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GUIDE
TO PLASTICS
ABS Excellent
impact strength and impact resistance. Used extensively in appliance,
automotive and computer components. May be painted and plated. Acetal
(Delrin®, Celcon®) Acetals display good impact resistance,
dimensional stability and outstanding surface hardness due to their high
degree of crystalinity. They have high dielectric strength and are resistant
to many solvents. They also exhibit negligible water absorption. Typical
applications include roller bearings, gears, reels, counters, control
cams, valves, and pump parts. CPVC
Chlorinating PVC results in a polymer that has all of PVC's good
qualities, plus improved fire retardance, weatherability, a higher maximum
working temperature and light-fastness. Ertalyte®
- (PET) Polyethylene terephthalate is a clear, crystalline plastic
possessing high strength and low vapor permeability. Because it is also
sterilizable and radiation resistant, it is used extensively as a container
for carbonated beverages, liquor and other food products. It is also generally
approved for use in the processing and packaging of pharmaceuticals. FEP®
- Fluorinated ethylene propylene has a low frictional coefficient, is
resistant to weathering and is useful from cryogenic temperatures to about
390°F. It has a low dielectric constant and is flame and ignition
resistant. Although its mechanical properties are not equal to some other
engineering fluoroplastics, it is commonly used for electrical insulation,
cable sheathing, and as chemically resistant coatings and films. Halar®
(ECTFE) Ethlene-chlorotrifluorethylene copolymer exhibits better
mechanical properties than many other fluoroplastics. But like other fluoroplastics,
its flame retardance, chemical resistance and low dielectric constant
remain constant over a wide temperature range. These qualities make it
suitable for use in such products as electrical insulation, monofilament,
tank linings, housing, and electrical components. It may be usefully employed
at temperatures from the cryogenic range to about 330°F. Isoplast®
- Isoplast® urethane resins are high tensile strength,
chemically resistant resins originally developed for medical use. They
are available in long glass fibre-filled grades. Isoplast®
combines the toughness and dimensional stability of amorphous resins with
the chemical resistance of crystaline materials. The long fibre reinforced
grades are strong enough to replace some metals in load bearing applications. Kel-F®
(PCTFE) Polychlorotrifluoroethylene is highly transparent. It also
exhibits good electrical properties, and is resistant to most common solvents
at room temperature. PCTFE is less permeable to gasses and water vapor
than any other transparent film. Kynar®
(PVDF) Polyvinylidene fluoride has a useful temperature range of
148°F to 302°F. It has good strength, creep resistance
and weatherability. Like some other chlorinated engineering plastics,
it will not support combustion in air. Lexan®
(PC) Polycarbonate exhibits the highest impact strength over a
range of temperatures from 60°F to 270°F. It is fine for
all precision parts, or where transparency is desired. Its water-clear
transmittance (89%) makes it excellent for visors or guards. It shows
good creep resistance and has a temperature-independent dielectric constant,
as well as good insulating properties. Noryl®
(PPE) Modified polyphenylene ether is one of the more widely known
engineering plastics and has gained UL and FDA approval for a broad spectrum
of moldable and formable grades. It has good impact strength at low temperatures
and is resistant to many agents, including steam. It may be furnished
in either unreinforced or reinforced grades and remains stable when processed.
Yield strength of reinforced grades is comparable to aluminum. Typical
end uses include computer and electric housings, automotive body parts,
and piping. Nylon
All grades possess toughness and resiliency and have high fatigue
strength. Resistance to oils and hydrocarbon solvents is also good. Almost
all formulations are also self-extinguishing and retain stable mechanical
properties at temperatures from 75°F to 225°F. They are
widely used for latches, cams, gears, and many other moving parts due
to their excellent abrasion and impact resistance. Nylon is also available
in a variety of cast forms and mobdylidenum disulphide filled grades (Nylatron®
GS). PEEK®
- Polyetheretherketone is a new material which has excellent chemical
resistance and is rated for continuous service to 470°F. It is tough
and strong, with low creep, and has the best fire safety rating of all
thermoplastics. It tolerates radiation to 1100 M rads without undergoing
significant change. Applications include engine parts, aerospace components
and other uses which require PEEK®'s unique qualities. PFA
- Perfluoroalkoxy resins, which are marketed under the Teflon®
trademark, have properties similar to FEP and PTFE. However, unlike FEP,
PFA may be used to temperatures of approximately 500°F. While PFA
shares PTFE's chemical resistance and low coefficient of friction, it
is also a moldable, and extrudable material. Some applications include
packing and seals, cable sheathing, and fire-retardant insulation. PES®
- Crystal clear polyethersulfone has truly outstanding creep resistance,
dimensional stability, and excellent mechanical properties. It can withstand
continuous use in air and water at temperatures to above 350°F. It
has low flammability and minimal smoke emission during burning. Its weatherability
and solvent resistance are also good. Since PES is sterilizable, it has
a wide variety of medical applications. Other applications include electronic
components of all types, and structural parts. Phenolic
- Phenolic laminates show outstanding temperature resistance, dielectric
strength and electrical resistance, all of which remain uniform to 420°F
or above. Most grades also exhibit good mechanical properties, such as
impact strength, also outstanding dimensional stability under loading.
