Glossary of Materials and Processes Terms
Bag molding: A process in which plastics are molded into curved shapes by applying fluid pressure through a flexible cover that forces the material to be molded against a rigid die.
Co extrusion blow molding: A process for the extrusion of multilayer products using extruded multilayer tube (parison) material centered in the mold. The mold is closed and gas pressure is used to expand the parison to fit the mold cavity.
Composite: A material or materials system composed of a mixture or combination of two or more micro constituents or macro constituents that differ in form and chemical composition.
Compression Molding: The compression molding process uses matched steel molds to compress a weighed "charge" of sheet molding compound into a new and specific shape.
Ditactic polymer: A polymer that contains two sites of stereoisomerisms in the main chain of the configurational base unit.
Elastoplastic: An elastomer that contains transient cross links, unlike most elastomers; it softens when heated for processing and becomes solid yet maintains its elastic behavior upon cooling. Elastoplastics are derived from polyolefin's, polyurethane, polyesters and styrene copolymers.
Elastoplasticity: The state exhibited by a material that has deformed both elastically and plastically.
Extrusion blow molding: A method of processing polymers in the form of an open-end tub surrounded by a mold. The tube is used to increase air pressure to expand the material to fit the mold.
Fiberglass: Used to reinforce and/or strengthen plastics.
Hydro plasticity: The occurrence of plastic behavior.
Injection molding: A process where molten plastic is injected into a mold. About 60% of all plastics processing machines are injection molding types.
LPMC: A low pressure molding compound, similar to sheet molding compound (SMC), but is moldable at pressures around 100 lbs/psi.
Micro moulding: An emerging technology that takes injection molding technology down to a smaller scale.
Mold 24i: is a new material-evaluation feature that uses the press as a tool to gauge melt viscosity and determine operating temperatures, pressures and velocities.
Mold: A hollow form into which molten plastic is poured to form a designed shape when the material cools.
Plastic anisotropy: Variations in directions in the resistance of a material to plastic deformation.
Plastic deformation: The permanent deformation arising from the relative displacement of atoms or molecules.
Plastic Zone: A heavily plastically deformed region in a material, generally adjacent to the tip of a crack that can cause crack-tip blunting.
Plasticity: Fact of being plastic.
Plasticization: A process used to lower glass transition temperature; to improve the flexibility of certain polymers, allowing them to remain flexible well below the glass transition temperature of unplasticized materials.
Elasticized: A material that is capable of imparting flexibility to nonplastic material.
Plasticorder: Instrument that measures the temperature, viscosity and shear-rate relationships of a plastic substance to determine its eventual behavior.
Plasticoviscosity: Material whose rate of plastic deformation when subjected to stresses exceeding the yield stress is a linear function of the applied stresses.
Plastics: Materials of high molecular weight that consist primarily of synthetic polymers or condensates which can be shaped by flow into objects of diverse shapes and sizes.
Plastisol: Dispersion of resin in a plasticicizer that gels when heated.
Polystyrene acrylonitrile resin: A tough thermoplastic copolymer with excellent resistance to acids, banes and a few solvents.
Polyurethane Foam: A flexible or rigid cellular substance that is created through the reaction of a polyester with a diisocyanate, used primarily for insulation or padding.
Ram-fed injection molding: A high pressure injection molding process that utilizes a ram to force the molten plastic into a mold.
Reciprocating-screw molding machine: An apparatus used in polymer processing in which pellets of a plastic are fed, compacted, melted and then forced into a mold cavity by means of a plunger.
SAAM (Self Aligning Actuating Mold): A low pressure, portable, turn-key. production molding system that requires no special site preparation.
Sandwich molding: A process by which a skin core structure, typically of two different polymers, is produced in a twin injection process.
Segmented polymer: Any of a class of thermoplastic elastomers derived from aromatic dicarboxylic acids, polyalkylene-ether glycols and short-chain diols; used for injection molded parts for footwear and automobiles and for wire coating, pressure sensitive adhesive, belts and hoses.
SMC (Sheet Molding Compound): A fiberglass reinforced composite material produced in a "sheet" format.
Specific modules: The modules of elasticity divided by the density.
Spectroscope: A device that can be used to identify the chemical composite of plastic waste containers and scraps.
Stress plastic: Show the stress lines in plastic using polarized light.
Stretch blow molding: A thermoplastic forming process in which an extruded or injection molded parison is stretched axially at a temperature close to its softening temperature and blow, either simultaneously or in two stages, to produce a final product of desired dimensions.
Styrene plastic: A plastic compound of polymerized styrene or copolymers containing styrene.
Styrene acrylonitrile resin: A solid thermoplastic copolymer of styrene and acrylonitrile that resists scratching, chemicals and stress.
Styrofoam: A form of polystyrene foams that is used in insulating materials, ice chests, drinking cups and flotation devices.
Superplasticity: The ability of a material to deform uniformly by an exceptionally large amount, usually at elevated temperatures.
Superpolymer: An extensive setting up of cross links between molecular chains, resulting in an infusible polymer such as in a thermosetting resin.
Symmetric laminates: Laminated fibrous composites with symmetrical stacking sequences for each ply above the midplane and there is a ply identical in composition and orientation at an equal distance below the midplane.
Synthetic polymer: A polymer that is manmade, such as plastics, elastomers and adhesive.
Thermoplastic recording: A form of recording in which the information is permanently impressed on plastic tape.
Thermoplastic: A group of polymers or relating to textile fibers and resin that can be easily softened on heating at high temperature; all synthetic fibers are thermoplastic.
Twin-screw compounding system: A system for mixing polymers with additives such as pigments, lubricants, stabilizers, cross-linking agents and plasticizers.
Twinning deformation: A plastic deformation process in which atoms are displaced to form a mirror image of the underformed region.
Vacuum forming: Plastic sheet forming in which a thermoplastic sheet is clamped to a holder and then heated and drawn into the mold by a vacuum.