The reason bubble caused in plastic product of injection molding

How should plastic product appear bubble to do? Our engineer’s answer is that the reason may in the equipment, plastic mold, and may also in the injection process, the following is the reason analysis of the process, hope to help you solve the problem.

  1. The back pressure of screw pre-molding is too low and the rotation speed is too high, which causes the screw to return too fast, and the air is easily pushed to the front end of the cylinder with the material.
  1. Use multi-stage injection to reduce silver streak: fill the runner at medium speed — fill the gate at slow speed — fill the mold at fast speed — fill the mold at low pressure and slow speed, so that the gas in the mold can be eliminated in each stage in time.
  1. Insufficient material, too large feeding cushion, too low material temperature or too low mold temperature will affect the flow of molten material and molding pressure, resulting in bubbles.
  1. The injection speed is too fast, so that the molten plastic is decomposed by large shear action, producing decomposition gas; The injection speed is too slow to fill the cavity in time, resulting in the product surface density is not enough to produce silver streak.
  1. The injection pressure is small and the pressure holding time is short, so that the molten material and the cavity surface are not closely attached.
  1. Too high material temperature, resulting in decomposition. Barrel temperature is too high or heating imbalance, should gradually reduce the barrel temperature. The temperature of feeding section is too high, so that part of plastic premature melting is full of spiral groove, air cannot be discharged from the feeding mouth.

In addition to the above 6 injection molding process reasons, about the plastic mold and equipment factors, but these two aspects uncontrollable reasons are many. Welcome to discuss more with Jasonmould.

About JasonMould Industrial Company Limited

Jasonmould is a China mold maker of plastic molds- injection mold, die casting moulds, plastic blow molding, rotational molding, medical plastic injection molding, two shot plastic injection molding, insert molding, overmolding, metal injection molding, micro injection molding, powder injection molding, ceramic injection molding, liquid injection molding, husky injection molding, household mold, casting mold, die mold tool, custom molds, china moulds, rapid prototyping tooling, plastic prototyping tooling, punch press tooling, die and tooling for mobile/ cell phone parts, automotive parts, vacuum cleaners, rechargeable tools, telephones, copiers, computers, multimedia speakers, and many other electronic products and household appliances. And also a plastic product manufacturer, mold manufacturer China– plastic parts, plastic water tank, plastic balls, plastic containers, plastic buckle, plastic anchor, plastic hanger, plastic spoon, plastic pipe fitting, plastic tumble, plastic tableware, plastic cups, plastic bottles, plastic tray, plastic cosmetic container, plastic case, plastic food container, plastic chairs, plastic caps, plastic cap closure, plastic tubes, plastic water pipes, plastic knobs, plastic tubing, plastic utility boxes, plastic racks and so on.

Person: James Yuan
Company: JasonMould Industrial Company Limited
Add:  LongGang Village,LongXi Town,BoLuo County,HuiZhou City,GuangDong Province, China
Tel: 86-752-6682869
Email: [email protected]