Welcome! My dear friend,
I’ve collected some of professional vocabularies and
their English definitions in plastic, molding and testing
fields. You can search the related words and information
by pushing the bellow linked alphabet.
Hope it will help you a lot!
A B C D A B C D
E F G H E F G H
I J K L I J K L
M N O P M N O P
Q R S T Q R S T
U V W X U V W X
Y Z Y Z
The ability of a material to withstand mechanical actions such as rubbing, scraping, or erosion, that tend progressively to remove material from its surface. Accelerator
Additive which speeds up the rate of a cure reaction, much like a true chemical catalyst, not truly a part of the reaction or otherwise required by or consumed in the reaction. Acceptable Runner/Cavity Ratio
Runner systems designed for high pressure drops to minimize material usage and increase frictional heating in the runner.
Additives are materials that are added to a polymer to produce a desired change in material properties or characteristics. A wide variety of additives are currently used in thermoplastics, to expand or extend material properties, enhance processability, modify aesthetics, or increase environmental resistance. Additives enhance properties like flame retardancy and UV light stability. Reinforcing fibers modify mechanical properties: improve modulus and lower impact. Fillers usually increase modulus values. Fillers are also used to modify molding properties or to lower costs. Plasticisers lower modulus and enhance flexibility.
The process of joining two or more plastic parts by means of an adhesive. Afterflame
Persistence of flaming of a material after the ignition source has been removed. After-flame time or duration of flame is the length of time for which a material continues to flame, under specified test conditions, after the ignition source has been removed. "Self-extinguishing" and "Self-extinguishability" are terms which are: not recommended, owing to the risk of misunderstanding.
Persistence of glowing of a material after flaming has stopped or - if no flaming occurs - after the ignition source has been removed.
Aging is a change in the chemical and/or physical structure of a material caused by heat or light. It can result in a major decrease of property values. Also called degradation or deterioration.
A method of atomizing paint by hydraulic pressure.
Terms used in the plastics industry to denote blends of polymers or copolymers with other polymers or elastomers. - i.e. ABS/Polycarbonate. Polymer blends are combinations of two or more different miscible polymers: mechanically entangled rather than chemically bonded. Blending is a process of mixing or reacting two or more polymer resins to obtain improved properties of the product. Blending allows for tailoring of specific properties. Each individual polymer has desirable characteristics but lacks some specific property. When these individual properties are combined the resultant blend or alloy will exhibit characteristics from each of the parent polymers. In general, no clear difference is seen between the terms 'alloys' and 'blends'. Ambient Temperature
The temperature of a medium surrounding an object. The term is often used to denote prevailing room temperature.
As a thermoplastic polymer melt solidifies, the chains of molecules can combine to form ordered molecular structures or crystallites. Amorphous polymers are polymers, which are not able to crystallize. They are randomly oriented and do not exhibit any ordered molecular structure at all. Amorphous resins rely on increased chain lengths (higher molecular weight) and physical entanglements for structural integrity. The structure "looks like spaghetti". A crystalline polymer has a polymer chain showing an ordered molecular structure - crystalline regions surrounded by amorphous ones. The term "crystalline" is actually wrong, since crystalline polymeric materials are only "semi-crystalline" in nature. The crystalline structure does not exist through the entire polymer: there are regions of ordered molecular structure and also regions of no order. Anisotropic/Isotropic
Anisotropic means, "exhibiting properties with different values when measured along axes in different directions". The properties in anisotropic materials may differ with the direction in which they are measured; in isotropic materials the properties are independent of the direction in which they are measured.
The tendency of a material to react differently to stresses applied in different directions. Annealing
The process of relieving stresses in molded plastic articles by heating to a predetermined temperature, maintaining this temperature for a predetermined length of time, and slowly cooling the articles to be painted which might craze due to solvent attack.
Abbreviation for American National Standards Institute.
Additives which prevent or reduce the condensation of water on a plastic film in the form of small droplets which resemble fog.
Additives which inhibit oxidation at normal or elevated temperatures.
An antistatic agent is a chemical which is compounded into a plastic material, or is a coating on the surface. It has the effect of decreasing the surface resistivity, which avoids generation of static electricity on the surface and avoids attraction of dust. Low level of agents: 搇ow dust.?Higher levels create 揳ntistatic?behavior.
Designers are interested in knowing the strain resulting from a known stress at a given temperature and time. The increased strain at constant stress may be reported as apparent modulus. Also called 搑educed modulus.? Indicates the stiffness of a material
after it has been under a load for a period of time.
An actual part molded out of thermoplastic material.
The ability of a plastic material to resist breakdown when a high voltage, low current electrical arc is sent just above the surface. The amount of time that it takes the arc to form along the surface instead of through the air is the listed rating. Useful for comparison only. Adherence to UL specifications must be maintained.
