rPET flakes or rPET pellets: which should you buy?
Both come from post-consumer PET bottles, but they behave very differently on a production line. The right choice depends on your process, your quality limits and your freight cost.
Recycled PET (rPET) reaches converters in two main forms. Flakes are bottles that have been sorted, ground and washed. Pellets are flakes that have gone one step further: melted in an extruder, filtered, sometimes upgraded in viscosity, and cut into uniform granules.
What is the difference between rPET flakes and pellets?
| rPET flakes | rPET pellets | |
|---|---|---|
| Form | Irregular flakes, typically 8–14 mm | Uniform granules of a few millimetres |
| Contamination control | Depends on sorting and washing | Adds melt filtration, removing many solid contaminants |
| Feeding and drying | Bulky; needs adapted feeding and drying | Free-flowing; behaves like virgin resin |
| Viscosity (IV) | As received from the bottle mix | Can be raised by solid-state polycondensation (SSP) |
| Freight | Low bulk density — fewer tonnes per container | Dense — the container is usually limited by weight |
| Typical price | Lower | Higher, reflecting the extra processing |
When do flakes make sense?
Flakes are the classic feedstock for polyester staple fiber and PET strapping. These lines usually dry the material and have their own melt filtration, so they can absorb the variability of flakes and benefit from the lower price. Clear hot-washed flakes with tight PVC and polyolefin limits are the most sought after; colored and cold-washed flakes find homes in less demanding fiber.
When are pellets worth the premium?
Pellets suit APET sheet, thermoforming, injection molding and blends with virgin resin, where consistent feeding, fewer black specks and predictable viscosity matter more than the price difference. With SSP, rPET pellets can reach the viscosity and acetaldehyde levels needed for demanding applications. Food-contact use always requires a decontamination process approved for that purpose and the corresponding documentation — see recycled plastic certifications.
What should you ask your supplier?
- Where do the bottles come from — deposit-return, curbside or post-industrial?
- Hot-washed or cold-washed? Which contamination limits are guaranteed?
- For pellets: what melt-filtration mesh is used, and is the material amorphous or crystallized?
- What is the IV range, and is there a certificate of analysis per lot?
- Can you send photos and a sample from the actual lot before loading?
General information only — not legal, tax or investment advice. Market conditions and regulations change; confirm the details for your case.
