Glossary of terms

Accelerated ageing - Procedures for subjecting material to far more severe conditions than are likely to be encountered normally, in order to predict behavior during natural ageing.

Acrylic - A synthetic polymer with excellent aging characteristics that can be used as either a single component adhesive or a coating or saturate, depending upon composition. 

Adhesive, pressure sensitive  -A term commonly used to designate a distinct category of adhesive tapes and adhesives that in dry (solvent-free) form are aggressively and permanently tacky at room temperature and firmly adhere to a variety of dissimilar surfaces upon mere contact without the need of more than finger or hand pressure. They require no activation by water, solvent, or heat.

Adhesion -A bond between two surfaces.

Adhesion (Peel) -The force required to remove a self-adhesive tape from a standard test panel at a specified angle and speed after the tape has been applied to the test panel under specified conditions.

Adhesion to backing -See Release.

Adhesive -A substrate capable of holding materials together by adhesion.

Adhesive, permanent -An adhesive with a high ultimate adhesion.

Adhesive, removable - An adhesive characterized by relatively high cohesive strength and low ultimate adhesion to a wide range of surfaces.

Adhesive, Transfer - The transfer of adhesive from its normal position on the tape to the surface to which the tape has been applied.

Backing - See liner

Bursting strength - the ability of a tape to resist damage when force is applied perpendicularly to the surface of a tape.

Caliper  - See Thickness.

Carrier - The adhesive coated material in self-adhesive tapes.

Cohesion, Cohesive strength - The internal strength of an adhesive.

Conformability - The ability of tape to fit snugly or make essentially complete contact with the surface of an irregular object without creasing or folding.

Core - The inner cylinder of cardboard or plastic on which the tape is wound.

Curling - The tendency of a tape to curl back on itself when unwound from the roll and allowed to hang from the roll.

Delamination - A separation or splitting of the tape into two distinct layers.

Dimensional stability -The constancy of materials dimensions.

Direction, cross -The direction at right angles to the machine direction of a web.

Direction, machine - The direction parallel to forward movement of a web.

Double coated -A carrier with adhesive on both sides, usually having a disposable liner to prevent the adhesive sticking face to face.

Elongation at break - The amount a tape has stretched lengthwise at the point of breaking. It is expressed as a percentage of the original unstretched length.

Films - Uniform, homogeneous, none fibrous synthetic webs.

Flame resistance - The ability to a tape to withstand exposure to flame. Fireproof materials will not burn even when exposed flame. Flame-resistant (fire-retardant, self-extinguishing) materials will burn when exposed to flame but will not continue to burn after the flame is removed.

Flexibility -The ability of a tape to be freely bent or flexed during application.

Foam - A soft cushiony material formed by creating bubbles in base material, such as natural or synthetic rubbers, or other elastomeric materials.

Gauge - See Thickness.

Glassine - A super calendered smooth dense transparent or semi-transparent paper.

Heat resistance - The ability of a tape to withstand exposure to specified temperatures after application to a surface. Clean removal after exposure may or may not be important to the user.

Holding power - See Shear adhesion.

Impact resistance - The ability of a tape to resist sudden pulls or shocks as may sometimes be encountered by packages in transit.

Key Failure - Failure of an adhesive bond such that separation is at the interface of the adhesive and carrier leaving no adhesive residue.

Kraft - A sulfate wood pulp paper.

Laminations, Laminate - Combinations of two or more materials that function as one backing, e.g. polyurethane foam and polyester film.

Lifting - Said to occur when sections of tape lose contact with the surface to which the tape is applied.

Liner - A web or sheet affixed to the adhesive for protection during handling and storage. It is removed and discarded before application.

Migration - The interaction between adhesive-molecules and substrate-molecules.

Opacity - The ability of a tape to prevent the transmission of light. In practice, opacity is needed when a tape covers printed material or dark background.

Peel adhesion - See Adhesion, Peel.

Plasticizer - A substance added to materials to impart flexibility, workability and distention.

Pressure sensitive adhesive - See Adhesive, pressure sensitive.

Pressure sensitive tape - A combination of pressure sensitive adhesive with carrier.

Reinforcement - A material added to a tape to provide additional strength.

Release -  1. The removal of a liner.

                 2. The force required to remove the liner.

Release coating - A coating applied to the liner to facilitate the unwinding and removal of the liner.

Removal -  The act of pulling a tape away from surface to which it has been applied.

Resistance to…  - The ability of a tape to resist exposure to such conditions after application and to perform satisfactorily.

Shear adhesion - The force required to pull a pressure sensitive tape from a standard flat surface in a direction parallel to the surface to which it has been applied.

Shelf life - See Storage stability.

Single Coated - Coated on one side with a pressure sensitive adhesive.

Storage stability - The ability of a tape to retain a specific level of its original properties after defined conditions of storage.

Substrate - The surface to which a pressure sensitive tape is applied.

Tack - The property of a pressure sensitive tape that causes it to adhere to a surface to a surface instantly without external pressure for better contact.

Tear resistance - The ability of a tape to resist tearing, after a tear has been started by cutting or nicking the edge.

Tensile strength - The property of a material that is measured by the force parallel to the plane of the material required to break it under specified conditions.

Thermoplastic adhesives - Describes behavior of adhesives that becomes softer as temperature increases, regardless of the number of heating cycles to which they are exposed.

Thermosetting adhesives - Describes the behavior of adhesives which sets up or hardens of first exposure to heat and remains set regardless of subsequent temperature cycles.

Thickness - The perpendicular distance between the two opposite surfaces of a complete tape. This is usually measured with a micrometer, which exerts a slight pressure.

Transfer tape - A double-sided tape consisting of a film of adhesive without a carrier, and protected by a release liner.

Transparency - That property of a material that transmits light rays through the specimen.

Ultimate adhesion - The force necessary to remove a strip of tape from a surface after an extended period of time.

Unwind adhesion - The force required to remove the tape from the roll under prescribed conditions.

Water absorption - The amount of water a material can absorb and retain under specified conditions.

Water vapor transmission - The weight a water vapor passing through a defined area of tape in a fixed period of time. The conditions of temperature and humidity are specified. Usually a desiccant is sealed in a container with the tape and exposed to a humid atmosphere.

Weather ability -The ability of material to withstand the effects of exposure to weather, without any physical or chemical changes.