All
| Term | Definition |
|---|---|
| Mandrel |
1.Core around which fiberglass impregnated with plastic resin is wound as in filament winding. 2.The portion of an extrusion die that forms the hollow centre in an extruded tube. |
| Manifold |
Configuration of piping in a block of metal that takes a single channel flow of resin from an extruder or injection molding machine and divides it into various flow channels to feed more than one outlet. |
| Masterbatch |
A concentrated blend of pigment, additives, filler, etc. in a base polymer. Masterbatch is added in small amounts to large volume of material (the same as or compatible with the base polymer) to produce the desired formulation. |
| Melt |
A thermoplastic stock which is in a molten state due to temperature. |
| Melt Fracture |
Is a phenomenon of melt extrudate in which the surface appears rough or wavy upon exit from the die. Melt fracture may appear uniformly or in certain sections only. |
| Melt Index |
The number of grams, of a thermoplastic resin which can be forced through a 0.0825 inch orifice when subjected to 2160 grams force in 10 minutes of 190 |
| Melt Instability |
An instability in the melt flow through a die that causes irregularities in the finished part. |
| Melt Strength |
The elastic strength of a polymer in the molten state. |
| Melting Point |
The temperature at which a resin changes from a solid to a liquid. |
| Metallocene Resins |
The structure of the metallocene catalyst molecule and the environment around its catalytic site can be changed to build different polymeric structures with specific properties. Each metallocene catalyst consists of identical molecules, which behave in the same way, resulting, in polymer consistency because each polymer chain produced in uniform. |
| Metering Zone |
The final zone of an extruder barrel, in which the melt is conveyed at a uniform rate to the breaker plate or die. |
| Micron |
A unit of length equal to .001 millimeter (0.00003937 inch). |
| Migration |
The exudation of an ingredient from one material by another material, such as the migration of a plasticizer from one material into an adjacent material with lower plasticizer content. |
| Modulus Of Elasticity |
The ratio of stress to strain below the yield point of the material. |
| Moisture Absorption |
The pick-up of water vapour from the atmosphere by a material. It relates only to vapour withdrawn from the atmosphere by a material and must be distinguished from water absorption, which is the take-up of water by immersion. |
| Moisture Vapour Transmission |
The rate of permeation of water through a material at a specific temperature and relative humidity rate. |
| Mold |
A hollow form or cavity into which molten plastic material is forced to give the shape of the required component. The term generally refers to the whole assembly of parts, which go to make up the section of the molding equipment in which the parts are formed. Also called a tool or die. Also used to describe the action of forming the part and the operation required for forming parts. |
| Molding Cycle |
1.The period of time occupied by the complete sequence of operations on a molding press requisite for the production of one set of moldings. 2. The operations necessary to produce a set of moldings without reference to the time taken. |
| Molecular Weight (Mw) |
The sum of the atomic weights of all atoms in a molecule. |
| Molecular Weight Distribution (Mwd) |
The relative amounts of polymers of different molecular weights (MW that makes up a specific polymer. |
| Monomer |
A single molecule which can join with another monomer or molecule to form a polymer or molecular chain. |
| Movable Platen |
The large back platen of an injection molding machine to which the back half of the mold is secured during operation. This platen is moved either by a hydraulic ram or a toggle mechanism. |
| Neck-In |
In extrusion coating, the difference between the width of the extrusion die opening and the width of the coating on the substrate. |
| Necking |
The localizing reduction in cross-section which may occur in a material when deformed. (ASTM D-883-65T). This phenomenon can occur in extrusion under certain conditions as the extrudate leaves the die, but the term most often refers to the cold drawing of fibres at temperatures below their melting points. Fibres of cyrstalline and some crystalline thermpolastics, e.g. polyethylene, exhibit necking at a critical stress near the yield point. |
| Needle Blow |
A specific blow molding technique where the blowing air is injected into the hollow article through a sharpened hollow needle which pierces the parison. |
| Newtonian Flow |
A flow characteristic evidenced by viscosity that is independent of shear rate, that is the rate of shear is directly proportional to the shearing stress. Water and thin mineral oils are examples of Newtonian fluids. |
| Nip |
The V-shaped gap between a pair of calendar rolls where incoming material is nipped and drawn between the rolls. |
| Nip Rolls |
|In film blowing, a pair of rolls situated at the top of the tower which close the blown film envelope, seal air inside of it, and regulate the rate at which the film is pulled away from the extrusion die. One roll is usually covered with a resilient material, the other being bare metal. |
| Notch Sensitivity |
Extent to which the sensitivity of a material to fracture is increased by the presence of a surface inhomogeneity, such as a notch. |
| Nozzle |
In injection of transfer molding, the orifice containing plug at the end of the injection cylinder or transfer chamber which contacts the mold sprue bushing and directs the molten resin into the mold. The nozzle is shaped to form a seal under pressure against the sprue bushing. Its orifice is shaped by tapering to maintain the desired flow of resin, and sometimes contains a check valve to prevent back flow, or an on-off valve to interrupt the flow at any desired point in the molding cycle. |
| Nuclear Magnetic Resonance (Nmr) |
Determinations of the number of hydrogen atoms in a complex molecule and the characteristic grouping in which they occur, conducted by placing the specimen in a strong constant magnetic field, then applying a perpendicular r.f. alternating magnetic field. At certain frequencies of the latter field, a hydrogen atom nucleus will absorb and emit energy, the frequency and amount of which are indicative of the characteristic grouping in which the atom is located |
| Nucleating Agent |
Finely divided solid material added to semicrystalline polymers to modify the crystalline structure by providing sites for initiation of crystalline growth. A properly nucleated polymer will possess improved clarity, hardness, and tensile strength. |
| Number-Average Molecular Weight (Mn) |
The average molecular weight of a high polymer expressed as the first moment of a plot of the number of molecules in each molecular weight range against the molecular weight. In effect, this is the total molecular weight of all molecules dived by the number of molecules. |
| Nylatron® |
Nylatron is the tradename for a range of specialist modified grades of nylon where additives and additions provide altered and improved physical properties when compared to virgin nylon grades. Main properties of our range of Nylatron sheet, rod and tube are High mechanical strength, fatigue and wear resistance, electrical insulating properties, machinability. Nylatron is a registered trademark of Quadrant Engineering Plastic Products, Inc. |
| Nylon |
Generic name for all long-chain polymers which have recurring amide groups (-CONH-) as an integral part of the main polymer chain. Various types of nylons are described in subsequent listings, the numbers of which relate to the number of carbon atoms in the various reactants. |