Meaning
Reprocessed linear low-density polyethylene resin originates from post-industrial scrap or post-consumer film waste streams collected for mechanical recycling. Pelletized lldpe recyclate contains short-chain branched alpha-olefin copolymers along with residual contaminants, crosslinked gel particles and mixed polyolefin fractions. The reprocessed material exhibits lower tensile strength, reduced puncture resistance, diminished clarity and narrower processing windows than virgin film grades.
Melt flow rate specifications on virgin datasheets assume uniform molecular weight, whereas recycled streams display variable rheological behavior caused by mixed feedstocks and heat history.
Processing Behavior
Melt filtration and degassing units remove moisture and solid contaminants during pelletization of post-consumer film scrap. Incorporating lldpe recyclate into blown film extruders alters bubble stability due to gel impurities and altered molecular weight distribution. Pressure fluctuations occur at the extrusion head when batch contamination shifts resin viscosity during continuous processing.
Higher melt temperatures assist melt homogeneity but accelerate thermal degradation when processing heavily recycled lots.
Property Variance
Oxidative degradation during previous service life cleaves polymer backbones and forms crosslinked gel networks within the reprocessed matrix. Blown films produced with high lldpe recyclate content suffer from reduced dart drop impact strength and decreased tear resistance. Cross-contamination from high-density polyethylene fractions increases density and stiffness while lowering film clarity.
Gel counts and melt flow variability dictate whether the material meets requirements for agricultural film or trash bag production.
Blend Economics
Compounding recycled resins with virgin polymer balances material cost reduction against processing performance losses. Blends containing twenty percent lldpe recyclate maintain structural performance in non-critical packaging layers without requiring die gap geometry modifications. Higher loading levels lower raw material expenses but increase scrap rates from web breaks during film blowing operations.
