Poka-yoke

 is a Japanese term that means "mistake-proofing" or "error prevention". A poka-yoke is any mechanism in a process that helps an equipment operator avoid (') mistakes (') and defects by preventing, correcting, or drawing attention to human errors as they occur. The concept was formalized, and the term adopted, by Shigeo Shingo as part of the Toyota Production System.
Etymology.
Poka-yoke was originally "", but as this means "fool-proofing" (or "idiot-proofing") the name was changed to the milder "poka-yoke".
Poka-yoke is derived from "" , a term in shogi that means avoiding an unthinkably bad move.
Usage.
More broadly, the term can refer to any behavior-shaping constraint designed into a process to prevent incorrect operation by the user.
A simple poka-yoke example is demonstrated when a driver of the car equipped with a manual gearbox must press on the clutch pedal (a process step, therefore a poka-yoke) prior to starting an automobile. The interlock serves to prevent unintended movement of the car. Another example of poka-yoke would be the car equipped with an automatic transmission, which has a switch that requires the car to be in "Park" or "Neutral" before the car can be started (some automatic transmissions require the brake pedal to be depressed as well). These serve as behavior-shaping constraints as the action of "car in Park (or Neutral)" or "foot depressing the clutch/brake pedal" must be performed before the car is allowed to start. The requirement of a depressed brake pedal to shift most of the cars with an automatic transmission from "Park" to any other gear is yet another example of a poka-yoke application. Over time, the driver's behavior is conformed with the requirements by repetition and habit.
History.
The term poka-yoke was applied by Shigeo Shingo in the 1960s to industrial processes designed to prevent human errors. Shingo redesigned a process in which factory workers, while assembling a small switch, would often forget to insert the required spring under one of the switch buttons. In the redesigned process, the worker would perform the task in two steps, first preparing the two required springs and placing them in a placeholder, then inserting the springs from the placeholder into the switch. When a spring remained in the placeholder, the workers knew that they had forgotten to insert it and could correct the mistake effortlessly.
Shingo distinguished between the concepts of inevitable human mistakes and defects in the production. Defects occur when the mistakes are allowed to reach the customer. The aim of poka-yoke is to design the process so that mistakes can be detected and corrected immediately, eliminating defects at the source.
Implementation in manufacturing.
Poka-yoke can be implemented at any step of a manufacturing process where something can go wrong or an error can be made. For example, a fixture that holds pieces for processing might be modified to only allow pieces to be held in the correct orientation, or a digital counter might track the number of spot welds on each piece to ensure that the worker executes the correct number of welds.
Shingo recognized three types of poka-yoke for detecting and preventing errors in a mass production system:
Either the operator is alerted when a mistake is about to be made, or the poka-yoke device actually prevents the mistake from being made. In Shingo's lexicon, the former implementation would be called a "warning" poka-yoke, while the latter would be referred to as a "control" poka-yoke.
Shingo argued that errors are inevitable in any manufacturing process, but that if appropriate poka-yokes are implemented, then mistakes can be caught quickly and prevented from resulting in defects. By eliminating defects at the source, the cost of mistakes within a company is reduced.
A methodic approach to build up poka-yoke countermeasures has been proposed by the Applied Problem Solving (APS) methodology, which consists of a three-step analysis of the risks to be managed:
This approach can be used to emphasize the technical aspect of finding effective solutions during brainstorming sessions.
Benefits of poka-yoke implementation.
A typical feature of poka-yoke solutions is that they don't let an error in a process happen. Other advantages include:


Dynamic packaging

Dynamic packaging is a method used in package holiday bookings to enable consumers to build their own package of flights, accommodation, and car rental instead of purchasing a pre-defined package. Dynamic packages differ from traditional package tours in that the pricing is always based on current availability, escorted group tours are rarely included, and trip-specific add-ons such as airport parking and show tickets are often available. Dynamic packages are similar in that often the air, hotel, and car rates are available only as part of a package or only from a specific seller. The term "dynamic packaging" is often used incorrectly to describe the less sophisticated process of interchanging various travel components within a package, however, this practice is more accurately described as "dynamic bundling". True dynamic packaging demands the automated recombination of travel components based on the inclusion of rules that not only dictate the content of the package but also conditional pricing rules based on various conditions such as the trip characteristics, suppliers contributing components, the channel of distribution, and terms of sale. Dynamic packages are primarily sold online, but online travel agencies will also sell by phone owing to the strong margins and high sale price of the product.
Dynamic packaging is dynamic at several levels. Firstly, inventory is sourced dynamically, meaning the dynamic packaging solution will source flights, accommodation and car rental components for the package in real-time. Secondly, these components are dynamically combined into packages. Thirdly, the package is dynamically priced and is usually given an opaque total price.
Benefits.
Dynamic packages are normally given a single, opaque price, meaning the wholesaler's cost of the individual components is hidden from the consumer. The wholesaler often obtains special package-only cost rates for travel components, such as negotiated fares for flights or special package rates for accommodation or car rental. These cost prices are typically significantly lower than the cost prices suppliers offer for the same products if they were to be sold as single components. Hence, the wholesaler will be able to offer the consumer a combined saving for the dynamic package, without reducing his own margins.
Opaque pricing of dynamic packages hide the price of the included components. This has several benefits. Suppliers of travel products often impose a minimum selling price for their products. For instance, a hotel might give the wholesaler a room at cost price "X", but on the condition that the room is not sold for less than "Y" (hotels do this to prevent wholesalers from competing with themselves). With dynamic packaging, the customer is not presented with the room price, only the overall package price, so hotels typically allow the wholesaler to discount the (hidden) price of the hotel more.
Opaque pricing also has benefits for airlines. Airlines tend to increase their fares the closer you get to the departure date, even if there are many available seats. This is to "train" the consumers to book early, making it easier for the airline to do proper revenue management. If airlines were to dump their fares if a flight failed to fill up, then this would train the customers to wait until very close to departure before booking. This would make it virtually impossible for an airline to manage their fares (fares could then only be determined based on historical data and not based on current demand). Dynamic packaging allows an airline to get rid of distressed inventory at discounted fares, as the discounted fare is effectively hidden from the consumer.
Application.
Dynamic packaging has experienced extensive integration across the travel industry, as many tour operators and online travel agencies (OTAs) have implemented these solutions to address the growing demand for personalized travel experiences. This has led to the development of sophisticated algorithms and software systems that can source, combine, and price travel components in real-time, providing greater flexibility and customization for travelers. Travel providers such as Guide to Europe offer travelers the flexibility to build their own package tour, combining flights, accommodations, and activities based on their preferences and budget.
The real-time nature of dynamic packaging enables travel providers to offer attractive last-minute deals by capitalizing on distressed inventory, such as unsold flight seats or hotel rooms. Dynamic packaging also enables travel providers to cater to specific market segments, such as adventure travelers, luxury travelers, or budget-conscious travelers, by offering customized packages that cater to their unique needs and preferences. Additionally, travel providers can leverage dynamic packaging to offer customized packages and exclusive deals to their loyalty program members, further enhancing customer loyalty and engagement.
Future outlook.
As technology continues to advance and consumer preferences evolve, dynamic packaging is expected to play an even more significant role in the travel industry. Some potential future developments include greater personalization through artificial intelligence (AI), which could further enhance the personalization capabilities of dynamic packaging by analyzing user data and preferences to recommend highly tailored travel packages. Advancements in data analytics and pricing algorithms may lead to more accurate and sophisticated dynamic pricing models, allowing travel providers to optimize revenue and offer even more competitive deals to travelers. The integration of dynamic packaging with emerging technologies, such as virtual reality or augmented reality, could enable travelers to preview their customized travel experiences before booking, further enhancing the personalization aspect of dynamic packaging.
Preconditions.
Dynamic Packaging is also often misunderstood since it requires that the provider of Dynamic Packaging be a wholesaler, who must also issue tickets, vouchers or other redeemable coupons in order to become a Dynamic Packager. Without an inventory management system, and a ticket, coupon or voucher issuing system to make the prices of the individual components appear as one price to the consumer and allow each travel service provider to know what rate to accept or charge the traveler; dynamic packaging does not work. Many travel retailers have mistakenly assumed they could provide dynamic packaging without an inventory management system, mark-up engine with business rules and a ticket issuing and resolution system.
The wholesaler must either directly control the inventory that is combined into packages or buy the package components up-front from other travel suppliers. This implies that dynamic packages (as with static packages) are always pre-paid by the customer.
The wholesaler would typically also require special discounted fares/rates from the travel suppliers. For car rental, the supplier (car rental company or intermediary) should ideally supply their price based on calendar days rather than hour-by-hour. Calendar day rates reduce the number of vehicle availability/pricing scans the wholesaler must make. For packages that include flights, the outbound arrival and return departure date/times determine the car rental pick-up and drop-off date/times. If car rental rates were by the hour they would differ for each flight option, hence the wholesaler would have to issue a vehicle availability search for each available flight, while with 24-hour rates one single vehicle availability search is enough to cater for all flight options.


