Below, we’ll provide a simple, layman’s term glossary of some of the more common technical terms used in technical data sheets and other materials about industrial strength adhesives:
Activators (or accelerators) can be used with adhesives to accelerate cure rate, activate inactive surfaces (where the adhesive requires a certain level of activity to initiate the cure), and to cure certain 2-part adhesives.
These are single-component adhesives that require the exclusion of air (so a tight-fitting joint) and the presence of a metal ion to initiate cure. These adhesives are typically used for gasketing between metal parts, retaining bearings, threadlocking, and pipe sealing.
The bond line is the space between two surfaces (the glue line or gap) that contains the adhesive.
Bond strength is, of course, the strength of the bond between the surfaces, but for reference, bond strength refers directly to the amount of force a bond can sustain.
Centipoise is a measure of viscosity, or thickness of an adhesive. For reference, water is measured at 1 cps, castor oil is 1,000 cps, and peanut butter is 250,000 cps, so the higher the cps, the thicker the substance. Another unit used for measurement is Pa.s (Pascal seconds) which work in a similar way.
Cyanoacrylate is a one-part adhesive that will cure instantly upon contact with the mated surfaces.
Density is the specific gravity (sg) of a material. Units are g/cm². Water has an sg of 1 which means 1cm3 volume of water weighs 1 gram (at 4°C).
Dielectric strength refers to the maximum voltage a material can withstand. Units are in volts per millimeter of thickness.
As measured with a durometer, this number refers to the hardness of a given material.
An elastomer is any rubber, plastic or polymer that can be stretched to twice its original length (or longer) and still return to its original shape.
The length to which a material will stretch without breaking. The elongation number refers to X percent of the original length, so a material with a 400% elongation would stretch to four times its original strength before snapping.
Epoxies are generally high strength products with good environmental and chemical resistance. They can be two-part (requiring mixing to cure) or single part (requiring heat to cure).
Simple definition: Pertains to a heat releasing chemical reaction.
In adhesives, filler means any substance added to an adhesive so as to alter the adhesive’s viscosity and flow control characteristics.
An industry term for any company which manufactures adhesives (ex: Permabond Adhesives).
Fibreglass Reinforced Plastic. Or GRP = glass reinforced plastic (or polyester).
This is the length of time you have from mixing and applying the adhesive, clamping / holding the joint shut. The handling time is the time at which you can remove the clamping pressure, and the adhesive will be strong enough to hold the joint together.
Hygroscopic refers to a material’s ability to absorb and retain moisture from the atmosphere.
A material’s resistance to sudden shock. Such as dropping heavy objects on that material, etc.
Inhibitors or stabilizers slow down chemical reactions and prolong the storage life of a product.
The amount of force or weight that a bond or material can sustain.
Peel strength refers to the force to peel one material from another. Brittle or rigid adhesives tend to have a lower peel strength than flexible, toughened adhesives.
Shear strength refers to the amount of force to pull one material from another in an overlap-type joint configuration.
A scale set up to assess the hardness of a material (see also Durometer). The test is done with a spring-weighted pin which measures the depth of penetration. Therefore, the higher the number, the harder the material. Shore A scale is for soft, flexible materials, Shore D is for more rigid, hard materials.
The thickness of a fluid, see Centipoise, above.
Working strength is the time at which a newly bonded joint can be put into a load bearing situation. The joint will have developed approximately 60% of its final strength (so it should not be overloaded).
Please contact us with any questions on technical data sheets.