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Tough polystyrene, PS-HI or S/B

Tough polystyrene

Characteristics: It is a copolymer of styrene and butadiene. With increasing amount of rubbery compound, strength, hardness and rigidity decrease, and ductility and impact increase; dielectric characteristics and chemical resistance slightly fall. It resists to acids, alkalis, fats, oils, alcohol, salty solutions; it doesn’t resist to chlorohydrocarbons and aromatic hydrocarbons, ketones and esters. It isn’t transparent, it is only translucent; it is colored witch covering colors. It has higher soakability compared to PS.

Usage: Food boxes, camping dishes, furniture parts, e.g. table drawers, refrigerator bowls, hanger for clothes, wheel nave covers in automotive, magnetic tape cassettes, inner parts of telephones, radio and TV set boxes, camera boxes, film reels, switches, manipulation boxes, flower pots and bowls.

Identification: It burns creating soot; when bent, it whites out in the bend place and usually doesn’t break. If so, then with tough fracture.


Styrene-acrylonitrile copolymer, SAN

SAN

Characteristics: It has better rigidity and toughness compared with PS, it is hard, transparent and resists to temperature changes. It can be easily colored, sprayed surfaces are glazy. It resists to acids, alkalis, fats, oils, alcohol and petrol. It has better consistency of shape compared to PS, an is much more resistant to corrosion under tension or weather impact. Dielectric characteristics are worse, soakability is higher. It has no adverse impacts to health.

Usage: Solids and transparent covers of kitchen equipment, mixer containers, bath sets, drink cups, dishes and settings for tourism, spice boxes, tooth-brush holders, transparent gramophone covers, tail light covers in automotive, transparent scales of analog radios, drawing templates, ball pen holders, table vents rotors.

Identification: Easily to ignite, burns with yellow flame creating soot. It breaks with crisp fracture when bent.

Acrylonitrile-butadiene-styrene terpolymer, ABS

ABS

Characteristics: There are many types differing in rigidity and thermal resistance, based on different ratio of copolymeration compounds. It is hard, rigid, but tough, even at lower temperatures. Special types can be used at temperatures down to –40 °C. It absorbs impacts and vibrations. Thermal resistance and shape consistency at higher temperatures is better compared to PS and SAN, as well as corrosion resistance under tension. It resists to temperature changes. It has worse electro-insulation characteristics, it is slightly hygroscopic. Electrostatic charge capacity is very low. It has limited weather impact resistance and it has no adverse impacts to health. Special types can be electrogalvanized. It burns. It resists to acids, alkalis, oils, fats, and some hydrocarbons. It doesn’t resist to chlorohydrocarbons and aromatic hydrocarbons, ketones and esters.

Usage: Home electrical appliances, telephone bodies and earphones, bodies of calculators, microphones, alarm-clocks, light supports, bodies of bread-cutters and kitchen weighing machines, toys, e.g. car and gun models, protective sport helmets, tool grips, chain covers, dashboards for bicycles, lawn mower covers, children seats, radiator and heating grills in automotive, decorative grills, headlight bodies, portable tool boxes, bath armatures for galvanic chromium-plating, vacuum-cleaner and hair-drier covers.

Identification: same as for PS: burns producing sooth, less aromatic smell, some types are self-extinguishing.

Processibility: Good, but worse then for PS. ITT is given for temperature of 200 °C and tension of 212 N. It is supplied in wide color scale and is opaque. When bent, it either doesn’t break or breaks with tough fracture.

Polyethylene terephtalate (PeT)

Characteristics: Thermoplastic polyethylene terephtalate (PET) is a plastic chemically classified as a polyester. In terms of chemical principle of polymerization, polyester is classified as condensation polymer, like polyamides or phenolic resins. Most of the polyesters are not typical thermoplastics, they are commonly known as a reactive resins (reactoplastics, formerly referred as thermosets) or fiber materials. PET was originally developed for production of high quality fibers. In last three decades, the area of practical use for this polymer had broadened significantly. Today, PET is still used as a typical fiber material; much bigger volumes, however, are produced for processing to foils (packaging materials, film bottoms, magnetic recording materials), hollow cases, and it is more and more used as a construction material, mostly in form of composites.

