facilities in Austin, TX, during the rise of Selective Laser Sintering; Poway, CA, during significant advances in Urethane technology with a strong focus on medical equipment; and Phoenix, AZ.
Joe Allison has since been awarded the Distinguished Innovator Operator Awards, known as DINOs (formerly known as the Dinosaur Awards) by the Additive Manufacturing Users Group (AMUG) for innovation in laser sintering technology. The awards honor additive manufacturing expertise. In 2001, Solid Concepts hired former AARK employee Jeff Lemker, who headed the evolution of cast urethane products at the company. Lemker forged the path for QuantumCast™ Cast Urethanes, a proprietary casting process trademarked by the company. The process involves heat and pressure to enhance the properties of the urethanes during casting. The casting process has found use in the medical industry. In 2008, Solid Concepts branded and trademarked ID-Light, which is a method of printing SLA and FDM parts that is 1/12 the weight of regular SLA and FDM parts. The process has allowed lighter props for movies involving huge set pieces, such as the robots in "Real Steel". Solid Concepts was ranked in the top twenty manufacturing companies in the greater San Fernando Valley by San Fernando Business Journal in 2007. In 2013, the company was awarded a Platinum Source Preferred Supplier by Northrop Grumman. In 2013, the National Additive Manufacturing Innovation Institute (NAMII) recognized a FDM 3D Printed duct manufactured by Solid Concepts. The air duct has been awarded a place in the visitors center at the facility with the purpose of immersing visitors in the evolution of additive manufacturing technology.
In late 2013, the company demonstrated a 3D printed version of an M1911 pistol made of metal, the 1911DMLS, using an industrial 3D printer.
Acquisitions.
In 2006, Solid Concepts acquired a model shop from Raytheon in Tucson, AZ, thus beginning their tooling and molding department. In 2008, Solid Concepts purchased former composites manufacturing company, Composite Tooling Technologies, to further develop a composites line. The acquisition facilitated a $1 million project for large MRI equipment, manufactured by Solid Concepts.
On April 2, 2014, Stratasys announced that they had entered into definitive agreements to acquire Solid Concepts and Harvest Technologies, which will be combined with RedEye, its existing digital manufacturing service business, to establish a single additive manufacturing services business unit. The acquisition was finalized on July 15, 2014.
Products and technologies.
Solid Concepts manufactures products for a range of industries, including aerospace, business consumer, medical, and transportation. The company manufactures architectural models, prototypes, anatomical models, and investment casting patterns for metal castings using QuickCast SLA. The company largely focused on prototypes during their early years, but have since branched out to manufacture large composite equipment for industrial use, tooling and injection molding, end-use cast urethanes, metals and a range of high quality plastics.
Solid Concepts offers the services of 3D Printing, composites, urethanes, tooling and injection molding rather than selling machines and equipment. Their additive manufacturing services include Stereolithography (SLA), PolyJet, Z-Corp Color 3D Prints, Fused Deposition Modeling (FDM), Direct Metal Laser Sintering (DMLS), and Selective Laser Sintering (SLS). The company also provides Computer Numerical Controlled (CNC) machining, composites, advanced cast urethanes, and injection molding and tooling.
Applications and industries.
Solid Concepts' services are utilized during early prototyping and design, market testing, and low to mass volume production. Solid Concepts' material offerings include durable thermoplastics, resins, nylons, and metals for uses ranging from large components and ducts in aerospace to RF Transparency protective equipment in the medical industry.
Industry specific applications include:
Headquarters.
Headquartered in Valencia, California, near the beginnings of the Angeles National Forest, Solid Concepts also has manufacturing facilities in Troy, Michigan, Austin, Texas, Phoenix and Tucson, Arizona, and Poway, California, and a partnership in China.
Manufacturing.
Solid Concepts manufactures all products in house.


Transfer line

A transfer line is a manufacturing system which consists of a predetermined sequence of machines connected by an automated material handling system and designed for working on a very small family of parts. Parts can be moved singularly because there’s no need for batching when carrying parts between process stations (as opposed to a job shop for example). The line can synchronous, meaning that all parts advance with the same speed, or asynchronous, meaning buffers exist between stations where parts wait to be processed. Not all transfer lines must geometrically be straight lines, for example circular solutions have been developed which make use of rotary tables, however using buffers becomes almost impossible.
A crucial problem for this production system is that of line balancing: a trade-off between increasing productivity and minimizing cost conserving total processing time.


