Electrical connector

Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between parts of an electrical circuit, or between different electrical circuits, thereby joining them into a larger circuit. Most electrical connectors have a genderi.e. the male component, called a "plug", connects to the female component, or "socket". The connection may be removable (as for portable equipment), require a tool for assembly and removal, or serve as a permanent electrical joint between two points. An adapter can be used to join dissimilar connectors.
Thousands of configurations of connectors are manufactured for power, data, and audiovisual applications. Electrical connectors can be divided into four basic categories, differentiated by their function:
In computing, electrical connectors are considered a physical interface and constitute part of the physical layer in the OSI model of networking.
Physical construction.
In addition to the classes mentioned above, connectors are characterised by their pinout, method of connection, materials, size, contact resistance, insulation, mechanical durability, ingress protection, lifetime (number of cycles), and ease of use.
It is usually desirable for a connector to be easy to identify visually, rapid to assemble, inexpensive, and require only simple tooling. In some cases an equipment manufacturer might choose a connector specifically because it is "not" compatible with those from other sources, allowing control of what may be connected. No single connector has all the ideal properties for every application; the proliferation of types is a result of the diverse yet specific requirements of manufacturers.
Materials.
Electrical connectors essentially consist of two classes of materials: conductors and insulators. Properties important to conductor materials are contact resistance, conductivity, mechanical strength, formability, and resilience. Insulators must have a high electrical resistance, withstand high temperatures, and be easy to manufacture for a precise fit
Electrodes in connectors are usually made of copper alloys, due to their good conductivity and malleability. Alternatives include brass, phosphor bronze, and beryllium copper. The base electrode metal is often coated with another inert metal such as gold, nickel, or tin. The use of a coating material with good conductivity, mechanical robustness and corrosion resistance helps to reduce the influence of passivating oxide layers and surface adsorbates, which limit metal-to-metal contact patches and contribute to contact resistance. For example, copper alloys have favorable mechanical properties for electrodes, but are hard to solder and prone to corrosion. Thus, copper pins are usually coated with gold to alleviate these pitfalls, especially for analog signals and high-reliability applications.
Contact "carriers" that hold the parts of a connector together are usually made of plastic, due to its insulating properties. "Housings" or "backshells" can be made of molded plastic and metal. Connector bodies for high-temperature use, such as thermocouples or associated with large incandescent lamps, may be made of fired ceramic material.
Failure modes.
The majority of connector failures result in intermittent connections or open contacts:
Connectors are purely passive componentsthat is, they do not enhance the function of a circuitso connectors should affect the function of a circuit as little as possible. Insecure mounting of connectors (primarily chassis-mounted) can contribute significantly to the risk of failure, especially when subjected to extreme shock or vibration. Other causes of failure are connectors inadequately rated for the applied current and voltage, connectors with inadequate ingress protection, and threaded backshells that are worn or damaged.
High temperatures can also cause failure in connectors, resulting in an "avalanche" of failuresambient temperature increases, leading to a decrease in insulation resistance and increase in conductor resistance; this increase generates more heat, and the cycle repeats.
Fretting (so-called "dynamic corrosion") is a common failure mode in electrical connectors that have not been specifically designed to prevent it, especially in those that are frequently mated and de-mated. Surface corrosion is a risk for many metal parts in connectors, and can cause contacts to form a thin surface layer that increases resistance, thus contributing to heat buildup and intermittent connections. However, remating or reseating a connector can alleviate the issue of surface corrosion, since each cycle scrapes a microscopic layer off the surface of the contact(s), exposing a fresh, unoxidised surface.
Circular connectors.
Many connectors used for industrial and high-reliability applications are circular in cross section, with a cylindrical housing and circular contact interface geometries. This is in contrast to the rectangular design of some connectors, e.g. USB or blade connectors. They are commonly used for easier engagement and disengagement, tight environmental sealing, and rugged mechanical performance. They are widely used in military, aerospace, industrial machinery, and rail, where MIL-DTL-5015 and MIL-DTL-38999 are commonly specified. Fields such as sound engineering and radio communication also use circular connectors, such as XLR and BNC. AC power plugs are also commonly circular, for example, Schuko plugs and IEC 60309.
The M12 connector, specified in IEC 61076-2-101, is a circular electrical plug/receptacle pair with 12mm OD mating threads, used in NMEA 2000, DeviceNet, IO-Link, some kinds of Industrial Ethernet, etc.
A disadvantage of the circular design is its inefficient use of panel space when used in arrays, when compared to rectangular connectors.
Circular connectors commonly use backshells, which provide physical and electromagnetic protection, whilst sometimes also providing a method for locking the connector into a receptacle. In some cases, this backshell provides a hermetic seal, or some degree of ingress protection, through the use of grommets, O-rings, or potting.
Hybrid connectors.
Hybrid connectors allow the intermixing of many connector types, usually by way of a housing with inserts. These housings may also allow intermixing of electrical and non-electrical interfaces, examples of the latter being pneumatic line connectors, and optical fiber connectors. Because hybrid connectors are modular in nature, they tend to simplify assembly, repair, and future modifications. They also allow the creation of composite cable assemblies that can reduce equipment installation time by reducing the number of individual cable and connector assemblies.
Mechanical features.
Pin sequence.
Some connectors are designed such that certain pins make contact before others when inserted, and break first on disconnection. This is often used in power connectors to protect equipment, e.g. connecting safety ground first. It is also employed for digital signals, as a method to sequence connections properly in hot swapping.
Keying.
Many connectors are keyed with some mechanical component (sometimes called a "keyway"), which prevents mating in an incorrect orientation. This can be used to prevent mechanical damage to connectors, from being jammed in at the wrong angle or into the wrong connector, or to prevent incompatible or dangerous electrical connections, such as plugging an audio cable into a power outlet. Keying also prevents otherwise symmetrical connectors from being connected in the wrong orientation or "polarity". Keying is particularly important for situations where there are many similar connectors, such as in signal electronics. For instance, XLR connectors have a notch to ensure proper orientation, while Mini-DIN plugs have a plastic projection that fits into a corresponding hole in the socket (they also have a notched metal skirt to provide secondary keying).
Locking mechanisms.
Some connector housings are designed with locking mechanisms to prevent inadvertent disconnection or poor environmental sealing. Locking mechanism designs include locking levers of various sorts, jackscrews, screw-in shells, push-pull connector, and toggle or bayonet systems. Some connectors, particularly those with large numbers of contacts, require high forces to connect and disconnect. Locking levers and jackscrews and screw-in shells for such connectors frequently serve both to retain the connector when connected and to provide the force needed for connection and disconnection. Depending on application requirements, housings with locking mechanisms may be tested under various environmental simulations that include physical shock and vibration, water spray, dust, etc. to ensure the integrity of the electrical connection and housing seals.
Backshells.
Backshells are a common accessory for industrial and high-reliability connectors, especially circular connectors. Backshells typically protect the connector and/or cable from environmental or mechanical stress, or shield it from electromagnetic interference. Many types of backshells are available for different purposes, including various sizes, shapes, materials, and levels of protection. Backshells usually lock onto the cable with a clamp or moulded boot, and may be threaded for attachment to a mating receptacle. Backshells for military and aerospace use are regulated by SAE AS85049 within the USA.
Hyperboloid contacts.
To deliver ensured signal stability in extreme environments, traditional pin and socket design may become inadequate. Hyperboloid contacts are designed to withstand more extreme physical demands, such as vibration and shock. They also require around 40% less insertion force as low as per contact,which extends the lifespan, and in some cases offers an alternative to zero insertion force connectors.
In a connector with hyperboloid contacts, each female contact has several equally spaced longitudinal wires twisted into a hyperbolic shape. These wires are highly resilient to strain, but still somewhat elastic, hence they essentially function as linear springs. As the male pin is inserted, axial wires in the socket half are deflected, wrapping themselves around the pin to provide a number of contact points. The internal wires that form the hyperboloid structure are usually anchored at each end by bending the tip into a groove or notch in the housing.
Whilst hyperboloid contacts may be the only option to make a reliable connection in some circumstances, they have the disadvantage of taking up greater volume in a connector, which can cause problems for high-density connectors. They are also significantly more expensive than traditional pin and socket contacts, which has limited their uptake since their invention in the 1920s by Wilhelm Harold Frederick. In the 1950s, Francois Bonhomme popularised hyperboloid contacts with his "Hypertac" connector, which was later acquired by Smiths Group. During the following decades, the connectors steadily gained popularity, and are still used for medical, industrial, military, aerospace, and rail applications (particularly trains in Europe).
Pogo pins.
"Pogo pin" or "spring loaded" connectors are commonly used in consumer and industrial products, where mechanical resilience and ease of use are priorities. The connector consists of a barrel, a spring, and a plunger. They are in applications such as the MagSafe connector where a quick disconnect is desired for safety. Because they rely on spring pressure, not friction, they can be more durable and less damaging than traditional pin and socket design, leading to their use in in-circuit testing.
Crown spring connectors.
Crown spring connectors are commonly used for higher current flows and industrial applications. They have a high number of contact points, which provides a more electrically reliable connection than traditional pin and socket connectors.
Methods of connection.
Whilst technically inaccurate, electrical connectors can be viewed as a type of adapter to convert between two connection methods, which are permanently connected at one end and (usually) detachable at the other end. By definition, each end of this "adapter" has a different connection methode.g. the solder tabs on a male phone connector, and the male phone connector itself. In this example, the solder tabs connected to the cable represent the permanent connection, whilst the male connector portion interfaces with a female socket forming a detachable connection.
There are many ways of applying a connector to a cable or device. Some of these methods can be accomplished without specialized tools. Other methods, while requiring a special tool, can assemble connectors much faster and more reliably, and make repairs easier.
The number of times a connector can connect and disconnect with its counterpart while meeting all its specifications is termed as "mating cycles" and is an indirect measure of connector lifespan. The material used for connector contact, plating type and thickness is a major factor that determines the mating cycles.
Plug and socket connectors.
Plug and socket connectors are usually made up of a male plug (typically pin contacts) and a female socket (typically receptacle contacts). Often, but not always, sockets are permanently fixed to a device as in a chassis connector , and plugs are attached to a cable.
Plugs generally have one or more pins or prongs that are inserted into openings in the mating socket. The connection between the mating metal parts must be sufficiently tight to make a good electrical connection and complete the circuit. An alternative type of plug and socket connection uses hyperboloid contacts, which makes a more reliable electrical connection. When working with multi-pin connectors, it is helpful to have a pinout diagram to identify the wire or circuit node connected to each pin.
Some connector styles may combine pin and socket connection types in a single unit, referred to as a hermaphroditic connector. These connectors includes mating with both male and female aspects, involving complementary paired identical parts each containing both protrusions and indentations. These mating surfaces are mounted into identical fittings that freely mate with any other, without regard for gender (provided that the size and type match).
Sometimes both ends of a cable are terminated with the same gender of connector, as in many Ethernet patch cables. In other applications the two ends are terminated differently, either with male and female of the same connector (as in an extension cord), or with incompatible connectors, which is sometimes called an "adapter cable".
Plugs and sockets are widely used in various connector systems including blade connectors, breadboards, XLR connectors, car power outlets, banana connectors, and phone connectors.
Jacks and plugs.
A jack is a connector that installs on the surface of a bulkhead or enclosure, and mates with its reciprocal, the plug. According to the American Society of Mechanical Engineers, the stationary (more fixed) connector of a pair is classified as a "jack" (denoted J), usually attached to a piece of equipment as in a chassis-mount or panel-mount connector. The movable (less fixed) connector is classified as a "plug" (denoted P), designed to attach to a wire, cable or removable electrical assembly. This convention is currently defined in ASME Y14.44-2008, which supersedes IEEE 200-1975, which in turn derives from the long-withdrawn MIL-STD-16 (from the 1950s), highlighting the heritage of this connector naming convention. IEEE 315-1975 works alongside ASME Y14.44-2008 to define jacks and plugs.
The term "jack" occurs in several related terms:
Crimp-on connectors.
Crimped connectors are a type of solderless connection, using mechanical friction and uniform deformation to secure a connector to a pre-stripped wire (usually stranded). Crimping is used in splice connectors, crimped multipin plugs and sockets, and crimped coaxial connectors. Crimping usually requires a specialised crimping tool, but the connectors are quick and easy to install and are a common alternative to solder connections or insulation displacement connectors. Effective crimp connections deform the metal of the connector past its yield point so that the compressed wire causes tension in the surrounding connector, and these forces counter each other to create a high degree of static friction. Due to the elastic element in crimped connections, they are highly resistant to vibration and thermal shock.
Crimped contacts are permanent (i.e. the connectors and wire ends cannot be reused).
Crimped plug-and-socket connectors can be classified as "rear release" or "front release". This relates to the side of the connector where the pins are anchored:
Soldered connectors.
Many plug and socket connectors are attached to a wire or cable by soldering conductors to electrodes on the back of the connector. Soldered joints in connectors are robust and reliable if executed correctly, but are usually slower to make than crimped connections. When wires are to be soldered to the back of a connector, a backshell is often used to protect the connection and add strain relief. Metal "solder buckets" or "solder cups" are provided, which consist of a cylindrical cavity that an installer fills with solder before inserting the wire.
When creating soldered connections, it is possible to melt the dielectric between pins or wires. This can cause problems because the thermal conductivity of metals causes heat to quickly distribute through the cable and connector, and when this heat melts plastic dielectric, it can cause short circuits or "flared" (conical) insulation. Solder joints are also more prone to mechanical failure than crimped joints when subjected to vibration and compression.
Insulation-displacement connectors.
Since stripping insulation from wires is time-consuming, many connectors intended for rapid assembly use insulation-displacement connectors which cut the insulation as the wire is inserted. These generally take the form of a fork-shaped opening in the terminal, into which the insulated wire is pressed, which cut through the insulation to contact the conductor. To make these connections reliably on a production line, special tools accurately control the forces applied during assembly. On small scales, these tools tend to cost more than tools for crimped connections.
Insulation displacement connectors are usually used with small conductors for signal purposes and at low voltage. Power conductors carrying more than a few amperes are more reliably terminated with other means, though "hot tap" press-on connectors find some use in automotive applications for additions to existing wiring.
A common example is the multi-conductor flat ribbon cable used in computer disk drives; to terminate each of the many (approximately 40) wires individually would be slow and error-prone, but an insulation displacement connector can terminate all the wires in a single action. Another very common use is so-called punch-down blocks used for terminating unshielded twisted pair wiring.
Binding posts.
Binding posts are a single-wire connection method, where stripped wire is screwed or clamped to a metal electrode. Such connectors are frequently used in electronic test equipment and audio. Many binding posts also accept a banana plug.
Screw terminals.
Screw connections are frequently used for semi-permanent wiring and connections inside devices, due to their simple but reliable construction. The basic principle of all screw terminals involves the tip of a bolt clamping onto a stripped conductor. They can be used to join multiple conductors, to connect wires to a printed circuit board, or to terminate a cable into a plug or socket. The clamping screw may act in the longitudinal axis (parallel to the wire) or the transverse axis (perpendicular to the wire), or both. Some disadvantages are that connecting wires is more difficult than simply plugging in a cable, and screw terminals are generally not very well protected from contact with persons or foreign conducting materials.
Terminal blocks (also called terminal "boards" or "strips") provide a convenient means of connecting individual electrical wires without a splice or physically joining the ends. Since terminal blocks are readily available for a wide range of wire sizes and terminal quantity, they are one of the most flexible types of electrical connector available. One type of terminal block accepts wires that are prepared only by stripping a short length of insulation from the end. Another type, often called "barrier strips", accepts wires that have ring or spade terminal "lugs" crimped onto the wires.
Printed circuit board (PCB) mounted screw terminals let individual wires connect to a PCB through leads soldered to the board.
Ring and spade connectors.
The connectors in the top row of the image are known as ring terminals and spade terminals (sometimes called fork or split ring terminals). Electrical contact is made by the flat surface of the ring or spade, while mechanically they are attached by passing a screw or bolt through them. The spade terminal form factor facilitates connections since the screw or bolt can be left partially screwed in as the spade terminal is removed or attached. Their sizes can be determined by the gauge of the conducting wire, and the interior and exterior diameters.
In the case of insulated crimp connectors, the crimped area lies under an insulating sleeve through which the pressing force acts. During crimping, the extended end of this insulating sleeve is simultaneously pressed around the insulated area of the cable, creating strain relief. The insulating sleeve of insulated connectors has a color that indicates the wire's cross-section area. Colors are standardized according to DIN 46245:
Blade connectors.
A blade connector is a type of single wire, plug-and-socket connection device using a flat conductive blade (plug) that is inserted into a receptacle. Wires are typically attached to male or female blade connector terminals by either crimping or soldering. Insulated and uninsulated varieties are available. In some cases the blade is an integral manufactured part of a component (such as a switch or a speaker unit), and the reciprocal connector terminal is pushed onto the device's connector terminal.


