Extrusion Coating
During the extrusion coating process, a polymer film is extruded through a flat die, stretched in air, then coated on a substrate (steel sheet in our case) in a laminator consisting of a chill roll and a flexible pressure roll. The nip, i.e., the area formed by the contact between the pressure and the chill rolls, constitutes the very heart of the extrusion coating process. Indeed, in this region, some of the most critical properties, such as adhesion, barrier properties, optical properties, are achieved. (RDC 2/2/2011) [Sollogoub et al, Poly. Eng. Sci., 51, #2, 341-346 (2011)]
Recent US Patents
11/2/2010
7,824,030
Extruded open-celled ink-receiving layer comprising hydrophilic polymer for use in inkjet recording
Laney et al of Eastman Kodak Company, New York developed an inkjet recording material consisting of a sheet extrusion coated with a porous hydrophilic thermoplastic polymer. The interconnecting voids (open-cell voiding) are created by void initiating particles and stretching. (RDC 2/22/2011)
Recent Journal Articles
2/4/2011
Origin of the bubble defect in the extrusion coating process
(347–357)Polymer Engineering & Science 51 #2 (2011)
Sollogoub et al of the UMR CNRS/Mines-Paristech, France have developed a bubble defect appearance criterion based on the the thermomechanical parameters of extrusion coating.