1977–78 UEFA Cup

The 1977–78 UEFA Cup was won by PSV Eindhoven on aggregate over Bastia.
The third club was revoked to Hungary and Romania, and it was assigned to Switzerland and Poland.
First round.
First leg.
"UEFA invalidated this game and awarded a 3–0 victory to Schalke 04 as Fiorentina fielded an ineligible player, Gianfranco Casarsa."
Second leg.
"Eintracht Frankfurt won 5–0 on aggregate."
"AZ Alkmaar won 16–1 on aggregate."
"Aston Villa won 6–0 on aggregate."
"Barcelona won 8–2 on aggregate."
"Bastia won 5–3 on aggregate."
"Bayern Munich won 12–0 on aggregate."
"Lazio won 5–1 on aggregate."
"Newcastle United won 4–0 on aggregate."
"Carl Zeiss Jena won 6–5 on aggregate."
"KB won 3–1 on aggregate."
"Schalke 04 won 5–1 on aggregate."
"Grasshoppers won 8–1 on aggregate."
"PSV Eindhoven won 11–2 on aggregate."
"Górnik Zabrze won 5–3 on aggregate."
"Dinamo Tbilisi won 1–0 on aggregate."
"1–1 on aggregate, Eintracht Braunschweig won on away goals."
"Ipswich Town won 6–0 on aggregate."
"Las Palmas won 8–4 on aggregate."
"Lens won 4–3 on aggregate."
"Újpest won 9–3 on aggregate."
"Magdeburg won 3–2 on aggregate."
"Dinamo Zagreb won 6–4 on aggregate."
"2–2 on aggregate, Widzew Łódź won on away goals rule."
"Marek Dupnitsa won 3–2 on aggregate."
"Inter Bratislava won 3–1 on aggregate."
"R.W.D. Molenbeek won 2–1 on aggregate."
"Athletic Bilbao won 2–1 on aggregate."
"3–3 on aggregate, Standard Liège won on away goals rule."
"Start won 8–0 on aggregate."
"AEK Athens won 3–1 on aggregate."
"Torino won 4–1 on aggregate."
"Zürich won 2–1 on aggregate."
Second round.
Second leg.
"Standard Liège won 6–3 on aggregate."
"2–2 on aggregate, Barcelona won in a penalty shoot-out."
"Aston Villa won 3–1 on aggregate."
"Bastia won 5–2 on aggregate."
"Bayern Munich won 3–2 on aggregate."
"Grasshoppers won 5–2 on aggregate."
"Ipswich Town won 4–3 on aggregate."
"Dinamo Tbilisi won 6–2 on aggregate."
"Lens won 6–2 on aggregate."
"Magdeburg won 7–3 on aggregate."
"2–2 on aggregate, Carl Zeiss Jena won in a penalty shoot-out."
"Eintracht Braunschweig won 4–1 on aggregate."
"Torino won 3–2 on aggregate."
"Athletic Bilbao won 3–2 on aggregate."
"PSV Eindhoven won 6–3 on aggregate."
"Eintracht Frankfurt won 7–3 on aggregate."
Third round.
Second leg.
"Aston Villa won 3–1 on aggregate."
"Bastia won 5–3 on aggregate."
"Carl Zeiss Jena won 4–1 on aggregate."
"Eintracht Frankfurt won 6–1 on aggregate."
"3–3 on aggregate, Barcelona won in a penalty shoot-out."
"Magdeburg won 4–2 on aggregate."
"PSV Eindhoven won 4–1 on aggregate."
"Grasshoppers won 4–1 on aggregate."
Quarter-finals.
Second leg.
"Barcelona won 4–3 on aggregate."
"Bastia won 9–6 on aggregate."
"PSV Eindhoven won 4–3 on aggregate."
"3–3 on aggregate, Grasshoppers won on away goals rule."
Semi-finals.
Second leg.
"3–3 on aggregate, Bastia won on away goals rule."
"PSV won 4–3 on aggregate."
Final.
Second leg.
"PSV Eindhoven won 3–0 on aggregate"