Remote center compliance

In robotics, a remote center compliance, remote center of compliance or RCC is a mechanical device that facilitates automated assembly by preventing peg-like objects from jamming when they are inserted into a hole with tight clearance. In a naive design without an RCC, a robot might pick up a peg with its gripper, center the peg over the hole, and then push the peg along the axis of the hole. If the peg is perfectly aligned and centered, it would then slide into the hole. However, if the peg's alignment or centering is slightly off, the peg contacts one side of the hole first and the peg's tip experiences a lateral force. As the robot's gripper is not perfectly stiff, the peg will tend to rotate about an axis in the plane of the gripper's fingers, called the center of compliance. Such a rotation further misaligns the peg, increasing the lateral force and causing more rotation, resulting in a jam that prevents the insertion from being completed.
The RCC changes the way the peg responds to a lateral force at its tip. The RCC is typically placed between the robot's wrist and the gripper, though it can be built into the gripper itself. The RCC lets the gripper assembly move in the plane perpendicular to the peg's axis, allowing the peg to rotate about an axis in the plane of the top of the hole, effectively moving the center of compliance from the gripper to the hole. With the RCC, the forces generated by any misalignment move the peg in a way that corrects the problem, rather than exacerbates it.


Speedwire

Speedwire is a solderless prototyping system manufactured by BICC-Vero for constructing electronic circuit boards. The system is based on a circuit board pre-drilled with holes in a regular 0.1-inch (2.54 mm) square grid. The boards are available in standard sizes such as Eurocard modules. Some of the holes are through-plated and interconnected with copper strips to form power and ground rails.
Special terminals are provided, which are inserted, using a special tool, into the holes in the prototyping board where components are to be fitted. Some boards are also available pre-populated with terminals. Each terminal is a metal tube with a component socket at one end and an insulation-displacement fork at the other. The component socket accepts a wire lead, such as the lead of a resistor or capacitor, or the leg of a 0.1-inch-pitch DIL package. The insulation-displacement fork accepts an insulated wire specially manufactured for the Speedwire system. The wire is pressed between the forks using a special tool. The forks cut through the insulation and grip the wire, making a gas-tight contact. The wire can then be cut off, or continued to another terminal. Wires can be pulled out of terminals and re-routed.