Soldering gun

A soldering gun is an approximately pistol-shaped, electrically powered tool for soldering metals using tin-based solder to achieve a strong mechanical bond with good electrical contact. The tool has a trigger-style switch so it can be easily operated with one hand. The body of the tool contains a transformer with a primary winding connected to mains electricity when the trigger is pressed, and a single-turn secondary winding of thick copper with very low resistance. A soldering tip, made of a loop of thinner copper wire, is secured to the end of the transformer secondary by screws, completing the secondary circuit. When the primary of the transformer is energized, several hundred amperes of current flow through the secondary and very rapidly heat the copper tip. Since the tip has a much higher resistance than the rest of the tubular copper winding, the tip gets very hot while the remainder of the secondary warms at a much slower rate. An additional secondary winding is often used to power a pilot lamp which illuminates the workpiece.
The soldering gun is useful when soldered joints must be made intermittently. A constant-heat device has to be set in a safe place when powered but not actually in use, to prevent damage or injury. The fast-switching gun cools quickly enough to be set down a few seconds after use.
Applications.
Soldering guns are used where more heat is needed than from the lower-power soldering irons. They can be used for heavy electrical connections, stained glass assembly, and light sheet-metal work. Typical soldering guns are rated at 100 to 240 watts power. A gun may include a two-stage trigger to give two heat settings. Tips designed for cutting and shaping plastic are available; soldering guns for general home use may be supplied with a kit of different tips.
The temperature of the soldering tip is regulated manually by holding the button until the solder melts, and then releasing it. When the solder is about to start solidifying, the button is pressed again, and so on. An experienced worker develops the skill to regulate the temperature according to need. Because the temperature of the tip is not automatically regulated, use of a soldering gun for joints on printed circuit boards can result in too much heat supplied to the joint, damaging the circuit board.
The copper tip slowly dissolves in the solder and eventually has to be replaced. The soldering gun generates an electromagnetic spike when the button is released, which can be a problem for electromagnetically-sensitive devices. The spike can be seen when a high-efficiency LED is soldered, as the LED flashes. The heavy magnetic field produced by the tip can attract and hold small ferrous metal pieces (screws, etc.).
History.
Pistol-grip electrically-heated soldering tools had been used since the 1920s. In 1941 Carl E. Weller invented and later obtained for a transformer-based soldering tool which heated and cooled rapidly, essentially as described in this article. Weller formed a company to manufacture and sell his invention commercially in 1946. The Weller company was bought in 1970 and merged into the Cooper Industries group, retaining the Weller brand for soldering equipment.


Procons

Procons Oy Ab is a Finnish company specialized in sheet metal roll forming and subcontracting. Main business areas include sliding door profiles, bike mudguards and stays, profiles for the electrical and mining industries as well as sheet metal products. The company was founded in 1934 and is located in Malax, Finland.
History.
The company that would become Procons Oy Ab was Waasan Vanne, founded in 1934 in Vikby, Finland. It developed and manufactured bicycle mudguards, luggage carriers and rims. In the 1990s, the company shifted its focus to the production of metal profiled products and built automated profiling production lines for thin sheet metal. In 2002, Leif Sandqvist, a former regional executive at Bosch, bought Waasan Vanne. He relocated the company to nearby Malax, his hometown, the next year and, in 2011, reincorporated it as Procons Oy Ab.
Products.
Bicycle parts.
Procons is one of Europe's largest manufacturers of bicycle fenders and stays with a production of about 750,000 fenders per year. The product range consists of various models and brands that are produced mainly from 0.5 mm sheet metal in a fully automated line.
Other.
The company acts as a subcontractor providing roll-form manufacturing of various profiles for heavy industry clients. It also develops and manufactures components for the assembly of sliding doors. Other business areas include eccentric pressing, welding, and assembly.


List of build automation software

Build automation involves scripting or automating the process of compiling computer source code into binary code. Below is a list of notable tools associated with automating build processes.
Build script generation.
These " generator" tools do not build directly, but rather generate files to be used by a "native" build tool (as the ones listed in the previous two sections).
Meta-build.
A meta-build tool is capable of building many different projects using a subset of existing build tools. Since these usually provide a list of packages to build, they are also often called package managers.


Rockman Industries

Rockman Industries, formerly Rockman Cycles limited, is an Indian auto components manufacturer, based in New Delhi, India. The company is one of India's largest auto component manufacturers. Rockman Industries is primarily engaged in the manufacturing of aluminum die casting components, machined and painted assemblies, auto chains and parts. In January 2017, Rockman Industries entered the carbon composites sector with the acquisition of Moldex Composites, a UK-India carbon composite design and manufacturing company. Rockman was founded in 1960 and is led by Suman Kant Munjal, Chairman and Ujjwal Munjal, Managing Director.
History.
A part of the Hero Group, Rockman Industries (formerly Rockman Cycles limited.) was set up in 1960 and started to manufacture bicycle chains and hubs for Hero Cycles. In 1999, it diversified into high pressure aluminium die cast components and automotive chains for Hero MotoCorp (Erstwhile Hero Honda). In 2005 it closed the bicycle chains and hubs business and from November 2005, is only manufacturing die casting components and auto parts. In 2008, Rockman Industries set up a new auto components plant in Uttaranchal. In February 2014, Rockman Industries acquired Sargam Die Casting company and started its new facility at Bawal (Haryana). In January 2017, Rockman Industries acquired a majority stake in Moldex Composites to enter the aerospace, motorsport and high-end auto component manufacturing space. In 2019, company inaugurated two new plants at Vadodara and Tirupati. In Tirupati plant company is manufacturing four wheeler alloy wheels.
Manufacturing units.
Rockman Industries has eight manufacturing plants at Ludhiana, Haridwar, Chennai , Bawal, Surat, Vadodara and Tirupati. In Ludhiana they have two plants, one for chains and the other for aluminium die casting products. All other locations manufacture die casting components. Surat's unit is manufacturing advanced composites parts.
Customers.
Rockman Industries supplies its products to Hero MotoCorp and various global automotive companies including: TVS, Honda, Royal Enfield, Revolt, Ather, Hyundai, Kia, Ford Motor, Mahindra, Tata, Bosch, Stanadyne, Dana, Denso, Nemak, PSA AVTEC, KSP Automotive, Continental, Magna, Hanon System, Wabco, Mando, Getrag, BorgWarner, iwis and others.


