The PET hot washing process is one of the most important steps in PET bottle recycling. Without proper hot washing, even the most advanced recycling line cannot produce high-quality flakes.
If your recycled PET still contains glue, oil, or odor, the problem is usually in the PET hot washing process.
What Is the PET Hot Washing Process?
The pet hot washing process uses heated water combined with chemical additives to remove contaminants that cannot be removed by cold washing alone. Typical setup includes:
- Heating system (electric or steam)
- Chemical dosing (NaOH + detergent)
- Agitation or mixing
Optimal Conditions for Effective Cleaning
For best results, the plastic hot washing line should operate under:
- Temperature: 80–90°C
- Reaction time: ~1–1.5 hours
- Chemicals: NaOH (caustic soda) + cleaning agents
These conditions help break down:
- Adhesives from labels
- Oil residues
- Organic contaminants
Why Cold Washing Is Not Enough
Cold washing can remove:
- Dust
- Loose dirt
But it cannot effectively remove:
- Glue
- Oil
- Sticky residues
This is why the hot washing machines are essential for producing high-grade PET flakes.
Role of NaOH in Hot Washing
NaOH plays a key role in the PET flakes hot washing process:
- Breaks down glue
- Dissolves organic contaminants
- Improves cleaning efficiency
However, concentration must be controlled to avoid damaging material quality.
Integration with Friction Washing
The best results are achieved when the pet hot washing process is combined with friction washing.
Hot washing loosens contaminants, while friction washing removes them completely.
Common Mistakes in Hot Washing
Many recycling plants fail because of:
- Low temperature (<70°C)
- Insufficient washing time
- Incorrect chemical dosage
- Lack of agitation
These issues reduce the effectiveness of the PET bottle washing line.
Final Results After Proper Hot Washing
A well-optimized pet hot washing process delivers:
- Clean PET flakes
- Reduced odor
- Low contamination
- Higher market value
Conclusion
If you want to upgrade your recycling quality, improving the pet hot washing process is the fastest and most effective solution.