Unilever Sri Lanka

Unilever Sri Lanka is a Sri Lankan consumer goods company located in Colombo. It is wholly owned by Unilever, a British multinational consumer goods company. Its products include food, beauty products, personal care, pharmaceuticals, and baby products. Unilever Sri Lanka was established in 1938 as Lever Brother Ceylon Limited. In 1972, it was renamed Unilever Sri Lanka. The company has been ranked as Most Valuable and Strongest Brand and Most Respected Entity. The company has over two dozen brands that are market leaders in Sri Lanka since the 1940s. Unilever operates from a factory complex in an industrial zone of Horana since 2012. About 96% of the company's products are manufactured locally, and more than twenty of its brands are exported outside Sri Lanka.
Awards.
Unilever Sri Lanka's largest factory facility, in Horana, is ISO 9001-certified. It manufactures up to 200 products, covering fourteen brands.
In 2015, the company won the SLIM Brand Excellence award.
Unilever Sri Lanka has developed a plastic-free, environmentally friendly packaging system. It was awarded the first eco-friendly baby product SLS certification in 2020.


QBS-09

The QBS-09 semi-automatic shotgun, also known as the Type 09 shotgun, is a semi-automatic shotgun developed by Norinco of the People's Republic of China.
Design and development.
The initial development of the QBS-09 dates back to 1989, with the project officially established in 2005. Multiple prototypes were created between 2005 and 2007, including one featuring an internal tube design, and a conventional magazine-fed design.
The QBS-09 uses specifically designed DBD-09 18.4mm tungsten alloy anti-personnel buckshot. The round is loaded with 14 pellets of high-density tungsten alloy buckshot set into plastic container with steel-case. Tungsten alloy is used as the penetration level of the lead pellets were unable to meet the PLA requirement. Each pellet is made of tungsten alloy ball of 5.3mm (~0.2“) in diameter, 1.4 gram (~22 grains) in weight.
The length of the round is 65mm and the whole round weighs 44 grams. The muzzle velocity is reported at 420 m/s (1380 fps), with an effective range of up to 100 meters. Due to the DBD-09 round generating high-impulse recoil, the QBS09 shotgun is equipped with a spring-buffered shoulder stock, which retracts every time the gun fires.
The Type 10 rubber round is also available as a less-lethal option. The Type 10 round weighs 33.96～39.66g, containing 28 rubber pellets with a diameter of 7.2mm. The Type 10 paintball gun is also available for law enforcement usage.


Health hazards in semiconductor manufacturing occupations are a major issue of occupational hygiene due to the chemical hazards required to produce semiconductors in the semiconductor industry. The manifestations of exposure to health hazards during the production process often occurs at a low level and the effects of the toxins may take decades to surface.
A Scientific Advisory Committee funded by the Semiconductor Industry Association concluded there was no evidence of increased cancer risk to cleanroom workers, although it could not rule out the possibility that circumstances might exist that could result in increased risk.
Impacts of Health Hazards in Semiconductor Manufacturing on Women.
Historically, semiconductor fabrication and the production roles involved in creating integrated circuits have often been the role of women. In the 1980s, it was estimated that 68% of tech production jobs (including semiconductor production) were performed by women. In Southeast Asia, one of the largest producers of semiconductors in the world, over 90% of the production jobs were said to be filled by women during this period. Today, the trend of women dominating production roles in the semiconductor industry continues.
Semiconductor fabrication, as previously stated, has a number of adverse impacts on workers' health. However, these effects are realized to a greater extent in female workers then with men. Digital Equipment, one American producer of semiconductors, found that women working in its factories had twice the chance of experiencing a miscarriage as compared to the general population. Subsequently, Bloomberg reported that the parent company behind Digital Equipment initially pledged to remove the teratogens from their manufacturing processes, however instead decided to outsource production to factories abroad where the regulations and public pressure for the use of these chemicals was less significant. Semiconductor producers continually subvert occupational safety and health regulations by operating abroad in countries where these regulations are lax and even nonexistent, which ultimately occurs at the detriment of the primarily female workers producing the chips.
Many semiconductor fabrication plants are associated with causing loss of eyesight and degradation of vision capabilities in workers. One plant in Hong Kong in the 1970s reported that workers over age 25 were called "Grandma" as they were the most susceptible to eyesight damage from the toxic chemicals involved in semiconductor fabrication. These health impacts can often cause workers to leave semiconductor production jobs earlier than expected, yet unable to easily find other jobs after they fully experience the health impacts of semiconductor fabrication in the first place.


Microdispensing

Microdispensing is the technique of producing liquid media dosages in volumes of less than one microlitre. The continuing miniaturization in almost all technical areas creates constant challenges for industry, development and research facilities. Microdispensing is one of those challenges. Ever smaller amounts of adhesive, liquid, oil, grease and a multitude of other media must be dispensed reliably and accurately in dosage and placement with short cycle times. The precise positioning and quantity of fluids such as glue, reagents or any other substance has a great influence on the overall quality of a medical device. A few examples are:
Microdispensing is also used in non-medical applications, like on-demand soda flavoring (the Coca-Cola Freestyle and Pepsi Spire), inkjet printing, and 3-D printing.
Dispensing techniques.
There are two basic types of dispensing techniques: classic contact dispensing and non-contact dispensing.
Contact dispensing.
In contact dispensing, the drop forms at the exit of a nozzle, and is deposited by contact, while the drop is still on the nozzle. The technique is as old as the wish to divide a medium, stored in a big container, into smaller amounts. A good example for this is applying adhesive with a tube: To apply the adhesive requires contact between the tip of the tube and the part for the bead of adhesive to be transferred. This method has disadvantages:
Despite all of these disadvantages, contact dispensing is still used in the majority of automated processes today, because of:
Typical technologies for contact dispensing.
Gear pump
Pressure-time systems
Non-contact dispensing (Jetting).
In non-contact dispensing, the drop also forms at the end of a nozzle, but far enough away from the target area that the drop separates from the nozzle before it hits. This, too, is a very old technique, as old as squirting liquid from a tube.
Because of increasing requirements in regards to cycle time and accuracy in almost all areas of production, non-contact dispensing is constantly gaining importance. A good example for this is the attachment of very small electronic parts (SMD parts) onto printed circuit boards and substrates. For this, the part carrier only needs to be positioned in one plane - after that the adhesive can be transferred without contact. The following examples show the advantages of non-contact dispensing:
Non-contact dispensing can be divided in two different methods:
Jet-forming dispensing.
Jet-forming dispensing exists when the flow velocity of a medium at the nozzle exit is high enough that the effects of gravitation and surface tension on the separation of the fluid from the nozzle are of secondary importance. This state is characterized by the Weber number:
where
The physical border line between drop- and jet-forming is around a Weber-number of 8. At this point the dynamic pressure of the flowing medium exceeds the pressure from the surface tension of the drop, which therefore sticks to the nozzle. This transitional stage can be demonstrated at a water tap by gradually increasing the flow, going from the dropping status until a continuous water jet has formed. The Weber-number in this case is, however, clearly above 8, because of the jet exit conditions of the nozzle.
By using the Weber-number, the theoretical lower limit of the mass flow can be found for the jet-forming conditions. In actual applications, to assure a safe dispensing process, the real Weber-numbers chosen should be between 20 and 50.
For a calculated estimation of the fluid flow velocity in the nozzle, for fluids with Newtonian flow behavior, the formula for capillary fluid flow according to the Hagen–Poiseuille law has been proven.
To avoid atomizing of the fluid at the nozzle exit, the fluid flow in the nozzle must be laminar, which is the case as long as the Reynolds number (Re) of the nozzle is smaller than the critical Reynolds-number of the nozzle:
Reynolds-number of the nozzle:
Critical Reynolds-number of the nozzle:
Thus, the theoretical range of the jet-forming dispension is enclosed at its lower limit by the Weber-number and at its upper limit by the critical Reynolds-number. For practical applications, a high kinetic energy in the fluid jet is not desirable, because the jet probably would burst and spatter tiny droplets around the target point. Jet-forming dispensing systems are therefore usually operated in the area of lower Weber-numbers.
In practice, the calculation of the Weber-number becomes more complicated when fluids with additives are used, which demonstrate a non-Newtonian (i.e. thixotropic) flow behavior and therefore the viscosity during the flow through the nozzle is different.
Dynamic drop dispensing.
Dynamic drop dispensing is characterised by separation of a drop from the nozzle exit through a dynamic process, because the static pressure of the liquid medium is insufficient for forming a fluid jet.
A well-known example is inkjet printing. In this application, the volume of a small dispensing chamber with adjoining nozzle becomes reduced through a short impulse, whereby the ink is ejected through the nozzle. Nozzle chamber, nozzle and ink reservoir are hereby fluidically connected without any valve in between. During the dispensing process, some of the medium is also flowing in the reverse direction (back into the reservoir). The surface tension of the fluid at the nozzle exit prevents air being sucked in and fluid from exiting the nozzle when the dispensing chamber is filled up again. The principle of this process is only useful for low-viscosity fluids and this principle is not applicable with higher fluid pressures.
Ink-jet systems have the following inherent properties:
• Very small single-drop volumes are achievable (8 picolitres)
• High dispensing frequencies can be realised (some kHz)
• Low costs for mass production
• Only certain low-viscosity media are dispensable (i.e. no volatile media)
• Principally not leak-proof
For industrial production, the dispensing amounts and the range of viscosity spectra of ink-jet systems for most applications are too small. In these fields of production, specially-designed valves with tappet drives of high dynamic pressure are used instead. These microdispensing systems are characterised by the following properties:
• Single drop volumes from 10 to 200 nanolitres
• Dispensing frequencies up to 100 Hz
• Dispensing accuracy < 1%
• Media viscosities up to 200 Pa·s (thixotropic)


