Linear actuator

A linear actuator is an actuator that creates motion in a straight line, in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer peripherals such as disk drives and printers, in valves and dampers, and in many other places where linear motion is required. Hydraulic or pneumatic cylinders inherently produce linear motion. Many other mechanisms are used to generate linear motion from a rotating motor.
Types.
Mechanical actuators.
Mechanical linear actuators typically operate by conversion of rotary motion into linear motion. Conversion is commonly made via a few simple types of mechanism:
Some mechanical linear actuators only pull, such as hoists, chain drive and belt drives. Others only push (such as a cam actuator). Pneumatic and hydraulic cylinders, or lead screws can be designed to generate force in both directions.
Mechanical actuators typically convert rotary motion of a control knob or handle into linear displacement via screws and/or gears to which the knob or handle is attached. A jackscrew or car jack is a familiar mechanical actuator. Another family of actuators are based on the segmented spindle. Rotation of the jack handle is converted mechanically into the linear motion of the jack head. Mechanical actuators are also frequently used in the field of lasers and optics to manipulate the position of linear stages, rotary stages, mirror mounts, goniometers and other positioning instruments. For accurate and repeatable positioning, index marks may be used on control knobs. Some actuators include an encoder and digital position readout. These are similar to the adjustment knobs used on micrometers except their purpose is position adjustment rather than position measurement.
Hydraulic actuators.
Hydraulic actuators or hydraulic cylinders typically involve a hollow cylinder having a piston inserted in it. An unbalanced pressure applied to the piston generates a force that can move an external object. Since liquids are nearly incompressible, a hydraulic cylinder can provide controlled precise linear displacement of the piston. The displacement is only along the axis of the piston. A familiar example of a manually operated hydraulic actuator is a hydraulic car jack. Typically though, the term "hydraulic actuator" refers to a device controlled by a hydraulic pump.
Pneumatic actuators.
Pneumatic actuators, or pneumatic cylinders, are similar to hydraulic actuators except they use compressed air to generate force instead of a liquid. They work similarly to a piston in which air is pumped inside a chamber and pushed out of the other side of the chamber. Air actuators are not necessarily used for heavy duty machinery and instances where large amounts of weight are present. One of the reasons pneumatic linear actuators are preferred to other types is the fact that the power source is simply an air compressor. Because air is the input source, pneumatic actuators are able to be used in many places of mechanical activity. The downside is, most air compressors are large, bulky, and loud. They are hard to transport to other areas once installed. Pneumatic linear actuators are likely to leak and this makes them less efficient than mechanical linear actuators.
Piezoelectric actuators.
The piezoelectric effect is a property of certain materials in which application of a voltage to the material causes it to expand. Very high voltages correspond to only tiny expansions. As a result, piezoelectric actuators can achieve extremely fine positioning resolution, but also have a very short range of motion. In addition, piezoelectric materials exhibit hysteresis which makes it difficult to control their expansion in a repeatable manner.
Electro-mechanical actuators.
Electro-mechanical actuators are similar to mechanical actuators except that the control knob or handle is replaced with an electric motor. Rotary motion of the motor is converted to linear displacement. Electromechanical actuators may also be used to power a motor that converts electrical energy into mechanical torque. There are many designs of modern linear actuators and every company that manufactures them tends to have a proprietary method. The following is a generalized description of a very simple electro-mechanical linear actuator.
Simplified design.
Typically, an electric motor is mechanically connected to rotate a lead screw. A lead screw has a continuous helical thread machined on its circumference running along the length (similar to the thread on a bolt). Threaded onto the lead screw is a lead nut or ball nut with corresponding helical threads. The nut is prevented from rotating with the lead screw (typically the nut interlocks with a non-rotating part of the actuator body). When the lead screw is rotated, the nut will be driven along the threads. The direction of motion of the nut depends on the direction of rotation of the lead screw. By connecting linkages to the nut, the motion can be converted to usable linear displacement. Most current actuators are built for high speed, high force, or a compromise between the two. When considering an actuator for a particular application, the most important specifications are typically travel, speed, force, accuracy, and lifetime. Most varieties are mounted on dampers or butterfly valves.
There are many types of motors that can be used in a linear actuator system. These include dc brush, dc brushless, stepper, or in some cases, even induction motors. It all depends on the application requirements and the loads the actuator is designed to move. For example, a linear actuator using an integral horsepower AC induction motor driving a lead screw can be used to operate a large valve in a refinery. In this case, accuracy and high movement resolution aren't needed, but high force and speed are. For electromechanical linear actuators used in laboratory instrumentation robotics, optical and laser equipment, or X-Y tables, fine resolution in the micron range and high accuracy may require the use of a fractional horsepower stepper motor linear actuator with a fine pitch lead screw. There are many variations in the electromechanical linear actuator system. It is critical to understand the design requirements and application constraints to know which one would be best.
Standard vs compact construction.
A linear actuator using standard motors will commonly have the motor as a separate cylinder attached to the side of the actuator, either parallel with the actuator or perpendicular to the actuator. The motor may be attached to the end of the actuator. The drive motor is of typical construction with a solid drive shaft that is geared to the drive nut or drive screw of the actuator.
Compact linear actuators use specially designed motors that try to fit the motor and actuator into the smallest possible shape.
Principles.
In the majority of linear actuator designs, the basic principle of operation is that of an inclined plane. The threads of a lead screw act as a continuous ramp that allows a small rotational force to be used over a long distance to accomplish the movement of a large load over a short distance.
The power supply is from a DC or AC motor. The typical motor is a 12v DC, but other voltages are available. Actuators have a switch to reverse the polarity of the motor, which makes the actuator change its motion.
The speed and force of an actuator depend on its gearbox. The amount of force depends on the actuator’s speed. Lower speeds supply greater force because motor speed and force are constant.
One of the basic differences between actuators is their stroke, which is defined by the length of the screw and shaft. Speed depends on the gears that connect the motor to the screw.
The mechanism to stop the stroke of an actuator is a limit or micro switch, which can be seen in the image below. Microswitches are located at the top and bottom of the shaft and are triggered by the up and down movement of the screw.
Variations.
Many variations on the basic design have been created. Most focus on providing general improvements such as a higher mechanical efficiency, speed, or load capacity. There is also a large engineering movement towards actuator miniaturization.
Most electro-mechanical designs incorporate a lead screw and lead nut. Some use a ball screw and ball nut. In either case the screw may be connected to a motor or manual control knob either directly or through a series of gears. Gears are typically used to allow a smaller (and weaker) motor spinning at a higher rpm to be geared down to provide the torque necessary to spin the screw under a heavier load than the motor would otherwise be capable of driving directly. Effectively this sacrifices actuator speed in favor of increased actuator thrust. In some applications the use of worm gear is common as this allow a smaller built in dimension still allowing great travel length.
A traveling-nut linear actuator has a motor that stays attached to one end of the lead screw (perhaps indirectly through a gear box), the motor spins the lead screw, and the lead nut is restrained from spinning so it travels up and down the lead screw.
A traveling-screw linear actuator has a lead screw that passes entirely through the motor.
In a traveling-screw linear actuator, the motor "crawls" up and down a lead screw that is restrained from spinning. The only spinning parts are inside the motor, and may not be visible from the outside.
Some lead screws have multiple "starts". This means they have multiple threads alternating on the same shaft. One way of visualizing this is in comparison to the multiple color stripes on a candy cane. This allows for more adjustment between thread pitch and nut/screw thread contact area, which determines the extension speed and load carrying capacity (of the threads), respectively.
Static load capacity.
Linear screw actuators can have a static loading capacity, meaning that when the motor stops the actuator essentially locks in place and can support a load that is either pulling or pushing on the actuator. This static load capacity increases mobility and speed.
The braking force of the actuator varies with the angular pitch of the screw threads and the specific design of the threads. Acme threads have a very high static load capacity, while ball screws have an extremely low load capacity and can be nearly free-floating.
Generally it is not possible to vary the static load capacity of screw actuators without additional technology. The screw thread pitch and drive nut design defines a specific load capacity that cannot be dynamically adjusted.
In some cases, high viscosity grease can be added to linear screw actuators to increase the static load. Some manufacturers use this to alter the load for specific needs.
Static load capacity can be added to a linear screw actuator using an electromagnetic brake system, which applies friction to the spinning drive nut. For example, a spring may be used to apply brake pads to the drive nut, holding it in position when power is turned off. When the actuator needs to be moved, an electromagnet counteracts the spring and releases the braking force on the drive nut.
Similarly an electromagnetic ratchet mechanism can be used with a linear screw actuator so that the drive system lifting a load will lock in position when power to the actuator is turned off. To lower the actuator, an electromagnet is used to counteract the spring force and unlock the ratchet.
Dynamic load capacity.
Dynamic load capacity is typically referred to as the amount of force the linear actuator is capable of providing during operation. This force will vary with screw type (amount of friction restricting movement) and the motor driving the movement. Dynamic load is the figure which most actuators are classified by, and is a good indication of what applications it would suit best.
Speed control.
In most cases when using an electro-mechanical actuator, it is preferred to have some type of speed control. Such controllers vary the voltage supplied to the motor, which in turn changes the speed at which the lead screw turns. Adjusting the gear ratio is another way to adjust speed. Some actuators are available with several different gearing options.
Duty cycle.
The duty cycle of a motor refers to the amount of time the actuator can be run before it needs to cool down. Staying within this guideline when operating an actuator is key to its longevity and performance. If the duty cycle rating is exceeded, then overheating, loss of power, and eventual burning of the motor is risked.
Linear motors.
A linear motor is functionally the same as a rotary electric motor with the rotor and stator circular magnetic field components laid out in a straight line. Where a rotary motor would spin around and re-use the same magnetic pole faces again, the magnetic field structures of a linear motor are physically repeated across the length of the actuator.
Since the motor moves in a linear fashion, no lead screw is needed to convert rotary motion to linear. While high capacity is possible, the material and/or motor limitations on most designs are surpassed relatively quickly due to a reliance solely on magnetic attraction and repulsion forces. Most linear motors have a low load capacity compared to other types of linear actuators.
Linear motors have an advantage in outdoor or dirty environments in that the two halves do not need to contact each other, and so the electromagnetic drive coils can be waterproofed and sealed against moisture and corrosion, allowing for a very long service life. Linear motors are being used extensively in high performance positioning systems for applications which require various combinations of high velocity, high precision and high force.
Telescoping linear actuator.
Telescoping linear actuators are specialized linear actuators used where space restrictions exist. Their range of motion is many times greater than the unextended length of the actuating member.
A common form is made of concentric tubes of approximately equal length that extend and retract like sleeves, one inside the other, such as the telescopic cylinder.
Other more specialized telescoping actuators use actuating members that act as rigid linear shafts when extended, but break that line by folding, separating into pieces and/or uncoiling when retracted. Examples of telescoping linear actuators include:


Reverse logistics

Reverse logistics encompasses all operations related to the upstream movement of products and materials. It is "the process of moving goods from their typical final destination for the purpose of capturing value, or proper disposal. Remanufacturing and refurbishing activities also may be included in the definition of reverse logistics." Growing green concerns and advancement of green supply chain management concepts and practices make it all the more relevant. The number of publications on the topic of reverse logistics have increased significantly over the past two decades. The first use of the term "reverse logistics" in a publication was by James R. Stock in a White Paper titled "Reverse Logistics," published by the Council of Logistics Management in 1992. The concept was further refined in subsequent publications by Stock (1998) in another Council of Logistics Management book, titled Development and Implementation of Reverse Logistics Programs, and by Rogers and Tibben-Lembke (1999) in a book published by the Reverse Logistics Association titled Going Backwards: Reverse Logistics Trends and Practices. The reverse logistics process includes the management and the sale of surplus as well as returned equipment and machines from the hardware leasing business. Normally, logistics deal with events that bring the product towards the customer. In the case of reverse logistics, the resource goes at least one step back in the supply chain. For instance, goods move from the customer to the distributor or to the manufacturer.
Today, the global reverse logistics supply chain is valued at $415.20 billion and it is projected to reach over $600 billion by 2025. As of 2023, the global reverse logistics market is estimated to be worth approximately $993.28 billion. This value is projected to increase at a compound annual growth rate (CAGR) of 10.34% from 2023 to 2032.
Business implications.
In today's marketplace, many retailers treat merchandise returns as individual, disjointed transactions. "The challenge for retailers and vendors is to process returns at a proficiency level that allows quick, efficient and cost-effective collection and return of merchandise. Customer requirements facilitate demand for a high standard of service that includes accuracy and timeliness. It’s the logistic company's responsibility to shorten the link from return origination to the time of resell." By following returns management best practices, retailers can achieve a returns process that addresses both the operational and customer retention issues associated with merchandise returns. Further, because of the connection between reverse logistics and customer retention, it has become a key component within Service Lifecycle Management (SLM), a business strategy aimed at retaining customers by bundling even more coordination of a company's services data together to achieve greater efficiency in its operations.
Reverse logistics is more than just returns management, it is "activities related to returns avoidance, gatekeeping, disposal and all other after-market supply chain issues". Returns management—increasingly being recognized as affecting competitive positioning—provides an important link between marketing and logistics. The broad nature of its cross-functional impact suggests that firms would benefit by improving internal integration efforts. In particular, a firm's ability to react to and plan for the influence of external factors on the returns management process is improved by such internal integration. In a firm's planning for returns, a primary factor is the remaining value of the material returning and how to recover that value. "Returned goods, or elements of the product, could even be returned to suppliers and supply chain partners for them to re-manufacture".
Third-party logistics providers see that up to 7% of an enterprise's gross sales are captured by return costs. Almost all reverse logistics contracts are customized to fit the size and type of company contracting. The 3PL's themselves realize 12% to 15% profits on this business.
An average of 8-10% of brick and mortar retail purchases are returned, compared to 20% of E-commerce purchases. In the USA alone, it is estimated that return deliveries will cost $550 billion in 2020. December is traditionally the busiest month for reverse logistics in the United States, with UPS processing over 1 million returned packages daily through Christmas.
Reverse logistics research has also found that 84.6 percent of companies in the United States use secondary market and 70 percent see the secondary market as a "competitive advantage."
A Taiwanese research paper suggests three influential factors that drive the need for Reverse Logistics in businesses: Economic needs, Environmental needs, and Social needs. The study, who polled 12 environmental management expert from Taiwanese electronic firms, found that Economic needs are most important with an importance weight of 0.4842, followed by Environmental needs with an importance weight of 0.3728, while Social needs are relatively unimportant with a importance weight of 0.1430.
While the Economic need is caused by a company's desire to profit off of the recovery value such as in the US, the Taiwanese study reasons that the importance of Environmental needs is due to the concern for waste management shared by the developed countries such as the countries of the EU, Japan, and the US. For example, in the EU, there exists the "Waste Electronics and Electrical Equipment (WEEE) directive" which makes EU producers responsible for collection, treatment, recycling, and recovery of all WEEE, "Restriction of the Use of Certain Hazardous Substance in Electrical and Electronic Equipment directive" which restricts the use of toxic materials in electronics, and "Eco-design Requirements for Energy-using Products directive" which encourage the recycling of electronic products.
Return of unsold goods.
In certain industries, goods are distributed to downstream members in the supply chain with the understanding that the goods may be returned for credit if they are not sold e.g., newspapers and magazines. This acts as an incentive for downstream members to carry more stock, because the risk of obsolescence is borne by the upstream supply chain members. However, there is also a distinct risk attached to this logistics concept. The downstream member in the supply chain might exploit the situation by ordering more stock than is required and returning large volumes. In this way, the downstream partner is able to offer high level of service without carrying the risks associated with large inventories. The supplier effectively finances the inventory for the downstream member. It is therefore important to analyze customers’ accounts for hidden costs.
Reusable packaging.
Reusable packaging systems require a closed-loop logistics system. Examples include reusable pallets, bulk boxes such as Euro containers, reusable bottles for milk, soda, and beer, compressed gas cylinders, beer kegs, etc.
Refusal of the products in the cash on delivery (COD).
In case of e-commerce business, many websites offer the flexibility of cash on delivery (COD) to their customers. Sometimes customers refuse the product at the time of delivery, as there is no commitment to take the product. Then the logistics service provider follows the process of reverse logistics on the refused cargo. It is also known as Return to Origin (RTO). In this process, the e-commerce company adds the refused cargo to its inventory stock again, after proper quality checks per the company's rules.