Component placement

Component placement is an electronics manufacturing process that places electrical components precisely on printed circuit boards (PCBs) to create electrical interconnections between functional components and the interconnecting circuitry in the PCBs (leads-pads). The component leads must be accurately immersed in the solder paste previously deposited on the PCB pads. The next step after component placement is soldering.
Placement process.
Basic placement sequence generally includes: board indexing, board registration, fiducial vision alignment, component pick-up, component centering/vision inspection, component placement and board indexing. Component pick-up, component centering/vision inspection, component placement are repeated for each component. Sometimes, adhesive dispensing and on-line electrical verification are also included in the sequence.
Through the process of board indexing, the stencil-printed PWB is loaded to the appropriate position. Fiducial marks, also known as fiducial markers, provide common measurable points for all steps in the assembly process. There are many types of fiducials. Global fiducials are used to locate the position of all features on an individual printed circuit board. When multiple boards are processed as a panel, the global fiducials may also be referred to as panel fiducials if used to locate the circuits from the panel datum. Local fiducials are used to locate the position of an individual land pattern or component that may require more precise location, such as a pitch QFP.
Board is located by identify global fiducials on the PWB. Then the feeders pick up and center the components at a known distance from the component. Higher placement accuracy requires help from local fiducials visualized by optical or laser sensors. Vacuum pickup head removes components from feeders. In the end, the component is placed at the correct X, Y and theta location with all leads ion the correct pads in contact with solder paste. The PWBs with all components correctly placed will then move to the reflow process.
There are three primary attributes that shall be considered in the component placement system: accuracy, speed and flexibility. Accuracy involves the aspects of resolution, placement accuracy and repeatability. Speed involves the aspects of equipment placement rate, de-rating strategy and production through-put. Placement rate is determined by machine type and the distance between components on a board. Flexibility involves the aspects of component variety, number of feeders and PCB size range.
Types of pick and placement machines.
A pick and placement machine is a robotic style machine that places some variety of types of components. It includes features such as: component pickup feeder locations, vacuum pickup, vision system, automatic component realignment, repeatable placement accuracy, and transportation system for PCBs.
The pick and place machine is often the most important piece of manufacturing equipment for placing components reliably and accurately enough to meet throughput requirements in a cost-effective manner. Typically, surface mount pick and place equipment, including a full complement of feeders constitute about 50% of the total capital investment required for a medium volume surface mount manufacturing line.
There are two major types of pick and placement machine:
Chip shooter.
Chip shooters are being used for as much as 90% of the most common components, like passives and small actives. Chip shooters are fast (20,000 to 80,000 per hour, can be as fast as 100,000 per hour) with a relatively low accuracy (generally 70 μm). As a result, chip shooters are not used for placing active components, which require better accuracy. There are three major types of chip shooters: stationary turret, overhead gentry, and revolver head.
Flexible placer.
Comparing to chip shooters, flexible placers are slow (6,000 to 40,000 per hour) with a high accuracy (as low as 25 μm). As a result, flexible placers are being used to place complex and high I/O active components like QFPs as higher performance I/O components generally require higher accuracy. There are three major types of flexible placer: overhead gantry, revolver head and split-axis. Chip shooters and flexible placers are typically combined to use and they can take account of nearly 65% of the total assembly line cost.
Types of placement heads.
Overhead gantry.
Overhead gantry-style positioning system's placement head is mounted on a gantry beam (X-axis). During the sequence, the beam moves perpendicular to the direction of the placement head movement, which offers two degrees of freedom (X and Y alignment) in a plane parallel to the machine table. The PCB and feeders keep stationary during placement. The PCB is located on the table by identifying global and local fiducials through a vision system. This placement head moves along the axis beams to pick components from a feeder, and then moves into position to place the components. A vacuum nozzle on the placement head moves up and down vertically to provide Z-axis and rotates in the horizontal plane to provide theta angular alignment. Sometimes a secondary vision system is also applied to check the correctness and alignment of the components after pick-up and before placement. As the PCB and feeders remain stationary in the placement sequence, the additional sources of positional inaccuracy are eliminated. Overhead gantry-style machine has the best placement accuracy among all types and is utilized by flexible placers exclusively. It offers greater flexibility and accuracy, but cannot match the speeds of other styles. Machines with multiple gantries can achieve faster speed.
Stationary turret/fixed turret.
Stationary turret system has a relatively higher speed due to a series of identical heads rotating on a single turret. The feeder moves in the X direction to a fixed pickup location. As many as 36 vacuum nozzles around the perimeter of the rotating turret provide Z and theta alignment. Turret rotates multiple heads between pickup and placement locations. The PCB moves in X and Y direction under the rotating heads, pausing beneath the correct placement location. Comparing to a gantry head, the simultaneous movements of feeders and PCBs greatly improve the average placement rate. Because passive components do not demand a great placement accuracy, it is exclusively applied in chip shooters. Stationary turret system has a limitation of requiring large footprint for the moving feeder bank (footprint =2*total feeder length). The possibility of dislodging components due to the moving board mechanism is another limitation.
Revolver head.
This system combines the speed advantage of stationary turret and the footprint advantage of overhead gantry. It was first being used by Siemens. The stationary turret with multiple pickup heads performs simultaneous functions while moving components from pickup to placement locations. Multiple revolvers are mounted on independent gantries to pick multiple parts from stationary feeders before moving to the PWB. The moving turret and multiple turrets offer higher placement speed and make revolver head can be used in both chip shooters and flexible placers. But utilizing it in flexible placers had limited success in reality.
Split-axis.
In a split-axis system, the placement head moves in the X, theta and Z directions, while the PWB moves in the Y direction. As two moving components are involved, split-axis machine slightly more difficult to achieve high accuracy comparing to the overhead gantry machine. But it greatly improves placement speed.
Vacuum nozzle and grippers.
Vacuum nozzles are commonly used for handling all the components during the placement operations. There are a variety of vacuum nozzle sizes for different component sizes. For handling small components, positive pressure is often supplied in addition to vacuum at the moment of placement so that the component would be completely release from the nozzle.
In addition to vacuum nozzles, mechanical grippers could be required for handling of some odd-shaped parts. Self-centering mechanical grippers allow simultaneous pickup and automatic centering without the need for a vacuum. A pair of tweezers-type grippers would hold the part while centering it along one axis. However, there are some disadvantages with self-centering mechanical grippers: it is possible that the gripper edges could have contact with epoxy or solder paste. In addition, extra space is required between the components to accommodate the grippers.
Types of feeders.
Feeders are used to feed components to the moveable pick-up mechanism of placement machines. Feeders move individual components to a fixed location and also assist the pickup head in removing components from their packaging. As the flexibility and placement rate of systems has increased, so have the demands made on the component feeder systems. A high product mix and correspondingly small batch sizes result in frequent feeder changing. Quick feeder changeover is required in order to minimize machine down-time, so feeders must be designed for fast replacement. Here are some of the common types of feeders.
Tape and reel feeders.
Tape and reel feeder is the most commonly used feeder design. Tape-on-reel feeders are loaded with a reel, which is placed onto a reel-reception. The peel-off carriage pulls the reel tape forward until the next component is in the pick-up position. When the sensor indicates that the component is at the pickup position, a holder moves down and locks-down the tape.
Tape feeders are most suitable for placing large quantities of identical small components. Tape feeders come in a variety of sizes and can be used for Small-outline integrated circuits (SOICs) and plastic leaded chip carriers (PLCCs).
The main disadvantage of the tape format is the inability to recycle the empty tapes. Especially in the case of small chip devices, the tape waste material weighs several times more than the packaged components. Moreover, there is additional cost for placing small inexpensive components in tape.
Stick feeders.
Stick feeders are designed for components packed in linear sticks (small ICs issued in low volumes). Components are moved to the pick-up location by gravity or vibration. It feeds any ordinary SOP, SOT and PLCC which are packaged in stick form. Due to the various possibilities of adjusting the size of the lane, the feeder can easily be adapted to many different component types.
Matrix tray feeders.
Matrix tray feeders are used for large, delicate or expensive components. They are developed out of the necessity for handling quad flat packs and fine pitch components. These hold the components securely without damaging the fragile leads. An entire matrix-profiled tray of components are moved to bring rows or individual components to pick-up location. This process is often slower compared to tape feeders as the components fed in matrix trays often require higher level of placement accuracy.
Bulk feeders.
Bulk feeders can handle chip style components that are used in large numbers. A bulk feeder usually dispenses components, which are stored in a bulk case, using a unique rotary positioning mechanism to position and orient components and feed them to the pick-up position using a stainless steel belt. They are cheaper compared with tape feeders as there are no tape packing, but traditionally the performance of bulk feeders is problematic because of construction and debris created during the feeding process.
Direct die feeder.
The direct die feeders are mostly used for flip-chip or chip-on board. Direct die feeder could eliminate separate and dedicated production lines for SMT, bare die, and flip chip by combining them into one. It could also enabling total assembly solutions with much higher speed and flexibility, resulting in lower cost per placement. In addition, it could eliminate costly processes such as intermediate die transfer into pocketed tape, surf-tape, or waffle packs prior to placement.
Placement speed.
The placement speed is influenced by many factors in the placement process.
Feeder breakdown.
The placement speed is affected by the line downtime. Since feeder problems are the a major source of downtime, the repair and maintenance of feeders are crucial for the component placement operations. Here are the common ways to detect feeder problems:
Placement system set up.
All on-line setup reduces the capacity and improper setup procedures could also create additional line downtime. No boards could be produced if the placement system is not set up. Due to the complexity of the feeder set up and changeover process, it is important for operators to be aware of the variety types of feeder mechanisms. There are additional tools that could be implemented to assist the placement set up, such as roll-up feeder carts, just-in-time (JIT) methods and smart feeders.
Placement speed derating.
In practice it is not possible to obtain the quoted theoretical maximum throughput rate for machines in a placement system. It is necessary to derate the theoretical numbers to obtain realistic values, due to unexpected downtime, board load and unload time and machine configuration. Other factors include PWB size, component mix, and the requirement for more complex vision recognition for fine-pitch components. There are many techniques of derating. Global derating considers system-wide stops, slow-downs and set ups as well as machine factors. To calculate the amount of global or system derating, one should take the average of the number of total components placed per hour in a long period (i.e. an entire product shift). Regularly scheduled stops should be included when determining the level of global derating the system requires. Rigorous derating, which considers each piece of equipment in service for a particular product individually, must be conducted by specific machine model for the line balancing. Rigorous derating values are necessary for full optimization of the process.


Process layout

In manufacturing engineering, process layout is a design for the floor plan of a plant which aims to improve efficiency by arranging equipment according to its function. The production line should ideally be designed to eliminate waste in material flows, inventory handling and management.
In process layout, the work stations and machinery are not arranged according to a particular production sequence. Instead, there is an assembly of similar operations or similar machinery in each department (for example, a drill department, a paint department, etc.)
It is also known as function layout. In this layout machining operation are performed in group together and not arranged according to any sequence.
Criticism.
A common criticism of this layout is that the work can be monotonous for staff, especially if they are involved only in one stage of the process.
This criticism can however be eliminated if the staff are rotated to different departments (involving different processes) thus developing a multi-skilled body of staff.


