rPET flake is PET bottle material that has been ground, washed and dried. Buyers making fibre, strapping, sheet or new bottles judge flake by a short list of measurable points. A test report from the supplier or an independent lab should state each one.
Hot wash or cold wash
Hot washing (with caustic at high temperature) removes glue, oil and residues much better than cold washing. Sheet, strapping and bottle-grade uses usually need hot-washed flake; some fibre uses accept cold-washed.
The points on a test report
- PVC (ppm): the most important limit, because PVC degrades PET in the melt. Typical limits are a few tens of ppm or less for demanding uses.
- Other polymers (ppm): PE and PP from caps and labels, and other plastics.
- Glue, paper and metal: residues that block filters and cause defects.
- Moisture (%): affects drying cost and weight.
- Colour: share of blue, green and other colours, often given as a percentage or in ppm.
- Flake size: minimum and maximum, often around 8 to 14 mm, and the share of fines or dust.
- Bulk density: affects feeding and loading.
- Melt test: a sample is melted and baked to show yellowing, black specks and other contamination.
Intrinsic viscosity (IV)
Bottle flake usually starts around 0.70 to 0.80 dl/g. Bottle-to-bottle and strapping need higher IV; fibre accepts lower.
What to send for a quote
- Your end use: fibre, strapping, sheet or bottles
- Hot or cold wash, and limits for PVC, other polymers, glue, metal and moisture
- Colour you accept and flake size range
- The test report you require, and whether you want a sample first
- Quantity, packing (big bags), destination port and Incoterm