The following guide is offered as an aid to understanding some of the language used in our website and throughout the rubber industry.
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 - top
Abrasion Resistance
Accelerator
Aging
Ambient Temperature
Antioxidant
Antistatic Agents
Ash Content
Assembly
ASTM
Autoclave
B - top
Barrel
Blast Finishing
Blister
Bloom
Brittleness Temperature
Burned
C - top
Calender
Cavity
CTE
Coextrusion
Composite
Compound
Compounding
Compression Moulding
Compressive Strength
Conditioning
Copolymer
Cross-Linking
Cryogenic
Cure time
Custom Moulder
Cycle Time
D - top
Degradation
Delamination
Density
Die
Dimensional stability
Durometer
E - top
Elasticity
Elastomer
Engineering Plastics
Extrudate
Extruder
Extrusion
F - top
Fatigue Strength
FDA
Filler
Finish
Flame Retardant
Flame Retardants
Flash
Flex Life
Forming
Fracture
G - top
Gasket
Gauge
H - top
Hardness
I - top
Impact Resistance
Impact Strength
Injection Moulding
Insert
ISO
J - top
K - top
K-Factor
Kink
L - top
Low Temperature Flexibility
M - top
Material Safety Data Sheets
Mechanical Property
Memory
Mineral Reinforcements
Minimum Specifications
Modulus
Modulus in Compression
Modulus in Flexure
Modulus in Shear
Modulus of Elasticity
Modulus of Resilience
Moisture Absorption
Mould (n)
Mould (v)
Mould Release
Moulding Cycle
Moulding Pressure
Molecular Weight
Molecule
Monomer
N - top
O - top
Opaque
Open Steam Cure
Optimum Cure
Oxygen Index
Ozone Resistance
P - top
Parting Line
Plastic
Plastic Deformation
Plasticity
Plasticize
Plasticizer
Poisson's Ratio
Polymer
Polymerization
Polymer Structure
Proportional Limit
Prototype Tool
Purging
Pure Gum
Q - top
R - top
Recovery
Regrind
Reinforced Plastic
Reinforcement
Reversion
S - top
Screw
Shear Strength
Shot
Shot Capacity
SI
Solvents
Specific Gravity
Specific Volume
Stiffness
Stock
Strain
Stress
Stress-Strain Curve
T - top
Tack
Tensile Strength
Thermoforming
Thermoplastics
Thermoplastic Elastomers
Thermosets
Tool
U - top
Ultimate Elongation
Ultimate Strength
V - top
Virgin Material
Viscosity
Void
Vulcanisation
W - top
Weathering
X - top
Y - top
Z - top
The ability of a material to withstand mechanical actions such as rubbing, scraping, or erosion, that tend progressively to remove material from its surface.
An additive which changes the rate of cure of a rubber compound.
The process of, or the results of, exposure of rubber to natural or artificial environmental conditions for a prolonged period of time.
The temperature of a medium surrounding an object. The term is often used to denote prevailing room temperature.
Additives which inhibit oxidation at normal or elevated temperatures.
Chemicals which impart a slight to moderate degree of electrical conductivity to elastometric or plastic compounds, thus reducing the accumulation of electrostatic charges on finished articles.
The solid residue remaining after a substance has been incinerated or heated to a temperature sufficient to drive off all combustible or volatile substances.
The process of joining parts by any of several methods.
Abbreviation for American Society for Testing and Materials.
Vessel used for vulcanising rubber under heat and steam pressure.
That part of an extruder inside which the feed screw is located.
The process of removing flash from moulded objects and/or dulling their surfaces, by impinging media such as crushed apricot pits, walnut shells or plastic pellets upon them with sufficient force to fracture the flash.
An imperfection on the surface of a rubber article caused by a pocket of air or gas beneath the surface.
Cloudy effect or whitish powdery deposit on the surface of a plastic article caused by the exudation of a compounding ingredient such as a lubricant, stabiliser pigment, plasticiser, etc. often deliberately incorporated as an antitoxidant layer to the moulded part.