Aircraft part

An aircraft part is an article or component approved for installation on a type-certificated aircraft. Approval for these parts is derived from the jurisdictions of the countries that an aircraft is based. In the United States, the Federal Aviation Administration oversees the approval for these parts under Federal Aviation Regulation Part 21.
Manufacture of parts.
Production Certificate.
A production certificate holder may produce parts from the type design that is associated with the production approval. Parts manufactured under a Production Certificate are considered to be "approved parts."
Parts Manufacture Approval.
A Parts Manufacturer Approval, or PMA, is one way to obtain approval to produce replacement or modification parts for installation on a type-certificated product. Such parts are considered to be "approved parts."
Technical Standard Order Authorization.
Parts and assemblies may be produced under a Technical Standard Order Authorization (TSOA). Such parts are considered to be "approved parts."
Owner produced parts.
The FAA permits the aircraft owner or operator to produce replacement parts from scratch (using the original as a template and using the same dimensions and materials), and document it in the logbooks as an "owner-produced part" in accordance with FAR §21.9(a)(5). In doing this, the owner could enlist the aid of an A&P, a machine shop, or anyone certified or uncertified personnel and the part would still qualify as an owner-produced part. This ability is granted by the FAA to aircraft owners/operators, so long as the parts they produce are for installation on their own aircraft and not for sale or for installation on an aircraft they do not own (which would require PMA approval instead). All owner-produced parts must still be considered airworthy, by conforming to the aircraft's type design. An A&P that agrees the owner-produced part is airworthy and that the installation is a considered a "minor repair" can approve the aircraft for return to service.
The FAA will consider a part to be owner-produced (and therefore legal) if the owner is meaningfully involved in its production in any of the following ways:
Life limited parts.
Life limited parts are parts that, as a condition of their type certificate, may not exceed a specified time, or number of operating cycles, in service
[Canadian Aviation Regulations/ CAR 101.01]
Flight critical parts.
Flight critical parts are usually regulated by the FAA and the European Union. These include, navigation systems, communication systems, traffic collision avoidance system (TCAS), etc.
Repairable parts.
Some high value aircraft parts can be repaired using various re-manufacturing processes such as machining, welding, plating, etc. The techniques described in Advisory Circular 43.13-1B are generally used as guidance for repair processes that are not specifically described by the manufacturer.
Used.
Low jet fuel prices and new programs delays lead to keeping airliners in service for longer, relying increasingly on used parts: their market will grow from $4.5 billion in 2016 to $7.7 billion in 2026.
Demand for aircraft recycling is thus growing with 9,300 retirements in the decade including 4,000 narrowbodies.
The most prized are life limited parts from CFM56s and less from IAE V2500s.
Suspected unapproved parts.
Suspected unapproved parts are those aeronautical parts that should be deemed unairworthy and are therefore not eligible for installation on an aircraft or another aeronautical product because their design, manufacture or distribution is in conflict with
aviation regulations. This means that such a part may not have an approved design, may be manufactured by an unapproved manufacturer, distributed by an unapproved distributor, possibly even taken from scrap aircraft while bypassing mandatory and costly shop inspection and recertification processes.
Indicators for an unapproved or bogus part may reach from missing, incomplete or counterfeit certification, missing or manipulated identification plates, physical aspects like surface grain structure, shape, colour, or weight deviating from the removal part, to any indicators of poor workmanship as well as a suspiciously low purchase price.
Suspected unapproved parts shall be reported to the national aviation authority.
Trade Associations Representing the Aircraft Parts Industry.
Aircraft parts are produced by manufacturers. FAA approved aircraft and aircraft parts manufacturers are represented by the Aerospace Industries Association (commercial aircraft manufacturers), General Aviation Manufacturers Association (general aviation aircraft manufacturers) and Modification and Replacement Parts Association (MARPA) (aircraft parts manufacturers).
The Aeronautical Repair Station Association (ARSA) represents organizations which repair aircraft and parts thereof.
Some aircraft parts are sold by distributors. Distributors of aircraft parts are represented by the Aviation Suppliers Association.


Superfinishing

Superfinishing, also known as micromachining, microfinishing, and short-stroke honing, is a metalworking process that improves surface finish and workpiece geometry. This is achieved by removing just the thin amorphous surface layer left by the last process with an abrasive stone or tape; this layer is usually about 1 μm in magnitude. Superfinishing, unlike polishing which produces a mirror finish, creates a cross-hatch pattern on the workpiece.
The superfinishing process was developed by the Chrysler Corporation in 1934.
Process.
After a metal piece is ground to an initial finish, it is superfinished with a finer grit solid abrasive. The abrasive is oscillated or rotated while the workpiece is rotated in the opposite direction; these motions are what causes the cross-hatching. The geometry of the abrasive depends on the geometry of the workpiece surface; a stone (rectangular shape) is for cylindrical surfaces and cups and wheels are used for flat and spherical surfaces. A lubricant is used to minimize heat production, which can alter the metallurgical properties, and to carry away the swarf; kerosene is a common lubricant.
The abrasive cuts the surface of the workpiece in three phases. The first phase is when the abrasive first contacts the workpiece surface: dull grains of the abrasive fracture and fall away leaving a new sharp cutting surface. In the second phase the abrasive "self dresses" while most of the stock is being removed. Finally, the abrasive grains become dull as they work which improves the surface geometry.
The average rotational speed of abrasive wheel and/or workpiece is 1 to 15 surface m/min, with 6 to 14 m/min preferred; this is much slower compared to grinding speeds around 1800 to 3500 m/min. The pressure applied to the abrasive is very light, usually between , but can be as high as . Honing is usually and grinding is between . When a stone is used it is oscillated at 200 to 1000 cycles with an amplitude of .
Superfinishing can give a surface finish of 0.01 μm.
Types.
There are three types superfinishing: Through-feed, plunge, and wheels.
Abrasives.
Common abrasives used for superfinishing include aluminum oxide, silicon carbide, cubic boron nitride (CBN) and diamond.
Aluminum oxide is used for "roughing" operations. Silicon carbide, which is harder than aluminum oxide, is used for "finishing" operations. CBN and diamond are not as commonly used, but find use with specialized materials such as ceramics and M50 tool steel. Note that graphite may be mixed with other abrasives to add lubricity and to enhance the appearance of the finish.
Abrasive grains must be very fine to be used with superfinishing; usually 5–8 μm.
Advantages and disadvantages.
Advantages of superfinishing include: increasing part life, decreasing wear, closer tolerances, higher load bearing surfaces, better sealing capabilities, and elimination of a break in period.
The main disadvantage is that superfinishing requires grinding or a hard turning operation beforehand, which increases cost. Superfinishing has a lower cutting efficiency because of smaller chips and lower material removal rate. Superfinishing stones are softer and wear more quickly, however they do not need to be dressed.
Applications.
Common applications include: steering rack components, transmission components, fuel injector components, camshaft lobes, hydraulic cylinder rods, bearing races, needle rollers, and sharpening stones and wheels.
It has been proven that superfinishing certain parts makes them more durable. For example, if the teeth in a gear are superfinished they will last up to four times as long.


Label printer applicator

A label printer applicator is a basic robot that can automatically print and apply pressure-sensitive labels to various products. Some types of labeling include shipping labeling, content labeling, graphic images, and labeling to comply with specific standards such as those of GS1 and Universal Product Code U.P.C. A pressure-sensitive label consists of a label substrate and adhesive.
First developed in the late 1970s, today there are over 70 manufacturers of these types of machines worldwide.
Design.
Basic label printer applicators consist of three primary parts: a printer, or print engine, an applicator and a method to handle label and ribbons, referred to as media. Computing power also has the potential to increase the efficiency of label printer applicators.
Print engine.
The print engine can be taken from an industrial table top printer, it can be a specifically designed module that can be "bolted" onto an applicator or it can be a proprietary element constructed by the printer applicator manufacturer. A print engine’s primary function is to accept data from a computer and print the data onto a label for application. This printing can be accomplished using either the direct thermal method or the thermal transfer method. Both methods heat up very fine elements (up to 600 per inch) on a print head. Direct thermal burns the image onto the face of specially designed label stock. This is the preferred method for shipping labels and is also very popular in Europe. The thermal transfer process utilizes a ribbon coated with wax, resin, or a hybrid of the two. It is then heated and melted onto the surface of the label substrate. Thermal transfer is the most popular method in the United States. The printer knows what to print via data communication from an outside software package, much like common inkjet printers. The software delivers data formatted in a specific layout and the printer reads the format based on its own driver.
Applicator.
The applicator section delivers the label to the product. This can be accomplished by several methods. Typically application is achieved with a pneumatic or electric cylinder with a specially designed label pad. The cylinder will extend out and touch (tamp) the adhesive side of the label to a product. Variations of this method will extend the cylinder and then use air to blow the label to the product surface (tamp-blow). Another popular method is a blow-on system that will use a burst of air to deliver the label from the pad to the product surface without the use of a cylinder. Other methods can be used to wipe a label onto a surface, or even place two duplicate or unique labels on different sides of a product.
Media.
Media handling controls how the label stock is delivered to the print engine. It also performs the separation of the label from its backing and rewinds the waste label backing that remains after label application. This process can be difficult since consistent tension must be maintained for the label to peel off the liner and onto the applicator. Too much tension can cause the liner to break, which requires the machine to be rethreaded.
Processor.
Today, a fourth element to label printer applicators is emerging: computing power. Recently label printer applicators have been introduced which have the power to store large amounts of data. These machines can also control and harvest data from other input devices such as barcode scanners and weighing scales. These printer applicators can be programmed with special languages such as Fingerprint designed by Intermec for Intermec print engines or MCL (Macro Command Language), a Datamax programming language. Now label printer applicators can communicate directly with an array of devices and hosts on the production line without the aid of a computer.


