Common problems and Solutions in PC/ABS Producing (1)

Common problems and Solutions

1 Silver mark

Silver mark is the most common problem of ABS material. It is the white filiform stripe phenomenon appearing along the flow direction on the product surface. The main reason is the gas interference, which may be three components:

  (1) Air: involved in the melting and ejection phase;

  (2) Moisture: The moisture content of the material itself;

  (3) Pyrolysis gas: High temperature hydrolysis or thermal decomposition of gases.

Solution: First check whether the material is dry enough, after the confirmation, by adjusting the injection molding process to improve the silver defect. At the same time, the silver mark in injection also related to mold exhaust.

 

 

2 Flow Mark

The flow mark is produced during injection, because of the bad fluidity of material. Different from the silver mark, flow mark is not caused by water or material decomposition, and the appearance is not the same.

Solution: By improving the temperature of the material to improve its liquidity. Changing the mold or slowing down the injection speed can also solve the problem.

 

 

3 Shrinkage and indentation problems

The shrinkage is caused by insufficient filling of the material.

Solution: Improve the mold temperature and material temperature to improve the material fluidity, prolong the holding time of injection, increase injection pressure, increase the injection speed to increase the mold filling, also can enlarge the size of the gate, heat the gate flow channel to reduce and eliminate the shrinkage of the product;

 

Indentation is due to improper temperature of the material, as well as product design. The material temperature is too low, not only will causing shrinkage, but also indentation problems; the material temperature too high and mold temperature too high, will make the melt excessive shrinkage in cooling, and then results in indentation.

Solution: Adopt proper processing methods, improve injection speed and measure.

 

Haisi extrusion supply high quality and specialy designed twin screw extruder machine for making PC/ABS, modified PC/ABS extruder, enhanced PC/ABS granulator for automotive, home appliances making. Any interest please feel free to contact us!