1976–77 UEFA Cup

The 1976–77 UEFA Cup was the sixth season of the UEFA Cup, a club football competition organised by UEFA (the Union of European Football Associations). It was won by Italian club Juventus, who beat Athletic Bilbao of Spain in the two-legged final; both sides won one leg of the tie, which finished 2–2 on aggregate, but Juventus' solitary goal in the second leg at San Mamés Stadium in Bilbao saw them win on away goals. It was the first time that a team from Southern Europe had won the competition.
First round.
Second leg.
"Schalke 04 won 5–4 on aggregate."
"Slovan Bratislava won 8–0 on aggregate."
"Basel won 5–3 on aggregate."
"Kaiserslautern won 11–1 on aggregate."
"AEK Athens won 3–2 on aggregate."
"Manchester United won 2–1 on aggregate."
"Austria Salzburg won 5–2 on aggregate."
"Barcelona won 5-4 on aggregate."
"Wisła Kraków won 4-2 on aggregate."
"Derby County won 16–1 on aggregate."
"Milan won 2–1 on aggregate."
"Eintracht Braunschweig won 7–1 on aggregate."
"Espanyol won 4–3 on aggregate."
"Feyenoord won 4–2 on aggregate."
"Videoton won 5–2 on aggregate."
"Grasshoppers won 9–0 on aggregate."
"Hibernian won 1–0 on aggregate."
"Budapest Honvéd won 2–1 on aggregate."
"Köln won 3–1 on aggregate."
"Öster won 4–3 on aggregate."
"Magdeburg won 4–3 on aggregate."
"Juventus won 2–1 on aggregate."
"Molenbeek won 7–0 on aggregate."
"Queens Park Rangers won 11–0 on aggregate."
"Lokeren won 6–1 on aggregate."
"Akademik Sofia won 3–2 on aggregate."
"Shakhtar Donetsk won 4–1 on aggregate."
"Sportul Studențesc won 4–2 on aggregate."
"Wacker Innsbruck won 7–1 on aggregate."
"Dinamo Zagreb won 4–0 on aggregate."
"Athletic Bilbao won 5–1 on aggregate."
"Red Star Belgrade won 5–3 on aggregate."
Second round.
Second leg.
"AEK Athens won 5–2 on aggregate."
"Milan won 5–4 on aggregate."
"2–2 on aggregate; Red Star Belgrade won on away goals."
"Barcelona won 3–2 on aggregate."
"Athletic Bilbao won 4–2 on aggregate."
"Espanyol won 3–2 on aggregate."
"Öster won 4–3 on aggregate."
"Videoton won 2–1 on aggregate."
"Feyenoord won 7–2 on aggregate."
"Köln won 5–2 on aggregate."
"Magdeburg won 4–2 on aggregate."
"Juventus won 3–1 on aggregate."
"Shakhtar Donetsk won 6–2 on aggregate."
"Queens Park Rangers won 8–5 on aggregate."
"Schalke 04 won 5–0 on aggregate."
"2–2 on aggregate; Molenbeek won 5–4 on penalties."
Third round.
Second leg.
"3–3 on aggregate; AEK Athens won on away goals."
"Athletic Bilbao won 5–4 on aggregate."
"Feyenoord won 3–0 on aggregate."
"Juventus won 3–1 on aggregate."
"Magdeburg won 5–1 on aggregate."
"Barcelona won 8–1 on aggregate."
"4–4 on aggregate; Queens Park Rangers won on away goals."
"Molenbeek won 2–1 on aggregate."
Quarter-finals.
Second leg.
"Athletic Bilbao won 4–3 on aggregate."
"Molenbeek won 2–1 on aggregate."
"Juventus won 4–1 on aggregate."
"3–3 on aggregate; AEK Athens won 7–6 on penalties."
Semi-finals.
Second leg.
"1–1 on aggregate; Athletic Bilbao won on away goals."
"Juventus won 5–1 on aggregate."
Final.
Second leg.
"2–2 on aggregate; Juventus won on away goals."