Phenolics have long enjoyed industry-wide acceptance as insulators, electrical
housings, circuit boards, electric motor components, seals, and valves. Polyethylene
(PE) Because of its flexibility at low temperatures, excellent
electrical resistance and low dielectric constant, Polyethylene is unique.
PE's self-lubricating properties also make it ideal for applications such
as rollers, skids and other end-uses which call for a non-stick, low-friction
material. PE is available in a wide range of densities and formulations. Polyproylene
(PP) This natural has good impact resistance and structural rigidity.
It is unaffected by any solvent at room temperatures. It has excellent
insulating properties and is extremely lightweight. Its high fatigue strength
makes it a top choice under cyclic loading conditions. Polystyrene
(PS) is naturally clear. It exhibits excellent chemical resistance
and is more resistant to irradiation than is PE or PP. Electrical resistance
is also good. This, plus the ease with which PS can be painted or shielded,
has led to extensive electrical and electronic applications. PS is also
often used in appliances and housings. Special high gloss and high impact
grades are also widely available. Polysulfone
(PSO) is a naturally transparent, true engineering plastic
whose electrical and mechanical properties are constant up to temperatures
above 320°F. It is also rated for continuous service in steam to
300°F. It shows excellent resistance to alkalies, acids and salts,
as well as to many hydrocarbons. PSO is suited for microwave use, and
may also be plated or glass-filled. Amongst its many varied uses are many
medial, automotive, and electronic applications. PVC
Polyvinylchloride exhibits little or no water absorption. Since it
is chlorinated, PVC also possesses natural flame retardant qualities.
PVCs are available in a wide variety of colors and varying compositions.
They are typically employed in packaging, water and chemical piping assemblies,
appliances, furniture and other components. Teflon®
(PTFE) An extremely low coefficient of friction makes Polytetrafluorethylene
the ideal choice where surface wear might otherwise be a problem. PTFE
also exhibits a useful service life from below 100°F, to temperatures
of over 500°F. Its resistance to solvents is also excellent throughout
a wide range of temperature. Its low dielectric constant and electrical
resistance also remain constant throughout this range. Tefzel®
(ETFE) Ethylene-tetrafluoroethylene copolymer is a high impact
material with properties similar to ECTFE. It is commonly used to manufacture
pumps, valves, computer housings, and other electrical components. Torlon®
(PAI) Polyamide-imide possesses a combination of great mechanical
strength, the ability to withstand radiation, usability from approximately
300°F to 500°F, and resistance to most chemicals at room
temperature. It is also flame retardant and gives off almost no smoke
when burned. It is available in unreinforced and reinforced grades and
is readily machinable. This combination of assets makes it a good metal
substitute for aerospace and electronic applications. It is commonly used
for bushings, seals, and distributors in engines and machinery. ULTEM®
- Unreinforced ULTEM® (polyetherimide) keeps its hardness,
and mechanical properties from 40°F, up to temperatures of
356°F. It is radiation-resistant, microwave transparent and is naturally
flame-retardant. Reinforced grades have even higher mechanical strength.
Because of its unequalled properties, ULTEM® is the ideal replacement
for steel and other metals. It also has a wide range of electronic and
medical applications. UHMW
While ultrahigh-molecular-weight polyethylene retains the inherent
qualities of low-density polyethylene, its increased toughness allows
it use is a wide variety of rugged applications. It is commonly employed
to provide rollers, cams, impellers and bumper guards. Because of its
high lubricity, it is also used to coat conveyer-belts, ramps and hoppers.
UHMW's imperviousness to attack by steam and chemicals, and its continued
good performance at low temperatures, has also enabled it to gain FDA
approval for a variety of applications within the food and drug industries. |