Polyurethane is a unique material that offers the elasticity of rubber combined with
the toughness and durability of metal. Because urethane is available in a very broad
hardness range (eraser-soft to bowling-ball-hard), it can replace rubber, plastic or
metal while providing improved abrasion resistance and physical properties.
Urethanes have better abrasion and tear resistance than rubbers, while offering higher
load bearing capacity. When compared to plastics, urethanes offer superior impact
resistance, while offering excellent wear properties and elastic memory.
Urethanes have replaced metals in sleeve bearings, wear plates, sprockets, rollers and
various other parts, with benefits such as weight reduction, noise abatement and
improved wear resistance.
ADVANTAGES
• Abrasion resistance
Polyurethanes often outwear other materials (rubber, plastics and metal) by many times
in many applications when severe abrasion is a factor.
• Oil and solvent resistance
Polyurethane has excellent resistance to oils, solvents, fats, greases and gasoline.
• Load bearing capacity
Polyurethane has a higher load-bearing capacity than any conventional rubber. Because
of this characteristic, it is an ideal material for load wheels, heavy duty couplings,
metal-forming pads, shock pads, expansion joints and machine mounts.
• Tear resistance
The tear-strengths of various Polyurethanes range from 100 to 1000 lbs./linear inch,
which is far superior to rubbers. As a result, urethane is often used as drive belts,
diaphragms, roll covers, cutting pads, gaskets and chute liners.
• Weather resistance
Polyurethane has outstanding resistance to oxygen, ozone, sunlight and general weather
conditions.
• Noise abatement/reduction
Hard urethanes are now being used as gears in products where sound reduction is desired.
The soft urethanes are used to replace rubbers for improved sound/vibration dampening.
• Flex-Life
Most formulations offer extremely high flex-life and can be expected to outlast other
elastomer materials where this feature is an important requirement. Dust boots, bellows,
diaphragms, belts, couplings and similar products are made from urethane for this reason.
• Electrical properties
Polyurethane has excellent electrical insulating properties and is used successfully in
many molded wire and cable harness assemblies.
• Heat and cold resistance
Continuous use above 225°F is not recommended nor is urethane recommended in hot water
over 175°F. At low temperatures, polyurethane will remain flexible down to -90°F. A
gradual stiffening will occur at 0°F, but will not become pronounced until much lower
temperatures are reached.
PRECISION-CAST SHEETS
Cast sheets are ideal for fabrication into a wide variety of products. Standard sheets are
available in 12" square up to 48" square sheets in the following thicknesses: 1/32", 1/16",
3/32", 1/8", 5/32", 3/16", 1/4", 5/16", 3/8", 1/2", 5/8", 3/4", 1", 1-1/4", 1-1/2", 1-3/4"
and 2". Other sizes and thicknesses are available upon special order. Tolerances are:
1/32 to 3/16, +.010"; 1/4 to 3/8", +/-.015"; 1/2 to 1-1/4", +/-.025"; 1-1/2" and over, +/-3%.
FABRIC-BACKED SHEETS
Standard sheets are available integrally cast onto duck cloth (.048" thick), permitting
easy cementing to metal or other surfaces. This composite converts effectively to large
roll coverings or chute and bin liners. Bond strength between the fabric and the urethane
is excellent, and there is no strikethrough to the exposed side of the fabric. Sheet is
stocked in 3/16", 1/4", 5/16", 3/8", 7/16", and 9/16" overall thicknesses up to 48" square.
Custom sizes and thicknesses are available upon special order.
BARS
Bar stock is popular for metal forming uses. The precise size eliminates the need for a
matched female die. The material becomes the contact surface in forming, bending or
shaping metal without scratching or marring the finished product. Bar stock is also used
as press-brake pads, bumper pads, and wear strips, and is machined into a great variety
of prototype parts. Standard sizes are available 48" long and in thicknesses of 1" square,
2" square and 2" x 3". Custom sizes are available.
RODS
Cast rods are used for guide, drive and pinch rollers and outwear conventional rubber
rollers 20 to 1. They are excellent for bulge forming. Rod stock is used for prototype
parts like gears, bearings and bushing, and is easily machined to close tolerances.
Standard rods are 36" long and are available in diameters of 1/4", 3/8". 1/2", 5/8",
3/4", 7/8", 1", 1-1/4", 1-1/2", 1-3/4", 2", 2-1/4", 2-1/2", 2-3/4", 3", 3-1/4", 3-1/2",
3-3/4", 4", 4-1/4", 4-1/2",4-3/4", 5", 5-1/2" and 6". Custom sizes are available upon request.
TUBES
Cast tube stock makes excellent roll covers when press fitted over metal cores. They
are also converted into gaskets, seals and rings. Tubes are well suited for prototype parts.
Standard cast tubes are 36" long and are supplied in several diameters (custom sizes are
available upon request): Inside Diameter 1", 1-1/4", 1-1/2", 1-3/4", 2", 2-1/4", 2-1/2", 3"
Outside Diameter 2" 2-1/4" 2-1/2", 2-3/4", 3", 3-1/4", 3-1/2", 3-3/4", 4"
TYPICAL PROPERTIES of POLYURETHANES
NOTE: The information contained herein are typical values intended for
reference and comparison purposes only. They should NOT be used as a basis
for design specifications or quality control. Contact us for manufacturers'
complete material property datasheets.
All values at 73°F (23°C) unless otherwise noted.
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Copyright Boedeker Plastics, Inc.