POM DuPont Delrin 588P

POM DuPont Delrin® 588P

POM DuPont Delrin® 588P is a well‑balanced homopolymer‑acetal grade. It is famous for good stiffness and wear‑resistance, combined with outstanding impact‑resistance, favorable dimensional stability and chemical‑resistance。

Main Applications

Office‑automation equipment: mainly for OA‑device gears. Automotive industry: automotive components. Electrical & electronic: timer assemblies for washing‑machines and juicers. Consumer & others: toys, sports‑equipment, power‑tool accessories。

Physical‑Mechanical‑Thermal‑Electrical Properties

Property Category	Item	Test Standard	Typical Data	Unit
Physical Properties	Density	ASTM D‑792	1.42	g/cm³
	Water absorption	ASTM D‑570	0.36	%
	Molding shrinkage (flow direction)	ASTM D‑570	1.8‑2.1	%
Mechanical Properties	Tensile yield stress @23 ℃	ASTM D‑638	71	MPa
	Tensile yield stress @‑55 ℃	ASTM D‑638	109	MPa
	Tensile yield stress @70 ℃	ASTM D‑638	45	MPa
	Tensile yield stress @100 ℃	ASTM D‑638	28	MPa
	Tensile yield stress @122 ℃	ASTM D‑638	21	MPa
	Tensile breaking strain @23 ℃	ASTM D‑638	56	%
	Tensile breaking strain @‑55 ℃	ASTM D‑638	29	%
	Tensile breaking strain @70/100/122 ℃	ASTM D‑638	＞60	%
	Flexural strength @23 ℃	ASTM D‑790	105	MPa
	Flexural strength @‑55 ℃	ASTM D‑790	177	MPa
	Flexural strength @70 ℃	ASTM D‑790	54	MPa
	Flexural strength @100 ℃	ASTM D‑790	35	MPa
	Flexural strength @122 ℃	ASTM D‑790	25	MPa
	Flexural modulus @23 ℃	ASTM D‑790	3270	MPa
	Flexural modulus @‑55 ℃	ASTM D‑790	4330	MPa
	Flexural modulus @70 ℃	ASTM D‑790	1480	MPa
	Flexural modulus @100 ℃	ASTM D‑790	900	MPa
	Flexural modulus @122 ℃	ASTM D‑790	630	MPa
	Izod notched impact @23 ℃	ASTM D‑256	68‑75	J/m
	Izod un‑notched impact @23 ℃	ASTM D‑256	＞1500	J/m
	Compressive stress (1 % strain) @23 ℃	ASTM D‑695	28	MPa
	Compressive stress (10 % strain) @23 ℃	ASTM D‑695	105	MPa
	Shear strength @23 ℃	ASTM D‑732	64	MPa
	Rockwell hardness R‑Scale	ASTM D‑785	121	—
	Rockwell hardness M‑Scale	ASTM D‑785	87	—
Thermal Properties	HDT (0.46 MPa)	ASTM D‑648	168	℃
	HDT (1.82 MPa)	ASTM D‑648	125	℃
	Melting point	ASTM D‑2133	175	℃
	CLTE ‑40～29 ℃	ASTM D‑696	10.1	10⁻⁵ m/m·℃
	CLTE 29～60 ℃	ASTM D‑696	12.3	10⁻⁵ m/m·℃
	CLTE 60～104 ℃	ASTM D‑696	14.1	10⁻⁵ m/m·℃
	CLTE 104～150 ℃	ASTM D‑696	15.5	10⁻⁵ m/m·℃
Electrical Properties	Volume resistivity @23 ℃	ASTM D‑257	10¹⁵	Ω·m

Injection Molding Parameters

Process Stage	Parameter	Recommended Range	Unit	Remarks
Pre‑drying	Drying temperature	＞80	℃	Low moisture absorption (0.2‑0.5 %). Drying is recommended for wet raw material to stabilize production and surface quality.
	Drying time	＞2	h
Barrel temperature	Rear zone	150‑180	℃	Homopolymer‑POM has very narrow processing window (~10 ℃). Do NOT exceed 250 ℃, otherwise irritant formaldehyde gas will be generated by decomposition.
	Middle zone	170‑190	℃
	Front zone	180‑200	℃
	Nozzle temperature	Slightly lower than front‑zone temperature	℃	Prevent drooling.
	Melt temperature(POM‑H)	190‑230	℃	Typical range for homopolymer‑POM.
	Mold temperature	80‑105	℃	Higher mold temperature improves crystallization, dimensional stability, surface gloss and reduces sink marks.
Injection parameters	Injection pressure	700‑1200	bar	Adjust according to part geometry and wall‑thickness.
	Hold‑up pressure	—	—	Proper hold‑pressure is required to compensate high volumetric shrinkage (~17 %) and avoid sink marks.
	Injection speed	Medium‑to‑high	—
	Back pressure	As low as possible (max 200 bar)	bar	High back‑pressure causes thermal‑shear degradation.
Runner & gate	Gate type	Any type	—	For submarine gate: adopt short‑type. Hot‑tip runner is preferred for homopolymer POM.
Screw	Screw type	Mutant‑type screw	—	Mutant‑type screw is recommended.
Nozzle	Nozzle type	Straight‑through nozzle	—	Straight‑through nozzle preferred.
	Barrel residence time	As short as possible	min	Long residence inside barrel leads to degradation.
Shutdown procedure	Short‑term shutdown	Drop barrel temperature to 150	℃	Thoroughly purge barrel for long‑term shutdown.
	Barrel purging material	PE / PP	—	Turn off heating, move screw forward. Keep barrel & screw clean. After halogen‑containing / acidic polymers, purge fully with PE before POM processing to avoid violent chemical reaction.
Post‑treatment	Annealing (if required)	—	—	Thermal stress‑relief annealing is needed for high‑quality parts working under non‑ambient conditions.

Note: All data above is for reference only！