Analysis of possible factors of discoloration of black spots on injection molded parts

1. Machine

As the heating control system is out of control, the barrel is overheated and decomposed into black

Due to the defects of screw or barrel, the molten materials are stuck in and accumulated, and the decomposition is caused by long-time fixed heating. Check whether the rubber head kit is worn or whether there are metal foreign matters in it

Some plastics, such as ABS, are cross-linked and coked by high heat in the barrel. They are difficult to melt under the condition of almost maintaining the original particle shape, and are crushed by screw and then entrained into the parts

2. Mould

Mold exhaust is not smooth, easy to scorch, or the size of the gating system is too small, shear too much, resulting in coking

There are improper oil lubricants and release agents in the mold

3. Plastics

Too much volatile matter, too much humidity, too much impurity, too much recycled material, and polluted

4. Processing

If the pressure is too high, the speed is too high, the back pressure is too high and the speed is too fast, the material temperature will decompose.

The barrel should be cleaned regularly to remove additives that are less resistant than the plastic.



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]


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