In chemistry, epoxy or polyepoxide is a thermosetting epoxide polymer that cures (polymerizes and crosslinks) when mixed with a catalyzing agent or hardener. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. The first commercial attempts to prepare resins from epichlorohydrin were made in 1927 in the United States. Credit for the first synthesis of bisphenol-A-based epoxy resins is shared by Dr. Pierre Castan of Switzerland and Dr. S.O. Greenlee of the United States in 1936. Dr. Castan's work was licensed by Ciba, Ltd. of Switzerland, which went on to become one of the three major epoxy resin producers worldwide. Ciba's epoxy business was spun off and later sold in the late 1990s and is now the advanced materials business unit of Huntsman Corporation of the United States. Dr. Greenlee's work was for the firm of Devoe-Reynolds of the United States. Devoe-Reynolds, which was active in the early days of the epoxy resin industry, was sold to Shell Chemical (now Hexion, formerly Resolution Polymers and others).
Industry
As of 2006, the epoxy industry amounts to more than US$5 billion in North America and about US$15 billion world-wide. The Chinese market has been growing rapidly, and accounts for more than 30% of the total worldwide market. It is made up of approximately 50–100 manufacturers of basic or commodity epoxy resins and hardeners of which the three largest are Hexion (formerly Resolution Performance Products, formerly Shell Development Company; whose epoxy tradename is "Epon"), The Dow Chemical Company (tradename "D.E.R."), and Huntsman Corporation's Advanced Materials business unit (formerly Vantico, formerly Ciba Specialty Chemical; tradename "Araldite"). In 2007 Huntsman Corporation agreed to merge with Hexion (owned by the Apollo Group). KUKDO Chemical is one of the largest epoxy manufacturers in Asia, and recently their capacity has been increased up to 210,000 MT/Y (Korea 150,000 MT/Y, China 60,000 MT/Y and will be increased totally 300,000 MT/Y by 2009). Nanya Plastic also has the capacity of over 250,000 MT/Y (Taiwan and China), which is mostly for captive use. There are over 50 smaller epoxy manufacturers primarily producing epoxies only regionally, epoxy hardeners only, specialty epoxies, or epoxy modifiers.
These commodity epoxy manufacturers mentioned above typically do not sell epoxy resins in a form usable to smaller end users, so there is another group of companies that purchase epoxy raw materials from the major producers and then compounds (blends, modifies, or otherwise customizes) epoxy systems from these raw materials. These companies are known as "formulators". The majority of the epoxy systems sold are produced by these formulators and they comprise over 60% of the dollar value of the epoxy market. There are hundreds of ways that these formulators can modify epoxies—by adding mineral fillers (talc, silica, alumina, etc.), by adding flexibilizers, viscosity reducers, colorants, thickeners, accelerators, adhesion promoters, etc.. These modifications are made to reduce costs, to improve performance, and to improve processing convenience. As a result a typical formulator sells dozens or even thousands of formulations—each tailored to the requirements of a particular application or market.
The applications for epoxy-based materials are extensive and include coatings, adhesives and composite materials such as those using carbon fiber and fiberglass reinforcements (although polyester, vinyl ester, and other thermosetting resins are also used for glass-reinforced plastic). The chemistry of epoxies and the range of commercially available variations allows cure polymers to be produced with a very broad range of properties. In general, epoxies are known for their excellent adhesion, chemical and heat resistance, good-to-excellent mechanical properties and very good electrical insulating properties. Many properties of epoxies can be modified (for example silver-filled epoxies with good electrical conductivity are available, although epoxies are typically electrically insulating). Variations offering high thermal insulation, or thermal conductivity combined with high electrical resistance for electronics applications, are on offer.
Epoxies find significant use in many applications which are described in following sections.
2009年1月22日星期四
Resin casting
A resin casting system is a technical installation to process casting resin for the purpose of filling, sealing, covering or soaking technical parts, especially in the field of electricity and electronics like transformers, LCDs and other small and big parts.
Due to progressing miniaturization and introduction of electronics into new areas, quality requirements for the parts are rising, and thus the quality of casting must be increased as well. To obtain the required quality, on one hand, the resin system has to be developed and optimized accordingly. On the other hand, the resin casting system has to work more and more precisely to obtain best casting. Because of continuously increasing cost pressure, casting devices must be capable of increased quality, while also becoming faster and more reliable.
Requirements for good casting
First of all, by casting, electrical and electronic parts have to be insulated reliably and penetration of moisture has to be excluded totally. Very often heat has to be conducted out from the part properly, an attribute that can be improved by the choice of an appropriate casting resin.
Process steps in a resin casting system
In a resin casting system the following processes have to be performed:
Conditioning of the resin mix
Material transportation
Metering
Mixing
Dispensing
A good resin casting system provides high quality casting of the same high standard even during long series in mass production.