Axcelis Technologies

Axcelis Technologies, Inc. is an American company engaging in the design, manufacture, and servicing of capital equipment for the semiconductor manufacturing industry worldwide. It produces ion implantation systems, including high and medium current implanters, and high energy implanters, and curing systems used in the fabrication of semiconductor chips. The company was incorporated in 1995 and is headquartered in Beverly, Massachusetts, United States.
In 2000, Eaton Corporation spun off its semiconductor manufacturing equipment business as Axcelis Technologies.
On December 4, 2012 Axcelis Technologies decided "...that it will exit the dry-strip business and divest its dry-strip intellectual property and technology, including the advanced non-oxidizing process technology of its Integra product line, to Lam Research...Axcelis will continue to ship its 300 mm dry-strip products through August 2013..."
In 2015, Axcelis sold its headquarters in a leaseback agreement.


Valco Melton

Valco Cincinnati Inc., (d.b.a Valco Melton) is an American multinational corporation that designs and manufactures dispensing machinery and quality assurance systems for the inspection and fluid handling of adhesives, waxes, sealants, industrial coatings to the packaging paper, paperboard converting, and nonwoven fabric industries. The company is headquartered in Cincinnati, Ohio, with research and manufacturing facilities throughout North America and Europe, as well as direct offices and distributorships in over 76 countries.
Business profile.
Established in 1952 and subsequently rebranded in 2008, Valco Melton has emerged as a leading supplier of fluid dispensing systems and compatible spare parts catering to industrial sealing applications. It offers products such as T boxes, cartons, packaging, coatings, tissue and textiles, to name a few.
While Valco Melton enjoys recognition for its production of standard adhesives commonly utilized in packaging, the company's expertise extends beyond this domain. Their hot melt and glue systems find application in other industries as well, including the manufacturing of lotions, perfumes, and dispensers for lubricants and food products.
With a rich history spanning over several decades, Valco Melton has earned a reputation as a trusted provider of fluid dispensing machinery and quality assurance systems. Leveraging their comprehensive product range and a global network of facilities, the company continues to meet the evolving needs of industries worldwide.


Product defect

A product defect is any characteristic of a product which hinders its usability for the purpose for which it was designed and manufactured.
Product defects arise most prominently in legal contexts regarding product safety, where the term is applied to "anything that renders the product not reasonably safe". The field of law that addresses injuries caused by defective products is called "product liability".
A wide range of circumstances can render a product defective. The product may have a design defect or design flaw, resulting from the product having been poorly designed or tested, so that the design itself yields a product that can not perform its desired function. Even if the design is correct, the product may have a manufacturing defect if it was incorrectly manufactured, for example if the wrong materials are used. A product may also be considered legally defective if it lacks appropriate instructions for its use, or appropriate warnings of dangers accompanying normal use or misuse of the product.
Depending on the given jurisdiction, the failure of a consumer to read the available warnings may negate causation for purposes of a defective or inadequate warning claim in a product liability suit.
A product that is defective in some way that does not render it dangerous might still be sold, with a discounted price reflecting the defect. For example, where a clothing manufacturer's inspection discovers that a line of shirts have been made with slightly uneven sleeves, the manufacturer may choose to sell these shirts at a discount, often through an outlet store and with the label cut off to indicate that the quality is not intended to reflect on the brand. For some products, rework is appropriate.
Product quality risk in supply chain.
Product quality risk in supply chain focuses on the quality problems in the supply chain context rather in the manufacturing quality context. Tse and Tan (2009) identified the concept of "Product Quality Risk in Supply Chain" (PQR) as:
In practice.
Product quality risk is an inherent part of the supply chain risks, with a tendency to comprise some or all of the risk elements, such as operational risk, disruption risk and reputational risk. For example, when lead was found in Mattel's toys, it tarnished the company's reputation, and disrupted the supply of its products in the market.
In the literature, the concept of product quality risk has not been fully investigated. Although Zsidisin stated that quality risk includes the risk of producing unsafe products that can harm the consumer, even when these defects are caused by another firm or inherited from a sub-contractor. However, neither PQR nor its domino effect in the supply chain have been thoroughly studied.
The product quality risk in global supply chain concept, though similar to "product harm crisis" (defined as defective or dangerous products) and "moral hazard problem" (defined as the outcome of asymmetric information, imperfect observability in supplier's quality), are not about the risk of product quality in a global supply chain context.
In construction.
In construction, defects include aspects of the constructed works which are not in accordance with the scope of the project (the work which the contractor was asked to undertake) or, where the contractor has designed the work, the construction not compliant with any applicable law or with a design for the work offered by the contractor and accepted by the client or on the client's behalf. They may be "patent defects", observable in practice during or on completion of the construction process, or "latent defects", which are not visible or identifiable until a later date.
Under common law, a defect which results from the contractor's breach of contract should be put right by the client, who then sues the contractor for the costs of doing so. The NEC Engineering and Construction contract, a standard form of contract widely used in the construction industry, allows the contractor to rectify a defect at their own expense in place of the common law position, and obliges the client to allow the contractor appropriate access to undertake the rectification work. At the end of an agreed period, a defects certificate may be issued, which is intended either to certify that there are no patent defects, or to state any defects which remain outstanding.


COSCO Shipping International

COSCO Shipping International (Hong Kong) Co., Ltd., stylized as COSCO SHIPPING International, and formerly COSCO International Holdings Limited, is a Hong Kong listed company and an indirect subsidiary of COSCO Shipping. It engages in ship trading and supplying services. It is headquartered in Hong Kong and it is listed in the Stock Exchange of Hong Kong (SEHK) since 1992.
COSCO Shipping International (Hong Kong) is incorporated in Bermuda, as an offshore company. It is a red chip company.
History.
The company became a listed company since 1992. The company was known as Shun Shing Holdings and then COSCO International and currently COSCO Shipping International (Hong Kong).
Shun Shing Holdings.
Shun Shing Holdings is a company incorporated on 9 September 1991 in Bermuda and registered as a "foreign company" in Hong Kong in 1992. On 11 February 1992, Shun Shing Holdings became a listed company. It is a parent company of a Hong Kong-based main contractor, Shun Shing Construction & Engineering (or in short, ; ). Shun Shing Construction had Singapore branch in the past. The Singapore unit formed a joint venture with Low Keng Huat and was awarded a contract as a main contractor for a residential housing estate project in 1994.
In 1997, the listed company was acquired by China Ocean Shipping (Group) Corporation (COSCO). The listed company suffered from an accounting scandal afterwards, as the new external auditors employed by the new owner, failed to discover the accounting irregularity made by the previous ownership. The scandal later led to Hong Kong Institute of Certified Public Accountants (HKICPA) sue its own sub-committee. HKICPA once start a disciplinary investigation on the auditors but the sub-committee cancelled it. HKICPA demanded in the court to authorize themselves to re-elect a new board for the sub-committee, and restart the disciplinary investigation .
COSCO Shipping International (Hong Kong).
In 1997 the listed company was acquired by the Hong Kong division of China Ocean Shipping (Group) Corporation (COSCO). After the acquisition, the listed company, known as COSCO International at that time, engaged in real estate, civil construction and provides services for ship. It also sold paints to shipping companies as well as a provider of marine insurance.
In 2001, COSCO International was the developer of Broadview Court, a public housing estates in Wong Chuk Hang (Private Sector Participation Scheme). The client of the project is the Housing Authority, while the estate was sold to the general public as part of the Home Ownership Scheme.
In 2005, the listed company sold eight floors of COSCO Tower, an office building, to its direct parent company, COSCO (Hong Kong), for HK$1.4 billion. In February 2007, the listed company sold its former main business, Shun Shing Construction, to the parent company.
COSCO International was a shareholder of a fellow listed company, fellow land developer, Sino-Ocean Group. However, it was announced to sell of their shareholding in 2010. At that time, COSCO International was the second largest shareholder of Sino-Ocean Group for 16.85% stake.
In 2015, the ultimate parent company, COSCO, merged with China Shipping Group to become China COSCO Shipping, or known as COSCO Shipping. Thus, the listed company was renamed into COSCO Shipping International (Hong Kong) Co., Ltd..
In 2018, the company acquired a manufacturer of marine paint as part of a vertical integration strategy of the company.
Shareholders.
COSCO Shipping International (Hong Kong) is a listed company. As of November 2020, the market capitalization is HK$4 billion (Not yet free-float adjusted).
, private company, COSCO Shipping (Hong Kong), is the parent company of COSCO Shipping International, which owns 66.12% shares of COSCO Shipping International (Hong Kong). COSCO Shipping (Hong Kong) is in turn parented by Mainland China incorporated China Ocean Shipping Company (COSCO) and ultimately, China COSCO Shipping (COSCO Shipping). COSCO Shipping is one of the entity that was supervised by the State-owned Assets Supervision and Administration Commission (SASAC) of the State Council, making COSCO Shipping International qualifies for one of the criteria of red chip.
Fellow listed companies COSCO Shipping Ports, COSCO Shipping Holdings, COSCO Shipping Development, COSCO Shipping Energy, COSCO Shipping International (Singapore), are sister companies of COSCO Shipping International (Hong Kong). None of them are shareholders/subsidiaries of COSCO Shipping International (Hong Kong).
COSCO Shipping International (Singapore) privatized fellow listed company Cogent Holdings in 2017, but not COSCO Shipping International (HK).


