Glossary

Cast nylon film (see Nylon). Used mostly for thermo formable packaging applications.

Cast Polypropylene film. Unlike OPP, it is heat sealable, but at much higher temperatures than LDPE, thus it is used as a heat-seal layer in retort able packaging. It is, however, not as stiff as OPP film.

Plastic film produced from synthetic resins (such as polyethylene) by the cast process. In this process, the molten resin is extruded through a slot die onto an internally cooled chill roll.

Simultaneous extrusion of two or more different thermoplastic resins into a sandwich-like film with clearly distinguishable individual layers.

Coefficient of friction, a measurement of “slipperiness” of plastic films and laminates. Measurements are usually done film surface to film surface. Measurements can be done to other surfaces as well, but not recommended, because COF values can be distorted by variations in surface finishes and contamination on test surface.

A pressure relief valve added to coffee pouches to allow natural unwanted gasses to be vented whilst maintaining the freshness of the coffee. Also called an aroma valve as it allows you to smell the product through the valve.

A pressure sensitive adhesive coating on plastic films or laminates that will allow the packages to be sealed by application of pressure (with no heat or minimal heat).