Compliant bonding

Compliant bonding is used to connect gold wires to electrical components such as integrated circuit "chips". It was invented by Alexander Coucoulas in the 1960s. The bond is formed well below the melting point of the mating gold surfaces and is therefore referred to as a solid-state type bond. The compliant bond is formed by transmitting heat and pressure to the bond region through a relatively thick indentable or "compliant medium", generally an aluminum tape (Figure 1).
Comparison with other solid state bond methods.
Solid-state or pressure bonds form permanent bonds between a gold wire and a gold metal surface by bringing their mating surfaces in intimate contact at about 300 °C which is well below their respective melting points of 1064 °C, hence the term solid-state bonds.
Two commonly used methods of forming this type of bond are thermocompression bonding and thermosonic bonding. Both of these processes form the bonds with a hard faced bonding tool that makes direct contact to deform the gold wires against the gold mating surfaces (Figure 2).
Since gold is the only metal that does not form an oxide coating which can interfere with making a reliable metal to metal contact, gold wires are widely used to make these important wire connections in the field of microelectronic packaging. During the compliant bonding cycle the bond pressure is uniquely
controlled by the inherent flow properties of the aluminum compliant tape (Figure 3). Therefore, if higher bond pressures are needed to increase the final deformation (flatness) of a compliant bonded gold wire, a higher yielding alloy of aluminum could be employed. The use of a compliant medium also overcomes the thickness variations when attempting to bond a multiple number of conductor wires simultaneously to a gold metalized substrate (Figure 4). It also prevents the leads from being excessively deformed since the compliant member deforms around the leads during the bonding cycle thus eliminating mechanical failure of a bonded wire due to excessive deformation from a hard faced tool (Figure 3) which is employed by thermocompression, and thermosonic bonding.
History.
An important application for compliant bonding arose in the early 1960s, when techniques were developed for fabricating a beam leaded silicon integrated circuit “chip” consisting of pre-attached electroformed 0.005-inch thick gold leads or “beams” extending from the silicon chip (Figure 5). Thus the beam leaded “chip” eliminated the need to thermosonically bond wires directly onto metallized pads of the fragile silicon chip (as shown in Figure 6) The extended ends of the electroformed beams could then be permanently solid-state bonded to a matching metallized sunburst circuit which has been pre-deposited on a ceramic substrate appropriately packaged in a computer in the making. Figure 7. shows a preshaped hard faced tool thermocompression bonding all of the beam leads of a chip in one bonding cycle. In order to avoid excessively deforming the fine beam leads with the hard bonding tool and putting them at risk of mechanical failure, the applied bonding forces have to be carefully monitored.
The invention of compliant bonding eliminated the problems associated with a hard faced bonding tool and therefore was ideally suited to simultaneously bond all of the extended electroplated gold beam leads to a matching gold metallized sunburst patterned ceramic substrate packaged in a computer (Figure 8). For example, compliant bonding eliminated the problems of using a hard faced bonding tool such as: attempting to uniformly deform the nominally 0.005-inch thick beams leads having slight variations in their thickness; excessive lead deformation that could cause mechanical damage and an ultimate "costly" failure of these fine beam leaded silicon chips which are the "brains" of our computers. The compliant bonding tape media offered the additional advantage of carrying the "beam leaded silicon chip" to the bonding site thus facilitating production.
Figures 9. and 10 show that the compliant tape offers the advantage of carrying the beam leaded chip to the bonding site as discussed above. Figure 11 shows a beam leaded silicon integrated circuit compliantly bonded to a gold metallized sunburst pattern deposited on an alumina ceramic substrate which will be encapsulated and packaged in a computer-type device. Figure 12 shows the spent compliant member used to bond the chip in Figure 11 which clearly shows a mirror image of the uniformly bonded beam leads.
Silicon integrated circuit.
The two forms of integrated circuits discussed above were the beam leaded integrated circuit composed of attached electroformed gold leads or beams (Figure 5) and the silicon integrated circuit chip (Figure 6). With respect to the beam leaded silicon chip, both compliant and thermocompression bonding can be employed since each have their advantages. At this time, the most widely used form is the silicon integrated circuit chip, without the beam leads, which therefore requires electrical connections directly to the metallized silicon Chip (Figure 6). If wire connections is the method of choice to form these connections, thermosonic bonding gold wires directly to the silicon chip has been the process most widely used because of its proven reliability as a result of the low bonding parameters of force, temperature, and time needed to form the bond.


Strati (automobile)

Strati is an electric car developed by Local Motors and manufactured in collaboration with Cincinnati Incorporated and Oak Ridge National Laboratory. It is the world's first electric car to heavily utilize 3D printing during the production process. The car was manufactured using a Large Scale 3D Printer developed by ORNL and Cincinnati Inc. The car took just 44 hours to print during the 2014 International Manufacturing Technology Show in Chicago, Illinois. The printing was followed by three days of milling and assembling, with the completed car first test-driven on September 13, 2014. Strati is claimed to be the world's first 3D-Printed electric car.
Design.
In April 2014, Local Motors organized the 3D Printed Car Design Challenge crowdsourcing to assist in the production of a full-body 3D-printed car. Seven finalists were selected from more than 200 submissions. In June 2014, Local Motors announced that the challenge was won by Michele Anoé of Italy, who was awarded the $5,000 prize. After the contest, Local Motors took the design and made several modifications so that the car could be manufactured through 3D-Printing.
Specifications.
The two-seat Strati is considered to be a "neighborhood" electric car. Depending on the configuration of the battery packs, the range of the car can be with top speeds of . The car is not designed to be used on highways, as it does not meet the required safety test requirements. Production is planned by the end of 2015, with prices between $18,000 and $30,000.
Manufacturing.
Following the design competition, Local Motors handed off the design to the engineers at ORNL who perfected the process of Large Scale 3D Printing such that the Local Motors design could actually be manufactured. ORNL worked with Cincinnati Incorporated to develop the printer that would allow for the printing of the entire car. With the printer, ORNL and Cincinnati Inc. manufactured all body parts of the car and allowed for easy mounting of the mechanical parts, such as the electric motors and batteries.
Strati is printed from thermoplastic using a big area additive manufacturing (BAAM) machine (a large FDM 3D-printer). This material is fully recyclable, which can be chopped and reprocessed to be used in printing another car. After the car is printed, the mechanical and electrical parts such as battery, motors, and suspension are manually assembled.
The printing process has been improved by ORNL since July 2014, bringing the printing time of 140 hours down to less than 45 hours in September. Since IMTS, ORNL has brought the printing time of the Strati to less than 24 hours and is continuing their research efforts with the hope of printing the car in less than 10 hours.
The world's first title.
Disputes exist over the title of the world's first 3D-printed car. In 2010, a hybrid car "Urbee" was 3D-printed using an additive manufacturing process for the entire body. Local Motors claimed that Urbee's manufacturer only 3D-printed the panels and other exterior parts, but used standard parts for the internal structure. For Strati, the company claimed that 3D printing was used for all except the parts that are "mechanically involved". Strati claims to be the world's first 3D-printed electric car.


Choc Nut

Choc Nut (stylized as Choc⋆Nut) is a trademark for a candy bar manufactured by Annie's Sweets Manufacturing and Packaging Corporation, a Philippine-based company. The ingredients of Choc Nut include peanuts, sugar, milk powder, cocoa powder and vanilla.Asian supermarkets and Filipino stores overseas sell the candy. Many restaurants and cafes in the Philippines use Choc Nut as a popular ingredient in confections, drinks, and even cocktails.
History.
Choc Nut was originally manufactured by New Unity Sweets Manufacturing Corporation (Unisman) in Malabon. In 2013, the brand came under the ownership of Annie's Manufacturing and Packaging Corporation, the company that produces Choc Nut's rival brand, Hany.
In 2018, Choc Nut extended its product line to include a sweetened chocolate peanut spread.
Packaging.
Choc Nut comes in 24-piece "King" or 16-piece "SP" packages. The 24-piece "King" package consists of twenty-four 8-gram bars, while the 16-piece "SP" package consists of sixteen 16-gram bars. Each bar is individually-wrapped in paper-backed foil and an outer packaging film (white paper during the Unisman era) bearing the brand's logo and signature red stripes. The packages are a bronze colour with white and red lines running through it horizontally.
In popular culture.
In recognition of its status as a pop culture icon, Choc Nut was given a prominent role in the graphic novel series "Trese" by Budjette Tan and Kajo Baldisimo. The references were also picked up in the animated series.


Supply & Demand Chain Executive

"Supply & Demand Chain Executive" is the only publication covering the entire global supply chain, focusing on trucking, warehousing, packaging, procurement, risk management, professional development and more. Supply & Demand Chain Executive is a digital-only publication, and reaches over 109,000 industry subscribers via its twice-weekly e-newsletter, reaching executives in corporate procurement, purchasing, logistics and operations management in manufacturing and non-manufacturing industries.
Overview.
This digital-only brand reaches executives in corporate procurement, purchasing, logistics and operations management in manufacturing and non-manufacturing industries. These are the supply chain technology leaders who select solutions and service providers to enhance efficiency within their specific sector. Go to https://www.supplychainnetworkmediakit.com/ for more information.
Interactive Opportunities.
"Supply & Demand Chain Executive" is the only publication covering the entire global supply chain, focusing on trucking, warehousing, packaging, procurement, risk management, professional development and more. Supply & Demand Chain Executive is a digital-only publication, and reaches over 109,000 industry subscribers via its twice-weekly e-newsletter, reaching executives in corporate procurement, purchasing, logistics and operations management in manufacturing and non-manufacturing industries. SDCExec.com is home to thought leadership pieces from supply chain industry experts, as well as SCN Summit, the Women in Supply Chain Forum, several awards and the Global Supply Chain Insights e-newsletter. Go to https://acbusiness.dragonforms.com/loading.do?omedasite=SDCEprefs&pk=managepref to subscribe.
In-Person Events.
"Supply & Demand Chain Executive" owns and operates the Women in Supply Chain Forum, the industry’s premier networking and educational forum tailored to men and women in executive-level positions to expand their professional network and enhance their businesses through thought-provoking discussion panels. Go to https://www.womeninsupplychainforum.com/ for more information.
Virtual Events.
"Supply & Demand Chain Executive" owns and operates the SCN Summit, the premier virtual event aimed at educating logistics professionals on critical issues impacting the supply chain industry. Go to https://www.scnsummit.com/ for more information.