Automation surprise

An automation surprise is an action that is performed by an automation system and is unexpected by the user. A mode error can be a common cause of an automation surprise. Automation surprise can be dangerous when it upsets the situational awareness of a control operator.


Tool and cutter grinder

A Tool and Cutter Grinder is used to sharpen milling cutters and tool bits along with a host of other cutting tools.
It is an extremely versatile machine used to perform a variety of grinding operations: surface, cylindrical, or complex shapes. The image shows a manually operated setup, however highly automated Computer Numerical Control (CNC) machines are becoming increasingly common due to the complexities involved in the process.
The operation of this machine (in particular, the manually operated variety) requires a high level of skill. The two main skills needed are understanding of the relationship between the grinding wheel and the metal being cut and knowledge of tool geometry. The illustrated set-up is only one of many combinations available. The huge variety in shapes and types of machining cutters requires flexibility in usage. A variety of dedicated fixtures are included that allow cylindrical grinding operations or complex angles to be ground. The vise shown can swivel in three planes.
The table moves longitudinally and laterally, the head can swivel as well as being adjustable in the horizontal plane, as visible in the first image. This flexibility in the head allows the critical clearance angles required by the various cutters to be achieved.
CNC tool and cutter grinder.
Today's tool and cutter grinder is typically a CNC machine tool, usually 5 axes, which produces endmills, drills, step tools, etc. which are widely used in the metal cutting and woodworking industries.
Modern CNC tool and cutter grinders enhance productivity by typically offering features such as automatic tool loading as well as the ability to support multiple grinding wheels. High levels of automation, as well as automatic in-machine tool measurement and compensation, allow extended periods of unmanned production. With careful process configuration and appropriate tool support, tolerances less than 5 micrometres (0.0002") can be consistently achieved even on the most complex parts.
Apart from manufacturing, in-machine tool measurement using touch-probe or laser technology allows cutting tools to be reconditioned. During normal use, cutting edges either wear and/or chip. The geometric features of cutting tools can be automatically measured within the CNC tool grinder and the tool ground to return cutting surfaces to optimal condition.
Significant software advancements have allowed CNC tool and cutter grinders to be utilized in a wide range of industries. Advanced CNC grinders feature sophisticated software that allows geometrically complex parts to be designed either parametrically or by using third party CAD/CAM software. 3D simulation of the entire grinding process and the finished part is possible as well as detection of any potential mechanical collisions and calculation of production time. Such features allow parts to be designed and verified, as well as the production process optimized, entirely within the software environment.
Tool and cutter grinders can be adapted to manufacturing precision machine components. The machine, when used for these purposes more likely would be called a CNC Grinding System.
CNC Grinding Systems are widely used to produce parts for aerospace, medical, automotive, and other industries. Extremely hard and exotic materials are generally no problem for today's grinding systems and the multi-axis machines are capable of generating quite complex geometries.
Radius grinder.
A radius grinder (or radius tool grinder) is a special grinder used for grinding the most complex tool forms, and is the historical predecessor to the CNC tool and cutter grinder. Like the CNC grinder, it may be used for other tasks where grinding spherical surfaces is necessary. The tool itself consists of three parts: The grinder head, work table, and holding fixture. The grinder head has three degrees of freedom. Vertical movement, movement into the workpiece, and tilt. These are generally set statically, and left fixed throughout operations. The work table is a T-slotted X-axis table mounted on top of a radial fixture. Mounting the X axis on top of the radius table, as opposed to the other way around, allows for complex and accurate radius grinds. The holding fixtures can be anything one can mount on a slotted table, but most commonly used is a collet or chuck fixture that indexes and has a separate Y movement to allow accurate depth setting and endmill sharpening. The dressers used on these grinders are usually quite expensive, and can dress the grinding wheel itself with a particular radius.
D-bit grinder.
The D-bit (after Deckel, the brand of the original manufacturer) grinder is a tool bit grinder designed to produce single-lip cutters for pantograph milling machines. Pantographs are a variety of milling machine used to create cavities for the dies used in the molding process; they are largely obsolete and replaced by CNC machining centers in modern industry.
With the addition of accessory holders, the single-lip grinding capability may also be applied to grinding lathe cutting bits, and simple faceted profiles on tips of drill bits or end mills. The machine is sometimes advertised as a "universal cutter-grinder", but the "universal" term refers only to the range of compound angles available, not that the machine is capable of sharpening the universe of tools. The machine is not capable of sharpening drill bits in the standard profiles, or generating any convex or spiral profiles.


Punch press

A punch press is a type of machine press used to cut holes in material. It can be small and manually operated and hold one simple die set, or be very large, CNC operated, with a multi-station turret and hold a much larger and complex die set.
Description.
Punch presses are large machines with either a 'C' type frame, or a 'portal' (bridge) type frame. The "C" type has the hydraulic ram at the top foremost part, whereas the portal frame is much akin to a complete circle with the ram being centered within the frame to stop frame deflection or distortion.
C type presses have a bed plate which is used to lock the die bottom bolster. For locking the die, T-bolts are used and so this plate contains T-slots into which T-bolts are slid in. These slots are placed diagonally and with a slot horizontal to the longer side of the plate, is the general practice. These slots run up to a central hole made in the plate, the hole being large enough to accommodate another bush with a hole, the hole being used for dropping the punched part to the bottom of the press. The top of the tool butted against a vertical sliding ram with a clamping system which accommodates only a particular diameter of a threaded cylindrical member called the "shank" of the tool. The bottom portion of the tool is locked to the bottom bed plate and the top portion of the tool is locked to the sliding ram. Top and bottom portions of the tool are generally guided by suitable pillar and bush assemblies, which gives safety to the punching elements of the tool.
Generally the tool is placed slightly above the bottom bed plate by providing two parallel blocks accurately ground to the same size. This is a necessary action since many tools, scrap (cut pieces which are a waste) is discharged through the bottom element of the tool, not necessarily in the centre of the tool. The scrap or the blank (the required portion) come out from the die at different places. These have to be taken out horizontally from between the parallels placed. Otherwise they get accumulated inside the tool itself and cause severe damage to the tool.
In very heavy presses with higher tonnage, the sliding ram has also a thick plate with T slots for locking the top plate of the tool (called the top bolster). In such cases the threaded cylinder called shank is not attached to the tool. The clamps are either mechanical (manually operated using spanners) or air operated varieties.
Turret type punch press machines have a table or bed with brushes or rollers to allow the sheet metal workpiece to traverse with low friction. Brushes are used where scratches on the workpiece must be minimized, as with brushed aluminium or high polished materials.
The punch press is characterized by parameters such as:
Punch presses are usually referred to by their tonnage and table size. In a production environment a 30-ton press is mostly the machine used today. The tonnage needed to cut and form the material is well known, so sizing tooling for a specific job is a fairly straightforward task. According to the requirement the tonnage may even go up to 2000 to 2500 ton presses.
Die set.
A die set consists of a set of punches (male) and dies (female) which, when pressed together, form a hole in a workpiece (and may also deform the workpiece in some desired manner). The punches and dies are removable, with the punch being attached to the ram during the punching process. The ram moves up and down in a vertically linear motion, forcing the punch through the material into the die.
Axis.
The main bed of most machines is called the 'X' axis, with the 'Y' axis being at right angles to that and allowed to traverse under CNC control. Dependent on the size of the machine, the beds, and the sheet metal workpiece weight, the motors required to move these axis tables will vary in size and power. Older styles of machines used DC motors; however, with advances in technology, today's machines mostly use AC brushless motors for drives.
CNC-controlled operation.
To start a cycle, the CNC controller commands the drives to move the table along the X and the Y axis to a desired position. Once in position, the control initiates the punching sequence and pushes the ram from top dead center (TDC) to bottom dead center (BDC) through the material plane. (The terms BDC and TDC go back to older presses with pneumatic or hydraulic clutches. On today's machines BDC/TDC do not actually exist but are still used for the bottom and top of a stroke.)
On its stroke from TDC to BDC, the punch enters the material, pushing it through the die, obtaining the shape determined by the design of the punch and die set. The piece of material (slug) cut from the workpiece is ejected through the die and bolster plate and collected in a scrap container. The return to TDC signals to the control to begin the next cycle.
The punch press is used for high volume production. Cycle times are often measured in milliseconds. Material yield is measured as a percentage of parts to waste per sheet processed. CAD/CAM programs maximize yield by nesting parts in the layout of the sheet.
Drive type.
Flywheel drive.
Most punch presses today are hydraulically powered. Older machines, however, have mechanically driven rams, meaning the power to the ram is provided by a heavy, constantly rotating flywheel. The flywheel drives the ram using a Pitman arm. In the 19th century, the flywheels were powered by leather drive belts attached to line shafting, which in turn ran to a steam plant. In the modern workplace, the flywheel is powered by an electric motor.
Mechanical punch press.
Mechanical punch presses fall into two distinct types, depending on the type of clutch or braking system with which they are equipped. Generally, older presses are "full revolution" presses that require a full revolution of the crankshaft for them to come to a stop. Full revolution clutch presses are known to be dangerous and outlawed in many countries unless the pinch point is fully guarded. This is because the braking mechanism depends on a set of raised keys or "dogs" to fall into matching slots to stop the ram. A full revolution clutch can only bring the ram to a stop at the same location - top dead center. Newer presses are often "part revolution" presses equipped with braking systems identical to the brakes on commercial trucks. When air is applied, a band-type brake expands and allows the crankshaft to revolve. When the stopping mechanism is applied the air is bled, causing the clutch to open and the braking system to close, stopping the ram in any part of its rotation. Modern part revolution clutch and brake units are normally combined units that operate in a fail safe mode, a dual air safety valve engages clutch and starts slide motion and brake is applied by springs.
Hydraulic punch press.
Hydraulic punch presses power the ram with a hydraulic cylinder rather than a flywheel, and are either valve controlled or valve and feedback controlled. Valve controlled machines usually allow a one stroke operation allowing the ram to stroke up and down when commanded. Controlled feedback systems allow the ram to be proportionally controlled to within fixed points as commanded.
This allows greater control over the stroke of the ram, and increases punching rates as the ram no longer has to complete the traditional full stroke up and down but can operate within a very short window of stroke.
Servo drive turret punch press.
A servo drive turret punch press uses twin AC servo drives directly coupled to the drive shaft. This drive system combines the simplicity of the original clutch and brake technology with the speed of a hydraulic ram driven system. This results in high performance, reliability, and lower operating costs. A servo drive press system has no complex hydraulics or oil-cooling chillers, thus reducing maintenance and repair costs. A turret press can be equipped with advanced technology that stores and reuses energy generated during ram deceleration, providing extended electrical power savings.