The temperature at which plastics and elastomers rupture by impact under specified conditions.
Showing evidence of excessive heating during processing or use of a rubber, as evidenced by blistering, discolouration, distortion or destruction of the surface.
A multi-rolled machine used to form thin sheets of uncured compound for onward processing. Also used to friction or impregnate fabric with rubber compound.
A depression, or a set of matching depressions, in a plastics-forming mould which forms the outer surfaces of the moulded articles.
Coefficient of Thermal Expansion: The change in length of a material for a unit change in temperature, per unit of length.
The process of extruding two or more materials through a single die with two or more orifices arranged so that the extrudates merge and weld together into a laminar structure before chilling.
An article or substance containing or made up of two or more different substances.
A mixture of base polymer and the ingredients necessary to modify the resin to a form suitable for processing into finished articles.
The step of mixing base polymer with additives such as stabilisers, fillers, pigments into a form suitable for processing into finished articles.
A method of moulding in which the moulding material, generally preheated, is placed in an open heated mould cavity, the mould is closed with a top force, pressure is applied to force the material into contact with all mould areas, and heat and pressure are maintained until the moulding material has cured. This process is most often used with thermoses.
The load sustained by a test specimen in a compressive test divided by the original area of the specimen.
Subjecting a material to standard environmental and/or stress history prior to testing.
This term usually, but not always, denotes a polymer of two chemically distinct monomers.
The setting up of chemical links between the molecular chains.
Pertaining to very low temperatures.
The length of time required for a material to achieve a desired state of cure with its physical properties developed.
A firm specializing in the moulding of items or components to the specifications of another firm which handles the sale of distribution of the item, or incorporates the custom moulded components in one of its own products.
In a moulding operation, cycle time is the time elapsing between a particular point in one cycle and the same point in the next cycle.
A deleterious change in the chemical structure, physical properties or appearance of a plastic caused by exposure to heat, light, oxygen or weathering.
Separation of two or more surfaces in a composite material.
(Absolute) Mass per unit volume of a substance.
Tooling through which uncured compound is forced in the extrusion process to form a profile.
The ability of a plastic part retain the precise shape in which it was moulded.
An instrument used for measuring the hardness of a material.
The ability of a material to quickly recover its original dimensions after removal of a load that has caused deformation.
A material which at room temperature can be stretched repeatedly and, upon immediate release of the stress, will return with force to its approximate original length.
A broad term covering all plastics, with or without fillers or reinforcements, which have mechanical, chemical and thermal properties suitable for use, in construction, machine components and chemical processing equipment.
The product or material delivered from an extruder, for example, profiles, tubing, squares.
A machine for producing more or less continuous lengths of rubber sections such as rods, sheets, tubes, and profiles.
The process of forming continuous shapes by forcing uncured rubber compound through a die.
The maximum cyclic stress a material can withstand for a given number of cycles before failure occurs.
Abbreviation for Food and Drug Administration, the U.S. agency under the Department of Health, Education and Welfare which is concerned with the safety of products marketed for consumer use.
A relatively inert substance added to a rubber compound to reduce its cost and/or to improve physical properties, particularly hardness, stiffness and tensile properties.
The surface texture of a finished article.
Having the ability to resist combustion (A flame retardant plastic is considered to be one that will not continue to burn or glow after the source of ignition has been removed.)
Additives that reduce the tendency of rubbers to burn.
The thin, surplus of material which if forced into crevices between mating mould surfaces during a moulding operation remains attached to the moulded article.
The time during which a material can be expected to resist cyclical bending.
A general term encompassing processes in which the shape of rubber extrusions is changed to a desired configuration.
The separation of a body, usually characterised as either brittle or ductile.
A deformable material clamped between two surfaces so as to prevent loss of material or pressure and to create a seal.
Thickness.