Hong Kong Electronics Fair

Hong Kong Electronics Fair (Autumn Edition) is organised by the Hong Kong Trade Development Council (HKTDC) and to be held at the Hong Kong Convention and Exhibition Centre in October every year. One of the fair's highlights is the Hall of Fame – a special section dedicated to high-quality electronic products that are distinguished by their design and function. The fair is organised into key thematic zones ranging from audio-visual products to navigation systems, and from home appliances to telecommunications products. At Technology Exchange Zone, Hong Kong's leading research facilities and companies display their latest technology ideas. In addition, a number of testing, inspection & certification services companies will exhibit at the fair, presenting an array of related services for the electronics industry.


Reflow oven

A reflow oven is a machine used primarily for reflow soldering of surface mount electronic components to printed circuit boards (PCBs).
In commercial high-volume use, reflow ovens take the form of a long tunnel containing a conveyor belt along which PCBs travel. For prototyping or hobbyist use PCBs can be placed in a small oven with a door.
Commercial conveyorised reflow ovens contain multiple individually heated zones, which can be individually controlled for temperature. PCBs being processed travel through the oven and through each zone at a controlled rate. Technicians adjust the conveyor speed and zone temperatures to achieve a known time and temperature profile. The profile in use may vary depending on the requirements of the PCBs being processed at the time.
Types of reflow ovens.
Infrared and convection ovens.
In infrared reflow ovens, the heat source is normally ceramic infrared heaters above and below the conveyor, which transfer heat to the PCBs by means of radiation.
Convection ovens heat air in chambers, using that air to transfer heat to the PCBs by means of convection and conduction. They may be fan assisted to control the airflow within the oven. This indirect heating using air allows more accurate temperature control than directly heating PCBs by infrared radiation, as PCBs and components vary in infrared absorptance.
Ovens may use a combination of infrared radiative heating and convection heating, and would then be known as 'infrared convection' ovens.
Some ovens are designed to reflow PCBs in an oxygen-free atmosphere. Nitrogen (N2) is a common gas used for this purpose. This minimizes oxidation of the surfaces to be soldered. The nitrogen reflow oven takes a few minutes to reduce Oxygen concentration to acceptable levels within the chamber. Thus nitrogen ovens typically have nitrogen injection in at all times which decreases defect rates.
Vapour phase oven.
The heating of the PCBs is sourced by thermal energy emitted by the phase transition of a heat transfer liquid (e. g. PFPE) condensing on the PCBs. The liquid used is chosen with a desired boiling point in mind to suit the solder alloy to be reflowed.
Some advantages of vapour phase soldering are:
This is also known as condensation soldering.
Thermal profiling.
Thermal profiling is the act of measuring several points on a circuit board to determine the thermal excursion it takes through the soldering process.
In the electronics manufacturing industry, SPC (statistical process control) helps determine if the process is in control, measured against the reflow parameters defined by the soldering technologies and component requirements.


Thermal cleaning

Thermal cleaning is a combined process involving pyrolysis and oxidation. As an industrial application, thermal cleaning is used to remove organic substances such as polymers, plastics and coatings from parts, products or production components like extruder screws, spinnerets and static mixers. Thermal cleaning is the most common cleaning method in industrial environment. A variety of different methods have been developed so far for a wide range of applications.
Process.
Heat is supplied for pyrolysis and air is supplied for oxidation. Depending on the procedure, pyrolysis and oxidation can be applied consecutively or simultaneously. During thermal cleaning, organic material is converted into volatile organic compounds, hydrocarbons and carbonized gas. Inorganic elements remain. Typical process temperatures range between 400 °C to 540 °C (750 °F to 1000 °F).
Several types of industrial thermal cleaning systems are available:
Fluidized bed systems.
Fluidized bed systems use sand or aluminium oxide (alumina) as heating medium. They apply pyrolysis and oxidation simultaneously. These systems clean fast, from 30 minutes process time up to two hours. The medium does not melt or boil, nor emit any vapors or odors. Thermal shock can be a problem with some parts. Pollution control devices may be needed to protect the environment.
Vacuum ovens.
Vacuum ovens use pyrolysis in a vacuum. This method is very safe because uncontrolled combustion inside the cleaning chamber is avoided. The cleaning process in this relatively new approach takes 8 to 30 hours. Vacuum pyrolysis is the only method that applies pyrolysis and oxidation consecutively. In two-chamber versions, molten plastic drains into an unheated chamber to capture the bulk of the polymer to reduce the fumes. Vacuum ovens are also electrically powered.
Burn-off ovens.
Burn-off ovens, also known as heat-cleaning ovens, are gas-fired and used for removing organics from heavy and large metal parts. The process time is moderate, approximately 4 hours. Fires can occur from the fumes created during cleaning. The design is simple and inexpensive. Different types are available. Modern types contain an additional afterburner that operates at a minimum of 1,500°F (816°C) and consumes any smoke created by the process.
Molten salt baths.
Molten salt baths belong to the oldest thermal cleaning systems. Cleaning with molten salt is fast: 15 to 30 minutes process time. The process has the risk of dangerous splatters due to chemical reactivity, or other potential hazards, like explosions or toxic hydrogen cyanide gas. Another disadvantage is that parts can be warped or altered in design tolerances. Molten salt baths can be environmentally unfriendly. Due to their disadvantages, they are rarely used today.


Dneprospetsstal

Dneprospetsstal , known as DSS, is a Ukrainian manufacturer of special stainless steel. The company is based in Zaporizhia in southeastern Ukraine, and was founded as a state-run enterprise in . Its full name is JPrSC Electrometallurgical Works Dneprospetsstal named after A. N. Kuzmin. It is a publicly traded company.
Dneprospetsstal manufactures and sells metal products of stainless, tool, high-speed (including those produced by the PM-method), bearing, structural, alloyed and carbon steel grades. Dneprospetsstal manufactures over 800 steel grades of 1200 section sizes.
DSS' products are used in the manufacture of machinery parts, tools for metal and alloy machining, seamless pipes and bearings.
Company’s steel production capacities comprise steel-making shops equipped with open basic electric arc furnaces, induction furnace and electro slag re-melting (ESR) and vacuum arc re-melting (VAR) facilities.
DSS steel processing is concentrated in a rolling shop, which contains blooming mills and a few rolling mills, a forging shop, a forging press shop, a cold drawing shop and a metal finishing shop.
DSS quality management system meets the requirements of international standards. In 2008, the enterprise was certified to ISO 9001:2008. Product quality meets the requirements of GOST (CIS), ASTM, AISI (USA), EN (EU), DIN (Germany), BS (Great Britain), AFNOR (France), JIS (Japan).


