TPU Covestro 285

TPU Covestro 285 is thermoplastic polyurethane elastomer featuring good transparency, excellent mechanical performance, outstanding abrasion‑resistance and favorable chemical resistance.

Main Applications

Transmission belts, seals, joints, hoses, cable connectors, casters, films and extruded profiles.

Physical Properties

Property Category	Item	Test Condition	Test Standard	Typical Reference Data	Unit
Physical Properties	Density	—	ISO 1183	1.20	g/cm³
Mechanical Properties	Shore Hardness	—	ISO 868	85	Shore A
	Ultimate tensile strength	—	ISO 37	34.5	MPa
	Elongation at break	—	ISO 37	500	%
	Stress at 300% strain	—	ISO 37	11.7	MPa
	Tear propagation strength(Die‑C)	Die "C"	ISO 34	87.6	kN/m
	Flexural modulus	23℃	ISO 178	27.6	MPa
	Compression set	23℃,22h	ISO 815	16	%
	Compression set	70℃,22h	ISO 815	65	%
	Abrasion loss(H‑18,1kg,1000cycles)	1000 cycles	ISO 4649	35	mg
Thermal Properties	Vicat softening point(Rate A)	Rate A	ISO 306	91	℃
	Glass transition temperature	DMA	DMA	‑42	℃
	Low‑temperature brittleness point	—	ISO 974	＜‑68	℃

Processing Parameters

Process	Parameter	Unit	Reference Range	Remarks
Pre‑drying	Drying temperature	℃	80‑110	Circulating hot‑air drying recommended; TPU is moisture‑sensitive, drying is mandatory
	Drying time	h	≥3	Until moisture＜0.05%
	Material bed thickness	mm	≤30	Guarantee drying efficiency
Injection molding	Rear feed zone temp	℃	150‑175	Slightly lower than compression zone; avoid premature plasticization
	Middle compression zone temp	℃	175‑195	Adjust on‑site according to actual condition
	Front metering zone temp	℃	195‑215	Adjust on‑site according to actual condition
	Nozzle temperature	℃	Equal‑to‑slightly lower than front zone	Prevent drooling or cold‑plug blockage
	Melt temperature	℃	190‑210	Strictly prohibit＞240℃ to avoid degradation; prohibit long‑term melt residence
	Mold temperature	℃	20‑40	Lower mold temp shortens cycle time & reduces sticking
	Injection pressure	bar	50‑100	Keep as low as possible while full filling
	Hold‑pressure	bar	30%‑60% of injection pressure	Excessive hold‑pressure & long hold‑time shall be avoided to reduce internal stress
	Screw speed	rpm	50‑100	High speed causes shear overheating
	Back pressure	bar	5‑15	Improve melt homogeneity; excessive back‑pressure generates extra heat

Note: All information above is for reference only!