Quality Control in Recycled Plastic: How to Ensure Clean and Consistent PP & HDPE Flakes

🧠 Why Quality Control Matters in Recycled Plastic

In the recycling industry, quality is everything. Even small differences in moisture, color, or contamination can cause production issues, machine blockage, or product rejection.

That’s why serious manufacturers and exporters focus heavily on quality control (QC) — to ensure every shipment of PP and HDPE flakes meets international standards.

At SJP Company, we believe quality control is not a step — it’s a mindset.

🔍 Step 1: Material Sorting and Identification

The QC process begins before recycling starts.
Each batch of plastic waste is manually and mechanically sorted by type and color:

• PP (Polypropylene)

• HDPE (High-Density Polyethylene)

• Removal of PVC, PET, or other contaminants

Proper sorting ensures the purity and consistency of the final flakes.

💦 Step 2: Washing and Contamination Control

The washing process is crucial. We use multi-stage washing systems to remove:

• Dirt, labels, and glue

• Oil and chemical residues

• Metal or non-plastic particles

After washing, flakes are rinsed and dried to keep moisture below 1%, which is essential for extrusion and injection molding performance.

⚙️ Step 3: Moisture and Density Testing

Every batch is tested for:

• Moisture Content: using moisture analyzers to ensure flakes are completely dry.

• Bulk Density: to check consistency for packaging and shipping.

Stable density and low moisture guarantee smooth processing in buyers’ production lines.

🎨 Step 4: Color Sorting and Visual Inspection

Flakes are visually inspected and separated based on color — natural, white, blue, green, or mixed.
This helps customers maintain color consistency in their final products and reduce the need for additional pigmentation.

Our team also checks for burnt or discolored flakes, which can indicate overheating during processing.

🧪 Step 5: Lab Testing and Quality Reporting

Some buyers require lab tests before shipment — such as:

• Melt Flow Index (MFI)

• Ash Content

• Contamination Percentage

We provide detailed reports and sample photos upon request to ensure transparency and buyer confidence.

📦 Step 6: Packaging and Final Check

Before loading into jumbo bags, flakes are filtered, inspected, and labeled by batch number.
Each bag is securely sealed, moisture-protected, and weighed accurately to ensure quantity consistency.

During container loading, we perform a final QC check to verify cleanliness, dryness, and labeling.

🌍 The Result: Trusted Quality, Shipment After Shipment

With these steps, SJP Company ensures that every container of PP and HDPE flakes shipped meets buyer expectations — clean, consistent, and ready to use.

That’s why many of our long-term clients trust us as their reliable recycled plastic supplier.

✅ Final Thoughts

In recycled plastic, quality equals reputation.
By maintaining strict inspection and testing standards, we ensure our buyers receive materials that help their production run smoothly and efficiently.

If you’re looking for a partner who understands the importance of quality — not just quantity — we’re ready to support your business.

📩 Want Consistent, Clean, and Tested Flakes?

Contact our QC team for specifications, lab reports, or product samples.
👉 Contact Us