Injection moulding

Injection moulding (U.S. spelling: injection molding) is a manufacturing process for producing parts by injecting molten material into a mould, or mold. Injection moulding can be performed with a host of materials mainly including metals (for which the process is called die-casting), glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers. Material for the part is fed into a heated barrel, mixed (using a helical screw), and injected into a mould cavity, where it cools and hardens to the configuration of the cavity. After a product is designed, usually by an industrial designer or an engineer, moulds are made by a mould-maker (or toolmaker) from metal, usually either steel or aluminium, and precision-machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars. Advances in 3D printing technology, using photopolymers that do not melt during the injection moulding of some lower-temperature thermoplastics, can be used for some simple injection moulds.
Injection moulding uses a special-purpose machine that has three parts: the injection unit, the mould and the clamp. Parts to be injection-moulded must be very carefully designed to facilitate the moulding process; the material used for the part, the desired shape and features of the part, the material of the mould, and the properties of the moulding machine must all be taken into account. The versatility of injection moulding is facilitated by this breadth of design considerations and possibilities.
Applications.
Injection moulding is used to create many things such as wire spools, packaging, bottle caps, automotive parts and components, toys, pocket combs, some musical instruments (and parts of them), one-piece chairs and small tables, storage containers, mechanical parts (including gears), and most other plastic products available today. Injection moulding is the most common modern method of manufacturing plastic parts; it is ideal for producing high volumes of the same object.
Process characteristics.
Injection moulding uses a ram or screw-type plunger to force molten plastic or rubber material into a mould cavity; this solidifies into a shape that has conformed to the contour of the mould. It is most commonly used to process both thermoplastic and thermosetting polymers, with the volume used of the former being considerably higher. Thermoplastics are prevalent due to characteristics that make them highly suitable for injection moulding, such as ease of recycling, versatility for a wide variety of applications, and ability to soften and flow on heating. Thermoplastics also have an element of safety over thermosets; if a thermosetting polymer is not ejected from the injection barrel in a timely manner, chemical crosslinking may occur causing the screw and check valves to seize and potentially damaging the injection moulding machine.
Injection moulding consists of the high pressure injection of the raw material into a mould, which shapes the polymer into the desired form. Moulds can be of a single cavity or multiple cavities. In multiple cavity moulds, each cavity can be identical and form the same parts or can be unique and form multiple different geometries during a single cycle. Moulds are generally made from tool steels, but stainless steels and aluminium moulds are suitable for certain applications. Aluminium moulds are typically ill-suited for high volume production or parts with narrow dimensional tolerances, as they have inferior mechanical properties and are more prone to wear, damage, and deformation during the injection and clamping cycles; however, aluminium moulds are cost-effective in low-volume applications, as mould fabrication costs and time are considerably reduced. Many steel moulds are designed to process well over a million parts during their lifetime and can cost hundreds of thousands of dollars to fabricate.
When thermoplastics are moulded, typically pelletised raw material is fed through a hopper into a heated barrel with a reciprocating screw. Upon entrance to the barrel, the temperature increases and the Van der Waals forces that resist relative flow of individual chains are weakened as a result of increased space between molecules at higher thermal energy states. This process reduces its viscosity, which enables the polymer to flow with the driving force of the injection unit. The screw delivers the raw material forward, mixes and homogenises the thermal and viscous distributions of the polymer, and reduces the required heating time by mechanically shearing the material and adding a significant amount of frictional heating to the polymer. The material feeds forward through a check valve and collects at the front of the screw into a volume known as a shot. A shot is the volume of material that is used to fill the mould cavity, compensate for shrinkage, and provide a cushion (approximately 10% of the total shot volume, which remains in the barrel and prevents the screw from bottoming out) to transfer pressure from the screw to the mould cavity. When enough material has gathered, the material is forced at high pressure and velocity into the part forming cavity. The exact amount of shrinkage is a function of the resin being used, and can be relatively predictable. To prevent spikes in pressure, the process normally uses a transfer position corresponding to a 95–98% full cavity where the screw shifts from a constant velocity to a constant pressure control. Often injection times are well under 1 second. Once the screw reaches the transfer position the packing pressure is applied, which completes mould filling and compensates for thermal shrinkage, which is quite high for thermoplastics relative to many other materials. The packing pressure is applied until the gate (cavity entrance) solidifies. Due to its small size, the gate is normally the first place to solidify through its entire thickness. Once the gate solidifies, no more material can enter the cavity; accordingly, the screw reciprocates and acquires material for the next cycle while the material within the mould cools so that it can be ejected and be dimensionally stable. This cooling duration is dramatically reduced by the use of cooling lines circulating water or oil from an external temperature controller. Once the required temperature has been achieved, the mould opens and an array of pins, sleeves, strippers, etc. are driven forward to demould the article. Then, the mould closes and the process is repeated.
For a two-shot mould, two separate materials are incorporated into one part. This type of injection moulding is used to add a soft touch to knobs, to give a product multiple colours, or to produce a part with multiple performance characteristics.
For thermosets, typically two different chemical components are injected into the barrel. These components immediately begin irreversible chemical reactions that eventually crosslinks the material into a single connected network of molecules. As the chemical reaction occurs, the two fluid components permanently transform into a viscoelastic solid. Solidification in the injection barrel and screw can be problematic and have financial repercussions; therefore, minimising the thermoset curing within the barrel is vital. This typically means that the residence time and temperature of the chemical precursors are minimised in the injection unit. The residence time can be reduced by minimising the barrel's volume capacity and by maximising the cycle times. These factors have led to the use of a thermally isolated, cold injection unit that injects the reacting chemicals into a thermally isolated hot mould, which increases the rate of chemical reactions and results in shorter time required to achieve a solidified thermoset component. After the part has solidified, valves close to isolate the injection system and chemical precursors, and the mould opens to eject the moulded parts. Then, the mould closes and the process repeats.
Pre-moulded or machined components can be inserted into the cavity while the mould is open, allowing the material injected in the next cycle to form and solidify around them. This process is known as Insert moulding and allows single parts to contain multiple materials. This process is often used to create plastic parts with protruding metal screws so they can be fastened and unfastened repeatedly. This technique can also be used for In-mould labelling and film lids may also be attached to moulded plastic containers.
A parting line, sprue, gate marks, and ejector pin marks are usually present on the final part. None of these features are typically desired, but are unavoidable due to the nature of the process. Gate marks occur at the gate that joins the melt-delivery channels (sprue and runner) to the part forming cavity. Parting line and ejector pin marks result from minute misalignments, wear, gaseous vents, clearances for adjacent parts in relative motion, and/or dimensional differences of the melting surfaces contacting the injected polymer. Dimensional differences can be attributed to non-uniform, pressure-induced deformation during injection, machining tolerances, and non-uniform thermal expansion and contraction of mould components, which experience rapid cycling during the injection, packing, cooling, and ejection phases of the process. Mould components are often designed with materials of various coefficients of thermal expansion. These factors cannot be simultaneously accounted for without astronomical increases in the cost of design, fabrication, processing, and quality monitoring. The skillful mould and part designer positions these aesthetic detriments in hidden areas if feasible.
History.
In 1846 the British inventor Charles Hancock, a relative of Thomas Hancock, patented an injection molding machine.
American inventor John Wesley Hyatt, together with his brother Isaiah, patented one of the first injection moulding machines in 1872. This machine was relatively simple compared to machines in use today: it worked like a large hypodermic needle, using a plunger to inject plastic through a heated cylinder into a mould. The industry progressed slowly over the years, producing products such as collar stays, buttons, and hair combs(generally though, plastics, in its modern definition, are a more recent development ).
The German chemists Arthur Eichengrün and Theodore Becker invented the first soluble forms of cellulose acetate in 1903, which was much less flammable than cellulose nitrate. It was eventually made available in a powder form from which it was readily injection moulded. Arthur Eichengrün developed the first injection moulding press in 1919. In 1939, Arthur Eichengrün patented the injection moulding of plasticised cellulose acetate.
The industry expanded rapidly in the 1940s because World War II created a huge demand for inexpensive, mass-produced products. In 1946, American inventor James Watson Hendry built the first screw injection machine, which allowed much more precise control over the speed of injection and the quality of articles produced. This machine also allowed material to be mixed before injection, so that coloured or recycled plastic could be added to virgin material and mixed thoroughly before being injected. In the 1970s, Hendry went on to develop the first gas-assisted injection moulding process, which permitted the production of complex, hollow articles that cooled quickly. This greatly improved design flexibility as well as the strength and finish of manufactured parts while reducing production time, cost, weight and waste. By 1979, plastic production overtook steel production, and by 1990, aluminium moulds were widely used in injection moulding. Today, screw injection machines account for the vast majority of all injection machines.
The plastic injection moulding industry has evolved over the years from producing combs and buttons to producing a vast array of products for many industries including automotive, medical, aerospace, consumer products, toys, plumbing, packaging, and construction.
Examples of polymers best suited for the process.
Most polymers, sometimes referred to as resins, may be used, including all thermoplastics, some thermosets, and some elastomers. Since 1995, the total number of available materials for injection moulding has increased at a rate of 750 per year; there were approximately 18,000 materials available when that trend began. Available materials include alloys or blends of previously developed materials, so product designers can choose the material with the best set of properties from a vast selection. Major criteria for selection of a material are the strength and function required for the final part, as well as the cost, but also each material has different parameters for moulding that must be taken into account. Other considerations when choosing an injection moulding material include flexural modulus of elasticity, or the degree to which a material can be bent without damage, as well as heat deflection and water absorption. Common polymers like epoxy and phenolic are examples of thermosetting plastics while nylon, polyethylene, and polystyrene are thermoplastic. Until comparatively recently, plastic springs were not possible, but advances in polymer properties make them now quite practical. Applications include buckles for anchoring and disconnecting outdoor-equipment webbing.
Equipment.
Injection moulding machines consist of a material hopper, an injection ram or screw-type plunger, and a heating unit. Also known as platens, they hold the moulds in which the components are shaped. Presses are rated by tonnage, which expresses the amount of clamping force that the machine can exert. This force keeps the mould closed during the injection process. Tonnage can vary from less than 5 tons to over 9,000 tons, with the higher figures used in comparatively few manufacturing operations. The total clamp force needed is determined by the projected area of the part being moulded. This projected area is multiplied by a clamp force of from 1.8 to 7.2 tons for each square centimetre of the projected areas. As a rule of thumb, 4 or 5 tons/in2 can be used for most products. If the plastic material is very stiff, it requires more injection pressure to fill the mould, and thus more clamp tonnage to hold the mould closed. The required force can also be determined by the material used and the size of the part. Larger parts require higher clamping force.
Mould.
Mould or die are the common terms used to describe the tool used to produce plastic parts in moulding.
Since moulds have been expensive to manufacture, they were usually only used in mass production where thousands of parts were being produced. Typical moulds are constructed from hardened steel, pre-hardened steel, aluminium, and/or beryllium-copper alloy. The choice of material to build a mould from is primarily one of economics; in general, steel moulds cost more to construct, but their longer lifespan offsets the higher initial cost over a higher number of parts made before wearing out. Pre-hardened steel moulds are less wear-resistant and are used for lower volume requirements or larger components; their typical steel hardness is 38–45 on the Rockwell-C scale. Hardened steel moulds are heat treated after machining; these are by far superior in terms of wear resistance and lifespan. Typical hardness ranges between 50 and 60 Rockwell-C (HRC). Aluminium moulds can cost substantially less, and when designed and machined with modern computerised equipment can be economical for moulding tens or even hundreds of thousands of parts. Beryllium copper is used in areas of the mould that require fast heat removal or areas that see the most shear heat generated. The moulds can be manufactured either by CNC machining or by using electrical discharge machining processes.
Mould design.
The mould consists of two primary components, the injection mould (A plate) and the ejector mould (B plate). These components are also referred to as "moulder" and "mouldmaker". Plastic resin enters the mould through a "sprue" or "gate" in the injection mould; the sprue bushing is to seal tightly against the nozzle of the injection barrel of the moulding machine and to allow molten plastic to flow from the barrel into the mould, also known as the cavity. The sprue bushing directs the molten plastic to the cavity images through channels that are machined into the faces of the A and B plates. These channels allow plastic to run along them, so they are referred to as runners. The molten plastic flows through the runner and enters one or more specialised gates and into the cavity geometry to form the desired part.
The amount of resin required to fill the sprue, runner and cavities of a mould comprises a "shot". Trapped air in the mould can escape through air vents that are ground into the parting line of the mould, or around ejector pins and slides that are slightly smaller than the holes retaining them. If the trapped air is not allowed to escape, it is compressed by the pressure of the incoming material and squeezed into the corners of the cavity, where it prevents filling and can also cause other defects. The air can even become so compressed that it ignites and burns the surrounding plastic material.
To allow for removal of the moulded part from the mould, the mould features must not overhang one another in the direction that the mould opens, unless parts of the mould are designed to move from between such overhangs when the mould opens using components called Lifters.
Sides of the part that appear parallel with the direction of draw (the axis of the cored position (hole) or insert is parallel to the up and down movement of the mould as it opens and closes) are typically angled slightly, called draft, to ease release of the part from the mould. Insufficient draft can cause deformation or damage. The draft required for mould release is primarily dependent on the depth of the cavity; the deeper the cavity, the more draft necessary. Shrinkage must also be taken into account when determining the draft required. If the skin is too thin, then the moulded part tends to shrink onto the cores that form while cooling and cling to those cores, or the part may warp, twist, blister or crack when the cavity is pulled away.
A mould is usually designed so that the moulded part reliably remains on the ejector (B) side of the mould when it opens, and draws the runner and the sprue out of the (A) side along with the parts. The part then falls freely when ejected from the (B) side. Tunnel gates, also known as submarine or mould gates, are located below the parting line or mould surface. An opening is machined into the surface of the mould on the parting line. The moulded part is cut (by the mould) from the runner system on ejection from the mould. Ejector pins, also known as knockout pins, are circular pins placed in either half of the mould (usually the ejector half), which push the finished moulded product, or runner system out of a mould.The ejection of the article using pins, sleeves, strippers, etc., may cause undesirable impressions or distortion, so care must be taken when designing the mould.
The standard method of cooling is passing a coolant (usually water) through a series of holes drilled through the mould plates and connected by hoses to form a continuous pathway. The coolant absorbs heat from the mould (which has absorbed heat from the hot plastic) and keeps the mould at a proper temperature to solidify the plastic at the most efficient rate.
To ease maintenance and venting, cavities and cores are divided into pieces, called "inserts", and sub-assemblies, also called "inserts", "blocks", or "chase blocks". By substituting interchangeable inserts, one mould may make several variations of the same part.
More complex parts are formed using more complex moulds. These may have sections called slides, that move into a cavity perpendicular to the draw direction, to form overhanging part features. When the mould is opened, the slides are pulled away from the plastic part by using stationary “angle pins” on the stationary mould half. These pins enter a slot in the slides and cause the slides to move backward when the moving half of the mould opens. The part is then ejected and the mould closes. The closing action of the mould causes the slides to move forward along the angle pins.
A mould can produce several copies of the same parts in a single "shot". The number of "impressions" in the mould of that part is often incorrectly referred to as cavitation. A tool with one impression is often called a single "impression" (cavity) mould. A mould with two or more cavities of the same parts is usually called a multiple "impression" (cavity) mould. (Not to be confused with "Multi-"shot" moulding" {which is dealt with in the next section.}) Some extremely high production volume moulds (like those for bottle caps) can have over 128 cavities.
In some cases, multiple cavity tooling moulds a series of different parts in the same tool. Some toolmakers call these moulds family moulds, as all the parts are related—e.g., plastic model kits.
Some moulds allow previously moulded parts to be reinserted to allow a new plastic layer to form around the first part. This is often referred to as overmoulding. This system can allow for production of one-piece tires and wheels.
Moulds for highly precise and extremely small parts from micro injection molding requires extra care in the design stage, as material resins react differently compared to their full-sized counterparts where they must quickly fill these incredibly small spaces, which puts them under intense shear strains.
Multi-shot moulding.
Two-shot, double-shot or multi-shot moulds are designed to "overmould" within a single moulding cycle and must be processed on specialised injection moulding machines with two or more injection units. This process is actually an injection moulding process performed "twice" and therefore can allow only for a much smaller margin of error. In the first step, the base colour material is moulded into a basic shape, which contains spaces for the second shot. Then the second material, a different colour, is injection-moulded into those spaces. Pushbuttons and keys, for instance, made by this process have markings that cannot wear off, and remain legible with heavy use.
Mould storage.
Manufacturers go to great lengths to protect custom moulds due to their high average costs. The perfect temperature and humidity level is maintained to ensure the longest possible lifespan for each custom mould. Custom moulds, such as those used for rubber injection moulding, are stored in temperature and humidity controlled environments to prevent warping.
Tool materials.
Tool steel is often used. Mild steel, aluminium, nickel or epoxy are suitable only for prototype or very short production runs. Modern hard aluminium (7075 and 2024 alloys) with proper mould design, can easily make moulds capable of 100,000 or more part life with proper mould maintenance.
Machining.
Moulds are built through two main methods: standard machining and EDM. Standard machining, in its conventional form, has historically been the method of building injection moulds. With technological developments, CNC machining became the predominant means of making more complex moulds with more accurate mould details in less time than traditional methods.
The electrical discharge machining (EDM) or spark erosion process has become widely used in mould making. As well as allowing the formation of shapes that are difficult to machine, the process allows pre-hardened moulds to be shaped so that no heat treatment is required. Changes to a hardened mould by conventional drilling and milling normally require annealing to soften the mould, followed by heat treatment to harden it again. EDM is a simple process in which a shaped electrode, usually made of copper or graphite, is very slowly lowered onto the mould surface over a period of many hours, which is immersed in paraffin oil (kerosene). A voltage applied between tool and mould causes spark erosion of the mould surface in the inverse shape of the electrode.
Cost.
The number of cavities incorporated into a mould directly correlate in moulding costs. Fewer cavities require far less tooling work, so limiting the number of cavities lowers initial manufacturing costs to build an injection mould.
As the number of cavities play a vital role in moulding costs, so does the complexity of the part's design. Complexity can be incorporated into many factors such as surface finishing, tolerance requirements, internal or external threads, fine detailing or the number of undercuts that may be incorporated.
Further details, such as undercuts, or any feature that needs additional tooling, increases mould cost. Surface finish of the core and cavity of moulds further influences cost.
Rubber injection moulding process produces a high yield of durable products, making it the most efficient and cost-effective method of moulding. Consistent vulcanisation processes involving precise temperature control significantly reduces all waste material.
Injection process.
Usually, the plastic materials are formed in the shape of pellets or granules and sent from the raw material manufacturers in paper bags. With injection moulding, pre-dried granular plastic is fed by a forced ram from a hopper into a heated barrel. As the granules are slowly moved forward by a screw-type plunger, the plastic is forced into a heated chamber, where it is melted. As the plunger advances, the melted plastic is forced through a nozzle that rests against the mould, allowing it to enter the mould cavity through a gate and runner system. The mould remains cold so the plastic solidifies almost as soon as the mould is filled.
Injection moulding cycle.
The sequence of the events during the injection mould of a plastic part is called the injection moulding cycle. The cycle begins when the mould closes, followed by the injection of the polymer into the mould cavity. Once the cavity is filled, a holding pressure is maintained to compensate for material shrinkage. In the next step, the screw turns, feeding the next shot to the front screw. This causes the screw to retract as the next shot is prepared. Once the part is sufficiently cool, the mould opens and the part is ejected.
Scientific versus traditional moulding.
Traditionally, the injection portion of the moulding process was done at one constant pressure to fill and pack the cavity. This method, however, allowed for a large variation in dimensions from cycle-to-cycle. More commonly used now is scientific or decoupled moulding, a method pioneered by RJG Inc. In this the injection of the plastic is "decoupled" into stages to allow better control of part dimensions and more cycle-to-cycle (commonly called shot-to-shot in the industry) consistency. First the cavity is filled to approximately 98% full using velocity (speed) control. Although the pressure should be sufficient to allow for the desired speed, pressure limitations during this stage are undesirable. Once the cavity is 98% full, the machine switches from velocity control to pressure control, where the cavity is "packed out" at a constant pressure, where sufficient velocity to reach desired pressures is required. This lets workers control part dimensions to within thousandths of an inch or better.
Different types of injection moulding processes.
Although most injection moulding processes are covered by the conventional process description above, there are several important moulding variations including, but not limited to:
A more comprehensive list of injection moulding processes may be found here:
Process troubleshooting.
Like all industrial processes, injection molding can produce flawed parts, even in toys. In the field of injection moulding, troubleshooting is often performed by examining defective parts for specific defects and addressing these defects with the design of the mould or the characteristics of the process itself. Trials are often performed before full production runs in an effort to predict defects and determine the appropriate specifications to use in the injection process.
When filling a new or unfamiliar mould for the first time, where shot size for that mould is unknown, a technician/tool setter may perform a trial run before a full production run. They start with a small shot weight and fills gradually until the mould is 95 to 99% full. Once they achieve this, they apply a small amount of holding pressure and increase holding time until gate freeze off (solidification time) has occurred. Gate freeze off time can be determined by increasing the hold time, and then weighing the part. When the weight of the part does not change, the gate has frozen and no more material is injected into the part. Gate solidification time is important, as this determines cycle time and the quality and consistency of the product, which itself is an important issue in the economics of the production process. Holding pressure is increased until the parts are free of sinks and part weight has been achieved.
Moulding defects.
Injection moulding is a complex technology with possible production problems. They can be caused either by defects in the moulds, or more often by the moulding process itself.
Methods such as industrial CT scanning can help with finding these defects externally as well as internally.
Tolerances.
Tolerance depends on the dimensions of the part. An example of a standard tolerance for a 1-inch dimension of an LDPE part with 0.125 inch wall thickness is +/- 0.008 inch (0.2 mm).
Power requirements.
The power required for this process of injection moulding depends on many things and varies between materials used. "Manufacturing Processes Reference Guide" states that the power requirements depend on "a material's specific gravity, melting point, thermal conductivity, part size, and molding rate." Below is a table from page 243 of the same reference as previously mentioned that best illustrates the characteristics relevant to the power required for the most commonly used materials.
Robotic moulding.
Automation means that the smaller size of parts permits a mobile inspection system to examine multiple parts more quickly. In addition to mounting inspection systems on automatic devices, multiple-axis robots can remove parts from the mould and position them for further processes.
Specific instances include removing of parts from the mould immediately after the parts are created, as well as applying machine vision systems. A robot grips the part after the ejector pins have been extended to free the part from the mould. It then moves them into either a holding location or directly onto an inspection system. The choice depends upon the type of product, as well as the general layout of the manufacturing equipment. Vision systems mounted on robots have greatly enhanced quality control for insert moulded parts. A mobile robot can more precisely determine the placement accuracy of the metal component, and inspect faster than a human can.


