A release liner is a paper or plastic-based film sheet (usually applied during the manufacturing process) used to prevent a sticky surface from prematurely adhering. It is coated on one or both sides with a release agent, which provides a release effect against any type of a sticky material such as an adhesive or a mastic. Release liners are available in different colors, with or without printing under the low surface energy coating or on the backside of the liner. Release is separation of the liner from a sticky material; liner is the carrier for the release agent. Release liners for tape applications are designed with a silicone release coating that provides the optimum release level for the final product. The single and double side coated release liners can be tailored to work well with adhesives intended for low tack applications all the way to permanent adhesive end uses. Release liners for the tape market utilize both low density polyethylene release liners or LDPE and high density polyethylene. LDPE is a thermoplastic that is made from monomer ethylene. LDPE is the most widely used plastic especially in containers and liquid holding canisters. The HD or HDPE release liners are high density polyethylene release liners which have a very large strength to density ratio meaning the liners are stronger and more durable than a normal release liner. Polyethylene terephthalate (sometimes written poly(ethylene terephthalate)), commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods, thermoforming for manufacturing, and in combination with glass fibre for engineering resins. PET tape, or polyester tape, is an exceedingly strong case sealing tape. The tape is resistant to tearing and does not stretch lengthwise or widthwise. PET tape has the ideal properties for a smooth, mechanical processing. And for closing heavy or overfilled boxes with high tension on the flaps. PET tapes maintain their excellent adhesion even at high and low temperatures.