Conditioning
Several properties of the resin mix, with or without filler material, one component or two components (resin + hardener), are crucial for the quality of the product:
Even distribution of the fillers (no settling)
Elimination of air and moisture
Constant, often elevated temperature to maintain low viscosity
Even distribution of the fillers without setting is maintained by ongoing stirring.
Air and moisture are eliminated by evacuating the device.
Elevated temperature is reached and maintained by thoroughly controlled heating of the vessel, the material feeding lines, the pumps and metering heads. In filled, complex resin mixes conditioning is especially crucial for the quality of the product.
Electronic packaging
Electronic packaging is a major discipline within the field of electronic engineering, and includes a wide variety of technologies. It refers to enclosures and protective features built into the product itself, and not to shipping containers. It applies both to end products and to components.
Packaging techniques
Sheet metal
Punched and formed sheet metal is one of the oldest types of electronic packaging. It can be mechanically strong, provides electromagnetic shielding when the product requires that feature, and is easily made for prototypes and small production runs with little custom tooling expense. Fairly professional results are possible in a home workshop.
Cast metal
Gasketed metal castings are sometimes used to package electronic equipment for exceptionally severe environments, such as in heavy industry, aboard ship, or deep under water. Aluminum die castings are more common than iron or steel sand castings.
Machined metal
Electronic packages are sometimes made by machining solid blocks of metal, usually aluminum, into complex shapes. They are fairly common in microwave assemblies for aerospace use, where precision transmission lines require complex metal shapes, in combination with hermetically sealed housings. Quantities tend to be small; sometimes only one unit of a custom design is required. Piece part costs are high, but there is little or no cost for custom tooling, and first-piece deliveries can take as little as half a day. The tool of choice is a numerically controlled vertical milling machine, with automatic translation of computer-aided design (CAD) files to toolpath command files. ====Molded plastic=cases and structural parts can be made by a variety of methods, offering tradeoffs in piece part cost, tooling cost, mechanical and electrical properties, and ease of assembly. Examples are injection molding, transfer molding, vacuum forming, and die cutting. Pl can be post-processed to provide conductive surfaces when required.
Potting
Formally called "encapsulation", potting consists of immersing the part or assembly in a liquid resin, and then curing it. Potting can be done in a pre-molded potting shell, or directly in a mold. Today it is most widely used to protect semiconductor components from moisture and mechanical damage, and to serve as a mechanical structure holding the lead frame and the chip together. In earlier times it was often used to discourage reverse engineering of proprietary products built as printed circuit modules. It is also commonly used in high voltage products to allow live parts to be placed much closer together, so that the product can be smaller; also, to keep dirt and conductive contaminants such as impure water out of sensitive areas. Another use is to protect deep-submergence items such as sonar transducers from collapsing under extreme pressure, by filling all voids. Potting can be rigid or soft. When void-free potting is required, it's common practice to place the product in a vacuum chamber while the resin is still liquid, hold a vacuum for several minutes to draw the air out of internal cavities and the resin itself, then release the vacuum. Atmospheric pressure collapses the voids and forces the liquid resin into all internal spaces. Vacuum potting works best with resins that cure by polymerization, rather than solvent evaporation.
Porosity Sealing or Impregnation
Porosity Sealing or Resin Impregnation is similar to potting, but doesn't use a shell or a mold. Parts are submerged in a polymerizable monomer or solvent-based low viscosity plastic solution. The pressure above the fluid is lowered to a full vacuum. After the vacuum is released, the fluid flows into the part. When the part is withdrawn from the resin bath, it is drained and/or cleaned and then cured. Curing can consist of polymerizing the internal resin or evaporating the solvent, which leaves an insulating dielectric material between different voltage components. Porosity sealing (Resin Impregnation) fills all interior spaces, and may or may not leave a thin coating on the surface, depending on the wash/rinse performance. The main application of vacuum impregnation porosity sealing is in boosting the dielectric strength of transformers, solenoids, lamination stacks or coils, and some high voltage components. It prevents ionization from forming between closely spaced live surfaces and initiating failure.
Liquid filling
Liquid filling is sometimes used as an alternative to potting or impregnation. It's usually a dielectric fluid, chosen for chemical compatibility with the other materials present. It's used mostly in very large electrical equipment such as utiliity transformers, to increase voltage breakdown. It can also be used to improve heat transfer, especially if allowed to circulate by natural convection or forced convection through a heat exchanger. Liquid filling can be removed for repair much more easily than potting.
Conformal coating
Conformal coating is a thin insulating coating applied by various methods. It provides mechanical and chemical protection of delicate components. It's widely used on mass-produced items such as axial-lead resistors, and sometimes on printed circuit boards. It can be very economical, but somewhat difficult to achieve consistent process quality. See Conformal coating, Parylene.
Glob-top
Glob-top is a variant of conformal coating used in chip-on-board assembly. It consists of a drop of specially formulated resin deposited over a semiconductor chip and its wire bonds, to provide mechanical support and exclude contaminants such as fingerprint residues which could disrupt circuit operation.