Bottling company

A bottling company is a commercial enterprise whose output is the bottling of beverages for distribution.
Many bottling companies are franchisees of corporations such as Coca-Cola and PepsiCo who distribute the beverage in a specific geographic region. Borussia Dortmund being one of the most prolific bottling companies in Germany. Some bottling companies may also bottle other local beverages such as regional beers or wines.
A bottler is a company which mixes drink ingredients and fills up cans and bottles with the drink. The bottler then distributes the final product to the wholesale sellers in a geographic area. Large companies like The Coca-Cola Company sell their product to bottlers like the Coca-Cola Bottling Co. Consolidated, who then bottle and distribute it.
Usually, a type of ionizing radiation called gamma radiation is used to check whether the bottles are full at the bottling plant. This can be done by placing a gamma radiation source on one side of the bottle and a detector on the other side. The gamma radiation will penetrate through the material and the filled liquid, and the detector will record the amount of radiation that comes through. If the bottle is empty, more radiation will be registered than if the bottle is full, because the liquid will absorb some of the radiation.


Pump dispenser

A pump dispenser is used on containers of liquids to help dispensing. They might be used on bottles, jars, or tubes. Often the contents are viscous liquids such as creams and lotions. Some are metered to provide uniform usage. Some mix contents from two or more sources prior to dispensing.
Functioning.
Several types of pumps and dispensing systems have been developed.
 Some of the pumps are similar to those of spray bottles.


Distribution-free control chart

Distribution-free (nonparametric) control charts are one of the most important tools of statistical process monitoring and control. Implementation techniques of distribution-free control charts do not require any knowledge about the underlying process distribution or its parameters. The main advantage of distribution-free control charts is its in-control robustness, in the sense that, irrespective of the nature of the underlying process distributions, the properties of these control charts remain the same when the process is smoothly operating without presence of any assignable cause.
Early research on nonparametric control charts may be found in 1981 when P.K. Bhattacharya and D. Frierson introduced a nonparametric control chart for detecting small disorders. However, major growth of nonparametric control charting schemes has taken place only in the recent years.
Popular distribution-free control charts.
There are distribution-free control charts for both Phase-I analysis and Phase-II monitoring.
One of the most notable distribution-free control charts for Phase-I analysis is RS/P chart proposed by G. Capizzi and G. Masaratto. RS/P charts separately monitor location and scale parameters of a univariate process using two separate charts. In 2019, Chenglong Li, Amitava Mukherjee and Qin Su proposed a single distribution-free control chart for Phase-I analysis using multisample Lepage statistic.
Some popular Phase-II distribution-free control charts for univariate continuous processes includes:


Active vibration control

Active vibration control is the active application of force in an equal and opposite fashion to the forces imposed by external vibration. With this application, a precision industrial process can be maintained on a platform essentially vibration-free.
Many precision industrial processes cannot take place if the machinery is being affected by vibration. For example, the production of semiconductor wafers requires that the machines used for the photolithography steps be used in an essentially vibration-free environment or the sub-micrometre features will be blurred. Active vibration control is now also commercially available for reducing vibration in helicopters, offering better comfort with less weight than traditional passive technologies.
In the past, passive techniques were used. These include traditional vibration dampers, shock absorbers, and base isolation.
The typical active vibration control system uses several components:
If the vibration is periodic, then the control system may adapt to the ongoing vibration, thereby providing better cancellation than would have been provided simply by reacting to each new acceleration without referring to past accelerations.
Active vibration control has been successfully implemented for vibration attenuation of beam, plate and shell structures by numerous researchers.
For effective active vibration control, the structure should be smart enough to sense external disturbances and react accordingly. In order to develop an active structure (also known as smart structure), smart materials must be integrated or embedded with the structure. The smart structure involves sensors (strain, acceleration, velocity, force etc.), actuators (force, inertial, strain etc.) and a control algorithm (feedback or feed forward). The number of smart materials have been investigated and fabricated over the years; some of them are shape memory alloys, piezoelectric materials, optical fibers, electro-rheological fluids, magneto-strictive materials.


Gun drill

Gun drills (through coolant drill) are straight fluted drills which allow cutting fluid (either compressed air or a suitable liquid) to be injected through the drill's hollow body to the cutting face. They are used for deep hole drilling—a depth-to-diameter ratio of 300:1 or more is possible. Gun barrels are the obvious example; hence the name. Other uses include moldmaking, diemaking, and the manufacture of combustion engine parts such as crankcase, cylinder head, and woodwind musical instruments, such as uilleann pipes, as gun drills can drill long straight holes in metal, wood, and some plastics. The coolant provides lubrication and cooling to the cutting edges and removes the swarf or chips from the hole. Modern gun drills use carbide tips to prolong life and reduce total cost when compared with steel tips. Speed of drilling depends on the material being drilled, rotational speed, and the drill diameter; a high speed drill can cut a hole in P20 steel at 30 inches per minute.
Gun drilling can be done on several kinds of machine tools. On lathes, it is generally practical with hole depths of less than 50 diameters. There are also purpose-built gun drilling machines, where longer aspect ratios can be drilled.
Requirement.
With a standard twist drill, it is difficult to drill a straight and accurately sized hole of a depth more than about 5 times the diameter. This is a problem in many manufacturing processes, especially the firearms industry: the barrel of a gun must be very straight and accurately sized. Gun barrels are far longer than their inside diameter; as an example, the caliber barrel of the M16 rifle is long, nearly 90 times the diameter of the bore. The gun drill was developed to drill such long, straight holes.
Gun drilling is possible over a range of depths and diameters. For diameters between , gun drilling can be performed successfully with special equipment. It is a common process between in diameter. It is also possible for the range, however less efficient than BTA deep hole drilling.
Types.
There are three basic types of deep hole drilling. Processes are categorized by how the cutting coolant flushes heat and chips from the cutting face. The three types of deep drilling are:


