Shanghai Daoqin Plastics Co., Ltd.

PVC material is 价廉, and tool anti property 质, but also strong/high hard solid, resistant chemical can force 佳, shrinkage rate is 0.2-0.6%, product in electrical appliances, machine 械, construction, day use product, toys, packaging upper application day 益广泛, for PVC material features, analysis product injection molding process lower:

一, PVC material features

PVC hot property defect, molding temperature degree and separation understanding temperature degree 接近, flow property 不佳, appearance easy formed defect defect, PVC material heat resistant property 不佳, most easy 烧焦, generate acid property gas 体进而腐蚀 mold, processing can add agent increase its flow property, generally must add additives use, its strong/high degree, electrical appliances insulation property, resistant product property 佳.

二, mold and gate design

is shrink short injection molding cycle, 注口越 short good, 横切面 need 园形, 射咀口 直径 most small is 6 mm, formed 园锥形, inner formed 5 degree, most good need add cold material 井, cold material can anti 止熔化 defect semi solid material material mold cavity, and other material material effect/influence to surface and product strong/high degree.
拔模斜 degree need in 0.50至10 between, ensure mold cavity inner has 足够 排 gas equipment, commonly used gas dimensions is 0.03- 0.05mm deep, 6mm wide, or 者每枚顶针周边间隙 is 0.03-0.05mm. mold application 不锈钢 manufacturing or hard 铬.

三, PVC molding process

PVC is hot property plastics, hot or degree 会引致 separation understanding, speed 蔓延, is its in types separation understanding material (例如 acid or HCI)会 generate catalytic function, process/workflow 进一步 separation understanding, acid property material more 会侵蚀 metal, make formed 凹陷, also make metal 保护层剥落, 引致生锈, for/regarding more add has 害.

1.  screw material: screw material in 2～3mm between, large type machine more large 一.

2.  injection amount: 实际筒滞留 time can ultra- 3 separation 钟.

3.  machine temperature degree 设置: provide temperature degree can as is 参考, according to machine, raw materials 实际情况 as adjustment, has can can ultra- 出 recommendation scope/range.

4.  machine 筒滞留 time: in 2000C temperature lower (胶 material) machine 筒滞留 time most more large can ultra- 5 separation 钟

5.  injection speed degree: injection speed degree need slow, 否则 份剪切会 make material material degradation, utilizing UPVC production degree light slip thick products 时, using/adopting more grade injection speed degree, if has shallow color strip/profile from gate injection shot, table/sheet material speed degree fast.

6.  back pressure: commonly used surface value is 5bar, increase back pressure has mixed color and gas, back pressure low good.

7. 停 machine: due to PVC heat stabilized property low, machine 部骤十 separation important, need machine 筒清洁 dry 净, semi 点PVC, can use its it heat stabilized property high also resistant 拒PVC thermoplastic property plastics, (例如PMMA, PP, LDPE, or GPPS), 切忌于同一 machine inner mixed combined POMT UPVC, 否则会引致 strong/high chemical reaction, for machine formed heavy loss bad.

8.  mixed material ratio/proportion: water material most more mixed material ratio/proportion is 20%, 否则会 effect/influence products quality.

9. 典 type products: UPVC main/primary applications is manufacturing water pipeline, or is electrical and electrical machine outer housing/shell, water pressure 槽, machine outer housing/shell, electrical table/sheet and gas outer housing/shell, printing machine transparent 罩, 通风格 and various electronics parts and other.