Glossary of Terms
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
A
Accelerator, Activator - Terms used to describe the materials which initiate the polymerization needed to cure anaerobic, cyanoacrylate and modified acrylic adhesives.
Adhesive - Substance for bonding, sticking or holding things together.
Adhesive, Anaerobic - An adhesive which only cures when air is excluded.
Adhesive, Cyanoacrylate - Group of adhesives which show "instant" cure properties and bond to a wide variety of substrates. Cure is by contact with alkaline materials. Weakly alkaline materials, such as water, cause the cure to start.
Aging, Heat - Artificial "aging" of adhesive by exposing to elevated temperatures for long periods.
Ambient Conditions - Temperature, humidity, sunlight, etc. which exist in the area surrounding the bond, normally room temperature, atmospheric pressure, daylight, etc.
Anaerobic Adhesive - An adhesive which only cures when air is excluded.
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Bond- Interface of the adhesive and the substrate.
Breakaway Torque - Measure of force needed to initiate movement of an unseated fastener in a loosening direction.
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Cohesive Failure - Condition of bond failure in which the adhesive falls apart.
Conditions, Ambient - Temperature, humidity, sunlight, etc. which exist in the area surrounding the bond, normally room temperature, atmospheric pressure, daylight, etc.
Cure Speed - Time needed for an adhesive to reach full strength.
Cyanoacrylate Adhesive - Group of adhesives which show "instant" cure properties and bond to a wide variety of substrates. Cure is by contact with alkaline materials. Weakly alkaline materials such as water, cause the cure to start. Commonly referred to as "super glue."
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Exotherm - Exothermic materials give off heat when they cure. When large quantities cure all at one time, the amount of heat given off (the exotherm) can be high enough to melt plastic containers.
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Failure, Cohesive - Condition of bond failure in which the adhesive falls apart.
Failure, Substrate - Condition of bond failure in which the substrate falls apart. The cohesive strength of the adhesive and the adhesive forces between the adhesive and substrate exceed the internal strength of the material being bonded.
Fill, Gap - Ability of an adhesive to fill the space between substrates and hold the substrates in place.
Fixture Time - Time needed for adhesive to reach sufficient strength to allow pieces to be handled and moved.
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Gap Fill - Ability of an adhesive to fill the space between substrates and hold the substrates in place.
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Heat Aging - Strength measured at room temperature after some period of aging at elevated temperature.
Hot Strength - Strength measured at elevated temperature.
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Impact Strength - Resistance to sharp, intense blows or force.
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Lap Shear - Test to measure resistance to shear stress by bonding the ends of flat bars in an overlapping position.
Locking Torque - Test designed to measure breakaway and prevailing torque of a threaded piece coated with thread locking adhesive.
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Monomer - Chemical which can be caused to join and form polymers.
MRO - Maintenance, repair and overhaul.
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OEM - Original equipment manufacturer.
Open Time - Time during which the adhesive remains active without curing after being applied to the substrate.
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pH - Measure of acidity. A pH of 1 would be very acidic. A pH of 7 is neutral. A pH of 10 is very alkaline.
Polymers - Substance made up of many units such as polyethylene, polystyrene, etc.
Prevailing Torque - Measurement of average force needed to provide continuing movement, after unseating, through first full turn.
Primer, Surface - A surface primer is a coating that changes the character of a surface so that an adhesive or coating will adhere to it more effectively.
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Rheology - Special consideration of viscosity. Considers the effect of such things as stickiness and sensitivity to shear on viscosity.
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Shear, Lap - Test to measure resistance to shear stress by bonding the ends of flat bars in an overlapping position.
Shear, Static - Test to measure resistance to shear stress by bonding a pin within a collar or ring.
Speed, Cure - Time needed for an adhesive to reach full strength.
Static Shear - Test to measure resistance to shear stress by bonding a pin within a collar or ring.
Strength, Hot - Strength measured at elevated temperature.
Strength, Impact - Resistance to sharp, intense blows or force.
Substrate - Material which is being joined or bonded.
Substrate Failure - Condition of bond failure in which the substrate falls apart. The cohesive strength of the adhesive and the adhesive forces between the adhesive and substrate exceed the internal strength of the material being bonded.
Surface Primer - A surface primer is a coating that changes the character of a surface so that an adhesive or coating will adhere to it more effectively.
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Thermoplastic - A thermoplastic material will soften when exposed to high temperature. It literally becomes plastic when heated. Usually, removing the heat restores the original strength.
Thermoset - Products that will only cure when exposed to heat are described as thermoset resins. After they are cured, subsequent heat exposure will have little or no effect on the properties of the cured resin.
Thixotropy - Term which describes the flow character of a liquid or paste. Liquids that are thixotropic flow under shear but flow less when the shear is removed. Best example is ketchup.
Time, Fixture - Time needed for adhesive to reach sufficient strength to allow pieces to be handled and moved.
Time, Open - Time during which the adhesive remains active without curing after being applied to the substrate.
Torque, Breakaway - Measure of force needed to initiate movement of an unseated fastener in a loosening direction.
Torque, Locking - Test designed to measure breakaway and prevailing torque of a threaded piece coated with thread locking adhesive.
Torque, Prevailing - Measurement of average force needed to provide continuing movement, after unseating, through first full turn.
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Viscosity - Measure of fluid thickness or resistance to flow expressed in poise or centipoise. Water is one centipoise. Thicker fluids have higher numbers. 30 weight oil has a viscosity of 400 centipoise (cps).
