A Linear Low Density Polyethylene with Exceptional Blown Film Haze and Gloss, and Low Film Blocking

摘要

A hexene linear low density polyethylene (LLDPE) product has recently been developed which, when blown intofilm, has a unique combination of high clarity, high gloss, film bl°Cking values much lower than one practiced intoday’s polyethylene science might expect, and stiffness higher than one might expect for its density. Twenty-fivemicron (1-mil) blown film haze value is in the range of 3.5-4.0%, 45-degree gloss value is about 82, film rebl°Ckingvalue at 38°C is only about 60 grams, and 1% secant moduli in the machine and transverse directions are about 325and 380 Mpa (47,000 and 55,000 psi), respectively. Addition of 1200 ppm erucylamide reduces the 38°C bl°Ckingvalue to zero grams while detracting only very slightly from the film’s optical properties. This LLDPE product’smelt index is 0.6 and its density is 0.926 g/cc. The film’s unusual combination of low haze, high gloss, lowbl°Cking, and high stiffness, while generally retaining the strength characteristics of a 0.926 g/cc LLDPE, makes thisproduct attractive for many film applications.