Blanking and piercing

Blanking and piercing are shearing processes in which a punch and die are used to produce parts from coil or sheet stock. Blanking produces the outside features of the component, while piercing produces internal holes or shapes. The web is created after multiple components have been produced and is considered scrap material. The "slugs" produced by piercing internal features are also considered scrap. The terms "piercing" and "punching" can be used interchangeably.
Die roll and burr formation.
Burrs and die roll are typical features of stamped components. Die roll is created when the material being stamped in compressed before the material begins to shear. Die roll takes the form of a radius around the outside edge of the blank and the pierced holes. After compression, the part shears for about 10% of the part thickness, and then fractures free of the strip or sheet. This fracturing produces a raised, jagged edge which is called a "burr". Burrs are typically removed by tumbling in a secondary process. Burr height can be used as an important indicator of tool wear.
Tooling design guidelines.
The selection criteria of all process parameters are governed by the sheet thickness and by the strength of the work-piece material being pierced.
The punch/die clearance is a crucial parameter, which determines the load or pressure experienced at the cutting edge of the tool, commonly known as point pressure. Excessive point pressure can lead to accelerated wear and ultimately failure. the surface quality of the trimmed edge is severely affected by the clearance, too.
Material specific design guidelines are developed by companies in order to define the minimum acceptable values of hole diameters, bridge sizes, slot dimensions. Similarly, the strip lay-out must be determined (strip width and pitch). The bridge width between the parts and the edge allowance between the part and the edge of the strip also have to be selected.
A simple operation may only need a pancake die. While many dies perform complex procedures simultaneously, a pancake die may only perform one simple procedure with the finished product being removed by hand.
Process variants.
There are various types of blanking and piercing: lancing, perforating, notching, nibbling, shaving, cutoff, and dinking.
Lancing.
Lancing is a piercing operation in which the workpiece is sheared and bent with one strike of the die. A key part of this process is that there is not reduction of material, only a modification in its geometry. This operation is used to make tabs, vents, and louvers.
The cut made in lancing is not a closed cut, like in perforation even though a similar machine is used, but a side is left connected to be bent sharply or in more of a rounded manner.
Lancing can be used to make partial contours and free up material for other operations further down the production line. Along with these reasons, lancing is also used to make tabs (where the material is bent at a 90 degree angle to the material), vents (where the bend is around 45 degrees), and louvers (where the piece is rounded or cupped). Lancing also helps to cut or slight shear of sheet on cylindrical shape.
Normally lancing is done on a mechanical press, lancing requires the use of punches and dies to be used. The different punches and dies determine the shape and angle (or curvature) of the newly made section of the material. The dies and punches are needed to be made of tool steel to withstand the repetitious nature of the procedure.
Perforating.
Perforating is a piercing tooling that involves punching a large number of closely spaced holes.
Notching.
Notching is a piercing operation that removes material from the edge of the workpiece.
Nibbling.
The nibbling process cuts a contour by producing a series of overlapping slits or notches. A nibbler may be employed to do this. This allows for complex shapes to be formed in sheet metal up to 6 mm (0.25 in) thick using simple tools. that is essentially a small punch and die that reciprocates quickly; around 300–900 times per minute. Punches are available in various shape and sizes; oblong and rectangular punches are common because they minimize waste and allow for greater distances between strokes, as compared to a round punch. Nibbling can occur on the exterior or interior of the material, however interior cuts require a hole to insert the tool.
The process is often used on parts that do not have quantities that can justify a dedicated blanking die. The edge smoothness is determined by the shape of the cutting die and the amount the cuts overlap; naturally the more the cuts overlap, the cleaner the edge. For added accuracy and smoothness, most shapes created by nibbling undergo filing or grinding processes after completion.
Shaving.
The shaving process is a finishing operation where a small amount of metal is sheared away from an already blanked part. Its main purpose is to obtain better dimensional accuracy, but secondary purposes include squaring the edge and smoothing the edge. Blanked parts can be shaved to an accuracy of up to 0.025 mm (0.001 in).
Shaving of metals is done in order to remove excess or scrap metal. A straight, smooth edge is provided and therefore shaving is frequently performed on instrument parts, watch and clock parts, and the like. Shaving is accomplished in shaving dies especially designed for the purpose.
Trimming.
The trimming operation is the last operation performed, because it cuts away excess or unwanted irregular features from the walls of drawn sheets.
Fine blanking.
Fine blanking is a specialized form of blanking where there is no fracture zone when shearing. This is achieved by compressing the whole part and then an upper and lower punch extract the blank. This allows the process to hold very tight tolerances, and perhaps eliminate secondary operations.
Materials that can be fine blanked include aluminium, brass, copper, and carbon, alloy, and stainless steels.
Fine blanking presses are similar to other metal stamping presses, but they have a few critical additional parts. A typical compound fine blanking press includes a hardened die punch (male), the hardened blanking die (female), and a guide plate of similar shape/size to the blanking die. The guide plate is the first applied to the material, impinging the material with a sharp protrusion or "stinger" around the perimeter of the die opening. Next, a counter pressure is applied opposite the punch, and finally, the die punch forces the material through the die opening. Since the guide plate holds the material so tightly, and since the counter pressure is applied, the material is cut in a manner more like extrusion than typical punching. Mechanical properties of the cut benefit similarly with a hardened layer at the cut edge of the part. Because the material is so tightly held and controlled in this setup, part flatness remains very true, distortion is nearly eliminated, and edge burr is minimal. Clearances between the die and punch are generally around 1% of the cut material thickness, which typically varies between . Currently parts as thick as can be cut using fine blanking. Tolerances between ± are possible, depending on the base material thickness and tensile strength, and part layout.
With standard compound fine blanking processes, multiple parts can often be completed in a single operation. Parts can be pierced, partially pierced, offset (up to 75°), embossed, or coined, often in a single operation. Some combinations may require progressive fine blanking operations, in which multiple operations are performed at the same pressing station. Due to the higher lifetime, blanking punches are usually covered by PVD protective coatings.
The advantages of fine blanking are:
One of the main advantages of fine blanking is that slots or holes can be placed very near to the edges of the part, or near to each other. Also, fineblanking can produce holes that are much smaller (as compared to material thickness) than can be produced by conventional stamping.
The disadvantages are:


National Centre for Food Manufacturing

The National Centre for Food Manufacturing (NCFM) is the food science campus of the University of Lincoln, situated on "Park Road" at Holbeach in the south of the county of Lincolnshire. It offers part-time apprenticeships and distance learning degrees for individuals working in the food industry.
Apprenticeships, Degree and Foundation Courses.
The National Centre for Food Manufacturing offers part time distance learning options to achieve Foundation and BSc (Honours) Food Manufacture degrees and higher degrees through research together with all levels of apprenticeships including Higher Apprenticeships (which includes a Foundation Degree). The Foundation and Undergraduate degrees cover areas including Food and Drink Operations and Manufacturing Management - Food Science and Technology – and Food Supply Chain Management. The Centre also offers part time Masters and PhDs - often progressed by food sector employees and focused on specific Food Manufacturing Industry Challenges.
The Higher and Degree Apprenticeships include the CMDA (Chartered Manager Degree Apprenticeship), Departmental Manager, Laboratory Scientist and Professional Technical degrees.
The Centre provides support to apprentices for Functional Skills development in maths and English as required by their relevant apprenticeship standard and offers employers a complete skills development programme for its employees.
NCFM has apprenticeship partnerships with 250 UK food businesses including Addo Food Group, Bakkavor, Bidfood, Dalehead Foods, Summers Butchery Services, Greencore Group, Tulip, Dovecote Park, Fresttime, Finlays, JDM Food Group, Kerry, Nestle, Worldwide Fruit, University Academy Holbeach, Produce World Group, J.O. Sims Ltd, Greenvale AP, FreshLinc, Ripe Now and Lincolshire Field Products.
Research.
NCFM advances food manufacturing and related food supply chain research initiatives via a wide range of industry and academic partnerships. The areas of core research include Robotics and Automation, Food Analysis (Microbiology & Food Chemistry), Advanced Food Processing Technologies, Food Insights & Sustainability, and Food Supply Chain Development.
The NCFM Research and Technical Resources coupled with industry and academic partnerships enable NCFM to readily progress multidisciplinary research and practical problem solving for the food industry. NCFM’s research agenda reflects the food sector’s innovation priorities and is informed by funding partners and directly by the needs of the diverse food sector including retailers and food businesses of all sizes from multinationals to SME and micro businesses. Research at NCFM is funded by a number of sources (dependent upon the specific challenge) including direct consultancy with business, Innovate UK, BBSRC, EPSRC, FSA, EU Interreg programmes and Horizon 2020 initiatives.
Short Courses.
NCFM offers Short Courses including courses in auditing, food safety, Hazard analysis and critical control points(HACCP), health and safety, management and team development, and technical and product development.
Commercial Partners.
The National Centre for Food Manufacturing maintains commercial partnerships with food industry organisations specialising in areas such as robotics, refrigeration, sustainability, packaging, manufacturing, innovative food supply chain management, food processing, productivity and several other areas.
Conferencing Facilities.
The National Centre for Food Manufacturing Holbeach campus offers facilities hire for conferences, seminars and exhibitions.


