Comon Terms and Definitions Used in the Manufacturing
Process of Epoxy and Urethane Compounds

  A chemical additive which speeds up the rate of a chemical reaction and thereby reduces the gel time and
  cure time. Another term is promoter.

  The property of forming a steady or firm attachment.

  The failure at the bond line between a substrate and an adhesive; the adhesive separating entirely from
  the substrate.

  The change in properties of a material with time under specific conditions.

  The temperature of the surrounding environment.

  The time required for an arc to establish a conductive path in a material.

  The intermediate stage during the curing process when the material has gelled but is not fully cured.

  A measure of force or pressure required to separate a layer of material from its base.

  The voltage at which the insulation between two conductors will break down.

  A term describing the tendency of materials to burn at different temperatures.

  To form plastic objects by pouring a fluid system into an open mold.

  A material which initiates and/or accelerates a chemical reaction but normally does not enter into the reaction.

  A unit of viscosity (with water as the standard) for indicating the fluidity or flow property of a liquid at room temperature.

  A measure of the sensitivity of a material to attack or corrosion by a chemical material.

  Arbitrary temperature ratings based on composition and/or experience with a particular material.

  A finishing, protecting, or enclosing layer that seals a component from its immediate environment.

  Coefficient Of Linear Thermal Expansion The fractional change in length of a material for a unit change in
  temperature. Measured in: inch / inch / °F - or - cm / cm / °C.

  The internal affinity of a material to itself.

  Failure within the adhesive under a stress, resulting in a broken bond with all adherent surfaces still covered
  with adhesive.

  A measure of the resistance of a material to a crushing load. Measured in pounds/square inch or megapascals.

  The reciprocal of volume resistivity. Conductance of a unit cube of any material.

  A compound resulting from the chemical reaction of two chemically different monomers with each other.

  Reacting together large molecules to change the physical properties of material. Cross-linking involves
  formation of a three dimensional molecular network with thermosetting resins.

  The time and temperature necessary for a material to reach most of its optimum properties.

  The time for reacting thermosetting plastic or rubber composition to reach certain properties. For materials
  which react under the conditions of mixing, the start of reaction is the time of initial exposure to the conditions
  necessary for reaction to occur.

  A cross-linking agent that reacts with a resin to form a copolymer.

  The temperature at which a material cross-links or cures.

  The weight per unit volume of a material. Measured in pounds/gallon, or kilograms/liter. Specific gravity is the
  density in kilograms/liter.

  The ratio of the capacitance of a material to the capacitance of air.

  The maximum electrical voltage which an insulating material can withstand without breakdown (conducting
  electricity). Expressed in volts/mil.

  The process of coating or impregnating of insulating materials by immersion into the uncured material.

  The measure of the loss of power which takes place in virtually all dielectric materials, usually in the form of
  heat. It's expressed as the ratio of the resistive (loss) component of the current to the capacitive component
  of current and is equal to the tangent of the loss angle.

  The increase in length of a material when stress in tension. Measured as a percentage increase over the unstressed material.

  The enclosure of an electronic, electrical, or electromechanical device in a resin matrix. Most commonly, the
  embedding matrix is composed of a thermosetting polymer than can be converted from a liquid to a solid
  by heat, chemical reaction and/or a combination of these. The device is buried or encased in the liquid,
  which then forms a protective shell when the liquid hardens.

  Enclosing an article in a closed envelope of a material.

  A specific type of chemical structure based on ethylene oxide.

  The amount of heat given off by a chemical reaction.

  An inert material added to a plastic to improve properties and/or decrease cost, most commonly limestone.

  The property of a material that extinguishes a flame once the source of heat has been removed.

  The property of a material that extinguishes a flame once the source of heat has been removed.

  The strength of a material in bending.

  The propensity of a material to form a gas during cure.

  The time it will take a thermosetting material to become solid at a given temperature and mass.

  The temperature at which cured resins undergo a change from a glassy state to a softer more rubbery state.

  A material added to a plastic composition which cross links another material, typically a polymer.

  Resistance of a material to deformation by indentation.

  HTD - The temperature at which a standard test bar will deflect 0.010" under a
  static load of 264 psi. A method to approximate Tg.

  A term replacing cycles-per-second as an indication of frequency. Abbreviated Hz.

  The ability to withstand shock loading; or, work required to fracture under shock loading a specified test
  specimen in a specified manner.

  To fill the voids of a material with a compound.

  Material having a high resistance to the flow of electric current.

  The amount of force necessary to fracture a notched piece of plastic with a hammer type impact.
  Measured in foot pounds/inch of notch.

   A measure of adhesive strength when placed between two metal coupons and pulled in a tensile mode.

  Meter-Mix-Dispense equipment. A dispensing machine that meters the proper amount of resin to hardener,
  mixes the two together and dispenses the mixture in to the unit to be potted.

  The optimum amount of resin and hardener that gives the desired properties.

  The measure of stress to strain in a material that is elastically deformed.

  The amount of water a material will absorb under certain conditions.

  The ability of a material to resist degradation from moisture in the air or when immersed in water.

  Composed of matter or chemicals of hydrocarbon origin.

  A high viscosity material that resists flowing on a vertical surface.

  A coloring agent.

  Highly polymeric materials that deform under stress and temperature. See Thermoset and Thermoplastic.

  To unite chemically two or more monomers of polymers of the same kind to form a
  molecule with higher molecular weight.

  Additional time/heat cycles to which a cured thermosetting plastic is subjected in order to enhance
  the properties.

  The amount of time a mixed material may be easily used at a specific temperature. It Is usually
  measured as the time it takes for a material to double in viscosity.

  The process where an insulating material is poured into a container and the container remains as an
  integral part of the unit.

  A process for molding in which the shrinkage is minimized by forcing the material under pressure into the
  mold and gelling it in stages.

  A chemical agent used to prevent a material from adhering to a surface such as a mold.

  An organic substance of natural or synthetic origin characterized by being polymeric in structure.

  The ability of a material to resist passage of electric current through itself or on its surface.

  The amount of time a material may remain useable in its original containers.

  A method of determining the hardness of a material using a pointed gauge. Shore A and 00 and
  000 is used to measure soft materials and Shore D is used to measure harder materials.

  Polymeric materials composed of molecules of silicon and oxygen.

  A liquid substance which dissolves other substances.

  Specific gravity is a ratio of the mass of a material to the mass of an equal volume of water at 4°C (39°F).

  The ultimate pulling force required to break a material. Measured in pounds/sq. Inch or megapascals.

  A measure of a material's ability to conduct heat. Measured in
  BTU-inch/hours-ft²/°F or calorie-cm/s² cm/°C.

  A plastic which will repeatedly flow under the application of heat and pressure.

  A plastic material that is capable of being changed into a non-melting or insoluble product by heat or
  chemical means.