Polyurethane PU Elastomers

Polyurethane PU Elastomers
 
Polyurethanes can be broadly classified into foam and solid types. The main solid PU applications include PU coatings, PU adhesives, and PU elastomers. PU elastomers are highly advantageous due to their wide hardness range, excellent mechanical and elastic properties, high abrasion and chemical resistance, and high customizability. These characteristics make PU elastomers suitable for a variety of applications and processing methods such as casting, reaction injection molding (RIM), injection, extrusion, and film blowing.
 

Casting PU Elastomers

Casting PU elastomers are produced by low-pressure mixing and pouring a degassed reactive liquid polyurethane resin into a mold. This process can be performed using low-pressure casting or RIM machines. The production involves a chemical reaction and curing within the mold to form thermoset PU elastomers, which exhibit excellent abrasion resistance and decent resistance to oil, petrol, and many common non-polar solvents. Generally, only strong bases, acids, oxidizing agents, and a few strong polar solvents affect fully cured casting PU elastomers. Common products made from casting PU resin include press-on tires, printing rollers, industrial off-road tires, forklift tires, skateboard wheels, and various other elastomeric industrial PU parts.
 

Thermoplastic PU Elastomers

Thermoplastic PU (TPU) elastomers, supplied as pellets or granules, can be processed using conventional thermoplastic techniques such as injection, extrusion, calendaring, and film blowing molding. TPU granules melt with heat and solidify upon cooling in mold or water to form elastomeric finished products. TPU elastomers combine high elongation and tensile strength with excellent abrasion and environmental resistance, allowing for precise mass production. Depending on the formulation, TPU elastomers can also have outstanding resistance to fuels, oils, solvents, and chemicals. Applications of TPU elastomers include industrial hoses, pneumatic tubes, high-pressure hoses, machine transmission belts, films, high-wear-resistant engineering parts, shoe soles, and other footwear components.
 

PU and Rubber Elastomers Comparison Chart

Materials vs Properties	PU	NBR	EPDM	SBR	FPM	CR	IIR	NR	SIL
Tensile Strength	◎	○	△	○	△	○	△	◎	●
Elongation	◎	○	○	○	●	○	○	◎	◎
Resilience	◎	○	○	△	△	◎	●	◎	△
Tear Strength	◎	○	△	△	△	○	△	◎	●
Abrasion Resistance	◎	◎	○	◎	△	○	◎	◎	●
Impact Resistance	◎	○	○	◎	△	◎	○	◎	●
Weather Resistance	○	△	◎	△	◎	○	◎	△	◎
Flame Resistance	○	●	◎	△	◎	○	◎	●	◎
Heat Resistance	△	△	◎	△	◎	○	○	●	◎
Low-temperature Resistance	○	△	○	△	○	△	△	○	◎
Oil Resistance	○	○	●	●	◎	△	●	●	△
Water Resistance	△	○	◎	○	○	○	◎	◎	○

○ Very Good
△ OK
● Bad
 
Link to TPUCO products:
Casting Polyurethane Resin:
https://www.taiwanpu.com/en/product/Casting-CPU
Thermoplastic Polyurethane Elastomer Granules:
https://www.taiwanpu.com/en/product/TPU-Granule