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

Acceptance Test
A test, or series of tests, conducted by the procuring agency, or an agent thereof, upon receipt to determine whether an individual lot of materials conforms to the purchase order or contract or to determine the degree of uniformity of the material supplied by the vendor or both.

Accelerator
A substance designed to accelerate or enhance the adhesive's curing process.

Acrylic Adhesive
A two-component structural adhesive capable of bonding to a large variety of materials. Cyabond® acrylic adhesives are known for excellent environmental resistance and fast-setting time.

Acrylonitrile Butadiene Styrene Resin (ABS)
A commonly found plastic offering good resistance to both high and low temperatures and impact. It bonds well with many adhesive types.

Activator
A substance, which initiates or accelerates the cure of an adhesive.

Adhere
To cause two surfaces to be held together by adhesion.

Adherend
A body, which is held to another body by an adhesive. (See also substrate)

Adhesion
The state in which two substrates are held together by interfacial forces which may consist of valence forces or interlocking action, or both.

Adhesion, Mechanical
Adhesion between surfaces in which the adhesive holds the parts together by interlocking action.

Adhesion, Specific
Adhesion between surfaces which are held together by valence forces of the same type as those which give rise to cohesion.

Adhesive
A substance capable of holding materials together by surface attachment.

Adhesive Dispersion
A two phase system in which one phase is suspended in a liquid.

Adhesive, Assembly
An adhesive that can be used for bonding parts together, such as in the manufacture of a boat, airplane, furniture, and the like.

Adhesive, Cold-Setting
An adhesive that sets at temperatures below 20°C (68°F).

Adhesive, Contact
An adhesive that is apparently dry to the touch and which will adhere to itself instantaneously upon contact; also called contact bond adhesive or dry bond adhesive.

Adhesive, Heat Activated
An adhesive, the apparent density of which has been decreased substantially by the presence of numerous gaseous cells dispersed throughout its mass.

Adhesive, Hot Melt
An adhesive that is applied in a molten state and forms a bond on cooling to a solid state.

Adhesive, Hot Melt
A dry adhesive film that is rendered tacky or fluid by application of heat or heat pressure to the assembly.

Adhesive, Hot-Setting
An adhesive that requires a temperature at or above 100°C (212°F) to set it.

Adhesive, Multiple Layer
A fil adhesive, usually supported, with a different adhesive composition on each side; designed to bond dissimiliar materials such as the core to face bond of a sandwich composite.

Adhesive, Pressure-Sensitive
A viscoelastic material which in solvent-free form remains permanatly tacky.  Such material will adhere instantaneously to most solid surfaces with the application of very slight pressure.

Adhesive, Room Temp. Setting
An adhesive that sets in the temperature range from 20 to 30°C (68 to 86°F), in accordance with the limits of Standard Room Temperature specified in ASTM Methods D 618, Conditioning Plastics and Electrical Insulating Materials for Testing.

Adhesive, Separate Application
A term used to describe an adhesive consisting of two parts, one part being applied to one adherend and the other part to the other adherend and the two brought together to form a joint.

Adhesive, Solvent
An adhesive having a volatile organic liquid as a vehicle.

Adhesive, Solvent Activated
A dry adhesive film that is rendered tacky just prior to use by application of a solvent.

Ambient temperature
The temperature in the surrounding area.

Anaerobic Adhesive
Anaerobic adhesives cure in the absence of air and the presence of active metals.

Aqueous
Relating to or made with water.

Assembly
A group of materials or parts, including adhesive, which has been placed together for bonding or which has been bonded together.

Assembly Time
The time interval between the spreading of the adhesive on the adherend and the application of pressure or heat, or both, to the assembly.

Autoclave
A steam sterilization process under pressure at 115-134°C.  Aggressive to many plastics and adhesives but can be tolerated by Cyabond®'s Single Part Epoxies.

B

Batch
The manufactured unit or a blend of two or more units of the same formulation and processing.

Binder
A component of an adhesive composition that is primarily responsible for the adhesive forces which hold two bodies together.

