How to solve the surface defects when processing products

Generally, in mold processing, if we need to use injection molding equipment to process the product surface, there will be large and small defects. Generally, these defects will appear in the gate position, which belongs to the starting position of mold processing, so these two positions are prone to problems, so we need to find ways to eliminate these defects, so that the display effect will be improved.

Dark spot defects and subtle defects will appear near the gate, which is the feeling when producing products with high viscosity and low fluidity materials, such as PC, PMMA, or especially ABS. When the resin flows away from the center of the surface layer of the cooled resin, the visible surface of such defects of the product may occur.

People often identify the existence of such technical defects, which occur frequently in the mold filling and pressure holding stage. In fact, dark spots appear near the gate, usually at the beginning and development stage of the injection time cycle. The experimental research shows that the problem of surface slip is actually due to the injection speed, more specifically, the flow velocity at the front end of the melt flow.

Even if the injection speed is constant when the melt enters the mold, its flow speed will change. When entering the mold gate area, the melt speed is very high, but after entering the mold cavity, the melt speed begins to decrease. This change in the flow velocity at the front end of the melt flow will lead to surface defects.

One way to solve this problem is to reduce the injection speed. In order to reduce the speed of the melt flow front at the gate, the injection can be divided into several stages and the injection speed can be gradually increased.

Another reason is that the low melting temperature of the product is the dark point. Increasing the barrel temperature can reduce the back pressure of the screw to improve the possibility of this phenomenon. In addition, the mold temperature is too low to produce surface defects, and the mold temperature is a feasible option to overcome the surface defects of the product.



About Huizhou Dj Molding Co., Ltd

Dj Mold 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: Huizhou Dj Molding 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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