The Fraunhofer Competence Field Additive Manufacturing integrates eighteen Fraunhofer institutes across Germany, which depending on their main focus, deal with subjects concerning additive manufacturing and represent the entire process chain. This includes the development, application and implementation of additive production processes as well as associated materials. Topics may cover all aspects of additive manufacturing, such as: materials and technologies, assessing and improving the quality of 3D printed parts, optimizing parts for various criteria (weight, stiffness, etc.) and digital workflow (slicers, adaptive machine control).
The network was founded as Fraunhofer Rapid Prototyping Alliance in 1998 and was relaunched as Fraunhofer Additive Manufacturing Alliance in 2008, when additive manufacturing took off as a manufacturing technology of the future. In 2021 Fraunhofer reorganizes its research areas in order to better meet the industrial requirements and the Fraunhofer Additive Manufacturing Alliance will bundle its expertise in the Fraunhofer Competence Field Additive Manufacturing.
Based on many years of experience in fulfilling nationally and internationally industrial contracts as well as research projects, the Fraunhofer Competence Field Additive Manufacturing develops customized designs for each customer and manages complex assignments. Its current focus is on bio-medical engineering, micro-system engineering, automotive engineering & aerospace, tool making as well as handling and assembly.
The two main fairs every year are the Rapid.Tech 3D in June and the formnext in November. The Rapid.Tech 3D is focussed on manufacturing of end products using additive techniques and how the technology can be transferred into mass production.
The formnext is a global trade fair dedicated to additive manufacturing and industrial 3D printing, where experts come from a wide range of industry sectors, such as automotive, aerospace, mechanical engineering, medical technology, electrical engineering and many more.
Direct Digital Manufacturing Conference (DDMC).
The Fraunhofer Competence Field Additive Manufacturing organizes the biannual DDMC, which is a cutting-edge forum for discussion on Additive Manufacturing, including its application in industry and the environmental impact of such new manufacturing technologies. Impact on health, sustainability and technology will also be discussed. DDMC brings together researchers, educators and practitioners from around the world and fosters an atmosphere conducive to developing new ideas and refining already existing research developments.
Fraunhofer-Institutes.
The Fraunhofer Competence Field Additive Manufacturing includes the following Fraunhofer-Institutes:


