The Effect of Resin Type and Coextrusion Film Structure on Gloss Measured at Multiple Geometries and the Correlation to Human Perception, 2005 PLACE Conference
A study was conducted to evaluate the effect of layer arrangement on the gloss of coextruded polyethylene blown films. Part 1 of this work examines the widely accepted preference for 45-degree gloss measurement within the plastic films industry by testing a series of polyethylene coextruded films at multiple angles of incidence, namely 20o, 45o, 60o and 85o. This research reveals that gloss-20 has the greatest sensitivity to change in coextruded film structure, gloss-45 and gloss-60 show good resolution between polyethylene films, gloss-60 provides the highest absolute values (with the exception of the low gloss film), and gloss-85 is ill-suited for providing resolution between samples. It also concludes that gloss-45 is a suitable choice for providing resolution between polyethylene blown films.
Part 2 of this paper explores the contribution to gloss-45 through varying the layer arrangement and layer composition in coextruded blown films. It is repeatedly demonstrated in this body of work that adding a high gloss polyethylene resin to a low gloss film has the ability to yield high overall gloss values. Furthermore, it is shown that a coextruded film with A/B/A construction has a higher gloss-45 value than an A/A/A film.