Polyethylene Technology in Extrusion Coating, 2001 European PLC Conference Proceedings

Martti Vähälä, Johan Van Grootel--The EC process imposes high demands on the polymers used. Traditionally, autoclave high pressure Low Density Polyethylene (LDPE) has offered the best processability behaviour with acceptable end-product properties. Hence, LDPE has been dominant throughout the coating history. However, the interest towards linear type of PE’s has grown also among the coating industry. In comparison to LDPE, LLDPE’s offer e.g. improved heat sealing properties, better mechanical properties (stiffness, elongation) and better Environmental Stress Cracking Resistance (ESCR). So far weak processability behaviour has been the main reason why LLDPE’s have not penetrated into EC markets as expected. This presentation introduces two new bimodal EC polyethylene grades, HDPE and LLDPE, produced with the Borstar technology. Compared to standard LDPE, these grades are giving large improvements in end-product properties without destroying the processing behaviour, opening opportunities for either down gauging or performance upgrading.