PET Flake Clumping Evaluation according APR PET-S-08 (Association of Plastic Recyclers)
While processing PET flake can be exposed to heat over 190°C up to 220°C. It is important that flakes of PET do not stick together to form hard clumps when exposed to high temperatures and loading in a hopper. Clumps of PET can cause bridging in feed systems that prevent material flow. This test method can be used in the laboratory to evaluate whether there is low melting polymer or other source of contamination in washed and elutriated PET flake that can create clumps of PET flake under heated conditions.