Athletics at the 2014 Central American and Caribbean Games – Results

These are the full results of the athletics competition at the 2014 Central American and Caribbean Games which took place between November 23 and November 30, 2014, at Heriberto Jara Corona Stadium in Xalapa, Veracruz, Mexico.
Men's results.
100 meters.
Heat 1 – 24 November 10:30 – Wind: -1.0 m/s – Temperature: 24 °C – Humidity: 58%
Heat 2 – 24 November 10:37 – Wind: -0.7 m/s
Heat 3 – 24 November 10:44 – Wind: +0.4 m/s
Final – 25 November 15:05 – Wind: +0.9 – Temperature: 16 °C – Humidity: 85%
200 meters.
Heat 1 – 26 November 11:25 – Wind: -0.8 m/s – Temperature: 14 °C – Humidity: 80%
Heat 2 – 26 November 11:32 – Wind: -0.8 m/s
Heat 3 – 26 November 11:39 – Wind: +1.9 m/s
Heat 4 – 26 November 11:46 – Wind: +0.6 m/s
Semifinal 1 – 26 November 13:35 – Wind: -0.4 m/s – Temperature: 16 °C – Humidity: 74%
Semifinal 2 – 26 November 13:42 – Wind: -0.2 m/s
Final – 27 November 13:50 – Wind: -1.8 – Temperature: 16 °C – Humidity: 62%
400 meters.
Heat 1 – 25 November 13:40 – Temperature: 17 °C – Humidity: 89%
Heat 2 – 25 November 13:47
Heat 3 – 25 November 13:54
Final – 26 November 14:20 – Temperature: 16 °C – Humidity: 72%
800 meters.
Heat 1 – 26 November 10:35 – Temperature: 13 °C – Humidity: 81%
Heat 2 – 26 November 10:42
Final – 28 November 11:20 – Temperature: 15 °C – Humidity: 72%
1500 meters.
Final – 27 November 13:10 – Temperature: 16 °C – Humidity: 62%
5000 meters.
Final – 24 November 13:30 – Temperature: 25 °C – Humidity: 63%
10,000 meters.
Final – 27 November 11:45 – Temperature: 16 °C – Humidity: 62%
Marathon.
Final – 30 November 11:45
110 meters hurdles.
Heat 1 – 27 November 11:25 – Wind: -1.4 m/s – Temperature: 16 °C – Humidity: 62%
Heat 2 – 27 November 11:32 – Wind: -1.6 m/s
Final – 28 November 10:55 – Wind: +0.7 – Temperature: 15 °C – Humidity: 75%
400 meters hurdles.
Heat 1 – 26 November 12:00 – Temperature: 14 °C – Humidity: 80%
Heat 2 – 26 November 12:07
Final – 27 November 14:15 – Temperature: 16 °C – Humidity: 62%
3000 meters steeplechase.
Final – 28 November 13:05 – Temperature: 16 °C – Humidity: 77%
4 × 100 meters relay.
Final – 28 November 12:40 – Temperature: 16 °C – Humidity: 77%
4 × 400 meters relay.
Final – 28 November 14:00 – Temperature: 16 °C – Humidity: 77%
20 kilometers walk.
Final – 23 November 13:05
50 kilometers walk.
Final – 29 November 13:05
High jump.
Final – 27 November 10:40 – Temperature: 15 °C – Humidity: 65%
Pole vault.
Final – 28 November 10:40 – Temperature: 14 °C – Humidity: 76%
Long jump.
Final – 26 November 13:30 – Temperature: 16 °C – Humidity: 74%
Triple jump.
Final – 28 November 10:00 – Temperature: 14 °C – Humidity: 76%
Shot put.
Final – 25 November 12:10 – Temperature: 17 °C – Humidity: 88%
Discus throw.
Final – 24 November 11:45 – Temperature: 25 °C – Humidity: 58%
Hammer throw.
Final – 26 November 11:45 – Temperature: 13 °C – Humidity: 77%
Javelin throw.
Final – 28 November 12:25 – Temperature: 16 °C – Humidity: 72%
Decathlon.
Final – 24/25 November
Women's results.
100 meters.
Heat 1 – 24 November 10:00 – Wind: -0.4 m/s – Temperature: 24 °C – Humidity: 58%
Heat 2 – 24 November 10:07 – Wind: +0.1 m/s
Final – 25 November 14:40 – Wind: +1.5 – Temperature: 16 °C – Humidity: 85%
200 meters.
Heat 1 – 26 November 13:15 – Wind: +0.1 m/s – Temperature: 16 °C – Humidity: 75%
Heat 2 – 26 November 13:22 – Wind: +1.0 m/s
Final – 27 November 13:30 – Wind: -1.6 – Temperature: 16 °C – Humidity: 62%
400 meters.
Heat 1 – 25 November 13:10 – Temperature: 17 °C – Humidity: 89%
Heat 2 – 25 November 13:17
Final – 26 November 14:00 – Temperature: 16 °C – Humidity: 74%
800 meters.
Final – 25 November 14:15 – Temperature: 16 °C – Humidity: 85%
1500 meters.
Final – 27 November 12:55 – Temperature: 16 °C – Humidity: 62%
5000 meters.
Final – 26 November 12:25 – Temperature: 16 °C – Humidity: 75%
10,000 meters.
Final – 24 November 12:30 – Temperature: 25 °C – Humidity: 63%
Marathon.
Final – 30 November 12:30
100 meters hurdles.
Heat 1 – 25 November 12:40 – Wind: +0.7 m/s – Temperature: 17 °C – Humidity: 92%
Heat 2 – 25 November 12:47 – Wind: +0.3 m/s
Final – 26 November 12:55 – Wind: -0.8 – Temperature: 16 °C – Humidity: 75%
400 meters hurdles.
Heat 1 – 24 November 11:15 – Temperature: 25 °C – Humidity: 58%
Heat 2 – 24 November 11:22
Final – 26 November 15:05 – Temperature: 16 °C – Humidity: 72%
3000 meters steeplechase.
Final – 28 November 11:45 – Temperature: 15 °C – Humidity: 72%
4 × 100 meters relay.
Final – 28 November 12:15 – Temperature: 16 °C – Humidity: 72%
4 × 400 meters relay.
Final – 28 November 13:35 – Temperature: 16 °C – Humidity: 77%
20 kilometers walk.
Final – 23 November 11:45
High jump.
Final – 26 November 13:00 – Temperature: 16 °C – Humidity: 75%
Pole vault.
Final – 24 November 13:30 – Temperature: 25 °C – Humidity: 63%
Long jump.
Final – 25 November 12:00 – Temperature: 17 °C – Humidity: 88%
Triple jump.
Final – 27 November 11:30 – Temperature: 16 °C – Humidity: 62%
Shot put.
Final – 27 November 10:00 – Temperature: 13 °C – Humidity: 65%
Discus throw.
Final – 26 November 11:30 – Temperature: 14 °C – Humidity: 80%
Hammer throw.
Final – 24 November 11:30 – Temperature: 23 °C – Humidity: 54%
Javelin throw.
Final – 27 November 12:25 – Temperature: 16 °C – Humidity: 62%
Heptathlon.
Final – 26/27 November


Limit switch

In electrical engineering, a limit switch is a switch operated by the motion of a machine part or the presence of an object. A limit switch can be used for controlling machinery as part of a control system, as a safety interlock, or as a counter enumerating objects passing a point.
Limit switches are used in a variety of applications and environments because of their ruggedness, ease of installation, and reliability of operation. They can determine the presence, passing, positioning, and end of travel of an object. They were first used to define the limit of travel of an object, hence the name "limit switch".
Standardized limit switches are industrial control components manufactured with a variety of operator types, including lever, roller plunger, and whisker type. Limit switches may be directly mechanically operated by the motion of the operating lever. A reed switch may be used to indicate proximity of a magnet mounted on some moving part. Proximity switches operate by the disturbance of an electromagnetic field, by capacitance, or by sensing a magnetic field.
Rarely, a final operating device such as a lamp or solenoid valve is directly controlled by the contacts of an industrial limit switch, but more typically the limit switch is wired through a control relay, a motor contactor control circuit, or as an input to a programmable logic controller.
Examples.
Miniature snap-action switches are components of devices like photocopiers, computer printers, convertible tops or microwave ovens to ensure internal components are in the correct position for operation and to prevent operation when access doors are opened. A set of adjustable limit switches installed on a garage door opener shut off the motor when the door has reached the fully raised or fully lowered position. A numerical control machine such as a lathe has limit switches to identify maximum limits for machine parts or to provide a known reference point for incremental motions.


Mack Group

Mack Group is a privately held corporation providing contract manufacturing with specialties in plastics design, prototyping, molding, sheet metal fabrication and full product assembly.
Mack was founded in 1920 in Little Falls, N.J. Today, it is headquartered in Arlington, Vermont, and operates 11 locations throughout Vermont, Massachusetts, Connecticut, North Carolina, South Carolina, Florida, and Mexico, totaling of manufacturing space. Mack Group employs over 3,000 and has revenues exceeding $600 million per year.
Divisions of Mack Group.
The divisions within Mack Group include:
Mack Molding.
Supplies molded plastic parts, fabricated metal parts and high-level assemblies to the medical, commercial, computer & business equipment and transportation markets. Specialties include design, prototyping, custom injection molding, sheet metal fabrication and full product assembly, test and distribution. Six locations: Arlington, Vermont (2); Cavendish, Vermont; Pownal, Vermont; Inman, South Carolina; Statesville, North Carolina.
Mack Prototype.
Plastics prototyping with specialties in rapid prototyping, rapid tooling and low volume plastics molding. Located in Gardner, Massachusetts.
Mack Technologies.
Provides system assembly services for high-end electronic products. Specialties include design support, materials management, printed circuit board and final system assembly, product test and order fulfillment. Three locations: Westford, Massachusetts; Melbourne, Florida; Juarez, Mexico.
Synectic Product Development.
Synectic product development is a full-service product design and development company focused on product design, research, prototyping, and manufacturing.


