Polymer Barrier Coatings and Pulpability Test Standards
Polymer barrier paperboard compliance requires passing 0.15mm laboratory slot screening with under 15 percent reject mass to prevent EPR fee penalties.
Pulpability Testing
Disintegration Potential
Laboratory evaluation of paper and paperboard stocks measures mechanical defibering ease and fiber release under controlled hydrapulping conditions. Systematic pulpability testing quantifies the time and energy required to break down paper products into individual cellulose fibers without damaging fiber structure. Testing procedures track flake reduction rates over specific slushing intervals to determine repulping efficiency.
Packaging boards with synthetic coatings or wet-strength chemicals exhibit high slushing resistance during evaluation.
Fiber Separation
Experimental equipment applies mechanical shear forces to aqueous pulp suspensions at fixed consistency and water temperature. Performing pulpability testing allows paper mills to predict how raw stock and converted waste streams perform in commercial hydrapulpers. Non-defibered flakes pass through coarse screens and lower usable pulp yield if dwell times remain insufficient.
Fiber length distribution measurements show whether extended pulping causes mechanical degradation or excessive fiber cutting. Chemical pulping aids or elevated pH levels are introduced during testing to enhance wet-strength breakdown when neutral pulping fails.
Processing Limit
Evaluation criteria establish minimum defibering percentages required within target operational timeframes. Highly cross-linked resin barriers prevent complete fiber separation and leave large unpulped flakes. Analysis stops once maximum defibering efficiency is reached or when fiber shortening degrades stock quality.
Test metrics guide mill decisions regarding pulper retention times and chemical dosages.