Blister
An elevation of the surface of an adherend, somewhat resembling in shape a blister on the human skin; its boundaries may be indefinitely outlined and it may have burst and become flattened.  A blister may be caused by insufficient adhesive; inadequate curing time, temperature or pressure; or trapped air, water, or solvent vapor.

Bond
The union of materials by adhesives. To unite materials by means of an adhesive.

Bond Line
The layer of adhesive, which attaches two adherends.

Bond Strength
The unit load applied in tension, compression, flexure, peel, impact, cleavage, or shear, required to break an adhesive assembly with failure occurring in or near the plane of the bond.

B-Stage
An intermediate stage in the reaction of certain thermosetting resins in which the material softens when heated and swells when in contact with certain liquids, but may not entirely fuse or dissolve.  The resin in an uncured thermosetting adhesive is usually in this stage.  Sometimes referred to as Resitol.

C

Cartridge (EDS)
A rigid container in which adhesives in pre-measured quantities are supplied. Cartridges can be either side-by-side (EDS) or a single tube. A dispensing gun is required.

Catalyst
A substance that markedly speeds up the cure of an adhesive when added in minor quantity as compared to the amounts of the primary reactants.

Centipoise (cP)
Viscosity measurement where water is 1 cP (also see mPas)

Coaxial joint
One where parts share the same axis.

Coefficient of thermal Expansion
The measured expansion of a product under heat measured per 1°C rise or fall in temperature.

Cohesion
The state in which, the particles of a single substance are held together by primary or secondary valence forces.  As used in the adhesive field, the state in which the particles of the adhesive (or the adherend) are held together.

Cold Pressing
A bonding operation in which an assembly is subjected to pressure without the application of heat.

Cold Storage
Some adhesives should be stored in refrigerators or freezers.  This is normally, specified by the manufacturer.

Composite
A substrate made up normally of two or more materials combined to obtain a synergistic effect. In some cases it may be comprised of combinations of one material aligned to achieve optimum properties for example plywood.

Compression Strength
The resistance to rupture under inward pressure.  Adhesives generally perform well under compression.

Condensation
A chemical reaction in which two or more molecules combine with the separation of water or some other simple substance.  If a polymer is formed, the process is called polycondensation.

Conditioner
A substance used to prepare a surface/substrate prior to bonding.

Consistency
That property of a liquid adhesive by virtue of which it tends to resist deformation.  Consistency is not a fundamental property but is comprised of viscosity, plasticity, and other phenomena.

Crazing
Fine cracks that may extend in a network on or under the surface of or through a layer of adhesive.

Creep
The dimensional change with time of a material under load, following the initial instantaneous elastic or rapid deformation. Creep at room temperature is sometimes called Cold Flow.

Crosslinking
The chemical combining of monomers, oligomers and/or polymers to enhance their properties which also renders them insoluble.

Cryogenic
Very low temperatures - usually below 115°Kelvin - almost all Cyabond® products are not suitable for this use.

Cure
To change the physical properties of an adhesive by chemical reaction, which may be condensation, polymerization, or vulcanization; usually accomplished by the action of heat and catalyst, alone or in combination, with or without pressure.

Cure Temperature
The temperature to which an adhesive or an assembly is subjected to cure the adhesive.

Cure Time
The period of time during which an assembly is subjected to heat or pressure, or both, to cure the adhesive.

Cyanoacrylate Adhesive
Cyanoacrylate adhesives are adhesives whose cure process is initiated with moisture.

Cytotoxicity Test
A biocompatibility test performed as an extract or overlay on tissue culture cells.

D

Damping
The property of a material to dissipate energy.

Dark Reaction
Reactions which take place in closed containers of light curable formulations - usually premature polymerization.

Delamination
The separation of layers in a laminate because of failure of the adhesive, either in the adhesive itself or at the interface between the adhesive and the adherend.

Dielectric Strength
A measurement of the maximum voltage the adhesive can withstand before electrical insulation breaks down.

Dilatant Fluid
A fluid whose viscosity increases with increased shear rate.

Diluent
An ingredient, usually added to an adhesive to reduce the concentration of the bonding materials.

Dismantling
The un-doing of a joint, either by force, soaking in solvent or applying excess heat to soften the adhesive before breaking the bond.

