Ejector mark is the phenomenon of stress whitening and stress elevation where appears on the opposite side of the nozzle facing the product, or where the ejector rod is located on the ejecting side of the tool. Why will it cause the ejector marks? The physical reason is when the demoulding force is too high or the surface of the ejector rod is relatively small, the surface pressure will be very hi...

Snake mark is an indication when injection molding. So what will cause the snake mark? When injecting a plastic part, the Gate is smaller, while the space of the mold cavity is relatively larger. At this time, the temperature of resin is cooling down before it fullly injects into the whole mould cavity frame. Therefore, it will have a flowing marks remaining on the part surface like a snake crawli...

The ultimate purpose of well controlled the processing procedure of injection mold is to produce high quality injection parts. To reach this goal, what should we pay attention?  1. The defect of product surface not allowed: short shot, burn mark, ejector marks, white lines, flash, bubbles, pulling lines (pull cracks/snap), wrinkle etc. 2. Welding lines: generally speaking, for circle punch, t...

Welding Line is refers to the slim line disappear in which the plastic raw material melting and collecting. Why it happens? 1. Insufficient liquidity of melting raw materials 2. Have air or volatile component 3. Release agent or colorant 4. Defect of mold design How to improve? 1. Change raw material to better liquidlity 2. Check and improve the air venting, decrease the injection speed 3. Use les...

How much do you know about the shrinkage of common plastic raw materials? Different plastic materials have different shrinkages. Today we will talk about the most commonly used material shrinkage. ABS : 0.5% PC: 0.5% PMMA: 0.5% PS: 0.5% PC+ABS: 0.5% PE  : 2% PP : 2% PA: 2% PVC : 2% POM : 2% When we make plastic mold, we should consider the plastic material shrinkage, otherwise the product wil...

Highlights are typical of non-mark injection molding highlights, but not all of the non-mark injection. We have been making high-light molds for several years, mainly for the external decorative parts of home appliance products, such as front panels, decorative pieces, etc., but every time we have encountered the same problem, that is, we cannot solve the fusion mark, shrinkage mark and other...