Hermetic metal/glass cases
Hermetic metal packaging began life in the vacuum tube industry, where a totally leak-proof housing was essential to operation. This industry developed the glass-seal electrical feedthrough, using alloys such as Kovar to match the coefficient of expansion of the sealing glass so as to minimize mechanical stress on the critical metal-glass bond as the tube warmed up. Some later tubes used metal cases and feedthroughs, and only the insulation around the individual feedthroughs used glass. Today, glass-seal packages are used mostly in critical components and assemblies for aerospace use, where leakage must be prevented even under extreme changes in temperature, pressure, and humidity.
Hermetic ceramic packages
Packages consisting of a lead frame embedded in a vitreous paste layer between flat ceramic top and bottom covers are more convenient than metal/glass packages for some products, but give equivalent performance. Examples are integrated circuit chips in ceramic Dual In-line Package form, or complex hybrid assemblies of chip components on a ceramic base plate.
Printed circuit assemblies
Printed circuits are primarily a technology for connecting components together, but they also provide mechanical structure. In some products, such as computer accessory boards, they're all the structure there is. This makes them part of the universe of electronic packaging.
Design considerations
An engineer or designer must balance many objectives and practical considerations when selecting packaging methods.
Hazards to be protected against: mechanical damage, exposure to weather and dirt, electromagnetic interference, etc.
Heat dissipation requirements
Tradeoffs between tooling capital cost and per-unit cost
Tradeoffs between time to first delivery and production rate
Availability and capability of suppliers
User interface design and convenience
Ease of access to internal parts when required for maintenance
Product safety, and compliance with regulatory standards
Esthetics, and other marketing considerations
Service life and reliability
Packaging techniques
Sheet metal
Punched and formed sheet metal is one of the oldest types of electronic packaging. It can be mechanically strong, provides electromagnetic shielding when the product requires that feature, and is easily made for prototypes and small production runs with little custom tooling expense. Fairly professional results are possible in a home workshop.
Cast metal
Gasketed metal castings are sometimes used to package electronic equipment for exceptionally severe environments, such as in heavy industry, aboard ship, or deep under water. Aluminum die castings are more common than iron or steel sand castings.
Machined metal
Electronic packages are sometimes made by machining solid blocks of metal, usually aluminum, into complex shapes. They are fairly common in microwave assemblies for aerospace use, where precision transmission lines require complex metal shapes, in combination with hermetically sealed housings. Quantities tend to be small; sometimes only one unit of a custom design is required. Piece part costs are high, but there is little or no cost for custom tooling, and first-piece deliveries can take as little as half a day. The tool of choice is a numerically controlled vertical milling machine, with automatic translation of computer-aided design (CAD) files to toolpath command files. ====Molded plastic=cases and structural parts can be made by a variety of methods, offering tradeoffs in piece part cost, tooling cost, mechanical and electrical properties, and ease of assembly. Examples are injection molding, transfer molding, vacuum forming, and die cutting. Pl can be post-processed to provide conductive surfaces when required.
Potting
Formally called "encapsulation", potting consists of immersing the part or assembly in a liquid resin, and then curing it. Potting can be done in a pre-molded potting shell, or directly in a mold. Today it is most widely used to protect semiconductor components from moisture and mechanical damage, and to serve as a mechanical structure holding the lead frame and the chip together. In earlier times it was often used to discourage reverse engineering of proprietary products built as printed circuit modules. It is also commonly used in high voltage products to allow live parts to be placed much closer together, so that the product can be smaller; also, to keep dirt and conductive contaminants such as impure water out of sensitive areas. Another use is to protect deep-submergence items such as sonar transducers from collapsing under extreme pressure, by filling all voids. Potting can be rigid or soft. When void-free potting is required, it's common practice to place the product in a vacuum chamber while the resin is still liquid, hold a vacuum for several minutes to draw the air out of internal cavities and the resin itself, then release the vacuum. Atmospheric pressure collapses the voids and forces the liquid resin into all internal spaces. Vacuum potting works best with resins that cure by polymerization, rather than solvent evaporation.
Porosity Sealing or Impregnation
Porosity Sealing or Resin Impregnation is similar to potting, but doesn't use a shell or a mold. Parts are submerged in a polymerizable monomer or solvent-based low viscosity plastic solution. The pressure above the fluid is lowered to a full vacuum. After the vacuum is released, the fluid flows into the part. When the part is withdrawn from the resin bath, it is drained and/or cleaned and then cured. Curing can consist of polymerizing the internal resin or evaporating the solvent, which leaves an insulating dielectric material between different voltage components. Porosity sealing (Resin Impregnation) fills all interior spaces, and may or may not leave a thin coating on the surface, depending on the wash/rinse performance. The main application of vacuum impregnation porosity sealing is in boosting the dielectric strength of transformers, solenoids, lamination stacks or coils, and some high voltage components. It prevents ionization from forming between closely spaced live surfaces and initiating failure.