Microelectronics

Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture (or microfabrication) of very small electronic designs and components. Usually, but not always, this means micrometre-scale or smaller. These devices are typically made from semiconductor materials. Many components of a normal electronic design are available in a microelectronic equivalent. These include transistors, capacitors, inductors, resistors, diodes and (naturally) insulators and conductors can all be found in microelectronic devices. Unique wiring techniques such as wire bonding are also often used in microelectronics because of the unusually small size of the components, leads and pads. This technique requires specialized equipment and is expensive.
Digital integrated circuits (ICs) consist of billions of transistors, resistors, diodes, and capacitors. Analog circuits commonly contain resistors and capacitors as well. Inductors are used in some high frequency analog circuits, but tend to occupy larger chip area due to their lower reactance at low frequencies. Gyrators can replace them in many applications.
As techniques have improved, the scale of microelectronic components has continued to decrease. At smaller scales, the relative impact of intrinsic circuit properties such as interconnections may become more significant. These are called parasitic effects, and the goal of the microelectronics design engineer is to find ways to compensate for or to minimize these effects, while delivering smaller, faster, and cheaper devices.
Today, microelectronics design is largely aided by Electronic Design Automation software.


Accumulative roll bonding

Accumulative roll bonding (ARB) is a severe plastic deformation (SPD) process. It is a method of rolling a stack of metal sheets, which are repeatedly rolled to a severe reduction ratio, sectioned into two halves, piled again and rolled. It has been often proposed as a method for the production of metal materials with ultrafine grain microstructure. The earliest works on ARB were by Nobuhiro Tsuji, Y. Saito and co-workers. To obtain a single slab of a solid material, the rolling involves not only deformation, but also roll bonding.


Multilayer soft lithography

Multilayer soft lithography (MSL) is a fabrication process in which microscopic chambers, channels, valves and vias are molded within bonded layers of elastomer.
Commercial PDMS stamps can mold materials such as optical adhesive in a sequential process to create the bonded layers.


Circle grid analysis

Circle grid analysis (CGA), also known as circle grid strain analysis, is a method of measuring the strain levels of sheet metal after a part is formed by stamping or drawing. The name itself is a fairly accurate description of the process. Literally, a grid of circles of known diameter is etched to the surface of the sheet metal to be formed. After the part is formed, the circles have been stretched into ellipses. By measuring the longest part of the ellipse (called the “major strain”) and the shortest part of the ellipse (called the “minor strain”), it is possible to determine how close any stamped part is to splitting or fracturing.
The goal of using circle grid strain analysis is to predict potential problems before they become problems. Once you have a forming problem, chances are circle grid analysis won’t be able to help you, unless it’s intermittent enough to form a “good” part from time to time.


Manufacturing Grocers' Employees' Federation of Australia (M.G.U.) was an Australian trade union existing between 1906 and 1988. The union was first established as the Federated Candle, Soap, Soda & Starch Employees' Union of Australia, before changing its name in 1914. The union represented workers employed in manufacturing grocers' sundries and non-edible grocery products, particularly in the southern states of South Australia and Victoria. In 1988 the union amalgamated with the Federated Millers and Mill Employees' Union to form the Federated Millers and Manufacturing Grocers Employees' Association of Australia, which in turn merged with a number of unions to form the National Union of Workers.
Activities.
The Manufacturing Grocers' Union undertook a wide variety of activities to pursue the interests of its members. The union made representations to government and the public in favour of protectionist measures to ensure the competitiveness of products manufactured in Australia with international imports. The M.G.U. also publicised the poor working conditions of its members, including problems such as noise, dust and physical fatigue. The South Australian trade union leader and later politician Theo Nicholls served as part-time secretary of the union in South Australia, and was active in its organisation.
Industrial disputes.
The Manufacturing Grocers' Union underwent several bitter industrial disputes during its history, including a number of strikes. The first major strike the union was involved in was in April 1916, when the M.G.U., along with a number of other unions, participated in a sympathy strike with the Storemen and Packers' Union over the dismissal of several men at a Parsons' Brothers factory in Melbourne. The strike lasted for several months and led to shortages of several products in Victoria, due to blockade of goods by the employers. The strike eventually collapsed in June 1916, with all strikers returning to work.
The Manufacturing Grocers' Union held another major strike in 1948 at the match factories of Bryant and May, in Richmond, Melbourne, over an increase in the required daily output of matches. The dispute was resolved when all parties agreed to allow the Commonwealth Statistician determine a fair daily output per worker.
Demarcation disputes.
The Manufacturing Grocers' Union made efforts to establish a branch of the union in New South Wales, the most populous state of Australia, but this attempt was thwarted by the Australian Workers' Union, who represented the relevant workers at the time.
Amalgamation.
In 1988 the Manufacturing Grocers' Union amalgamated with the Federated Millers and Mill Employees' Union, another small union representing workers in food processing. The resulting body, the Federated Millers and Manufacturing Grocers Employees' Association of Australasia, was short-lived and subsequently amalgamated with the National Union of Storeworkers, Packers, Rubber and Allied Workers to form the National Union of Workers.


Caldie

Caldie is a chromium-molybdenum-vanadium alloyed tool steel manufactured by Uddeholms AB. It is intended for cold work processes, such as blanking and piercing, applied to difficult materials such as advanced high strength steel, where compressive strength and chipping and cracking resistance are important.
Composition.
The steel's composition is
Properties.
Uddeholm Caldie is characterized by:
Application areas.
Uddeholm Caldie is suitable for short to medium run tooling where chipping and/or cracking are the predominant failure mechanisms and where a high compressive strength (hardness of over 60 HRC) is necessary. This makes Uddeholm Caldie very suitable for severe cold work applications where the combination of a hardness above 60 HRC and a high cracking resistance is of utmost importance e.g. as in the blanking and forming of ultra high strength steel sheets. Uddeholm Caldie is also very suitable as a substrate steel for applications where surface coatings are desirable or necessary.
This steel can be used in engineering applications where high compressive strength has to be combined with high ductility/toughness. Knives for fragmentation of plastics and metals and roll forming rolls are good examples


Flash welding

Flash welding is a type of resistance welding that does not use any filler metals. The pieces of metal to be welded are set apart at a predetermined distance based on material thickness, material composition, and desired properties of the finished weld. Current is applied to the metal, and the gap between the two pieces creates resistance and produces the arc required to melt the metal. Once the pieces of metal reach the proper temperature, they are pressed together, effectively forge welding them together.
Parameters.
According to a study published in Materials and Design, several parameters affect the final product. Flash time is the time that the arc is present. Upset time is the amount of time that the two pieces are pressed together. Flash time needs to be long enough to sufficiently heat the metal before it is pressed together. However, if it is too long, too much of the base metal begins to melt away. The upset time is critical in creating the desired mechanical properties of the finished weld. During the upset, any impurities in the base metal are pressed out creating a perfect weld. If the upset time is too short, some of the impurities may remain in the base metal creating a defective weld. The upset time is also crucial in the strength of the finished weld because it is during the upset that coalescence occurs between the two pieces of metal. If the upset time is too short, the two pieces of metal may not completely bond.
Very often flash butt welding is controlled by distance rather than time such that the flashing would occur for a pre-determined length, say 5 mm, before the upsetting cycle starts. Upsetting may then also be controlled by distance. A parameter would be set to apply the upsetting force until a certain distance has been upset. It is generally the upsetting distance that is more important than the upsetting time.
At the end of upsetting there is commonly a 'hold time' during which the joint is held still to allow the joint to cool and the two pieces of metal to completely bond.
Applications.
Railroads use flash welding to join sections of mainline rail together to create Long Welded Rail (LWR) in a factory setting or continuous welded rail (CWR) in track, which is much smoother than mechanically-joined rail because there are no gaps between the sections of rail. This smoother rail reduces the wear on the rails themselves, effectively reducing the frequency of inspections and maintenance. Continuous welded rail is particularly used on high-speed rail lines because of the smoothness of the rail head. Flash welding is also beneficial because it allows dissimilar metals, including non ferrous metals, to be joined. This allows switches and crossings, which are generally composed of high manganese steel, to be effectively welded to carbon steel rail with the use of a stainless steel insert, while keeping the desired mechanical properties of both the rails and the crossings intact. The ability of this single process to weld many different metals, with simple parameter adjustments, makes it very versatile. Flash welding is also used in the metal building industry to increase the length of the angle iron used to fabricate joists.
The aluminum industry uses flash welding to join aluminum, steel, and copper in various current-carrying conductors called busbars. The steel is used for strength, the copper is used for conductivity, and the aluminum is used for its combination of cost and conductivity.


