POM YANKUANG LUHUA M90 (30‑A)

POM Yankuang Luhua M90 (30‑A) is a well‑balanced copolymer‑acetal (POM‑C) engineering plastic. It is especially suitable for applications requiring good stiffness, wear‑resistance, dimensional stability and chemical‑resistance。

Main Applications

Automotive: gears, bearings, fuel‑system components, interior & exterior door handles, window transmission mechanisms. Electrical & electronic: washing‑machine and juicer components, timer assemblies, keyboards and switch parts. Precision machinery & industrial components: gears, bearings, cams, screws, levers, pulleys, sprockets and engineering fittings. Consumer & others: zippers, lighters, buckles, toys, sports‑equipment and other daily‑use articles。

Physical Properties

Property Category	Item	Test Standard	Typical Data Range	Unit
Physical Properties	Density	ISO 1183	1.41	g/cm³
	MFR (190℃ / 2.16 kg)	ISO 1133	9.0 ± 1.0	g/10min
	Water absorption (24 h)	ISO 62	0.2‑0.5	%
Mechanical Properties	Tensile yield strength	ISO 527‑2	58‑66	MPa
	Elongation at break	ISO 527‑2	30‑60	%
	Flexural strength	ISO 178	60‑88	MPa
	Flexural modulus	ISO 178	2400‑2800	MPa
	Charpy notched impact strength (23℃)	ISO 179/1eA	3.5‑7.0	kJ/m²
	Rockwell hardness (M‑Scale)	ISO 2039‑2	~80	—
Thermal Properties	HDT (1.8 MPa)	ISO 75‑2/A	90‑110	℃
Flammability	UL94 rating (1.5 mm)	UL 94	HB	—

Injection Molding Parameters

Process Stage	Parameter	Recommended Range	Unit	Remarks
Pre‑drying	Drying temperature	80‑90	℃	Drying is recommended for damp raw materials or high‑precision parts to avoid bubbles or silver streaks, despite low moisture absorption.
	Drying time	2‑4	h
Barrel temperature	Rear zone	150‑170	℃	Do not exceed 230 ℃, otherwise formaldehyde gas will be generated by decomposition. Avoid copper contact, since copper catalyzes POM degradation.
	Middle zone	170‑190	℃
	Front zone	180‑200	℃
	Nozzle temperature	180‑200	℃	Slightly lower than or close to front‑zone temperature.
	Melt temperature (POM‑K)	190‑210	℃
	Mold temperature	80‑90	℃	Higher mold temperature improves crystallization, dimensional stability and surface gloss.
Injection parameters	Injection pressure	80‑130	MPa	Adjust according to part geometry and wall thickness.
	Hold‑up pressure	40‑80 (or 50%‑80% of injection pressure)	MPa	Proper hold‑pressure reduces shrinkage and sink marks.
	Back pressure	0.5‑2.0	MPa	Keep as low as possible; excessive back‑pressure causes thermal‑shear degradation.
	Injection speed	Medium	—	Slow speed causes flow marks; excessive speed induces jetting and shear degradation.
	Screw speed	50‑100	rpm	Avoid high rotational speed to prevent excessive shear heat and material degradation.
	Barrel residence time	As short as possible (<20‑30)	min	Prevent degradation; approx. 20 min allowable residence at 205 ℃ for POM‑K.
Shutdown procedure	Short‑term shutdown	Drop barrel temperature to 150	℃	Thoroughly purge barrel for long‑term shutdown.
	Barrel purging material	PE / PP	—	Do NOT use PVC or halogen‑containing materials for purging to prevent violent reaction. Turn off heating.
Post‑treatment	Annealing (if required)	80‑100 ℃, 2‑4 h	—	Relieve internal stress and improve dimensional stability for high‑precision or non‑ambient‑service parts.

Note: All data above is for reference only！