Liquid filling
Liquid filling is sometimes used as an alternative to potting or impregnation. It's usually a dielectric fluid, chosen for chemical compatibility with the other materials present. It's used mostly in very large electrical equipment such as utiliity transformers, to increase voltage breakdown. It can also be used to improve heat transfer, especially if allowed to circulate by natural convection or forced convection through a heat exchanger. Liquid filling can be removed for repair much more easily than potting.
Conformal coating
Conformal coating is a thin insulating coating applied by various methods. It provides mechanical and chemical protection of delicate components. It's widely used on mass-produced items such as axial-lead resistors, and sometimes on printed circuit boards. It can be very economical, but somewhat difficult to achieve consistent process quality. See Conformal coating, Parylene.
Glob-top
Glob-top is a variant of conformal coating used in chip-on-board assembly. It consists of a drop of specially formulated resin deposited over a semiconductor chip and its wire bonds, to provide mechanical support and exclude contaminants such as fingerprint residues which could disrupt circuit operation.
Hermetic metal/glass cases
Hermetic metal packaging began life in the vacuum tube industry, where a totally leak-proof housing was essential to operation. This industry developed the glass-seal electrical feedthrough, using alloys such as Kovar to match the coefficient of expansion of the sealing glass so as to minimize mechanical stress on the critical metal-glass bond as the tube warmed up. Some later tubes used metal cases and feedthroughs, and only the insulation around the individual feedthroughs used glass. Today, glass-seal packages are used mostly in critical components and assemblies for aerospace use, where leakage must be prevented even under extreme changes in temperature, pressure, and humidity.
Hermetic ceramic packages
Packages consisting of a lead frame embedded in a vitreous paste layer between flat ceramic top and bottom covers are more convenient than metal/glass packages for some products, but give equivalent performance. Examples are integrated circuit chips in ceramic Dual In-line Package form, or complex hybrid assemblies of chip components on a ceramic base plate.
Printed circuit assemblies
Printed circuits are primarily a technology for connecting components together, but they also provide mechanical structure. In some products, such as computer accessory boards, they're all the structure there is. This makes them part of the universe of electronic packaging.
Design considerations
An engineer or designer must balance many objectives and practical considerations when selecting packaging methods.
Hazards to be protected against: mechanical damage, exposure to weather and dirt, electromagnetic interference, etc.
Heat dissipation requirements
Tradeoffs between tooling capital cost and per-unit cost
Tradeoffs between time to first delivery and production rate
Availability and capability of suppliers
User interface design and convenience
Ease of access to internal parts when required for maintenance
Product safety, and compliance with regulatory standards
Esthetics, and other marketing considerations
Service life and reliability
Tanning bed
A tanning bed or sunbed is a device emitting ultraviolet radiation (typically 95% UVA and 5% UVB, +/-3%) used to produce a cosmetic tan. Regular tanning beds use several fluorescent lamps that have phosphor blends designed to emit UV in a spectrum that is somewhat similar to the sun. Smaller home tanning beds usually have 12 to 28 100 watt lamps while systems found in salons can run from 24 to 60 lamps each consuming 100 to 200 watts.
There are also "high pressure" tanning beds that generate primarily UVA with some UVB by using highly specialized quartz lamps, reflector systems and filters. These are much more expensive, thus less commonly used. A tanning booth is quite similar to a tanning bed, but the individual stands while tanning and the typical power output of booths is higher.
Because of several alleged adverse effects on human health, the World Health Organization does not recommend the use of UV tanning devices for cosmetic reasons. For example, using a sunbed without goggles may lead to a condition known as arc eye.
Tanning beds are not used for somewhat different reasons in North America than in Europe. In North America, tanning is more seasonal, where most users begin in January and stop or slow down by June. It is most often used as a way to jump start the tanning process, so that once the summer begins, they can go to the beach or enjoy other outdoor activities and already have a significant base tan built up. This is also why tanning lotions and bronzers are more commonly used in North America.
Europeans may enjoy tanning seasonally, but less so than North Americans. This is due to many areas in Europe having significantly fewer days of sunshine than North America, so Europeans are more likely to use a tanning bed all year long, for both the cosmetic and mood altering benefits. European tanning beds generally use a different type of lamp as well, with UVB ratings in the 1% to 3% range (using US measuring methods) whereas most tanning beds sold in the US use 4.2% to 6.5% UVB ratings, and aftermarket lamps with up to 8.5% or higher being popular. Of course, these lamps have less UVA and will produce a sunburn quicker, but many Americans seem to like them because a short session produces a "reddening", or instant gratification. These lamps actually produce a slower deep tan (but a faster base tan) that fades faster, but are simply marketed as "hotter", although technically they have about the same amount of UV but with different ratios of UVA and UVB.
