How We Keep PVC Contamination Below 50 PPM in PET Flakes

In recycled Polyethylene Terephthalate (rPET) processing, Polyvinyl Chloride (PVC) contamination is the ultimate enemy. During thermal extrusion, PVC degrades at lower temperatures than PET, releasing corrosive hydrochloric acid gas. This acid damages costly extruder screws, degrades intrinsic viscosity (IV), causes filament breakage in textile spinning, and creates dark specs in final products.

For overseas procurement officers sourcing from a bangladesh pet flakes manufacturer, verifying sub-50 PPM PVC purity is the golden standard.

Here is an inside look at the technical protocols, sorting mechanisms, and industrial washing procedures Key Mart Limited uses to consistently deliver rPET flakes with PVC levels strictly below 50 PPM.

The 50 PPM Challenge: Why PVC Removal Is Critical

While both PET and PVC are widely used in beverage and container packaging, mixing them during recycling severely impacts downstream manufacturing:

Equipment Corrosion: Hydrochloric acid (HCl) released by melting PVC corrodes spinnerets, barrels, and filters.
Fiber Snap & Yarn Defects: In polyester staple fiber (PSF) spinning, microscopic PVC carbonization causes frequent thread breakage and downtime.
Color Degradation: Even trace amounts of burnt PVC turn clear rPET batches yellow or grey, destroying clarity for sheet extrusion.

Maintaining a maximum threshold of <50 PPM (Parts Per Million) ensures that rPET flakes can be fed directly into high-tenacity yarn spinning and APET sheet manufacturing without operational risk.

Step-by-Step: How Key Mart Limited Eliminates PVC Contamination

Achieving sub-50 PPM purity requires a zero-tolerance, multi-stage filtration system. Operating out of Dhaka, our processing facilities combine manual precision with automated industrial technologies.

1. Manual & Automated Pre-Sorting (Source Level)

Before bottles enter the crushing chamber, post-consumer material undergoes rigorous dry sorting:

Label & Cap Removal: Bales are de-baled and passed through mechanical trommels to remove PVC labels, PP caps, and loose debris.
Positive Manual Inspection: Trained technicians inspect bottle streams on high-speed conveyor belts to remove non-PET bottles (such as PVC oil jugs or blister packs).

2. High-Precision Optical Sensor Sorting

As an advanced pet flakes company bangladesh, our crushing lines feed flakes into near-infrared (NIR) optical sorting units:

Wavelength Identification: Optical sensors scan passing material in milliseconds, detecting the unique chemical signature of PVC polymers.
Air Jet Ejection: Targeted high-pressure air nozzles blast detected PVC particles out of the clear PET flake stream with surgical precision.

3. Caustic Industrial Hot-Washing (85°C – 95°C)

The core of our purification process takes place in our multi-chamber hot-washing system:

Thermal Glue Dissolution: High-temperature water mixed with precise caustic soda concentrations (NaOH) completely dissolves glue, adhesives, and paper residues.
Sink-Float Density Separation: Flakes enter continuous friction washers and flotation tanks. Since PET has a higher density (~1.38 g/cm³) than water, it sinks cleanly to the bottom, while residual PP/PE cap materials float to the surface for skimming.

4. Centrifugal Thermal Drying & Fine Air Elutriation

After hot washing, the material passes through centrifugal dryers and zig-zag air classifiers:

Moisture Retention Control: Drying cycles reduce moisture levels below 1%, preventing hydrolytic degradation.
Dust & Fine Removal: Heavy-duty air separators pull away microscopic film dust, residual label flakes, and light impurities.

PVC Contamination & Quality Benchmark

Quality Metric	Industry Standard	Key Mart Limited Export Specification
PVC Contamination	< 100 – 150 PPM	< 50 PPM (Guaranteed)
Moisture Content	< 1.5%	< 1.0%
Intrinsic Viscosity (IV)	0.65 – 0.70 dL/g	0.68 – 0.78 dL/g
Transparency & Clarity	Standard Clear	99%+ Crystal Clear White
Flake Granulation	Irregular (3–18 mm)	Uniform (3–14 mm)

How Key Mart Limited Fulfills Global Buyer Demand

As a leading pet flakes exporter and prominent pet flakes manufacturer dhaka, Key Mart Limited is structured to handle high-capacity B2B supply chains across Europe, North America, and Asia:

Batch-Tested Quality Verification: Every export container is backed by in-house lab reports confirming PVC PPM counts, IV stability, and moisture content before shipping.
Consistent Monthly Tonnage: Our high-capacity plants in Dhaka ensure continuous container allocations for long-term multi-container contracts without supply drops.
Export-Ready Bulk Packaging: Material is packed in heavy-duty 1.1-ton woven jumbo bags on heat-treated pallets to prevent moisture absorption and contamination during ocean transit.
Comprehensive Trade Management: Our export team manages Letters of Credit (L/C), Port of Chittagong customs clearance, and global maritime logistics.

Partner with Key Mart Limited Today

Safeguard your production machinery and elevate your rPET yarn spinning efficiency with export-grade, hot-washed clear PET flakes from Bangladesh. Contact our export desk today to request technical data sheets (TDS), lab samples, or wholesale pricing.

Company Name: Key Mart Limited
Head Office Address: Dhaka, Bangladesh
Official Website: www.keymartbd.com
Corporate Email: keymartltd@gmail.com | info@keymartbd.com
Direct Phone / WhatsApp: +8801760774499, +8801864935478

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How We Keep PVC Contamination Below 50 PPM in Industrial Hot-Washing Lines