1975–76 UEFA Cup

The 1975–76 UEFA Cup was won by Liverpool over Club Brugge on aggregate.
The third club was revoked from the Netherlands and Austria, and it was assigned to the Soviet Union and Sweden.
First round.
Second leg.
"Both legs were played in West Germany, MSV Duisburg won 10–3 on aggregate."
"Ajax won 14–1 on aggregate."
"4–4 on aggregate; Real Sociedad won on away goals."
"Barcelona won 6–2 on aggregate."
"Spartak Moscow won 2–1 on aggregate."
"Royal Antwerp won 5–1 on aggregate."
"Budapest Honvéd won 3–2 on aggregate."
"Carl Zeiss Jena won 4–0 on aggregate."
"Red Star Belgrade won 4–2 on aggregate."
"Milan won 1–0 on aggregate."
"Ipswich Town won 4–1 on aggregate."
"Śląsk Wrocław won 5–4 on aggregate."
"Hertha BSC won 6–2 on aggregate."
"Liverpool won 3–2 on aggregate."
"Stal Mielec won 3–1 on aggregate."
"Köln won 5–2 on aggregate."
"Club Brugge won 6–4 on aggregate."
"Öster won 6–1 on aggregate."
"Dynamo Dresden won 6–3 on aggregate."
"Lazio won 3–1 on aggregate."
"Porto won 10–0 on aggregate."
"Galatasaray won 3–2 on aggregate."
"Roma won 2–1 on aggregate."
"Torpedo Moscow won 5–2 on aggregate."
"Vasas SC won 4–2 on aggregate."
"AEK Athens won 3–1 on aggregate."
"Hamburg won 4–2 on aggregate."
"Athlone Town won 4–2 on aggregate."
"Inter Bratislava won 8–2 on aggregate."
"Dundee United won 6–0 on aggregate."
"Levski-Spartak Sofia won 7–1 on aggregate."
"Sporting CP won 5–2 on aggregate."
Second round.
First leg.
"Lazio refused to play for security reasons, claiming it would be impossible to play due to political demonstrations following the execution in Spain of five ETA and FRAP members on 27 September on terrorism charges. UEFA awarded Barcelona a 3–0 victory, ruling those three goals were not applicable for the away goals rule."
Second leg.
"4–4 on aggregate; Levski-Spartak Sofia won on away goals."
"Milan won 3–0 on aggregate."
"1–1 on aggregate; Stal Mielec won on penalties."
"Porto won 3–2 on aggregate."
"Torpedo Moscow won 7–2 on aggregate."
"Ajax won 4–2 on aggregate."
"Dynamo Dresden won 3–2 on aggregate."
"3–3 on aggregate; Inter Bratislava won on away goals."
"Club Brugge won 4–3 on aggregate."
"Spartak Moscow won 3–0 on aggregate."
"Roma won 2–1 on aggregate."
"Liverpool won 9–1 on aggregate."
"Hamburg won 5–1 on aggregate."
"Śląsk Wrocław won 3–2 on aggregate."
"Vasas SC won 4–3 on aggregate."
"Before the game, Johan Cruyff was given his Ballon d'Or award for the 1974 season."
"Barcelona won 7–0 on aggregate."
Third round.
Second leg.
"3–3 on aggregate; Levski-Spartak Sofia won on penalties."
"Barcelona won 4–1 on aggregate."
"Club Brugge won 2–0 on aggregate."
"Dynamo Dresden won 4–3 on aggregate."
"Hamburg won 3–2 on aggregate."
"Stal Mielec won 2–1 on aggregate."
"Liverpool won 5–1 on aggregate."
"Milan won 4–2 on aggregate."
Quarter–finals.
Second leg.
"Barcelona won 8–5 on aggregate."
"Club Brugge won 3–2 on aggregate."
"Liverpool won 2–1 on aggregate."
"Hamburg won 2–1 on aggregate."
Semi–finals.
Second leg.
"Liverpool won 2–1 on aggregate."
"Club Brugge won 2–1 on aggregate."
Final.
Second leg.
"Liverpool won 4–3 on aggregate."


