Common Defects&Solutions On Injection Product

As we known, there will be some defects on plastic product which produced by injection mold and injection machine. Here we will talk about some common defects and their solutions.

1. Not filled 

Analysis & Solutions: 

*the injection is not suitablt for the mold, the plasticizing capacity or injection volume is not good, so changing another injection machine; 

*the temperature is not high enough to melt the raw material, or speed for material flow is slow, so adding number of gating and locating reasonably with enough size;

*the cold slug well is not big enough to avoid the flow of material, so adding the cold slug well

2. Flash

Analysis & Solutions: 

*for clamping force, if not enough, there is gap between insert and joint face, so the material will flow to this gap, so adjusting the clamping force to appropriate data;

*the wear of guide bush or pull rod is curve because of insufficient intensity, which lead to the excursion of joint face, so need to solve these problems

*the temperature or backpressure is too high, so adjusting these parameter

3. Void or bubble

Analysis & Solutions: 

*void is caused by volume contraction in cooling process, bubble is a hole which caused because there is air, water or volatile gas in material, and left on product when injection 

*adding the gate number or increasing the size to have more pressure; sometimes also can adjust the location of gate if needed

*adding the pressure, extend the time of hold pressure, and decreasing the speed of material speed to make product fully compressed before solidification

*before producing, better to dry the material to remove the water

4. Sliver

Analysis & Solutions: 

*there is water or volatile in material, so drying the material adequately

*the temperature of mold is not high enough which lead to exhaust incompletely, so adjusting the mold temperature

*there is oil or water or mold release agent on mold surface, these will evaporate to gas and attach to the product, so cleaning the mold before producing or once during several hours

*the ejection pressure is too high or ejection speed is too fast, can't let gas or water remove overall, so adjusting the ejection parameter

5. Burn mark

Analysis & Solutions: 

*because of air trapping, the material is burned by high temperature and pressure, so increasing the air venting in the part

*decreasing the injection pressure, but pay attention to that if lower the pressurem the injection speed will be slow which will lead to weld mark, so need to check the parameter several times to find a suitable data

6. Weld mark

Analysis & Solutions: 

*the wall thickness is uneven, revise the design

*adding the material overflow well, and move the fusion line to the well part, which can be cut after producing

*adding the air venting in the part which appear the weld mark 

*revise the location or size of gate

*adjusting the mold temperature, pressure and injection speed

Except these defects, there will happen other problems when producing, if you need our help to solve it, you can contact Shine to get the solutions.

Posted by Shine

Email: [email protected]

Phone: +86 157 5766 8880

Http://www.chinaplasmould.com

Taizhou Huangyan Aoxu Mould Technology Co., Ltd