Unit load

The term unit load refers to the size of an assemblage into which a number of individual items are combined for ease of storage and handling, for example a pallet load represents a unit load which can be moved easily with a pallet jack or forklift truck, or a container load represents a unit for shipping purposes. A unit load can be packed tightly into a warehouse rack, intermodal container, truck or boxcars, yet can be easily broken apart at a distribution point, usually a distribution center, wholesaler, or retail store for sale to consumers or for use.
Function.
Most consumer and industrial products move through the supply chain in unitized or unit load form for at least part of their distribution cycle. Unit loads make handling, storage, and distribution more efficient. They help reduce handling costs and damage by reducing individual handling.
A typical unit load might consist of corrugated fiberboard boxes stacked on a pallet or slip sheet and stabilized with stretch wrap, pressure-sensitive tape, strapping or shrink wrap. About 2 billion unit loads are in daily use in the United States.
Unit load design.
There are three kinds of unit load design: component-based, systems-based, and standards-compliant. These have different applications.
Component-based design.
Component-based design is the outmoded "ad hoc" method of unit load design. Components are sometimes over-specified to get assured performance, or tested to get inexpensive economic performance.
Unit load storage and distribution systems consist of several interacting parts:
Considerable knowledge exists regarding the design of each of these components: their interactions have more recently been studied. When packaging, pallet, and handling systems are designed separately at different locations by different teams, the result might be inefficient unit load systems.
The consequences of independent component-based design in the supply chain can include:
Systems-based design.
Systems-based design is a proven process of unit load component cost optimization based on an understanding of how the pallet, packaging and material handling equipment interact during product distribution and storage to design the unit load component parts.
A systems-based approach to unit load design uses software tools and lab testing to create a package that uses just the right amount of material to protect the product, make for safe handling and transportation and minimize the use of non-recyclable materials.
Companies must now consider sustainability when determining how their packaging products will be reused or recycled at the end of their journey. By combining sustainability with unit load science, they not only create the optimal unit load, but also reduce the amount of packaging material used to transport that load, maximizing the materials that can be recycled and minimizing what goes into a landfill.
Unit loads move via an unpredictable combination of many types of vehicles and storage areas, and the exact set is difficult to predict. Therefore, unit loads must be designed to travel by any such vehicles, and be stored in a wide variety of places. There are many similarities in the requirements for long-term storage and long-distance transportation of unit loads.
Factors considered in unit load systems-based design include:
Often a few inexpensive additions to the packaging can stabilize or stiffen a critical part and give good unit-load performance at a low cost.
Standards-compliant design.
Standards permit a unit load to be designed and tested to meet a written specification or test method. A unit load can be verified to comply with a standard and validated to determine that the unit load is indeed effective.
Standards provide institutional memory of the many conditions in real logistic trains, and collect the best practices for design and testing unit loads. Standards also describe load requirements, so that logistic providers can plan to meet them.
ASTM D4169 has standard test protocols for unit loads. These vary based on the value of the load, the expected hazards, and the distribution environment. This is a performance-based standard.
Another standard for unit loads is MIL-STD-1660, a standard for ammunition unit loads. DOD unit loads generally use pallets, which unfortunately do not pack efficiently into ISO containers. They weigh less than to limit the stresses on handling equipment. They are weatherproof, and stack high. They often use steel pallets, steel straps with notched seals, outdoor plywood, and plastic film. MIL-STD-1660 mandates that loads must never be less than the width of a pallet, while permitting some overhang. The markings are LOGMARS bar codes and standard inventory numbers. The standard describes major parts of the logistic path, including storage, ship, air, truck, forklift and sling (i.e. ship-to-ship and parachute). There are auxiliary standards for ship-to-ship transfers, and amphibious transfers. There are tests for stacking, transport, sling, forklift and pallet jack, impact, drop tests, tip, water-retention (i.e. weather), and safe disassembly.
MIL-STD-1660 at first looks like overdesign to commercial unit-load designers. However, similar marking standards, safety, stability, volumetric efficiency, weight limits and impact resistance are routinely needed in commercial logistics. Sling handling is routine for small ports and noncontainer transports. Weatherproofness could be optional. It is sometimes valuable, and the baggies are cheap. High, standardized stacking could be optional as well. It is expensive, but sometimes valuable for rackless and military customers.


Cutting tool material

Cutting tool materials are materials that are used to make cutting tools which are used in machining (drill bits, tool bits, milling cutters, etc.) but not other cutting tools like knives or punches.
Cutting tool materials must be harder than the material of the workpiece, even at high temperatures during the process.
The following properties are required for cutting tool
There is no material that shows all of these properties at the same time. Very hard materials, have lower toughness and break more easily. The following cutting tool materials are used:


NPP Istok

Istok State Scientific Production  is a company (scientific production association) based in Fryazino, Russia. It is part of the Ruselectronics group.
Istok is a major producer of electronic components for space and military use, including magnetrons, klystrons, high-powered vacuum tubes, carbon dioxide lasers, electro-optical devices. It has also developed and manufactured consumer products for the national economy since the 1960s.
For 2020, the company implemented the IIoT.ISTOK Industrial Internet of Things system, which monitors technical processes


Thyssenkrupp Materials Services

thyssenkrupp Materials Services GmbH (tkMX) is the lead company of the business area of the same name and part of the diversified German industrial group thyssenkrupp AG. Materials Services is a global materials distributor as well as a technical and infrastructural service provider for the B2B-sector. The total revenue in the fiscal year 2015/2016 was 11.88 billion Euro.
Company structure.
thyssenkrupp Materials Services is divided in three so-called business units - Materials Distribution, Supply Chain Services and Special Materials. Over 19,700 employees work for the 81 Materials Services subsidiaries at around 480 branches in more than 40 countries.
Main customers are located in Europe and North America. They are specialist retailers and companies of the automotive sector or the metal processing industry.
Digital transformation.
Materials Services runs a Digital Transformation Office (DTO). The DTO forwards the business area’s digitalization goals. The strategy includes a progressive addition of e-commerce models as well as a cultural change to an integral and collaborative work environment.
The online shop "materials4me" was launched in Great Britain, Germany, Spain and Switzerland in 2016. The target group of materials4me are do-it-yourselfers, educational institutions as well as small and medium businesses. There are also two B2B-portals. "Materials Services Online-Portal" grants access to order documents, among others, for key accounts. On the website "onlinelaserworks" customers can upload CAD drawings to have blanks fully automatically cut to size.
At the Hannover trade fair thyssenkrupp announced the opening of a production center for Additive Manufacturing (3D-printing) in the city Mülheim in 2017.
In 2017, Materials Services also announced the self-developed platform "toii" in line with the Industrial Internet of Things (IIoT). This system is compatible with old and new machines from different manufactures. The tool should accelerate the automation of the production operations as well as make processes much more efficient.


