POM DuPont Delrin 511P

POM DuPont Delrin® 511P

POM DuPont Delrin® 511P is a well‑balanced medium‑viscosity, standard‑flow homopolymer‑acetal grade. It delivers good dimensional stability, excellent chemical‑resistance, broad service‑temperature range, outstanding wear‑resistance and comprehensive mechanical properties。

Main Applications

Automotive: handle‑parts, power‑window components, gears, bearings, auto‑parts, machine‑tool and instrument inner skeleton‑parts. Electrical & electronic: gears, bearings and structural components for home‑appliances such as washing‑machine / juicer parts, timer assemblies and keyboards. Precision‑machinery & industrial components: high‑precision, wear‑resistant, low‑friction mechanical structural parts including gears, bearings, cams, screws and pulleys. Consumer & others: daily‑use articles such as toys and sports‑equipment。

Physical‑Mechanical‑Thermal Properties

Property Category	Item	Test Standard	Typical Data	Unit
Physical Properties	MFR (190 ℃ / 2.16 kg)	ASTM D‑1238	7.0	g/10min
Mechanical Properties	Tensile yield strength	ASTM D‑638	72	MPa
	Elongation at break	ASTM D‑638	33	%
	Yield elongation	ASTM D‑638	11	%
	Tensile modulus	ASTM D‑638	3380	MPa
	Flexural modulus	ASTM D‑790	3300	MPa
	Flexural strength	ASTM D‑790	105	MPa
	Un‑notched Izod impact	ASTM D‑256	73	J/m
	Notched Izod impact	ASTM D‑4812	NB(No Break)	J/m
Thermal Properties	HDT (0.45 MPa)	ASTM D‑648	169	℃
	HDT (1.8 MPa)	ASTM D‑648	114	℃
	Melting point	ASTM D‑3418	178	℃
	CLTE (flow direction)	ASTM E‑831	1.11E‑4	/K
	CLTE (transverse)	ASTM E‑831	1.17E‑4	/K

Injection Molding Parameters

Process Stage	Parameter	Recommended Range	Unit	Remarks
Pre‑drying	Drying requirement	Normally not required	—	Low moisture absorption(0.22‑0.25 %). Pre‑heat around 80 ℃ benefits dimensional stability.
Barrel temperature	Rear zone	150‑180	℃	Homopolymer‑POM narrow processing window; do not exceed 220 ℃, otherwise irritant formaldehyde gas will be generated by decomposition.
	Middle zone	170‑190	℃
	Front zone	180‑200	℃
	Nozzle temperature	170‑190	℃	Slightly lower than front‑zone temperature to prevent drooling.
	Melt temperature	190‑210	℃
	Mold temperature	80‑100	℃	Higher mold temperature improves crystallization, dimensional stability, gloss and reduces sink marks.
Injection parameters	Injection pressure	80‑130	MPa	Higher(120‑150 MPa) for thin‑wall parts; lower(80‑120 MPa) for thick‑wall parts.
	Hold‑up pressure	Close to injection pressure	MPa	Sufficient hold‑pressure to reduce pressure drop and sink marks.
	Back pressure	0.5‑2.0	MPa	High back‑pressure causes thermal‑shear degradation.
	Injection speed	Medium	—	Strategy: medium pressure, medium speed, low melt temperature, high mold temperature. Slow speed causes flow marks; excessive speed causes jetting & shear degradation.
	Screw speed	30‑80	rpm	Avoid high rotational speed; keep small cushion to prevent thermal degradation.
	Barrel residence time	As short as possible (＜20)	min	Residence time shall not exceed 20 min at processing temperature.
Shutdown procedure	Short‑term shutdown	Drop barrel temperature to 150	℃	Thoroughly purge barrel for long‑term shutdown.

Note: All data above is for reference only！