Shanghai Daoqin Plastics Co., Ltd.

POM crystallization property plastics, melting point obvious, 一旦达 to melting point, melt viscosity speed decline. temperature degree ultra- 一定限 degree or melt hot time long, 会引起 separation understanding. in injection molding process in, has below/following attention/notes key points:

1, drying 处理

POM吸 water property small, generally is 0.2%-0.5%. in usually lower, POM不需 drying can processing, for wet raw materials must drying. drying temperature degree 80℃ above, time 2 small above, specific supply material 进行.

2, use material

recycled material use ratio/proportion generally ultra- 20-30%. need product types type and most applications 而定, has can 达100%.

3, machine selection

POM is crystallization material, most good use crystallization material screw or nylon PA screw, 但POM processing scope/range wide 泛, use generally injection molding machine can.

4, mold and gate design

Common mold temperature degree control is 80-90℃, runner has 3-6mm, gate long degree is 0.5mm, gate large small need 视胶壁 thick degree 而定, gate 直径至 less products thick degree 0.5-0.6倍, long gate wide degree usually is thick degree 2倍 or above, deep degree is thick 0.6倍, demolding degree 40′-1°30′ between.

排 gas system
POM-H thick degree 0.01-0.02mm wide 3mm
POM-K thick degree 0.04mm wide 3mm

5, temperature degree
POM-H can is 215℃ (190℃-230℃)
POM-K can is 205℃ (190℃-210℃)

6, injection speed degree
Common is in speed fast, slow easy generate 波纹, fast easy generate and hot.

7, back pressure
越 low good, generally ultra- 200bar

8, time
如 equipment has 熔胶滞留点, 则POM-H can in 215℃滞留35 separation 钟;POM-K can in 205℃滞留20 separation 钟不会 has heavy separation understanding.
in injection molding temperature degree lower melt can in machine inner ultra- 20 separation 钟. POM-K in 240℃ lower can 滞留7 separation 钟. if machine, machine temperature degree can drop to 150℃, need long machine must machine 筒子, add hot device.

9, machine
清理 machine must use PE or PP, electrical hot, screw in front 位. material and screw must maintain 清洁. or 污垢会改变POM heat stabilized property (especially is POM-H). therefore use 完含卤 polymer or its it acid property polymer rear, application PE清理 dry rear can 打POM material. function 不当 颜 material, lubricant or 含GF nylon material material, 会导致 plastics drop 质.

10, rear 处理
for/regarding non normal temperature use made parts quality requirements relatively high, must hot 处理. 退火处理效果, can will products concentrated degree is 30% salt acid solvent liquid in 浸30 separation 钟检查, rear use 肉眼观察判断 is has residual stress cracks generate.

11, other
copper is POM degradation catalytic agent, and POM melt 接触 部位应避免 use copper or copper material.