Poor appearance of plastic pellets is a common problem in granulation production, usually involving multiple aspects such as raw materials, process parameters, and equipment condition.

To solve this problem, you can check the following aspects:

Q: Uneven granule color or impurities?

Cause: The raw material contains different types of plastics, oil, metals, fibers, etc.

A: Strengthen raw material sorting and cleaning: Ensure the purity of the raw material. Use a high-efficiency filtration system: such as replacing with a higher mesh or dual-stage filter, or using a melt filter to remove fine impurities.

Q: Granules with air bubbles or loose texture?

Cause: The raw material has excessive moisture or contains volatile substances.

A: Thoroughly dry the raw material: Use a dryer or dehumidifier to pre-dry the raw material. Use a degassing/exhausting screw or two-stage plastic pelletizer: Effectively remove moisture and volatile gases during the melting process.

Q: Poor granule gloss?

Cause: Raw material degradation or thermal oxidation.

A: Use an appropriate amount of antioxidant or heat stabilizer: Improve the heat resistance of the plastic. Check and optimize processing temperature: Avoid localized overheating.

Problem: Irregular pellet shape or “stringy” pellets?

Cause: Improper die temperature (too high or too low), or mismatch between discharge speed and pelletizing speed.

A: Optimize die temperature: Adjust to the optimal temperature for the material to ensure uniform melt extrusion. Adjust pelletizing and traction speeds: Keep pelletizing and discharge synchronized and stable.

Q: Rough pellet surface?

Cause: Insufficient cooling or excessively rapid cooling.

A: Optimize water tank temperature and length: Ensure the plastic strip is properly and evenly cooled before entering the pelletizer. Adjust the cutter pressure and water temperature of the water ring/underwater pelletizer: Ensure smooth pelletizing and reduce pellet deformation and defects.

Q: Inconsistent pellet size?

Cause: Fluctuations in extrusion pressure or speed.

A: Maintain a stable extrusion rate: Ensure stable screw speed and feed rate. Check die orifice diameter: Check for blockages or uneven wear.

Why Choose Purui Machinery:

With over 25+ years of expertise and a footprint in over 100 countries, Purui Machinery continues to lead the way in plastic regeneration.

Purui Machinery is a high-tech enterprise specializing in the R&D and manufacturing of plastic recycling machinery. Its product portfolio includes plastic pelletizing lines, washing lines, and crushing equipment. Purui is dedicated to providing global customers with the most efficient, reliable, and intelligent plastic regeneration systems.

Contact Us to Get Your Customized Recycling Solution:

E-mail: [email protected]

Tel / Whatsapp: +8617701563079

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