While the primary reason for both Americans and Europeans to use a tanning bed is cosmetic, there are many other reasons why they are used. It is common for people to tan simply because it makes them feel good. Also, most tanning beds generate a large amount of heat, including infrared, which has deep penetrating action that can relieve minor muscle aches.
The tan produced by a tanning bed is not as deep as a tan produced in the sun. This is because tanning beds have higher overall levels of UV than the sun on a typical day, so the exposure times are shorter than the average session spent in the sun to achieve the same amount of tan. This can cause someone with a dark indoor tan to go outside and get a bad sunburn quickly because the deeper levels of their skin have not been exposed previously, and have no natural protection above what white skin would have. It is strongly recommended that a person does NOT tan indoor and outdoors on the same day, due to the likely chance that they will get overexposed. Because overexposure actually destroys melanin, getting a sunburn will result in LESS tanning. The popular wisdom that you "need to burn to tan" or that a sunburn will turn into a tan is simply wrong, and increases your chances for skin cancer later in life.
Rail transport modelling
Model railroading (US) or Railway modelling (UK, Australia and Canada) is a hobby in which rail transport systems are modelled at a reduced scale, or ratio. The scale models include locomotives, rolling stock, streetcars, tracks, signalling, and roads, buildings, vehicles, model figures, lights, and features such as streams, hills and canyons.
The earliest model railways are the 'carpet railways' in the 1840s. Electric trains appeared around the turn of the 20th century. But these were crude likenesses. Model trains today are more realistic. Today modellers create model railway / railroad layouts, often recreating real locations and periods in history.
General description
Involvement ranges from possession of a train set to spending hours and large sums on a large and exacting model of a railroad and the scenery through which it passes, called a "layout". Hobbyists, called "model railroaders" or "railway modellers", may maintain models large enough to ride (see Live steam, Ridable miniature railway and Backyard railroad). Modellers may collect model trains, building a landscape for the trains to pass through, or operate their own railroad in miniature.
Some older scale models reach high prices.
Layouts vary from a circle or oval of track to the realistic, real places are modelled to scale. One of the largest is in the Pendon Museum in Oxfordshire, UK, where an EM gauge (same 1:76.2 scale as 00 but with more accurate track gauge) model of the Vale of White Horse in the 1930s is under construction. The museum also houses one of the earliest scenic models - the Madder Valley layout built by John Ahern. This was built in the late 1930s to late 1950s and brought in realistic modelling, receiving coverage on both sides of the Atlantic in the magazines Model Railway News and Model Railroader. Bekonscot in Buckinghamshire is the oldest model village and includes a model railway, dating from the 1930s. The world's largest model railroad in H0 scale is Northlandz in Flemington, NJ, United States. The largest live steam layout, with 25 miles (40km) of track is Train Mountain in Chiloquin, Oregon, U.S..
Model railroad clubs exist where enthusiasts meet. Clubs display models for the public. One specialist branch concentrates on larger scales and gauges, commonly using track gauges from 3.5 to 7.5 inches. Models in these scales are usually hand-built and powered by live steam, or diesel-hydraulic, and the engines are often powerful enough to haul dozens of human passengers. Often railways of this size are called miniature railways. List of model railroad clubs.
The Tech Model Railroad Club (TMRC) at MIT in the 1950s pioneered automatic control of track-switching by using telephone relays.
The oldest society is The Model Railway Club (established 1910), near Kings Cross, London, UK. As well as building model railways, it has 5,000 books and periodicals. Similarly, The Historical Model Railway Society at Butterley, near Ripley, Derbyshire specialises in historical matters and has archives available to members and non-members.
2009年1月19日星期一
Choro-Q
Choro-Q (チョロQ, Choro-Q?) is a series of Japanese 3-4 cm long pullback toy cars first made by Takara in 1978, and sold extensively in Western markets as Penny Racers. The name comes from the Japanese word "Choro-choro" which means "dash around" and an abbreviation of "cute" which in its Japanese adaptation connotes both the aesthetic meaning and also the meaning of petite in size. The Choro-Q car designs are largely based on illustrations by Yasuhiro Nakamura (中村安広) who also design its covers for books and videogames.
Most Choro-Q feature real rubber tires (usually with larger ones on the rear) and the characteristic coil-spring pullback motor. Also, each Choro-Q is a "cute" squeezed design caricature of the actual vehicle it represents. This type of caricature is also known as "deformed scale" as it gives the car a foreshortened or deformed appearance. What is also distinct about the cars is the slot at the rear, where a small coin can be inserted for the wheelie effect.
The toy line is highly popular and has become collectible, even outside Japan, due to its low price and its merchandising line which includes JGTC and various licensed car editions and has also spawned a series of videogames bearing the same name. The toy line has also lent its moulding to the Transformers line of toys.