Arc tracking is the formation of a conducting path across the surface of an insulating material by arc discharge. Arc resistance is a measure for the insulation characteristics of a resin against that high voltage arc; it is the number of seconds that a material resists the formation of a surface conducting path when subjected to an intermittently occurring arc of high voltage, low current characteristics. Useful for comparison only. Tested according to UL746A or ASTM D495: See also PLC.
Arc Tracking Rate
The rate that an arc can be produced on the surface of a material. Typical units are in/min. Useful for comparison only. Adherence to UL specifications must be maintained.
Artificially Balanced Runner System
Balancing a runner system by adjusting the pressure drop of a long large diameter runner against a short small diameter runner. Since pressure drop over the small diameter runner will be much more affected by heat loss than the large diameter runner, an artificially balanced runner system will work with a set range of molding conditions.
The width of this range of molding conditions determines the stability of the molding.
The solid residue remaining after a substance has been incinerated or heated to a temperature sufficient to drive off all combustible or volatile substances. Assembly
The process of joining parts by any of several methods.
ASTM, or the American Society for Testing Materials - founded in 1898 - is a scientific organization formed for 搕he development of standards on characteristics and
performance of materials, products, systems and services? It is the world抯 largest
source of voluntary consensus standards.
The melt flows back out of the mold, returning to the runners.
The applied hydraulic pressure used to restrict the shot size formation. Applied to the back of a melt accumulator or reciprocating screw. Used to control screw drift, mixing, and shot size adjustments. In molding, back pressure increases the temperature of the melt, and contributes to better mixing of colors and homogeneity of the material. Balanced Runner
In injection molding, a runner system designed to place all cavities at the same distance from the sprue.
The ball indentation method determines the hardness of plastics by using a loaded ball indenter of predefined dimensions. Ball hardness H358/30 is derived: 358 newtons load divided by the surface area of the impression in the material after 30 seconds load application. It is expressed in N/mm2.
Ball Pressure Test
An indication of a material抯 ability to withstand heat generated by energized
electrical circuits. Material deformation is measured after heat and pressure have been applied. Components retaining live parts in position should pass at a minimum of 257oF (125oC).
Cylinder that contains the screw and the heaters. Built to withstand pressure of 7,500-20,000 psi.
Heaters that raise the barrel temperature in order to transform the thermoplastic material into a melt.
Solvent attack directly on the surface of the substrate.
Larger pieces of degraded material, typically caused by improper equipment design or lack of periodic preventive maintenance (size is 0.11 square millimeter or larger). Black Specks
A specific kind of inclusion/contamination often associated with degraded materials (0.10 square millimeter or smaller).
The process of removing flash from molded 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 plastic article caused by a pocket of air or gas beneath the surface.
An undesirable 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, stabilizer pigment, plasticizer, etc.
Blooming is the display of lubricant or plasticizer on the surface of a component. Plate-out is the separation of part of the stabilizer from the material which adheres to the metal surface of molds during the molding process.
The process of forming hollow articles by expanding a hot plastic element called a parison against the internal surfaces of a mold.
Blow Needles, Extrusion Blow Molding
Device used to pierce and inflate the parison, usually actuated by an air cylinder. Blow Pressure, Extrusion Blow Molding
Dimension of bottle divided by the parison diameter. Bottles usually have many ratios. However, only the maximum ratio usually needs to be considered.
A whitish surface appearance where moisture has condensed before solvent is all evaporated.
The tendency of a plastic article to turn white or chalky in areas that are highly stressed.
A protuberance provided on an article to add strength, facilitate alignment during assembly or for attaching the article to another part.
The growth of a new polymer chain from an active site on an established chain, in a direction different from that of the original chain.
The voltage required, under specific conditions, to cause failure of an insulation material. See Dielectric Strength.
Thick metal disc with several closely spaced holes that straighten the helical flow of the melt and hold the screen pack.
The characteristics of a brittle material - seen from the stress-strain curves - are a steep initial linear slope, low failure strain and little or no yielding. Ductile materials show a reduced initial slope, drastic deviation from linearity and a high failure strain. Toughness is the measure of a material抯 ability to absorb energy during plastic
deformation without showing brittle failure. Toughness can be calculated by the area beneath a stress/strain curve.
The temperature at which plastics and elastomers rupture by impact under specified conditions.
The density of a molding material in loose form expressed as a ratio of weight to volume.
The ratio of the volume of any given mass of loose plastic material to the volume of the same mass of the material after molding.
All physical and/or chemical changes that take place when a product and/or structure burns and/or is exposed to fire. "Rate of burning" or "burning rate" and "rate of flaming" are deprecated terms.