Disposable Nozzle
A tube made from plastic, which connects to the end of the cartridge to enable dispensing of adhesive fully mixed direct onto part to be bonded.

Doped Lamps
The specific wavelengths emitted from an ultraviolet lamp are mainly dependent upon the fill.  Using mercury as the norm, the spectral output can be changed by the addition of dopants such as beryllium or iron.

Ductility
A material property that allows deformation (bending, stretching, twisting) without fracture.

Durometer
A device used to determine the hardness of a material.

E

Elastomer
A macromolecular material which, at room temperature, is capable of recovering substantially in size and shape after removal of a deforming force.

Electromagnetic Spectrum
The entire range of wavelengths of electromagnetic radiation, extending from gamma rays to the longest radio waves and including microwave, ultraviolet, visible and infrared.

Electron Beam Sterilization
Special treatment, which destroys any organisms or microbes through a destruction of their vital molecules through an indirect chemical reaction. Similar to gamma irradiation.

Encapsulation
Process to completely envelop an object in adhesive, which is normally used to protect sensitive items.

Endothermic
A chemical reaction which absorbs heat.

Epoxy – 1 Part
Single part adhesive, which cures at elevated temperatures. Excellent durability but limited to whether the substrates can take the heat necessary to cure the adhesive.

Epoxy – 2 Part
A two part adhesive, which cures at room temperature.  Very versatile, used for many applications from fast repairs through to structural bonding.

EtO (ethylene oxide) Sterilization
Uses a toxic gas under very controlled environment.  This is a regulated process usually used by medical device manufacturers for sterlization purposes.

Exothermic
A chemical reaction which gives off heat.

Extinguishing/Self-Extinguishing
A compound or adhesive with resistance to burning.

F

Failure, Adhesive
Rupture of an adhesive bond, such that the separation appears to be at the adhesive adherend interface. Sometimes termed failure in adhesion.

Failure, Cohesive
Rupture of an adhesive bond, such that the separation appears to be within the adhesive.

Failure, Substrate
A situation where one or other of the substrates is damaged but the actual adhesive joint remains intact.

Filled
An adhesive, which incorporates solid particles to change its properties - i.e. electrical conductivity or to increase the gap-filling capability.

Filler
A relatively nonadhesive substance added to an adhesive to improve its working properties, permanence, strength, or other qualities.

Fillet
That portion of an adhesive, which fills the corner or angle formed where two adherends are joined.

Flash Point
The temperature in degrees °F (°C) at which a liquid gives off sufficient vapor to form a flammable or ignitable mixture with air.

Flow
Movement of an adhesive during the bonding process, before the adhesive is set.

Focal Distance
The distance from a lamp assembly at which the peak energy can be obtained.

Free Radical
A reactive species having an unpaired electron, which initiates a reaction with a double bond, e.g., acrylic polymerization.  It is produced from its stable paired state by energy absorption.

Free Radical Reaction
A chemical reaction, which takes place only when a free radical or molecule, which has lost one electron is generated.

FRP
Fiber Reinforced Plastic (see also GRP)

Full Cure
When the adhesive has reached its full strength - in contrast to its working strength.

G

Gel
A semisolid system consisting of a network of solid aggregates in which liquid is held.

Gel (cure)
A description of an adhesive as it hardens from liquid to solid.

Gel (viscosity)
Term to describe the viscosity of an adhesive which is gelling.

Gel Time
The amount of time it takes for an adhesive to reach a gel cure state.

Glass Transition Temperature (Tg)
The temperature where the material changes from a flexible condition to quite hard and brittle condition or vice versa.

Glue Line
The layer of adhesive which is between the two substrates.

GRP
Glass Reinforced Plastic (see also FRP)

H

Handling Time
The time after which a bonded unit may be moved to continue the assembly process, but no significant loads should be exerted on the bond line.

Hardener
A substance or mixture of substances added to an adhesive to promote or control the curing reaction taking part in it.  The term is also used to designate a substance added to control the degree of hardness of the cured film.

Hardness
When related to a fully cured adhesive, the Shore method is adapted. Usually adhesives are categorized as Shore D (being hard) and Shore A for more rubbery materials.

