TAP Glossary

Abrasion Resistance – the ability of a material or structure to withstand the effects of abrasion (repeated rubbing, scraping, and wearing) that tend to remove surface material.

Acetate – a salt or cellulose ester of acetic acid used to make plastic or textile fibers.

Acrylic Resin – a group of thermoplastic resins derived from acrylic acid, methacrylic acid, or related compounds.

Acrylonitrile (CH2CHCN) – a colorless, volatile, and flammable form of liquid nitrile (C3H3N) commonly used to make artificial fibers and polymers.

Acrylonitrile Butadiene Styrene (ABS) – a class of composite plastic polymers made from a synthesis of styrene and acrylonitrile with polybutadiene.

Additives – specialty chemicals or other substances compounded into plastic resins or added to the surface of finished products in order to modify certain characteristics.

Adhesive – an intermediate substance capable of holding two or more materials together by surface attachment.

Amorphous – a term used to describe polymers that do not exhibit any crystalline structures.

Anneal – to prevent or remove the formation of stresses within a material by cooling or heating.

Aramid – a group of lightweight and heat-resistant synthetic aromatic polyamide materials used to make fibers, filaments, or sheets.

Atactic – a polymer that does not exhibit any stereochemical regularity of structure.

– a material that is woven in the form of sheets or rolls which can be impregnated with resin to form laminated plastics.

Binder – an organic or inorganic material which condenses and bonds the base in reinforced or otherwise heterogeneous composites.

Bond Strength – the measure of force required to separate materials or objects that are bonded together.

Butyrate – a salt or cellulose ester of butyric acid.

Butyric Acid – a group of short-chain fatty acids used in the manufacture of cellulose acetate butyrate plastics.

– a compound composed of carbon with an element of lower or comparable electronegativity.

Carbon Fiber – a material made of thin crystalline filaments of carbon, used as a strengthening agent in resins and ceramics.

Cast – to form a plastic object by pouring a fluid monomer-polymer solution into an open mold where it completes the process of polymerization.

Catalyst – a substance that accelerates the speed of a chemical reaction.

Cellulose – a natural carbohydrate found in most plant cells and vegetable fibers.

Cement – a volatile solution of unvulcanized rubber or plastic in a solvent, sometimes used as an adhesive.

Coefficient of Expansion – also known as expansivity, the quantitative relation between length or volume of a material per unit change in temperature under constant pressure.

Coefficient of Friction – the quantitative relation between the force of friction between two objects.

Coefficient of Thermal Expansion – the physical change in dimension of a material per unit change in temperature.

Cold Flow or Creep – the deformation of solids under sustained pressure or strain of stress.

Composite – the chemical makeup of a material, including all the materials necessary for the end product.
  • Bulk Molding Compounds (BMC)
  • Sheet Molding Compounds (SMC)
  • Thick Molding Compounds (TMC)
Compressive Strength – the measure of a material’s resistance to breaking under compression or excessive force.

Copolymer – a polymer made by the reaction of two (or more) chemically different monomers.

Corrosion – a chemical reaction that causes a material’s surface to breakdown by oxidation or chemical combination.

Crazing – a network of fine cracks on the surface of a plastic or related material, usually resulting as a response to the environment.

Cure – 1) to modify the chemical, electrical, or physical properties of a material by chemical reaction, by the action of heat and a catalyst, with or without pressure. 2) to convert a low molecular weight polymer or resin to an insoluble, infusible state.

– the splitting of a laminate along the plane of its layers or of bonded insulation within the adhesive layer or at the adhesive interface.

Dielectric Strength – a material’s ability to retain precise size and shape under the maximum electric field.

Dissipation Factor – the measure of energy loss in an insulating material.

Epoxy Resin
– any class of thermosetting adhesives, plastics, or resins containing at least one three-membered ring consisting of two carbon atoms and one oxygenation.

Extrusion – the method of processing plastics by forcing a softened blank of plastic material through a die or the desired shape of the cross-section of a finished product.

Fabric-Base Laminate
– an insulating material shaped by bonding woven cloth with resin under heat and pressure.

Fiber – a strand or strand-like structure, such as cellulose, glass, silk, or wool yarn.

Flexural Strength – the bend strength of a material, denoted as the tensile stress of the outermost fibers of a bent test material at the moment of failure.

Formulation – a merging of ingredients prior to processing or formed into a finished product.

Glass Cloth
– a textile material used as an insulating base formed by weaving yarns made of glass filaments.

Glass Fiber – 1) a glass in fibrous form that has cooled to an inflexible state without crystallizing. 2) a strong plastic or textile that contains glass filaments for reinforcement.

High-Pressure Laminates (HPL)
– a class of decorative laminates that are molded and cured at pressures no lower than 1,000 psi.

Impact Resistance
– the relative vulnerability of a material to fracture by a blow or stress at high speeds.

Impact Strength – the ability of a material to withstand sudden load or physical shock, expressed in terms of energy.

Insulation – a material or substance with high resistance to the flow of electric current.

Insulation Resistance – the quantitative value between applied voltage and the total current between two electrodes in contact with a conductor under prescribed conditions of a test.

– an overlay made of a layer of plastic or some other protective material, usually bonded together under heat and pressure.

Light Transmission – the amount of light a material or substance will allow to pass.

Low Pressure Laminates (LPL) – a class of laminates molded and cured in a pressure range up to 400 psi.

– a randomly distributed piece of fabric used to reinforce plastic materials or products.

Moisture Resistance – a material’s ability to resist absorbing ambient moisture.

Monomer – the unpolymerized form of a compound used as the building block of a polymer.

– the quality or state of a material that causes it to allow liquids, gasses, or vapors to pass through it without chemically affecting its state.

Phenolic Resin – also known as phenol formaldehyde resins (PF), a synthetic resin obtained by the condensation of phenol or substituted phenol with an aldehyde, such as formaldehyde.

Plastic – a synthetic material or polymeric substance formed from a wide variety of organic polymers, such as polyvinyl chloride (PVC), polyethylene, nylon, etc.

Plasticizer – a chemical agent or solvent that is added to plastics in order to make them softer and more malleable.

Polyethylene – a tough, flexible synthetic resin formed by polymerizing ethylene, used in the manufacture of plastic bags, food containers, and other packaging materials.

Polymer – any class of complex organic compounds produced by polymerization and capable of being molded, extruded, drawn into filaments for textile fibers, or cast into various shapes and films.

Polypropylene – a synthetic compound of propylene, used in the manufacture of fabrics and molded objects.

Polyurethane – a synthetic resin in which the polymer units are linked by urethane groups, used in the manufacture of adhesives, foams, paints, and varnishes.

– a material or substance used to reinforce, strengthen, or increase the dimensional stability of another material.

Resin – an organic substance which is polymeric in structure and predominantly amorphous.

Shear Strength
– the ability of a material to withstand shear stress or stress at which a material typically fails.

Surface Resistivity – the ability of an insulating material to resist a current of leakage along its surface.

Tear Strength
– also known as tear resistance, the measurement of how well a material can withstand the effects of tearing.

Tensile Strength – the capacity of a material or structure to withstand breaking under tension.

Thermal Conductivity – 1) the ability of a material to conduct heat. 2) the rate at which heat passes through a material.

Thermoplastic – a class of plastics capable of being repeatedly softened by temperature increase and hardened by temperature decrease.

Thermoset – a class of plastic resins or other synthetic materials that cure from being heated and cannot be molded softened again.

– a synthetic plastic or resin derived from polyvinyl chloride or a related polymer.

Volume Resistivity – the ability of an insulating material to resist a current of leakage through its body.