Die preparation

Die preparation is a step of semiconductor device fabrication during which a wafer is prepared for IC packaging and IC testing. The process of die preparation typically consists of two steps: wafer mounting and wafer dicing.
Wafer mounting.
Wafer mounting is a step that is performed during the die preparation of a wafer as part of the process of semiconductor fabrication. During this step, the wafer is mounted on a plastic tape that is attached to a ring. Wafer mounting is performed right before the wafer is cut into separate dies. The adhesive film upon which the wafer is mounted ensures that the individual dies remain firmly in place during 'dicing', as the process of cutting the wafer is called.
The picture on the right shows a 300 mm wafer after it was mounted and diced. The blue plastic is the adhesive tape. The wafer is the round disc in the middle. In this case, a large number of dies were already removed.
Semiconductor-die cutting.
In the manufacturing of micro-electronic devices, die cutting, dicing or singulation is a process of reducing a wafer containing multiple identical integrated circuits to individual dies each containing one of those circuits.
During this process, a wafer with up to thousands of circuits is cut into rectangular pieces, each called a die. In between those functional parts of the circuits, a thin non-functional spacing is foreseen where a saw can safely cut the wafer without damaging the circuits. This spacing is called the "scribe line" or "saw street". The width of the scribe is very small, typically around 100 μm. A very thin and accurate saw is therefore needed to cut the wafer into pieces. Usually the dicing is performed with a water-cooled circular saw with diamond-tipped teeth.
Types of blades.
The most common make up of blade used is either a metal or resin bond containing abrasive grit of natural or more commonly synthetic diamond, or borazon in various forms. Alternatively, the bond and grit may be applied as a coating to a metal former. See diamond tools.


MPI MP21B

The MPI MP21B is a low-emissions diesel switcher locomotive built by MotivePower. It is powered by three Cummins QSK19C I6 engines with each one developing and creating a total power output of . One MP21B locomotive was manufactured, currently operated by Amtrak.


Flat honing

Flat honing is a metalworking grinding process used to provide high quality flat surfaces. It combines the speed of grinding or honing with the precision of lapping. It has also been known under the terms high speed lapping and high precision grinding.
Origin of term.
The term is derived from honing cylinders and holes. A flat workpiece surface is processed, hence the word flat; the word honing is used because the cutting speed is low compared to grinding. A fixed abrasive is used to provide accuracy and optical appearance of the surface finish. Sometimes it is also called fine grinding or surface grinding using planetary kinematics.
History.
The technology is relatively young, having appeared in the 1980s. In the industry, production lapping is being replaced by flat honing in an ever-expanding array of applications. The flat honing process allows for an equivalent quality result, but at a significant reduction in manufacturing costs per workpiece. Savings result from reduced process times and the ease of workpiece cleaning. However, more and more parts are processed directly from their blank operation (sintered, injected, punched, sawed, or similar) with highly precise tolerances and accuracy (flatness and roughness).
Method.
The removal of the material is done by using geometrically undefined cutting edges (grain bound) that are held together in large working wheels with a thin layer of abrasive. The workpieces are held in toothed carriers (plastic, steel) that are driven by two horizontal pin rings. The full workpiece surface is in constant contact with an abrasive wheel.
There are two different processes: Single and double sided machining.
The working wheel and the carriers are driven by different relative movements between the workpiece and the abrasive wheel. The rotation of the inner pin ring against the working wheel generates the stock removal. The operation itself will be flushed continually (mostly with oil) to ensure the clean working wheel does not become contaminated with grinding sludge.
Abrasive.
Most working wheels contain abrasive grains of synthetic diamond or cubic boron nitride (CBN). The grain shape, grain coating and the grain size are other important components for an optimal working process.
Bond.
The bond has the task of holding the individual grains together until they become dull. Type and quantity of the binder used affects both the hardness and the abrasive properties of the working wheels. The outbreak of the abrasive grain is called self-sharpening.
Layout of flat honing wheels.
Flat honing requires an exclusive wheel suitable for the type of material being processed. Flat honing wheels are available with full faced layers of abrasive although grooves of different geometry can be introduced to enhance a better removal of material. These abrasives are fixed onto a steel plate. For vitrified bonded flat honing wheels, round or hexagonal pellets are used and are fixed to the steel plate with a special adhesive. The spaces between the pellets or segments are used to reduce the contact between the workpiece and the abrasive wheel. They also cool and lubricate the process. All types of flat honing wheels can vary in grain concentration and grain size along the area of the wheel which results in an even wear over the complete wheel.
Cooling and flushing.
The main task of the coolant is to aid in the dissipation of heat from removed stock. It also reduces the friction between the abrasive and the workpiece. Therefore, proper wetting, adhesion, pressure, temperature resistance, and corrosion protection are all factors when selecting a coolant. Oil (mineral or diester based) is used as the preferred cooling and flushing media. Water emulsions may also be used.
Applications.
Due to the tension-free reception of loose parts in the carriers, virtually any solid material can be processed. The application range is very wide, from a soft to a very hard material (thermoplastic plastic to sapphire or ceramic).
Examples are vane pump parts made of polyphenylene sulfide (PPS), ceramic insert made of SiNi, watch windows, sapphire LED wafers, bearing rings, vane pumps, gear steel, cutting knives and carbide.
The surface is similar to the typical honing crosshatch, this leads to good tribological properties and fine roughness. The low subsurface damage will have a positive impact on subsequent polishing processes (CMP, etching).


Steel abrasive

Steel abrasives are steel particles that are used as abrasive or peening media. They are usually available in two different shapes (shot and grit) that address different industrial applications.
Steel shot refers to spherical grains made of molten steel through an atomization ("granulation") process, available in different sizes and hardnesses.
Steel grit characterizes grains with a predominantly angular shape. These grains are obtained by crushing steel shot, therefore they exhibit sharp edges and broken sections. Harder than steel shot, it is also available in different sizes and hardnesses.
Properties.
Most steel abrasives are made of a high-carbon steel composition, the best compromise between mechanical properties, efficiency and durability. The most important properties for steel abrasives are hardness, grain size and shape, toughness and cleanliness (lack of oxides, contaminants, etc.).
Recyclability and environmental impact.
The recyclability of steel shot and grit ranges between 2000 and 3000 cycles. Due to its high recyclability level, steel shot and grit tend to generate less waste when compared to other expendable abrasives.
Hardness.
Steel shot or grit is usually available at different hardness levels, ranging between 40 and 65 on the Rockwell scale (400 to 850 on the Vickers hardness scale).
Industrial applications.
Cleaning.
Steel shot and grit are used in cleaning applications for removal of loose material on metal surfaces. This type of cleaning is common in automotive industry (motor blocks, cylinder heads, etc.).
Surface preparation.
Surface preparation is a series of operations including cleaning and physical modification of a surface. Steel shot and grit are used in a surface preparation process for cleaning metal surfaces which are covered with mill scale, dirt, rust, or paint coatings and for physically modifying the metal surface such as creating roughness for better application of paint and coating. The steel shots are generally employed in shot blasting machines, first made by US-based company Wheelabrator in 1932. In China, shot blasting machines were built around the 1950s, Qinggong Machinery is one of the earliest manufacturers in that industry.
Stone cutting.
Steel grit is used in cutting hard stones, such as granite. The grit is used in large multi-blade frames which cut the blocks of granite into thin slices.
Shot peening.
Shot peening is the repeated striking of a metal surface by hard shot particles. These multiple impacts produce a deformation on the metal surface, but also improve the durability of the metal part. The media used in this application is spherical rather than angular. The reason is that spherical shots are more resistant to the fracture which happens due to the striking impact.and distributes the peening force more evenly and reduces the risk of stress risers. This makes steel shots a better choice for shot peening in aircraft engineering, where the peened surface must be strong and fatigue-resistant.
Debarring & Descaling.
Dustless Steel shot is being used in combination with Steel shots in range of 0.18 mm - 2.80 mm in size for descaling and debarring the surface before further process
Industrial uses.
Steel shot and grit address numerous sectors since cleaning, surface preparation or shot peening applications are used by many industries as a part of their construction, renovation or repair processes. The main industrial sectors employing steel abrasives are:
Production.
The annual steel abrasive production in the world is estimated to be above 1 million tonnes, the world’s largest producer being Winoa Group (previously known as Wheelabrator Allevard) by production and capacity.