PET Flake Clumping Evaluation according APR PET-S-08 (Association of Plastic Recyclers)

During processing, PET flakes can be exposed to heat above 190°C up to 220°C. It is important that PET flakes do not stick together and form hard clumps when exposed to high temperatures and filled into a hopper. PET clumps can cause bridging in feed systems that prevent material flow. This test method can be used in the laboratory to evaluate whether low-melting polymers or other sources of contamination are present in washed and eluted PET flakes that can form clumps of PET flakes under heated conditions.