Numerical control

Numerical control (also computer numerical control, abbreviated CNC) is the automated control of machining tools (such as drills, lathes, mills, grinders, routers and 3D printers) by means of a computer. A CNC machine processes a piece of material (metal, plastic, wood, ceramic, stone, or composite) to meet specifications by following coded programmed instructions and without a manual operator directly controlling the machining operation.
A CNC machine is a motorized maneuverable tool and often a motorized maneuverable platform, which are both controlled by a computer, according to specific input instructions. Instructions are delivered to a CNC machine in the form of a sequential program of machine control instructions such as G-code and M-code, and then executed. The program can be written by a person or, far more often, generated by graphical computer-aided design (CAD) or computer-aided manufacturing (CAM) software. In the case of 3D printers, the part to be printed is "sliced" before the instructions (or the program) are generated. 3D printers also use G-Code.
CNC offers greatly increased productivity over non-computerized machining for repetitive production, where the machine must be manually controlled (e.g. using devices such as hand wheels or levers) or mechanically controlled by pre-fabricated pattern guides (see pantograph mill). However, these advantages come at significant cost in terms of both capital expenditure and job setup time. For some prototyping and small batch jobs, a good machine operator can have parts finished to a high standard whilst a CNC workflow is still in setup.
In modern CNC systems, the design of a mechanical part and its manufacturing program are highly automated. The part's mechanical dimensions are defined using CAD software and then translated into manufacturing directives by computer-aided manufacturing (CAM) software. The resulting directives are transformed (by "post processor" software) into the specific commands necessary for a particular machine to produce the component and then are loaded into the CNC machine.
Since any particular component might require the use of several different tools – drills, saws, etc. – modern machines often combine multiple tools into a single "cell". In other installations, several different machines are used with an external controller and human or robotic operators that move the component from machine to machine. In either case, the series of steps needed to produce any part is highly automated and produces a part that meets every specification in the original CAD drawing, where each specification includes a tolerance.
Description.
Motion is controlling multiple axes, normally at least two (X and Y), and a tool spindle that moves in the Z (depth). The position of the tool is driven by direct-drive stepper motors or servo motors to provide highly accurate movements, or in older designs, motors through a series of step-down gears. Open-loop control works as long as the forces are kept small enough and speeds are not too great. On commercial metalworking machines, closed-loop controls are standard and required to provide the accuracy, speed, and repeatability demanded.
Parts description.
As the controller hardware evolved, the mills themselves also evolved. One change has been to enclose the entire mechanism in a large box as a safety measure (with safety glass in the doors to permit the operator to monitor the machine's function), often with additional safety interlocks to ensure the operator is far enough from the working piece for safe operation. Most new CNC systems built today are 100% electronically controlled.
CNC-like systems are used for any process that can be described as movements and operations. These include laser cutting, welding, friction stir welding, ultrasonic welding, flame and plasma cutting, bending, spinning, hole-punching, pinning, gluing, fabric cutting, sewing, tape and fiber placement, routing, picking and placing, and sawing.
History.
The first CNC machines were built in the 1940s and 1950s, based on existing tools that were modified with motors that moved the tool or part to follow points fed into the system on punched tape. These early servomechanisms were rapidly augmented with analog and digital computers, creating the modern CNC machine tools that have revolutionized machining processes.
Other CNC tools.
Many other tools have CNC variants, including:
Tool/machine crashing.
In CNC, a "crash" occurs when the machine moves in such a way that is harmful to the machine, tools, or parts being machined, sometimes resulting in bending or breakage of cutting tools, accessory clamps, vises, and fixtures, or causing damage to the machine itself by bending guide rails, breaking drive screws, or causing structural components to crack or deform under strain. A mild crash may not damage the machine or tools but may damage the part being machined so that it must be scrapped. Many CNC tools have no inherent sense of the absolute position of the table or tools when turned on. They must be manually "homed" or "zeroed" to have any reference to work from, and these limits are just for figuring out the location of the part to work with it and are no hard motion limit on the mechanism. It is often possible to drive the machine outside the physical bounds of its drive mechanism, resulting in a collision with itself or damage to the drive mechanism. Many machines implement control parameters limiting axis motion past a certain limit in addition to physical limit switches. However, these parameters can often be changed by the operator.
Many CNC tools also do not know anything about their working environment. Machines may have load sensing systems on spindle and axis drives, but some do not. They blindly follow the machining code provided and it is up to an operator to detect if a crash is either occurring or about to occur, and for the operator to manually abort the active process. Machines equipped with load sensors can stop axis or spindle movement in response to an overload condition, but this does not prevent a crash from occurring. It may only limit the damage resulting from the crash. Some crashes may not ever overload any axis or spindle drives.
If the drive system is weaker than the machine's structural integrity, then the drive system simply pushes against the obstruction, and the drive motors "slip in place". The machine tool may not detect the collision or the slipping, so for example the tool should now be at 210mm on the X-axis, but is, in fact, at 32mm where it hit the obstruction and kept slipping. All of the next tool motions will be off by −178mm on the X-axis, and all future motions are now invalid, which may result in further collisions with clamps, vises, or the machine itself. This is common in open-loop stepper systems but is not possible in closed-loop systems unless mechanical slippage between the motor and drive mechanism has occurred. Instead, in a closed-loop system, the machine will continue to attempt to move against the load until either the drive motor goes into an overload condition or a servo motor fails to get to the desired position.
Collision detection and avoidance are possible, through the use of absolute position sensors (optical encoder strips or disks) to verify that motion occurred, or torque sensors or power-draw sensors on the drive system to detect abnormal strain when the machine should just be moving and not cutting, but these are not a common component of most hobby CNC tools. Instead, most hobby CNC tools simply rely on the assumed accuracy of stepper motors that rotate a specific number of degrees in response to magnetic field changes. It is often assumed the stepper is perfectly accurate and never missteps, so tool position monitoring simply involves counting the number of pulses sent to the stepper over time. An alternate means of stepper position monitoring is usually not available, so crash or slip detection is not possible.
Commercial CNC metalworking machines use closed-loop feedback controls for axis movement. In a closed-loop system, the controller monitors the actual position of each axis with an absolute or incremental encoder. Proper control programming will reduce the possibility of a crash, but it is still up to the operator and programmer to ensure that the machine is operated safely. However, during the 2000s and 2010s, the software for machining simulation has been maturing rapidly, and it is no longer uncommon for the entire machine tool envelope (including all axes, spindles, chucks, turrets, tool holders, tailstocks, fixtures, clamps, and stock) to be modeled accurately with 3D solid models, which allows the simulation software to predict fairly accurately whether a cycle will involve a crash. Although such simulation is not new, its accuracy and market penetration are changing considerably because of computing advancements.
Numerical precision and equipment backlash.
Within the numerical systems of CNC programming, the code generator can assume that the controlled mechanism is always perfectly accurate, or that precision tolerances are identical for all cutting or movement directions. This is not always a true condition of CNC tools. CNC tools with a large amount of mechanical backlash can still be highly precise if the drive or cutting mechanism is only driven to apply cutting force from one direction, and all driving systems are pressed tightly together in that one cutting direction. However, a CNC device with high backlash and a dull cutting tool can lead to cutter chatter and possible workpiece gouging. The backlash also affects the precision of some operations involving axis movement reversals during cutting, such as the milling of a circle, where axis motion is sinusoidal. However, this can be compensated for if the amount of backlash is precisely known by linear encoders or manual measurement.
The high backlash mechanism itself is not necessarily relied on to be repeatedly precise for the cutting process, but some other reference object or precision surface may be used to zero the mechanism, by tightly applying pressure against the reference and setting that as the zero references for all following CNC-encoded motions. This is similar to the manual machine tool method of clamping a micrometer onto a reference beam and adjusting the Vernier dial to zero using that object as the reference.
Positioning control system.
In numerical control systems, the position of the tool is defined by a set of instructions called the part program. Positioning control is handled using either an open-loop or a closed-loop system. In an open-loop system, communication takes place in one direction only: from the controller to the motor. In a closed-loop system, feedback is provided to the controller so that it can correct for errors in position, velocity, and acceleration, which can arise due to variations in load or temperature. Open-loop systems are generally cheaper but less accurate. Stepper motors can be used in both types of systems, while servo motors can only be used in closed systems.
Cartesian coordinates.
The G & M code positions are all based on a three-dimensional Cartesian coordinate system. This system is a typical plane often seen in mathematics when graphing. This system is required to map out the machine tool paths and any other kind of actions that need to happen in a specific coordinate. Absolute coordinates are what are generally used more commonly for machines and represent the (0,0,0) point on the plane. This point is set on the stock material to give a starting point or "home position" before starting the actual machining.
Coding.
G-codes.
G-codes are used to command specific movements of the machine, such as machine moves or drilling functions. The majority of G-Code programs start with a percent (%) symbol on the first line, then followed by an "O" with a numerical name for the program (i.e. "O0001") on the second line, then another percent (%) symbol on the last line of the program. The format for a G-code is the letter G followed by two to three digits; for example G01. G-codes differ slightly between a mill and lathe application, for example:
M-codes.
[Code Miscellaneous Functions (M-Code)]. M-codes are miscellaneous machine commands that do not command axis motion. The format for an M-code is the letter M followed by two to three digits; for example:
Example.
O0001
G20 G40 G80 G90 G94 G54(Inch, Cutter Comp. Cancel, Deactivate all canned cycles, moves axes to machine coordinate, feed per min., origin coordinate system)
M06 T01 (Tool change to tool 1)
G43 H01 (Tool length comp. in a positive direction, length compensation for the tool)
M03 S1200 (Spindle turns CW at 1200RPM)
G00 X0. Y0. (Rapid Traverse to X=0. Y=0.)
G00 Z.5 (Rapid Traverse to z=.5)
G00 X1. Y-.75 (Rapid traverse to X1. Y-.75)
G01 Z-.1 F10 (Plunge into part at Z-.25 at 10in per min.)
G03 X.875 Y-.5 I.1875 J-.75 (CCW arc cut to X.875 Y-.5 with radius origin at I.625 J-.75)
G03 X.5 Y-.75 I0.0 J0.0 (CCW arc cut to X.5 Y-.75 with radius origin at I0.0 J0.0)
G03 X.75 Y-.9375 I0.0 J0.0(CCW arc cut to X.75 Y-.9375 with radius origin at I0.0 J0.0)
G02 X1. Y-1.25 I.75 J-1.25 (CW arc cut to X1. Y-1.25 with radius origin at I.75 J-1.25)
G02 X.75 Y-1.5625 I0.0 J0.0 (CW arc cut to X.75 Y-1.5625 with same radius origin as the previous arc)
G02 X.5 Y-1.25 I0.0 J0.0 (CW arc cut to X.5 Y-1.25 with same radius origin as the previous arc)
G00 Z.5 (Rapid traverse to z.5)
M05 (spindle stops)
G00 X0.0 Y0.0 (Mill returns to origin)
M30 (Program End)
Having the correct speeds and feeds in the program provides for a more efficient and smoother product run. Incorrect speeds and feeds will cause damage to the tool, machine spindle, and even the product. The quickest and simplest way to find these numbers would be to use a calculator that can be found online. A formula can also be used to calculate the proper speeds and feeds for a material. These values can be found online or in Machinery's Handbook.


Economic production quantity

The economic production quantity model (also known as the EPQ model) determines the quantity a company or retailer should order to minimize the total inventory costs by balancing the inventory holding cost and average fixed ordering cost. The EPQ model was developed by E.W. Taft in 1918.
This method is an extension of the economic order quantity model (also known as the EOQ model). The difference between these two methods is that the EPQ model assumes the company will produce its own quantity or the parts are going to be shipped to the company while they are being produced, therefore the orders are available or received in an incremental manner while the products are being produced. While the EOQ model assumes the order quantity arrives complete and immediately after ordering, meaning that the parts are produced by another company and are ready to be shipped when the order is placed.
In some literature, "economic manufacturing quantity" model (EMQ) is used for "economic production quantity" model (EPQ). Similar to the EOQ model, EPQ is a single product lot scheduling method. A multiproduct extension to these models is called "product cycling problem".
Overview.
EPQ only applies where the demand for a product is constant over the year and that each new order is delivered/produced incrementally when the inventory reaches zero. There is a fixed cost charged for each order placed, regardless of the number of units ordered. There is also a holding or storage cost for each unit held in storage (sometimes expressed as a percentage of the purchase cost of the item).
We want to determine the optimal number of units of the product to order so that we minimize the total cost associated with the purchase, delivery and storage of the product
The required parameters to the solution are the total demand for the year, the purchase cost for each item, the fixed cost to place the order and the storage cost for each item per year. Note that the number of times an order is placed will also affect the total cost, however, this number can be determined from the other parameters
Total cost function and derivation of EPQ formula.
Where formula_3 is the average inventory level, and formula_4 is the average holding cost. Therefore, multiplying these two results in the holding cost per year.
Where formula_6 are the orders placed in a year, multiplied by K results in the ordering cost per year.
We can notice from the equations above that the total ordering cost decreases as the production quantity increases. Inversely, the total holding cost increases as the production quantity increases. Therefore, in order to get the optimal production quantity we need to set holding cost per year equal to ordering cost per year and solve for quantity (Q), which is the EPQ formula mentioned below. Ordering this quantity will result in the lowest total inventory cost per year.