Ability of a material to resist indentation. Measured using a prescribed hardness tester and expressed in International Rubber Hardness Degrees (IRHD)
The resistance of plastic articles to fracture under stresses applied at high speeds.
The ability of a material to withstand shock loading.
The method of forming objects from granular or powdered plastics, most often of the thermoplastic type, in which the materials is fed from a hopper to a heated chamber in which it is softened, after which a ram or screw forces the material into a mould. Pressure is maintained until the mass has hardened sufficiently for removal from the mould.
An article of metal or other material which is incorporated into a rubber moulded part either by pressing the insert into the finished moulded part or by placing the insert in the cavity so that it becomes an integral part of the moulding.
Abbreviation for the International Standards Organisation.
A term sometimes used for thermal insulation value or coefficient of thermal conductivity.
Deformation caused by bending or twisting a tube or profile so that it returns upon itself.
The ability of a plastic or rubber to be bent without fracture at reduced temperatures.
Documentation regarding the toxicity or hazards associated with contact with some substances. These are prepared by the manufacturer of the substance.
Properties of rubber and plastics which are classified as mechanical include abrasion resistance, creep, ductility, friction resistance, elasticity hardness, impact resistance, stiffness and tensile properties.
The tendency of a plastic article to revert in dimension to a size previously existing at some stage in its manufacture.
Inorganic substances used as filler for rubber and plastics. Some common examples are: clay, mica, talc.
The minimum values, usually of mechanical properties, that a compound must meet by Quality Assurance prior to shipment.
Derived from the Latin world meaning "small measure", modulus is the ratio of stress to strain in the linear region of the s-e curve.
The ratio of compressive stress to strain within elastic limits of the material.
The ratio of the flexure stress to strain, within elastic limits of the material.
The ratio of shear stress to strain within elastic limits of the material.
The ratio of stress to corresponding strain below the proportional limit of a material in tensile testing.
The energy that can be absorbed per unit volume without creating a permanent distortion.
The pick-up of moisture from the environment by a material.
A hollow form or matrix into which a plastic or rubber compound is placed and which imparts to the material its final shape as a finished article.
To impart shape to a plastic mass by means of a confining cavity or matrix.
In injection moulding, a lubricant used to coat the surface of the mould to enhance ejection of the moulded article or prevent it from sticking to the tool.
The period of time occupied by the complete sequence of operations on a moulding press requisite for the production of one set of moulded articles.
The pressure applied to the ram of an injection machine or press to force the softened plastic completely to fill the mould cavities.
The sum of the atomic weights of all atoms in a molecule.
The smallest unit quantity of matter which can exist by itself and retain all of the properties of the original substance.
A relatively simple compound, usually containing carbon and of low molecular weight, which can react to form a polymer by combination with itself or with other similar molecules or compounds.
Not able to transmit light.
Vulcanisation process during which the material to be cured is directly exposed to steam. On many compounds this leaves a distinctive surface signature.
The point at which the rubber compound has achieved its best possible physical properties.
A flammability test based on the principle that a certain volumetric concentration of oxygen is necessary to maintain combustion of a specimen after it has been ignited.
The ability of a material to withstand exposure to natural or machine produced ozone without crazing or cracking.
The mark on a moulded article caused by flow of material into the crevices between mould parts.
A material that contains as an essential ingredient one or more organic polymeric substances of large molecular weight, is solid in its finished state, and, at some stage in its manufacture or processing into finished articles, can be shaped by flow.
A change in dimensions of an object under load that is not recovered when the load is removed.
The ability of a material to withstand continuous and permanent deformation by stresses exceeding the yield value of the material without rupture.
To render a material softer, more flexible and/or more mouldable by the addition of a plasticiser.
A substance or material incorporated in a material (usually a plastic or an elastomer) to increase its flexibility, workability or extensibility.
The constant relating the changes in dimensions which occur when a material is stretched. It is obtained by dividing the change in width per unit length by the change in length per unit length.