In addition to "Penny Racers," Choro-Q pullback cars were also marketed under the Tonka branding in the late 1980s as "Tonka Turbo Tricksters." "Penny Racers" in the US are still marketed by Funrise, but are less popular for collectors compared with their true-to-life counterparts marketed elsewhere, and versus the ones formerly sold by Tonka. "Penny Racers" tend to be garishly colored and given silly names, ignoring the actual names of the makes and models, and marketed for US children, whereas the Choro Q in the far East are made to a much higher quality standard and many are specifically designed for the adult collector, with high detail and/or tiny, incredibly detailed racing graphics and occasionally other realistic gimmicks such as fold-out headlights.
Originally produced in Japan, the manufacture subsequently has occurred variously in Taiwan, Macau and China. The models represent various makes and models of all kinds of actual cars, trucks, trains, and even planes and military and construction vehicles. There are even versions representing just about every bus and train line in Japan. Choro-Q are also produced in limited special runs for promotional purposes. Models are licensed and produced for automotive manufacturers and dealers, or as tchotchkes for marketing of other products and services. They even released a Major League Baseball line.
The first Choro-Q cars were more geared toward children, with primary colors and low detail. They have grown more sophisticated over time and now are for the most part cast in a uniform clear, colored or smoked resin plastic which is then painted, thus leaving the windshields and headlights, etc. transparent for added realism. From early on, Takara offered accessories and various spare parts and modification parts, including different motors to give a higher speed. Recently the newer Choro-Q are sold from the factory with various styles of spring-wound motors, including slow (for trucks and machinery), normal (for normal cars), and fast (for sports cars). There is even a 2-speed motor that starts out slow and then shifts to a higher gear.
Unusual Choro-Q which have the wheels and pull-back motor but are not modelled after vehicles are also common, often sold as special collectibles. This includes Choro-Q in the shape of common regional symbols such as carved wood bears of Hokkaido and popular symbols from other regions such monkeys, salmon eggs, sea urchin, etc. sold only in certain regions and marketed at local domestic tourists.
The Choro-Q brand has been extended, often with a small name change which is a pun on the original name, to cover other small toys or novelties, both with and without the wheels and motor, including
Digi-Q: Electronic remote control versions of Choro-Q cars which used infrared technology instead of radio control. These products were developed in conjunction with Konami.
Choco-Q: Chocolate egg with a small capsule toy inside
Puka-Q: Bath salts compressed into an egg shape, which, when dissolved in the bath, reveals a small toy inside
Choro-Ju: ("Ju" means monster in Japanese)Small monster toys which moved with a friction motor and had other gimmicks such as sparks shooting from the mouth.
Choro-Chu ("Chu" means insect in Japanese): Realistic plastic and rubber figures of various beetles, with wheels and a pull-back motor for movement.
Jumbo Choro-Q: This is a large-scale version of the small toys but approximately 30 cm in length. They have the same pull-back motor gimmick and the hood also opened to reveal a storage space for standard sized Choro-Q toys.
Q-steer: A more inexpensive infra-red remote control version of Choro-Q cars than the earlier Digi-Q, this line was first released in 2006 after the merger with TOMY and for several years became one of the best selling toy lines in Japan.
CQ Motors: The most ambitious brand extension of all, this wholly owned subsidiary of Takara, founded in 2002, manufactured and sold actual single-passenger, electric automobiles modelled after the toy cars. The cars are street-legal (though not permitted on highways), require a standard driver's license for operation and have a top speed of about 50 km/h and a range of about 80 km on a single charge. Several models were sold, priced in the 1-1.5 million yen range. Although sales have been discontinued, as many as 500 were sold in all. In a country known for the prowess of its automobile industry it is remarkable that at one point, Takara, a toy company, had the highest share of electric cars on the road in Japan.
Choro-Q Deck System (CDS): A system of special customizable Choro-Q cars and track designed for head-on crash "battle" competitions. The innovative "deck system" allows the easy swapping of the principle car components by putting each component in a card-like frame. Swappable components include the chassis-engine, front-end battering ram, outer body and special deflecting side wings. After stacking a unique combination of component cards like a deck of cards, a unique vehicle comes together which can be easily detached from the deck and put into battle on the track. The object of the competition is to design a vehicle which will knock the opponent off the track in a head-to-head crash battle.
Video Games
Dozens of Choro Q video games using the Choro-Q brand and themes have been released. These games, which have been released on many platforms, are racing genre with varying customization and RPG elements. Many of the games have been ported and translated with moderate success internationally, sometimes under the Choro-Q name, but also under other names such as Penny Racers, Gadget Racers and Road Trip.
Most Choro-Q feature real rubber tires (usually with larger ones on the rear) and the characteristic coil-spring pullback motor. Also, each Choro-Q is a "cute" squeezed design caricature of the actual vehicle it represents. This type of caricature is also known as "deformed scale" as it gives the car a foreshortened or deformed appearance. What is also distinct about the cars is the slot at the rear, where a small coin can be inserted for the wheelie effect.
The toy line is highly popular and has become collectible, even outside Japan, due to its low price and its merchandising line which includes JGTC and various licensed car editions and has also spawned a series of videogames bearing the same name. The toy line has also lent its moulding to the Transformers line of toys.
