GENERAL DESCRIPTIONPolyethylenes are semi-crystalline materials with excellent chemical resistance, good fatigue and wear resistance, and a wide range of properties (due to differences in length of the polymer chain.) Polyethylenes are easy to distinguish from other plastics because they float in water.
GENERAL PROPERTIES OF POLYETHYLENESPolyethylenes provide good resistance to organic solvents, degreasing agents and electrolytic attack. They have a higher impact strength, but lower working temperatures and tensile strengths than polypropylene. They are light in weight, resistant to staining, and have low moisture absorption rates.
POLYETHYLENE GRADESLow Density Polyethylene (LDPE)
This extruded material offers good corrosion resistance and low moisture permeability. It can be used in applications where corrosion resistance is important, but stiffness, high temperatures, and structural strength are not. A highly flexible product, LDPE is used widely in orthopaedic products, or where mobility without stress fatigue is desired. LDPE is also frequently used in comsumer packaging, bags, bottles, and liners.
High Density Polyethylene (HDPE)
Representing the largest portion of the polyethylene applications, HDPE offers excellent impact resistance, light weight, low moisture absorption, and high tensile strength. HDPE is also non-toxic and non-staining and meets FDA and USDA certification for food processing.
Ultra High Molecular Weight Polyethylene (UHMW PE)
Light weight (1/8 the weight of mild steel), high in tensile strength, and as simple to machine as wood, UHMW PE is the ideal material for many wear parts in machinery and equipment as well as a superb lining in material handling systems and storage containers. UHMW PE is self-lubricating, shatter resistant, long-wearing, abrasion and corrosion resistant. It meets FDA and USDA acceptance for food and pharmaceutical equipment and is a good performer in applications up to 180 °F (82 °C) or when periodically cleaned with live steam or boiling water to sterilize.
( see also Tivar® 1000 AntiStatic UHMW Specifications )
( see also QuickSilver® Liners )
TYPICAL PROPERTIES of POLYETHYLENE
|ASTM or UL test||Property||LDPE||HDPE||UHMW|
|D570||Water Absorption, 24 hrs (%)||<0.01||<0.01||<0.01|
|D638||Tensile Strength (psi) at 72°F||1,400||4,600||5,800|
|D638||Tensile Strength (psi) at 150°F||400||400||400|
|D638||Tensile Modulus (psi)||57,000||200,000||80,000|
|D638||Tensile Elongation at Break (%)||100||400||300|
|D790||Flexural Strength at Yield (psi)||1,500||4,600||3,500|
|D790||Flexural Modulus (psi)||29,000||174,000||88,000|
|D695||Compressive Strength (psi)||1,400||4,600||3,000|
|D695||Compressive Modulus (psi)||54,000||100,000||80,000|
|D732||Shear Strength (psi)||-||-||3,000|
|D785||Hardness, Shore D||D45||D69||D62-D66|
|D256||IZOD Notched Impact (ft-lb/in)||No Break||1.3||No Break|
|D696||Coefficient of Linear Thermal Expansion
(x 10-5 in./in./°F)
|D648||Heat Deflection Temp (°F / °C)
at 66 psi
at 264 psi
120 / 48
116 / 46
170 / 76
176 / 80
203 / 95
180 / 82
|D3418||Approx. Melting Temperature (°F / °C)||244 / 118||260 / 125||275 / 136|
|-||Max Operating Temp (°F / °C)||160 / 71||180 / 82||180 / 82|
(x 10-4 cal/cm-sec-°C)
|D149||Dielectric Strength (V/mil) short time, 1/8" thick||460-700||450-500||2300|
|D150||Dielectric Constant at 1 MHz||2.25-2.30||2.30-2.35||2.30-2.35|
|D150||Dissipation Factor at 1 kHz||0.0002||0.0002||0.0005|
|D257||Surface Resistivity (ohm/square) at 50% RH||> 1015||> 1015||> 1015|
|D495||Arc Resistance (sec)||135-160||200-250||250-350|
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.