 

Chemical structure: PET is a semi-crystalline polymer used mostly in amorphous form.

Benefits: Amorphous PET has tough keeping relatively high rigidity. Highly valued characteristic of PET is that it is nearly impermeable for gases, referred also as a “barrier”, that is used with advantage for package production.

Polycarbonate

Usage

Polycarbonate is a technical plastic used as a raw material for solid boards chamber boards, or for granulate injection. It is suitable for demanding technical applications, e.g. security covers for machines etc. Chamber polycarbonate is used in construction as a plastic to roof indoor gardens pools, etc.

Thermal moulding

Polycarbonate foils and boards can be also thermally shaped. Operating temperatures are between 170 and 200 °C, optimum is around 180 °C.

Heating time depends on the number and performance of heating elements, distance of board and the heaters, and surrounding temperature.

Tooling

Polycarbonate can be easily tooled. Various intermediates are supplied for tooling shaped to rods, tubes, and boards. During tooling the surface can turn white because of friction heat heating of the product or consequences of frozen tensions in form of many surface cracks. The tooling speed must be thus precisely set and cutting tools must be cooled.

Bonding

Polycarbonate products can be imprinted, lacquered and metal-plated. Bonding is performed with welding or sticking. Solvents based on chlorine-methane or chlorine-ethane. To bond polycarbonate with other plastics are suitable two-part adhesives, e.g. epoxy. Cyanide-acrylate second adhesives can be used as well..

Welding

The most suitable method for welding polycarbonate is to use ultrasound. Welded parts can be perfectly bonded very fast, often in less than 1 second. That’s why this technique is very wide-spread today. Internal tensions are created during welding, so it must be finished with tempering.

Optics

Polycarbonate is widely-used particularly in optics. It is used for construction parts of cameras, video-cameras, flashes, projectors, binoculars, their cassettes, finders, shades, etc. Polycarbonate is used to produce lightguides and optical systems. Today, the most important optical application of polycarbonate is in production of optical discs – CD, where combination of excellent optical characteristics and mechanical strength and toughness is used with advantage.

Traffic

In traffic, polycarbonate product transparency is used to produce lamp covers, automotive lamps, flashers, signal lights or various transparent covers of gauges and counters. The transparency of polycarbonate combined with impact resistance is used for manufacturing of protective helmets and glasses.

Machinery pieces

Many engineering applications take advantage of excellent mechanical characteristics of polycarbonate, especially its toughness and strength. It is used for production of many demanding parts of pumps, valves, vents, pneumatic distributors, through-finders, control buttons, grips of manual machine tools, drills, grinders, etc.

Construction

In construction, polycarbonate foils and boards are used as an esthetic article, too. It is used anywhere to replace normal glass. Compared to glass, polycarbonate excels in high impact resistance, and thus unbreakability. It is used for various roofing applications, windows, doors, pool covers and covers of hall or stadiums. Chamber boards are successfully used here.

Polyvinyl chloride unsoftened, PVC-U

Polyvinyl chloride unsoftened

Characteristics: It is an amorphous thermoplastic, hard, tough, rigid, in temperatures under –5 °C goes fragile, its thermal resistance is only up to 60 to 70 °C, electro-insulation characteristics are good, dielectrical characteristics are poor. It is translucent to transparent, self extinguishing, and resistant to damping. It is also resistant to acids, alkalis, fats, oils, alcohols, and petrol. However, it is not resistant to chlorohydrocarbons and aromatic hydrocarbons, ketones and esters. It can be easily colored.

Usage: Shaped pipes, e.g. knees and Y-branches, electro-installing boxes, basins and tanks for waste water, electric apparatus and vent covers, shapes of roof eaves.

Identification: It burns badly with green-colored flame on sides, it spits (sparkles), and dies after source flame is removed; it is self-extinguishing. The smoke smells much like the hydrogen chloride acid. It turns white when bent.

Processibility: Difficult because of low liquidity and high tendency to heat degradation during processing. Liquidity depends on molecular weight, both judged by so called K-value. The higher the K-value is, the higher is the molecular weight, the lower is liquidity, but mechanical and electrical characteristics are better. Liquidity for granulate is measured using ITT. The processibility is better when you add a small amount of emollient.


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