Abstract
The current study considers the use of a selection of engineered ground calcium carbonates in two different polyethylene film systems. The calcium carbonate grades selected cover a range of particle sizes and include uncoated and organically treated examples. Alterations in the processing requirements on mineral addition are reported and their implications for film and masterbatch production considered with respect to energy usage and throughput. Inclusion of the engineered additives allowed production of the same weight of material at lower energy uses or improved productivity at the same energy usage. The effects on the mechanical properties of the composite films with increasing mineral loading have also been measured, demonstrating enhancements particularly in the areas of tear strength and impact resistance. These enhancements allow the possibility of film downgauging relative to the unfilled film without loss of performance and yield a raw material cost saving by reduction of polymer usage.