(Synthetic) The product of a polymerisation reaction. The product of polymerisation of one monomer is called a homopolymer, monopolymer or simply a polymer. when two monomers are polymerised simultaneously the product is called a copolymer. The term terpolymer is sometimes used for polymerisation products of three monomers.
A chemical reaction in which the molecules of a simple substance (monomer) are linked together to form large molecules whose molecular weight is a multiple of that of the monomer.
A general term referring to the relative positions, arrangement in space, and freedom of motion of atoms in a polymer molecule.
The greatest stress which a material is capable of sustaining without deviation from proportionality of stress and strain. (Hooke's Law).
A preliminary mould built upon which the final mould will be based.
In extrusion or injection moulding, the cleaning of one colour or type of material from the machine by forcing it out with the new colour or material to be used in subsequent production, or with another compatible purging material.
Natural Rubber compound devoid of fillers, containing only curing agents. Also known as Para Rubber.
The degree to which a material will resume its shape after deformation under stress.
Waste material such as sprues, runners, excess parison material and reject parts from injection moulding, blow moulding and extrusion, which has been reclaimed by shredding or granulating. Regrind is usually mixed with virgin compound at a predetermined percentage for remoulding.
A plastic composition in which fibrous reinforcements are imbedded, with strength properties greatly superior to those of the base resin.
A strong, inert fibrous material incorporated in a plastic or rubber mass to improve its physical properties.
Degradation of a rubber compound characterised by tackiness due to overcure in manufacture or excessive heat in service.
In extrusion, the shaft provided with helical grooves which conveys the material from the hopper outlet through the barrel and forces it out through the die.
The maximum load required to shear the specimen in such a manner that the moving portion has completely cleared the stationary portion.Sheets are distinguished from films in the plastics industry only according to their thickness. In general, sheets have thicknesses greater than .040" .
One complete cycle of a moulding machine.
The maximum weight of material that can be delivered to an injection mould by one stroke of the ram.
Abbreviation for Le Systeme International d'Unites.
Substances with the ability to dissolve other substances.
The ratio of the density of a material as compared to the density of water at standard atmospheric pressure (1 ATM) and room temperature (73F).
The volume of a unit of weight of a material; the reciprocal of density.
The capacity of a material to resist elastic displacement under stress.
Uncured rubber compound with given composition from which a specific item is to be manufactured.
In tensile testing, the ratio of the elongation to the gauge length of the test specimen, that is, the change in length per unit of original length.
The force producing or tending to produce deformation in a body measured by the force applied per unit area.
The curve plotting the applied stress on a test specimen versus the corresponding strain. Stress can be applied through shear, compression, flexure, or tension.
Stickiness.
The maximum tensile stress sustained by the specimen during a tension test
The process of forming a thermoplastic sheet into a three-dimensional shape by clamping the sheet in a frame, heating it to tender it soft and flowable. Then applying differential pressure to make the sheet conform to the shape of a mould or die positioned below the frame.
Materials that become soft when heated and solid when cooled to room temperature. This softening and setting may be repeated many times.
The family of polymers that resemble elastomers in that they can be repeatedly stretched without distortion of the unstressed part shape, but are true thermoplastics and thus do not require curing.
Materials that may not be reheated and softened again. Once the structural framework is set, these plastics cannot be reformed.
The term used to describe an extrusion die or mould.
In a tensile test the elongation at rupture.
Term used to describe the maximum unit stress a material will withstand when subjected to an applied load in a compression, tension, flexural, or shear test.
Any compound or resin that has not been subjected to use or processing other than that required for its original manufacture.
A measure of the resistance to flow due to internal friction when one layer of fluid is caused to move in relationship to another layer.
In a solid rubber, an unfilled space.
A chemical reaction in a rubber compound caused by heat and pressure taking it from the uncured to the cured state.
A broad term encompassing exposure of plastics to solar or ultraviolet light, temperature, oxygen, humidity, rain, snow' wind, and air-borne biological and chemical agents.