In addition to "Penny Racers," Choro-Q pullback cars were also marketed under the Tonka branding in the late 1980s as "Tonka Turbo Tricksters." "Penny Racers" in the US are still marketed by Funrise, but are less popular for collectors compared with their true-to-life counterparts marketed elsewhere, and versus the ones formerly sold by Tonka. "Penny Racers" tend to be garishly colored and given silly names, ignoring the actual names of the makes and models, and marketed for US children, whereas the Choro Q in the far East are made to a much higher quality standard and many are specifically designed for the adult collector, with high detail and/or tiny, incredibly detailed racing graphics and occasionally other realistic gimmicks such as fold-out headlights.
Originally produced in Japan, the manufacture subsequently has occurred variously in Taiwan, Macau and China. The models represent various makes and models of all kinds of actual cars, trucks, trains, and even planes and military and construction vehicles. There are even versions representing just about every bus and train line in Japan. Choro-Q are also produced in limited special runs for promotional purposes. Models are licensed and produced for automotive manufacturers and dealers, or as tchotchkes for marketing of other products and services. They even released a Major League Baseball line.
The first Choro-Q cars were more geared toward children, with primary colors and low detail. They have grown more sophisticated over time and now are for the most part cast in a uniform clear, colored or smoked resin plastic which is then painted, thus leaving the windshields and headlights, etc. transparent for added realism. From early on, Takara offered accessories and various spare parts and modification parts, including different motors to give a higher speed. Recently the newer Choro-Q are sold from the factory with various styles of spring-wound motors, including slow (for trucks and machinery), normal (for normal cars), and fast (for sports cars). There is even a 2-speed motor that starts out slow and then shifts to a higher gear.
Unusual Choro-Q which have the wheels and pull-back motor but are not modelled after vehicles are also common, often sold as special collectibles. This includes Choro-Q in the shape of common regional symbols such as carved wood bears of Hokkaido and popular symbols from other regions such monkeys, salmon eggs, sea urchin, etc. sold only in certain regions and marketed at local domestic tourists.
The Choro-Q brand has been extended, often with a small name change which is a pun on the original name, to cover other small toys or novelties, both with and without the wheels and motor, including
Digi-Q: Electronic remote control versions of Choro-Q cars which used infrared technology instead of radio control. These products were developed in conjunction with Konami.
Choco-Q: Chocolate egg with a small capsule toy inside
Puka-Q: Bath salts compressed into an egg shape, which, when dissolved in the bath, reveals a small toy inside
Choro-Ju: ("Ju" means monster in Japanese)Small monster toys which moved with a friction motor and had other gimmicks such as sparks shooting from the mouth.
Choro-Chu ("Chu" means insect in Japanese): Realistic plastic and rubber figures of various beetles, with wheels and a pull-back motor for movement.
Jumbo Choro-Q: This is a large-scale version of the small toys but approximately 30 cm in length. They have the same pull-back motor gimmick and the hood also opened to reveal a storage space for standard sized Choro-Q toys.
Q-steer: A more inexpensive infra-red remote control version of Choro-Q cars than the earlier Digi-Q, this line was first released in 2006 after the merger with TOMY and for several years became one of the best selling toy lines in Japan.
CQ Motors: The most ambitious brand extension of all, this wholly owned subsidiary of Takara, founded in 2002, manufactured and sold actual single-passenger, electric automobiles modelled after the toy cars. The cars are street-legal (though not permitted on highways), require a standard driver's license for operation and have a top speed of about 50 km/h and a range of about 80 km on a single charge. Several models were sold, priced in the 1-1.5 million yen range. Although sales have been discontinued, as many as 500 were sold in all. In a country known for the prowess of its automobile industry it is remarkable that at one point, Takara, a toy company, had the highest share of electric cars on the road in Japan.
Choro-Q Deck System (CDS): A system of special customizable Choro-Q cars and track designed for head-on crash "battle" competitions. The innovative "deck system" allows the easy swapping of the principle car components by putting each component in a card-like frame. Swappable components include the chassis-engine, front-end battering ram, outer body and special deflecting side wings. After stacking a unique combination of component cards like a deck of cards, a unique vehicle comes together which can be easily detached from the deck and put into battle on the track. The object of the competition is to design a vehicle which will knock the opponent off the track in a head-to-head crash battle.
Video Games
Dozens of Choro Q video games using the Choro-Q brand and themes have been released. These games, which have been released on many platforms, are racing genre with varying customization and RPG elements. Many of the games have been ported and translated with moderate success internationally, sometimes under the Choro-Q name, but also under other names such as Penny Racers, Gadget Racers and Road Trip.
Porosity sealing
Porosity sealing is a process by which a porous substrate is saturated with a liquid that then solidifies sufficiently to block differential pressure. In short, parts that suffer leakage through the material are sealed.