Hardness Change
Hardness (durometer) gained or lost by a material after exposure to a test.

HDPE
High density polyethylene - tough waxy material with good chemical resistance, may be bonded but needs special surface treatment.

Heat curing
To effect the change from liquid to solid for an adhesive which has to be heated - usually anywhere between 30 - 180°C.

Hygroscopic
Materials which have a tendency to absorb moisture from the atmosphere.

I

Impact Strength
The measurement of a material’s ability to withstand shock loading.

Impregnating
The process of imbedding a liquid into a porous solid to change its physical properties.

Induction curing
Cures the adhesive by heating one of the ferrous metal substrates using induction. Very rapid setting times can be achieved.

Infrared Energy
Photon energy having wavelengths between 1 and 100 microns.

Inhibitor
A substance that slows down chemical reaction. Inhibitors are sometimes used in certain types of adhesives to prolong storage or working life.

Initiator
A substance, which starts the cure process.

IR
Infra red

ISO 10993
International Standard for biocompatibility testing. Test selection is based on the type of device; Surface Device, External Communicating Device, and Implant Devices.

J

Joint
The location at which two adherends are held together with a layer of adhesive.

Joint, Lap
A joint made by placing one adherend partly over another and bonding together the overlapped portions.

Joint, Scarf
A joint made by cutting away similar angular segments of two adherends and bonding the adherends with the cut areas fitted together.

Joint, Starved
A joint that has insufficient amount of adhesive to produce a satisifactory bond.  This condition may result from too thin a spread to fill the gap between the adherends, excessive penetration of the adhesive into the adherend, too short an assembly time, or the use of excessive pressure.

K

Kelvin (K)
A temperature scale with the same increments as the Celsius, beginning at absolute zero (-273°C, or –459.67°F).

L

Laminate
A product made by bonding together two or more layers of material or materials.  To unite layers of material with adhesive.

Lap Shear
The stress which is seen on an overlapping joint when loaded in tension.

M

Microwave
Energy having wavelengths between 1 and 10 millimeters.

Migrating
The movement of atoms from one position to another in molecular rearrangement.

Modifier
Any chemically inert ingredient added to an adhesive formulation that changes its properties.

Modulus of Elasticity
The measure of the inherent value of elasticity, which a material possesses.

Monomer
A molecule of relative low molecular weight and simple structure capable of combining with itself or other similar molecules through reactive sites to form polymers.

MPa.s
Millipascal (Mpa.s.) seconds is a measurement of viscosity where water equals 1. Same as centipose (cP).

N

Nanometer
A unit of distance commonly used in measuring wavelength in the electromagnetic spectrum - one billionth of a meter (10^-9 meter).

Novolak
A phenolic-aldehydic resin that, unless a source of methylene groups is added remains permanently thermoplastic.

Nylon
The common name for a family of plastics, also known as polyamides.

O

Oligomer
A lower molecular weight resin or polymer which is used in a radiation cureable formula.

Outgassing
The vapors/fumes which are given off when an adhesive is subject to heat or to vacuum.

Oxygen Inhibition
The effect of oxygen which terminates or retards the rate of polymerization.

P

Paste
An adhesive composition having a characteristic plastic-type consistency, that is, a high order of yield value, such as that of a paste prepared by heating a mixture of starch and water and subsequently cooling the hydrolyzed product.

PC
Polycarbonate (PC) is a rigid plastic susceptible to stress cracking with certain adhesives.

PEEK
Polyether etherketone

Peel Strength
Measured adhesive performance when substrates are peeled apart.

PEI
Polyether imide (PEI) is a heat resistant thermoplastic.

Perspex
A clear acrylic material (trade name for acrylic polymer), that can be bonded.  Susceptible to stress cracking.

PES
Polyether sulphone (PES) is a thermoplastic offering good chemical resistance.

PET
Polyethylene terephtalate (PET) is a rigid thermoplastic offering good wear resistance and good chemical resistance which is bondable but surface preparation is important.

Photoinitiator
A molecule which when exposed to a specific wavelength of energy forms a reactive species which starts the chain reaction to cause polymer formation.