1974–75 UEFA Cup

The 1974–75 UEFA Cup was won by Borussia Mönchengladbach over Twente on aggregate.
The third club was revoked to Scotland and Belgium, and it was assigned to the Netherlands and Austria.
First round.
Second leg.
"Lyon won 11–1 on aggregate."
"Portadown won 2–1 on aggregate."
"Derby County won 6–2 on aggregate."
"3–3 on aggregate, Twente won on away goals rule."
"1–1 on aggregate, Ajax won on away goals rule."
"RWD Molenbeek won 5–2 on aggregate."
"Hibernian won 12–3 on aggregate."
"Porto won 5–4 on aggregate."
"Inter Milan won 3–0 on aggregate."
"Partizan won 5–2 on aggregate."
"Djurgården won 7–1 on aggregate."
"Dinamo București won 4–0 on aggregate."
"3–3 on aggregate, Velež Mostar won on away goals rule."
"Steagul Roșu Brașov won 3–2 on aggregate."
"Borussia Mönchengladbach won 4–2 on aggregate."
"2–2 on aggregate, Royal Antwerp won on away goal rules."
"1–1 on aggregate, Dynamo Dresden won on away goal rules."
"Hamburg won 4–0 on aggregate."
"Rapid Wien won 3–2 on aggregate."
"Baník Ostrava won 5–0 on aggregate."
"4–4 on aggregate, Raba ETO Győr won 5–4 in penalty shoot-out."
"4–4 on aggregate, Dynamo Moscow won on away goals rule."
"Nantes won 3–2 on aggregate."
"Napoli won 3–1 on aggregate."
"Juventus won 4–2 on aggregate."
"Grasshopper won 3–2 on aggregate."
"Fortuna Düsseldorf won 4–2 on aggregate."
"Köln won 9–2 on aggregate."
"Both legs were played in Amsterdam, the second leg was formally a 'home' game for Hibernians. Amsterdam won 12–0 on aggregate."
"Atlético Madrid won 6–3 on aggregate."
"Real Zaragoza won 5–1 on aggregate."
Second round.
Second leg.
"4–4 on aggregate, Derby County won 7–6 in penalty shoot-out."
"Juventus won 8–2 on aggregate."
"Partizan won 6–1 on aggregate."
"Baník Ostrava won 2–1 on aggregate."
"Köln won 4–3 on aggregate."
"Fortuna Düsseldorf won 3–2 on aggregate."
"Velež Mostar won 2–1 on aggregate."
"1–1 on aggregate, Dynamo Dresden won 4–3 in penalty shoot-out."
"Real Zaragoza won 6–2 on aggregate."
"Borussia Mönchengladbach won 6–2 on aggregate."
"Hamburg won 10–1 on aggregate."
"Twente won 3–1 on aggregate."
"Dukla Prague won 5–1 on aggregate."
"Amsterdam won 2–1 on aggregate."
"Napoli won 2–0 on aggregate."
"2–2 on aggregate, Ajax won on away goals rule."
Third round.
Second leg.
"Baník Ostrava won 3–1 on aggregate."
"Hamburg won 6–3 on aggregate."
"Twente won 6–3 on aggregate."
"Köln won 5–2 on aggregate."
"Borussia Mönchengladbach won 9–2 on aggregate."
"Amsterdam won 5–1 on aggregate."
"2–2 on aggregate; Juventus won on away goals."
"Velež Mostar won 5–4 on aggregate."
Quarter-finals.
Second leg.
"Juventus won 2–0 on aggregate."
"Köln won 8–3 on aggregate."
"Twente won 2–1 on aggregate."
"Borussia Mönchengladbach won 4–1 on aggregate."
Semi-finals.
Second leg.
"Twente won 4–1 on aggregate."
"Borussia Mönchengladbach won 4–1 on aggregate."
Final.
Second leg.
"Borussia Mönchengladbach won 5–1 on aggregate."


