extrusion coating

Extrusion coating is a process used to apply functional coatings, primarily polyethylene plastic, to paper and paperboard. This technique has become significant in packaging applications due to polyethylene's desirable properties, such as being waterproof, grease-resistant, and flexible.1

In an extrusion-coating machine, polyethylene resin is melted and extruded through a slot die to form a continuous film. This hot film is then stretched and bonded to the paper or paperboard between a pair of pressure and cooling rolls, creating a permanent bond before the plastic cools. This process enhances the material's properties for packaging and other uses.1