Other common names for the porosity sealing process are vacuum impregnation, metal impregnation, polymer impregnation, porous metal sealing and Loc-Tite-ing.
Porosity Sealing is a four step process:
Step 1: Air within the pores is expanded under reduced pressure (vacuum).
Step 2: Pressure reversal (adding pressure outside the part) saturates pores with monomer.
Step 3: Excess monomer is rinsed from the exterior surfaces of the part.
Step 4: The liquid monomer within the porosity is polymerized into a solid to seal the passage.
Common Applications
Die cast and permanent mold cast Aluminum and Magnesium parts contain internal porosity. This porosity is generally localized to the deepest cross-sections of the part and does not extend to the outer skin. However, if the part is also machined, the internal porosity will be exposed and the part will leak if pressurized. Machined die castings that need to hold fluids (intake manifolds, coolant connectors, transmission cases, pump housings and fluid power components) are routinely sealed for life using acrylic resins. Because the sealant is internal to the part, the exterior dimensions and appearance of the part are unchanged.
Powder Metal (PM) components are sealed in preparation for plating and to reduce internal corrosion. Plating operations typically involve submerging the parts in acid solutions. After plating, residual acid internal to the part can promote corrosion and/or preclude an acceptable plating finish. The solution to this problem is to seal the internal voids prior to plating. As explained above, the porosity is saturated with monomer and is then rinsed completely clear of the surface. The resin cures to a durable polymer. Thus, the exposed surface metal is free to be plated while the interior spaces are sealed dry.
The porosity in powder metal parts becomes a liability when the part must resist a differential pressure. PM applications for compressed air, fuel handling or hydraulic housings are common and effective; however, they must be sealed first. The polymer does not add structural strength to the physical part, but it will hold high pressures without creeping. If the wall thickness of the part exceeds 1/4 inch, the leak pressure is typically on the same order of magnitude as the burst pressure of the part.
Powder Metal is also impregnated for machinability enhancement. PM parts are generally difficult to machine and some compositions may not be machinable without ruining the cutting tool. Porosity sealing improves the life of cutting tools by ten to one-hundred times. Resin impregnation is more effective than compacting additives and can be selectively applied for near net pressed parts.
Porosity Sealing via polymer impregnation is very similar in physics to the processes used to saturate bronze PM bearings with oil, the process of pressure-treating lumber with insecticide, the process of urethane impregnating wire coils (motors and transformers) and even the process of saturating peanuts with salt prior to roasting.
Other common names for the porosity sealing process are vacuum impregnation, metal impregnation, polymer impregnation, porous metal sealing and Loc-Tite-ing.
Porosity Sealing is a four step process:
Step 1: Air within the pores is expanded under reduced pressure (vacuum).
Step 2: Pressure reversal (adding pressure outside the part) saturates pores with monomer.
Step 3: Excess monomer is rinsed from the exterior surfaces of the part.
Step 4: The liquid monomer within the porosity is polymerized into a solid to seal the passage.
Common Applications
Die cast and permanent mold cast Aluminum and Magnesium parts contain internal porosity. This porosity is generally localized to the deepest cross-sections of the part and does not extend to the outer skin. However, if the part is also machined, the internal porosity will be exposed and the part will leak if pressurized. Machined die castings that need to hold fluids (intake manifolds, coolant connectors, transmission cases, pump housings and fluid power components) are routinely sealed for life using acrylic resins. Because the sealant is internal to the part, the exterior dimensions and appearance of the part are unchanged.
Powder Metal (PM) components are sealed in preparation for plating and to reduce internal corrosion. Plating operations typically involve submerging the parts in acid solutions. After plating, residual acid internal to the part can promote corrosion and/or preclude an acceptable plating finish. The solution to this problem is to seal the internal voids prior to plating. As explained above, the porosity is saturated with monomer and is then rinsed completely clear of the surface. The resin cures to a durable polymer. Thus, the exposed surface metal is free to be plated while the interior spaces are sealed dry.
The porosity in powder metal parts becomes a liability when the part must resist a differential pressure. PM applications for compressed air, fuel handling or hydraulic housings are common and effective; however, they must be sealed first. The polymer does not add structural strength to the physical part, but it will hold high pressures without creeping. If the wall thickness of the part exceeds 1/4 inch, the leak pressure is typically on the same order of magnitude as the burst pressure of the part.
Powder Metal is also impregnated for machinability enhancement. PM parts are generally difficult to machine and some compositions may not be machinable without ruining the cutting tool. Porosity sealing improves the life of cutting tools by ten to one-hundred times. Resin impregnation is more effective than compacting additives and can be selectively applied for near net pressed parts.
Porosity Sealing via polymer impregnation is very similar in physics to the processes used to saturate bronze PM bearings with oil, the process of pressure-treating lumber with insecticide, the process of urethane impregnating wire coils (motors and transformers) and even the process of saturating peanuts with salt prior to roasting.
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