1972–73 UEFA Cup

The 1972–73 UEFA Cup was the second season of the UEFA Cup, a football competition organised by UEFA for clubs affiliated to its member associations. It was won by Liverpool, who beat Borussia Mönchengladbach over two legs in the final. The first leg was played at Anfield in Liverpool, where Liverpool won the match 3–0. Mönchengladbach won the second leg in Germany 2–0 for an aggregate score of 3–2.
First round.
Summary.
1 Hvidovre walkover, HJK withdrew.
Matches.
"Liverpool won 2–0 on aggregate."
"Norrköping won 4–1 on aggregate."
"Levski-Spartak won 6–5 on aggregate."
"AEK Athens won 4–2 on aggregate."
"Beroe Stara Zagora won 10–1 on aggregate."
"Twente won 4–2 on aggregate."
"Slovan Bratislava won 8–2 on aggregate."
"Ruch Chorzów won 3–1 on aggregate."
"Dynamo Dresden won 4–2 on aggregate."
"Red Star Belgrade won 7–4 on aggregate."
"OFK Beograd won 5–3 on aggregate."
"Tottenham Hotspur won 12–3 on aggregate."
"Viking won 1–0 on aggregate."
"Club Brugge won 6–5 on aggregate."
"Frem won 5–2 on aggregate."
"Budapest Honvéd won 4–0 on aggregate."
"Köln won 5–1 on aggregate."
"Borussia Mönchengladbach won 9–5 on aggregate."
"BFC Dynamo won 3–2 on aggregate."
"Feyenoord won 21–0 on aggregate."
"Valencia won 4–3 on aggregate."
"Grasshoppers won 4–2 on aggregate."
"Kaiserslautern won 5–3 on aggregate."
"Las Palmas won 4–2 on aggregate."
"Inter Milan won 7–1 on aggregate."
"Vitória de Setúbal won 6–2 on aggregate."
"Ararat Yerevan won 2–0 on aggregate."
"Fiorentina won 5–1 on aggregate."
"Olympiacos won 3–1 on aggregate."
"CUF Barreiro won 3–0 on aggregate."
"Porto won 4–1 on aggregate."
"Hvidovre walkover, HJK withdrew."
Second round.
Matches.
"Köln won 9–2 on aggregate."
"Liverpool won 6–1 on aggregate."
"Beroe Stara Zagora won 3–1 on aggregate."
"BFC Dynamo won 3–2 on aggregate."
"Red Star Belgrade won 4–1 on aggregate."
"Kaiserslautern won 3–2 on aggregate."
"Dynamo Dresden won 4–0 on aggregate."
"Borussia Mönchengladbach won 6–1 on aggregate."
"Twente won 9–0 on aggregate."
"Ararat Yerevan won 7–3 on aggregate."
"5–5 on aggregate; OFK Beograd won on away goals."
"Tottenham Hotspur won 4–1 on aggregate."
"Inter Milan won 4–2 on aggregate."
"Las Palmas won 3–2 on aggregate."
"2–2 on aggregate; Vitória de Setúbal won on away goals."
"Porto won 5–3 on aggregate."
Third round.
Matches.
"Borussia Mönchengladbach won 5–0 on aggregate."
"Liverpool won 3–1 on aggregate."
"OFK Beograd won 3–1 on aggregate."
"2–2 on aggregate; Kaiserslautern won on penalties."
"Twente won 4–2 on aggregate."
"Tottenham Hotspur won 2–1 on aggregate."
"Dynamo Dresden won 3–1 on aggregate."
"Vitória de Setúbal won 2–1 on aggregate."
Quarter-finals.
Matches.
"Borussia Mönchengladbach won 9–2 on aggregate."
"Twente won 4–3 on aggregate."
"Liverpool won 3–0 on aggregate."
"2–2 on aggregate; Tottenham won on away goals."
Semi-finals.
Matches.
"2–2 on aggregate; Liverpool won on away goals."
"Borussia Mönchengladbach won 5–1 on aggregate."
Final.
Matches.
"Liverpool won 3–2 on aggregate."


Spillage

In industrial production, spillage is the loss of production output due to production of a series of defective or unacceptable products which must be rejected. Spillage is an often costly event which occurs in manufacturing when a process degradation or failure occurs that is not immediately detected and corrected, and in which defective or reject product therefore continues to be produced for some extended period of time.
Spillage results in costs due to lost production volume, excessive scrap, delayed delivery of product, and wastage of human and capital equipment resources. Minimization of the occurrence and duration of manufacturing spillage requires that closed-loop control and associated process monitoring and metrology functions be integrated into critical steps of the overall manufacturing process. The extent to which process control is complete and metrology is high resolution so as to be comprehensive determines the extent to which spillages will be prevented.