Photon
Radiant energy viewed as bundles of energy.

Plastic
Term for a wide range of synthetic materials fabricated from organic compounds.

Plasticity
A property of adhesives that allows the material to be deformed continuously and permanently without rupture upon the application of a force that exceeds the yield value of the material.

Plasticizer
A material incorporated in an adhesive to increase its flexibility, workability, or distensibility.  The addition of the plasticizer may cause a reduction in melt viscosity, lower the temperature of the second order transistion, or lower the elastic modulus of the solidified adhesive.

Polymer
A macromolecule consisting of a large number of monomer units.  The molecular weights may range from about 20,000 into the millions.

Polymerisation
See Polymerization

Polymerization
A chemical reaction in which the molecules of a monomer are linked together to form large molecules whose molecular weight is a multiple of that of the original substance.  When two or more monomers are involved, the process is called copolymerization or heteropolymerization.

Polypropylene (PP)
Polypropylene is a low cost thermoplastic, which may be bonded but requires special surface treatment.

Porosity Sealing
Sealing of pin holes in welded or cast materials.

Post Cure
A treatment (normally involving heat) applied to an adhesive assembly following the initial cure, to modify specific properties.  To expose an adhesive assembly to an additional cure, following the initial cure, for the purpose of modifying specific properties.

Pot Life
The time in which an adhesive may be used before it starts to skin or film over.

Potting
The processes of filling or coating parts to protect them from shock, vibration or environmental hazards such as water.

PPO
Polyphenylene oxide - rigid strong thermoplastic.

Preproduction Test
A test or series of tests conducted by 1) and adhesive manufacturer to determine conformity of an adhesive batch to established production standards, 2) a fabricator to determine the quality of an adhesive before parts are produced, or 3) an adhesive specification custodian to determine conformance of an adhesive to the requirements of a specification not requiring qualification tests.

Primer
A coating applied to a surface, prior to the application of an adhesive, to improve the performance of the bond.

Psi
Pounds per Square inch - for measuring pressure, shear, compression or tensile stress.

PSU
Polysulfone - tough rigid high strength thermoplastic

PTFE
Polytetrafluroethylene

PVC- Polyvinyl Chloride (uPVC)
PVC is a soft flexible plastic, which may be made rigid and is then known as uPVC.

PVDF
Polyvinylidene fluoride

Q

Qualification Test
A series of tests conducted by the procuring activity, or an agent thereof to determine conformance of materials, or materials system, to the requirements of a specification which normally results in a qualified products lists under the specification.  Generally, qualification under a specification requires conformance to all tests in the specification, or it may be limited to conformance to a specific type or class, or both, under the specification.

QUV Exposure
A common test used to measure the yellowing of a surface. A coated panel is exposed for 500 hours in a QUV(R) chamber.  The chamber runs on a cycle of 12 hours of UV light exposure and 12 hours of 40°C/100% humidity.

R

Reactive Diluent
A chemical, which serves two purposes in a formulation: thinning or viscosity reduction and providing reactivity with other ingredients for curing or polymerization.

Resin
A solid, semisolid, or psuedosolid organic material that has an indefinite and often high molecular weight, exhibits a tendency to flow when subjected to stress, usually has a softening or melting range, and usually fractures conchoidally.

Rheology
The way materials flow - relating to liquids and plastics.

Room Temperature
Generally taken as being between 20°C and 30°C (68°F and 86°F).

S

Sag
Also known as slump relating to the flow of the adhesive.

Service Temperature
A range between which a cured adhesive may be used and considered to perform adequately.

Set (Setting)
To convert an adhesive into a fixed or hardened state by chemical or physical action, such as condensation, polymerization, oxidation, vulcanization, gelation, hydration, or evaporation of volatile constituents.

Shear Strength
The measured ability of a material to withstand shear stress.

Shear Stress
The effects of forces acting in parallel but opposite directions.

Shelf Life
The amount of time a material may be stored under specified conditions with no significant changes in properties.

Silicone
Generally very flexible sealants

Solids Content
Percentage by weight of the nonvolatile matter in the adhesive.