Four-die forging device

Four-die forging device is a special forging tool designed for manufacturing forgings with long axis by four-side radial forging method in conventional open-die hydraulic forging press. A similar stand-alone machine is known as a radial forging machine.
The device is used for deformation treatment of ingots and blanks from ordinary and high-alloy steels and alloys, including hard-to-deform ones, in wide range of shapes and grades to obtain various solid and hollow forgings, including round, square and polygonal forged bars of constant and variable cross-section, blanks of smooth and stepped shafts, axles, thick-wall pipes, mechanical tube, shells, etc.
Design and Operation.
The device consists of the upper case and the lower case with the upper die and the lower die installed therein respectively, and sliders that are kinematically interconnected with the cases by means of guides of special design and hold side dies attached thereto. The device is installed on a tool table of an open-die forging press as easy as ordinary dies. Thereat, the lower case of the device is fixed to the tool table and always remains stationary while the upper case is attached to the press ram and always travels along with it. When the press ram goes up the upper die also goes up and the side dies are retracted opening the device working space whereto a work piece is fed by a manipulator. When the press ram goes down the work piece is reduced simultaneously by four dies. Then the cycle repeats.
From Two Dies to Four.
The second half of the 19th century was marked with the appearance of hydraulic forging presses that started to replace hammers at forging works. Forging in forging presses is carried out by two dies of which one makes reciprocal movements and the other one remains stationary. This is the reason for relatively low productivity and high labour intensity of conventional forging in presses. The forging of low-ductility and hard-to-deform steels and alloys by two dies using conventional forging methods is very difficult and sometimes is practically impossible because of high tensile stresses in deformation zone leading to various forging defects and high percentage of rejected products.
In the 1970s the mechanical radial forging machines (RFM) started to be used for the large-scale production of long-axis forgings where a work piece is reduced in radial directions simultaneously by several pairs of dies. The process of radial forging in mechanical RFM features high productivity of forging. However small single reductions of a work piece restricted by the design of these machines lead to localization of strains mainly in surface zones of the work piece while metal in the core zone remains unworked. In 80-90s hydro-mechanical and hydraulic radial forging machines appeared that do not have the disadvantages inherent to mechanical RFM. Nevertheless, radial forging machines are very specific and very expensive equipment in comparison with multipurpose forging presses. The application of such machines at enterprises with a wide range of forgings manufactured is economically disadvantageous and inexpedient.
The problem of manufacturing long-axis forgings by radial forging method in open-die hydraulic forging presses can be solved with use of multi-die forging devices. First such devices different in design and principle of operation appeared in the 1980s. At present, the most widespread and famous is the four-die forging device of the above described design engineered by Ukrainian and Russian scientists. The four-die forging devices have no analogues in the world now. They are successfully used at works in Russia, Ukraine, Spain, China and Germany.
Advantages of Forging with Four-Die Forging Device.
The use of four-die forging devices in hydraulic forging presses provides for the following advantages in comparison with conventional methods of forging by two dies:


Maryland Steamer

The Maryland Steamer automobile was manufactured in Luke, Maryland in 1900 and 1901
History.
The Maryland Automobile Manufacturing company developed a runabout with a two-cylinder vertical steam engine and a chain drive. In December 1900 the factory was blown down by gale force winds. The factory was insured and production continued in 1901. The Company offered bodies as a Tourist Carriage, Runabout, Surrey, Phaeton, Omnibus, Delivery Wagon and Racing Machine. The company was reported in receivership by May 1901. The factory became a bottling plant.
External Links.
Maryland Automobile Manufacturing Co. at the Virtual Steam Car Museum


Aichi Steel

History.
Aichi Steel was one of the earliest subsidiaries of the Toyota Group. Kiichiro Toyoda, the founder of Toyota, struggled to manufacture automobiles as the steel producers were uninterested to supply his small workshop with the steel sheets for automobiles. To address the problem, Toyoda bought his own furnace that provided his company with the casting expertise and forming equipment that would shape a car. This iron workshop became the precursor to Aichi Steel.
The company was established in 1934 as Aichi Seiko, the steel manufacturing department of Toyoda Automatic Loom Works, the predecessor to Toyota Industries. The company derived its name from Aichi Prefecture, where Toyota's headquarters and major production facilities are located. It became an independent company in 1940 and changed its name to its present one in 1945.
Today, Aichi Steel supplies 40% of the steel, springs and forged products for automotive use to members of the Toyota Group. This volume underscored Toyota's reliance on the partnership given the sophisticated nature of Aichi's manufacturing services, which few suppliers can replicate. In January 2016, a furnace explosion in one of Aichi's steel mills suspended production at Toyota's entire assembly plants for one week and threatened further disruptions to the company's operations for almost two months.