Glossary

Abrasion-resistance: A measure of the ability of tubing to resist damage by mechanical means.

Adhesive Liner: Lining that melts and flows inside a sleeve filling any voids in between the substrate and the sleeve.

Aging: Change in the properties of a material over time and under specific conditions. Generally refers to the environmental stimulus such as heat and light.

ASTM (American Society for Testing and Materials): A nonprofit industry wide organization that formulates test methods and material specifications, and publishes standards, testing methods, recommended practices, definitions, and other materials.

Braid: A woven metallic or fiber layer applied over wire or cable to act as a protective barrier or shielding.

Brittle Temperature: The temperature below which a material becomes brittle, often measured by a cold impact test.

Chemical Resistance: The ability of the insulation to withstand the presence of materials - such as acids, bases, water, salt water, and fuels - that can deteriorate an insulation.

Cold Blend: A test conducted by rapping tubing around a mandrel or by bending it in an arc while at a low temperature.

Conduit: A tubular raceway for holding wires or cables.

Continuity: A continuous path for the flow of current in an electrical circuit.

Continuous Operating Temperature: Maximum temperature at which a component will maintain an acceptable lifetime performance, based on accelerated aging prediction.

Crosslinking: The formulation of bonds between molecular chains in a polymer by means of chemical canalization or electron bombardment. The properties of the resulting thermosetting material are usually improved.

Crosslinking by Irradiation: A method of crosslinking polymers that makes a nonflowing material. This generally improves the properties of the polymer.

CSA (Canadian Standards Association): An agency that has developed standard specifications for products with particular emphasis on safety in the end use.

Dielectric Strength: The maximum voltage a dielectric can withstand without rupture. Usually expressed as volts per mil.

Elastic Memory: The ability of a crosslinked polymer to be deformed to some predetermined shape, hold that shape for a period, and then return to its original shape upon application of heat.

Elastomer: A material that exhibits very low or zero crystallinity and a high degree of flexibility.

Elongation: The ultimate elongation, or elongation at rupture. Expressed as a percentage of the original strength.

Encapsulation: Covering and sealing.

Environmentally Sealed: Description of a system to keep out moisture, dirt, air, or dust that might reduce performance.

Expanded ID: The specified minimum (as supplied) internal diameter of tubing.

Extrusion: A process that conveys plastic insulation material, generally via a screw, through forming dies and subsequently cools the insulation material to form a predetermined shape.

Flame-Resistant: A descriptor applied to material that is inherently resistant to burning.

Flame Retardant: A descriptor applied to material that has been made or treated so as to resist burning.

Fluoropolymer: A polymer that contains atoms of fluorine.

Gauge: A term used to denote the physical size of the wire.

Hardness: A general term that correlates with strength, rigidity, and resistance to abrasion or penetration. Measured on Shore or Rockwell scales.

Heat-shrinkable: A polymeric material capable of being reduced in size when exposed to heat.

I.D.: The internal diameter of a tubing.

Insulated Terminal: A solderless terminal with an insulated sleeve over the barrel to prevent a short circuit in certain installations.

Irradiation: In insulations, the exposure of the material to high-energy emissions for the purpose of favorably altering the molecular structure via crosslinking.

Kynar: Trade name (of Elf Atochem North America) for polyvinylidene fluoride and its copolymers.

Lacing Cord or Twine: Used for lacing and tying cable forms, hookup wires, cable end, cable bundles, and wire harness assemblies. Available in various materials and impregnates.

Longitudinal Change ( Shrink Tubing): The change in length of tubing when recovered. Expressed in the percent change from the original length.

Lot Number: The number that identifies one production run of material.

Marking: A printed identification number or symbol applied to the surface of tubing.

Melting Point: The temperature at which crystallinity disappears when crystalline material is heated.

Mil: A unit equal to one one-thousandth of an inch (.001").

MIL-SPEC: Abbreviation for Military Specification, which is a document that the U.S. Government issues to define a product that will be used in military end-use applications.

Nominal: A descriptor applied to a dimension representing the center of the range of tolerance or a value if no tolerance is applied.

OFT (Optional Flame Test): Canadian Standards Association's test for flame retardance. Tubing with an OFT rating is highly flame-retardant.

Operating Temperature: The maximum internal temperature at which a system, harness, or connector may operate in continuous service, generally expressed as a time and temperature.

Plasticizer: A softener or lubricant added to a compound that makes it easier to process or more flexible in use.

Plating: The overlaying of a thin coating of metal on metallic components to improve conductivity, facilitate soldering, or preventing corrosion.

Polyamide: A polymer formed by the reaction of a diamine and a diacid. Nylons are commercial polyamides characterized by toughness, solvent resistance, and sharp melting point.

Polyolefin: A family of polymers (such as polyethylene and polypropylene) made from olefin monomers.

PVC: (Polyvinyl Chloride): A polymer compound used as wire insulation.

PVDF: Polyvinylidene fluoride.

Rated Temperature: The maximum temperature at which a component can operate for extended periods with acceptable changes in its basic properties.

Rated Voltage: The maximum voltage at which a component can operate for extended periods without undue degradation.

Recovered ID: In heat-shrink tubing the guaranteed maximum internal diameter of tubing after being freely recovered.

Sealant: Soft, tacky, pliable material that seals where mechanical strength is not required.

Shelf Life: Generally, the length of time a product or material may be stored without deterioration. Specifically, the length of time during which shrink tubing will retain its expanded ID and return to its recovered ID.

Shore: A scale for comparing hardness. Higher shore values represent harder materials.

Shrink Ratio: An expression of how much the inside diameter of shrink tubing will reduce in size when recovered. The inverse of the expansion ratio.

Solvent Resistance: The ability of a material to retain physical and electrical properties after being immersed in specific solvents.

Specific Gravity: The ratio of the density (mass per unit volume) of a material to that of water.

Strain Relief: The technique for or act of removing or lessening the strain or stress on a joint, splice, or termination.

Temperature Rating: The maximum temperature at which the insulating material may be used in continuous operation without loss of its basic properties. Usually time dependent.

Tensile Strength: The pull stress (in force per unit area) required to break a given specimen.

Thermoplastic: A material that softens (melts or flows) when heated and becomes firm when cooled. A type of plastic that can be re-melted a number of times without any important changes in properties.

Tolerance: The total amount by which a quantity is allowed to vary from nominal; thus, the tolerance is half the algebraic difference between the maximum and minimum limits.

UL (Underwriters' Laboratories): A nonprofit independent organization that operates a listing service for electrical and electronic materials and equipment.

Ultraviolet Degradation: The degradation caused by long-time exposure of a material to sunlight or other ultraviolet radiation.

Volume Resistivity: Reciprocal of conductivity; the resistance of a material to the flow of electrical current, usually expressed in ohm-cm.

VW-1: A rating determined by the Underwriters' Laboratories (UL) optional Vertical Wire Flame Test - the most difficult flame test for tubing. Tubings with a VW-1 rating are highly flame-retardant.

Wall Thickness: The thickness of the tubing wall.

Wicking: The longitudinal flow of a liquid in a wire or cable construction due to capillary action.