Laminated object manufacturing

Laminated object manufacturing (LOM) is a rapid prototyping system developed by Helisys Inc. (Cubic Technologies is now the successor organization of Helisys) In it, layers of adhesive-coated paper, plastic, or metal laminates are successively glued together and cut to shape with a knife or laser cutter. Objects printed with this technique may be additionally modified by machining or drilling after printing. Typical layer resolution for this process is defined by the material feedstock and usually ranges in thickness from one to a few sheets of copy paper.
Process.
The process is performed as follows:


Hoshin Kanri

Hoshin Kanri (Japanese: 方針管理, "policy management") is a 7-step process used in strategic planning in which strategic goals are communicated throughout the company and then put into action. The Hoshin Kanri strategic planning system originated from post-war Japan, but has since spread to the U.S. and around the world. Translated from Japanese, Hoshin Kanri aptly means "compass management". The individual words "hoshin" and "kanri" mean direction and administration, respectively.
Overview.
Hoshin Kanri requires a strategic vision in order to succeed. From there, strategic objectives need to be clearly defined, with goals being written for long periods of a one to five-year-long timeframe. Once the long term timeframe goals are completed, the team can focus on yearly objectives. Management needs to avoid picking too many vital goals in order to stay focused on what is strategically important. The big goals then need to be broken down into smaller goals, at a weekly and monthly basis and then implemented so that everyone, from management to the factory floor, is in agreement on what needs to be accomplished. The satisfaction of goals should be reviewed on a monthly basis, with a larger annual review at the end of the year. Performance measurement is also a key part of the process.
Hoshin Kanri is a top-down approach, with the goals being mandated by management and the implementation being performed by employees. As a result, systems need to be in place to ensure that objectives from senior management are effectively communicated all the way down the chain of command. As such, a catchball system is often used in order to aid in the execution of the strategic plan. A catchball system seeks to get opinions of both managers and employees through meetings and interactions in order to ensure the bidirectional flow of goals, feedback, and other information throughout the organization.
Usage.
Companies that use Hoshin Kanri often follow a Think, Plan, Implement, and Review process, which is comparable to W. Edwards Deming's Plan Do Check Act cycle. This is because Deming played a role in the spreading of quality control principles that influenced the development of Hoshin Kanri. The cyclical process is a way to plan for the future, not just to react to what is happening now. The principles of PDCA are heavily embedded into the Hoshin Kanri planning process. Beyond PDCA, Joseph M. Juran also played a role in spreading quality control principles that influenced Hoshin Kanri, specifically focusing on management's role in the process.
The Hoshin Kanri technique is often aided with a Hoshin Kanri Matrix, on which companies list and align their various-length objectives and goals. The matrix can also incorporate Key Performance Indicators and priority values and be accompanied by detailed plans, resource assignment demands, or value stream maps.


DMG Mori Seiki Co.

DMG Mori Co., Ltd. (DMG森精機株式会社, DMG Mori Seiki Kabushiki-gaisha) (formerly Mori Seiki Co., Ltd. and DMG Mori Seiki Co., Ltd.) is a Japanese company headquartered in Tokyo and Nara City, engaged primarily in the manufacture and sale of machine tools. Since its establishment, DMG Mori has become the largest machine tool builder in the world.
History.
DMG Mori Co., Ltd. was founded in 1948 by the three Mori brothers. It originally produced textile machinery, but in 1958, the company entered the machine tool manufacturing industry, and by 1968, it began manufacturing numerical control (NC) lathes.
In 2001, grinding machine manufacturer Taiyo Koki joined the DMG Mori Group and in 2002, DMG Mori Co., Ltd. acquired business assets of Hitachi Seiki in Japan. In November 2009, the U.S. headquarters were inaugurated during a four-day event.
In the same year, Mori Seiki Co., Ltd. entered into a strategic partnership with Germany's Gildemeister AG, which controlled the brand DMG. As a result, the US operations of both companies were merged into one unit on April 1, 2010. This partnership with Gildemeister AG led to the renaming of the two entites with the same name of DMG Mori in 2013, and in 2016, the Japanese company acquired majority shares of the German company.
In June 2018, the Tokyo Digital Innovation Center (DIC) was established, along with the opening of a new plant in Pleszew, Poland the same year.
Company Structure.
DMG Mori Co., Ltd. is directed by President , has a revenue of 3,418 million Euros and employs 12,626 individuals internationally. The company has a dual headquarters system, with headquarters located in Shiomi, Koto-ku, Tokyo (Global headquarters) and in Nara City, Nara Prefecture.
The corporate governance structure is that of a Japanese Kabushiki-gaisha.
DMG Mori has a sales, service and engineering network with 16 Production sites and 113 Sales and Services sites in 43 countries and a leading global market share of 10%.
The shareholders of the DMG Mori Co., Ltd. are Baillie Gifford & Co. (10.0%), Global Alpha Capital Management Ltd. (7.5%), Sumitomo Mitsui Trust Asset Management Co., Ltd. (3.7%), DMG Mori Seiki Employee Stock Ownership Plan (3.6%), Nomura Asset Management Co., Ltd. (3.2%), Mori Masashiko/Mori Seiki (2.8%), Mori Manufacturing Research & Technology Foundation (2.7%), BlackRock Fund Advisors (2.7%), The Vanguard Group, Inc. (2.1%) and Norges Bank Investment Management (1.6%).
DMG Mori AG.
DMG Mori AG, headquartered in Bielefeld, Germany, is headed by Alfred Geißler as CEO and had revenues of 2,365.7 million Euros in 2022.
DMG Mori Co., Ltd., through its subsidiary, holds 87.37 % of the shares in its subsidiary DMG Mori AG.
DMG Mori AG has a supervisory board, which holds a higher rank than the executive board. This supervisory board is entrusted with the tasks of appointing directors and approving major business plans and investments.
DMG MORI Production sites.
DMG Mori has production sites in Japan (Nara Campus, Iga Campus, Taiyo Koki and Magnescale), Germany (Pfronten, Seebach, Bielefeld and Stipshausen), Italy (Bergamo and Tortona), Poland (Pleszew) and the USA (Davis). The sites in Germany are run by the group companies Deckel Maho (Pfronten and Seebach), Gildemeister (Bielefeld) and Sauer (Stipshausen). The group companies Gital (Bergamo) and Graziano (Tortona) manage the sites in Italy and Famot (Pleszew) runs the base in Poland. DMG Mori also has a manufacturing partner in India, Lakshmi Machine Works Limited. The company also operated a plant in Ulyanovsk, Russia. In response to the Russian invasion of Ukraine in 2022, DMG Mori has withdrawn from the Russian market.
Products and Technologies.
DMG Mori produces and distributes machine tools, corresponding products and measuring instruments. The company manufactures numerically controlled (NC) machine tools like high-speed precision lathes, as well as horizontal and vertical machining centers (MCs), among other machine tools designed for diverse functions. It also deals with machining centers, repair and restoration, engineering services and software.
The company provides 5-axis and multi-axis machines and automation and digitization solutions. It installed 100,000 machines internationally and builds 8,000 to 10,000 machines a year.
Sports Involvement.
DMG Mori has partnered with Red Bull Racing Honda since 2012, and also had a partnership with the Toyota Gazoo Racing World Rally Team. In 2020, the DMG Mori Sailing Team completed the Vendée Globe as the first Asian team with Kojiro Shiraishi as skipper.


Reorder point

The reorder point (ROP) is the level of inventory which triggers an action to replenish that particular inventory stock. It is a minimum amount of an item which a firm holds in stock, such that, when stock falls to this amount, the item must be reordered. It is normally calculated as the forecast usage during the replenishment lead time plus safety stock. In the EOQ (Economic Order Quantity) model, it was assumed that there is no time lag between ordering and procuring of materials.
Continuous Review System.
The reorder point for replenishment of stock occurs when the level of inventory drops down to zero. In view of instantaneous replenishment of stock the level of inventory jumps to the original level from zero level.
In real life situations one never encounters a zero lead time. There is always a time lag from the date of placing an order for material and the date on which materials are received. As a result the reorder point is always higher than zero, and if the firm places the order when the inventory reaches the reorder point, the new goods will arrive before the firm runs out of goods to sell. The decision on how much stock to hold is generally referred to as the order point problem, that is, how low should the inventory be depleted before it is reordered.
The two factors that determine the appropriate order point are the delivery time stock which is the Inventory needed during the lead time (i.e., the difference between the order date and the receipt of the inventory ordered) and the safety stock which is the minimum level of inventory that is held as a protection against shortages due to fluctuations in demand.
Therefore: Reorder Point = Normal consumption during lead-time + Safety Stock .
Several factors determine how much delivery time stock and safety stock should be held. In summary, the efficiency of a replenishment system affects how much delivery time is needed. Since the delivery time stock is the expected inventory usage between ordering and receiving inventory, efficient replenishment of inventory would reduce the need for delivery time stock. And the determination of level of safety stock involves a basic trade-off between the risk of stockout, resulting in possible customer dissatisfaction and lost sales, and the increased costs associated with carrying additional inventory.
Another method of calculating reorder level involves the calculation of usage rate per day, lead time which is the amount of time between placing an order and receiving the goods and the safety stock level expressed in terms of several days' sales.
Reorder level = Average daily usage rate × lead-time in days .
From the above formula it can be easily deduced that an order for replenishment of materials be made when the level of inventory is just adequate to meet the needs of production during lead-time.
Example.
If the average daily usage rate of a material is 50 units and the lead-time is seven days, then:
Reorder level = Average daily usage rate × Lead time in days = 50 units per day × 7 days = 350 units
When the inventory level reaches 350 units an order should be placed for material. By the time the inventory level reaches zero towards the end of the seventh day from placing the order materials will reach and there is no cause for concern.
Reorder point = Average Lead Time*Average Demand + Service Level*
More information on above formulation is given here:
http://scm.ncsu.edu/scm-articles/article/reorder-point-formula-inventory-management-models-a-tutorial
Reorder point = S × L + J (S × R × L)
Where
See also.
Re-order in Aviation is calculated based on actual usage.
Resources.
Reorder Point Software freeware. Use it for simulations and studies.