Glossary

Polymerization is a chemical reaction involving a catalyst, heat, light, or electron irradiation in which relatively small molecules are linked in chains to form a macromolecule.

Polyolefin is a soft plastic film that is easily deformed by pressure and has good conformability. Examples are polyethylene and polypropylene.

Polypropylene, abbreviated PP. Polyolefin film, similar in properties to polyethylene, but with higher heat resistance and strength.

Polystyrene is a colorless thermoplastic material formed as a result of the polymerization of styrene. It has excellent electrical insulating properties and is relatively unaffected by moisture. The film of this material breaks easily and has limited heat resistance.

Pressure Sensitive Adhesive (PSA) is a term often used to refer to a specific category of adhesive tapes and adhesives. These adhesives are very tacky at room temperature in dry form and adhere reliably to a wide variety of surfaces applied just with finger or hand. They do not require water or solvent activation and provide good adhesion to paper, plastics, glass, wood, cement and metals. They have fairly good cohesion and elasticity. Despite their aggressive stickiness, they can be touched with fingers and removed from smooth surfaces without leaving any marks.