CAMPUS-Computer Aided Material Pre-selection by Uniform Standards - is a database system on PC diskettes developed by the plastics manufacturing industry to help the selection of materials for a specific application. It provides: -comparable data through uniform test specimen preparation and test methods (ISO standards) - continuous updates on product ranges and selection of test methods. For further information readers are asked to contact their local GE Plastics representative. Carrier
The pellet of resin, wax or other mechanism used to compound the active ingredient in manufacturing the chemical blowing agent.
In the true chemical sense, catalyst is a material which speeds up a reaction without truly being a part of the reaction or consumed by it. Red Spot and others in the trade incorrectly also call the polyisocyanate prepolymers portion of their two component polyurethane products "catalyst."
the interior opening in the mold where the part is formed.
The pressure generated in the mold cavity during the resin injection phase of the process.
CBA: Chemical Blowing Agent
A powder, liquid or pellet form blended with resin at a ratio to produce adequate foaming. The blowing agent decomposes during plastification resulting in a release of an inert gas. The gas is mixed with molten resin in the barrel and is held under pressure until injection
Usually denoted in stress equations by a lower case c, it is the maximum distance from the neutral axis to the outer surface. Important in determining the stresses on a part. Often with tall ribs, the centroidal distance becomes great, causing stress levels to exceed their allowable limits. It is not a material property; it is based entirely on the geometry of the part.
Dry chalk-like appearance or deposit on the surface of the part.
The amount of material used to load a mold at one time or during one cycle.
Charpy Impact Test
A destructive test of impact resistance, consisting of placing the specimen in a horizontal position between two supports, then applying a blow of known magnitude. If the specimen does not break, a new specimen is put in position and the magnitude is increased until the specimen breaks. (ASTM D-256, Method B)
Compatibility of plastic materials with a chemical agent, or environment, is highly influenced by contact time, stress level of the parts, temperature and other phenomena. Environments - harmless to unstressed parts - may cause stress corrosion problems with highly stressed parts. In certain environments when a stressed part is combined with a chemical substance, failure occurs: this phenomenon is known as stress corrosion failure for crystalline polymers and environmental stress cracking (ESC) for amorphous polymers. Micro crazing is initiated, the agent penetrates the plastic, which in turn promotes cracks. These cracks may lead to deterioration and finally complete failure of the part after a period of time. Certain chemicals known as "solvents" may dissolve thermoplastics. Cracks and crazes are defined as follows. A craze is a defect at or under the surface of a plastic, due to apparent cracks, commonly caused by ESC. A crack is a fissure that may or may not penetrate the external surface of a plastic. The material is completely separated between the crack walls. These cracks may lead to deterioration and finally complete failure of the part after an unpredictable period of time. Chemical resistance is defined as the resistance to change of mass, dimensions or other properties of plastics after immersion in chemicals, when tested according to ISO 175. Test data on standardized specimen only give an indication. Chemical compatibility should always be tested on formed components under actual conditions.
A type of fiber reinforcement consisting of strands of individual glass fibers which have been chopped into short pieces.
The pressure required to keep the mold closed during resin injection. Usually between 3 to 5 tons per square inch of projected area.
The largest rated molding area an injection press can hold closed under full molding pressure.
In injection molding, the pressure which is applied to the mold to keep it closed, in opposition to the fluid pressure of the compressed molding material within the mold cavity and the runner system.
In injection molding, the pressure applied to the mold to keep it closed during the molding cycle.
Coefficient of Thermal Expansion (CTE)
A measure of how much a material will lengthen (or shorten upon cooling) based on its original length and the temperature difference it is exposed to. It becomes important when dimensions are critical or when two different materials with different CTE's are attached to each other, such as an unfilled thermoplastic and steel. Stress induced by this difference can become considerable.
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.
Material deformation under a load (at the glass transition temperature or below). Cold Slug
A hard piece of semi-cured resin usually a result from a nozzle drool. A surface imperfection close to the resin gate often resembling a nail.
Dyes or pigments which impart color to plastics.
A plastic compound which contains a high percentage of pigment, to be blended in appropriate amounts with the base resin so that the correct final color is achieved. Combustion
Exothermic reaction of a substance with an oxidizer, generally accompanied by flames and/or glowing and/or smoke emission. Combustible: capable of burning. Non-combustible: not capable of undergoing combustion under specified test conditions. Glowing combustion: combustion of a material in the solid phase without flame but with emission of light from the combustion zone. Incandescence: emission of light produced by a material when intensely heated; it can be produced with or without combustion.
Comparative Track Index
The voltage which causes an arc to go across the surface of a material after 50 drops of 0.1% ammonium chloride solution have fallen on the surface in between the electrodes. Useful for comparison. Adherence to UL specifications should be checked. Composite
A solid product consisting of two or more distinct phases: a binding material (matrix) and a fibrous material, such as glass mat. Examples are TPS resins: Azdel, Azloy and