ABS sheets often exhibit surface defects such as bubbles, silver streaks, and pitting.
1. Insufficient raw material drying: This easily leads to bubble formation during extrusion; uneven mixing of moisture and melt results in silver streaks.
2. Localized overheating of the extruder barrel: Excessive temperature causes degradation of the ABS molecular chains, producing small volatile molecules that form surface pitting.
3. Impurities or excessive moisture in recycled material: Failure to re-dry recycled material or the presence of dust after pulverization exacerbates defects.
Dry the raw material: The raw material should be dried at 80-90℃ for 3-4 hours. Recycled material needs to be dried separately, and its addition ratio should not exceed 20%.
Strictly control the barrel temperature: Regularly clean the hopper, screw, and die flow channels to prevent material accumulation and degradation.
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