Solids, %
See Solids Content

Solvent
A liquid, which is capable of dissolving uncured and cured adhesives.  Also, may be used as a catalyst to initiate cure of some types of adhesives.

Specific Gravity (SG)
Ratio of the density of a substance to that of water, where water is equal to 1.

Static Mixer
A nozzle, which is used in conjunction with a twin barrelled cartridge.  The nozzle contains a mixing element to ensure that as the adhesive is pushed down through the nozzle it mixes thoroughly. These nozzles allow fully mixed product to be applied direct to the work piece, and remove the need to mix by hand and the risk of entrapping air within the adhesive.

Stress cracking
Certain adhesives may cause some plastics to "relax" or "crazy pave".

Structural Acrylic Adhesive
An adhesive whose formulation is based on acrylic chemistry, which is capable of meeting significant load requirements.

Structural Adhesive
A bonding agent used for transferring required loads between adherends exposed to service environments typical fro the structure involved.

Substrate
A material upon the surface of which an adhesive-containing substance is spread for any purpose, such as bonding or coating.  A broader term than adherend.

Surface Preparation
A physical or chemical preparation, or both, of an adherend to render it suitable for adhesive joining.  A method by which a substrate is made suitable to be bonded.

Synthetic
A material produced by chemical means, which is not naturally occurring.

T

Tack
The property of an adhesive that enables it to form a bond of measurable strength immediately after adhesive and adherend are brought into contact under low pressure.

Tensile Strength
The stress an adhesive can withstand without fracturing, normal to the duration of loading.

Thermocouple
An electric device used to monitor temperature.

Thermoplastic
A material capable of being repeatedly softened by heat and hardened by cooling.

Thermoset
A material that will undergo or has undergone a chemical reaction by the action of heat, catalysts, ultraviolet light, etc., leading to a relatively infusible state. A plastic which, when heated, will not melt but will eventually char and burn.

Thixotropic
Non-drip characteristic – an adjective to describe a material, which will thin on shearing and then recover a gel like structure on standing.

Thixotropy
A property of adhesive systems to thin upon isothermal agitation and to thicken upon subsequent rest.

Torque strength
The resistance to a turning force about an axis.

Toughening
A system designed to arrest crack propagation within an adhesive.

U

UHMWPE
Ultra high molecular weight polyethylene - good wear resistance, good impact performance but to be bonded needs special surface treatments.

Ultraviolet Light (UV)
Radiant energy in the wavelength band of 180 to 400 nanometers.

USP Class VI Test
A set of biocompatibility tests, in which extracts and strips of cured adhesive or plastic are tested on mice and rabbits.

UV Curable Adhesive
An adhesive whose cure is initiated by UV light.

V

Viscosity
A measurement of the thickness of a liquid - usually measured in cP (centipoise) or mPa.s (millipascal seconds).  The ratio of the shear stress existing between laminae of moving fluid and the rate of shear between these laminae.  A fluid is said to exhibit Newtonian behavior when the rate of shear is proportional to the shear stress.  A fluid is said to exhibit non-Newtonian behavior when an increase or decrease in the rate of shear is not accompanied by a proportional increase or decrease in the shear stress.

Volatile OrganicCompounds
Organic chemicals, which evaporate easily (at low or ambient temperatures).

Vulcanization
A chemical reaction in which the physical properties of a rubber are changed in the direction of decreased plastic flow, less surface tackiness, and increased tensile strength by reacting it with sulfur or other suitable agents.

W

Warp
A significant variation from the original, true or plane surface.

Wedge test
Aircraft crack resisting test originated by Boeing.

Weight Change
Weight gained or lost by a material after exposure to a test condition.

Wetting
The coating of a substrate surface with an adhesive.

Wicking
The flow of a liquid along a surface into a narrow space, similar to capillary action.

Working Life
The period of time during which an adhesive, after mixing with catalyst, solvent, or other compounding ingredients, remains suitable for use.

Working Strength
A guide as to when the adhesive has sufficient strength to withstand a light, working load but is not yet fully cured.

Y

Yield Value
The stress (either normal or shear) at which a marked increase in deformation occurs without an increase in load.