What are the common problems encountered during ABS sheet production?
Frequently occurring problems on the surface of ABS sheets:
White streaks, bubbles, and cloudy watermarks frequently appear on the sheet surface. There are four main causes:
1. Insufficient raw material drying (ABS is highly hygroscopic, with a moisture content > 0.05%)
2. Excessively high barrel/die temperature, leading to thermal decomposition and gas generation from the material
3. Poor venting, insufficient screw back pressure, and air entrapment in the melt
4. Dead corners in the die flow channel, causing melt retention and degradation.
How to troubleshoot problems encountered during ABS sheet production?
1. Drying temperature/time
2. Observe the barrel temperature
3. Inspect
4. Clean the die head
5. Vent the screw.
