>> Monday, 9 February 2009
CAD - Computer Aided Design. Use of computer to draw/design parts.
Cap - Closure
Capacity - The rated amount of volume (# parts) produced by a mold/molding machine per year.
Capper - Machine that applies a closure to a bottle on a packing line.
Cavitation - The number of molding stations within a mold.
Cavity - Mold component(s) which form the exterior or external surfaces of a part.
Centerline - A line drawn down on part drawing that represents the geometrical center of the part in that axis.
Charge - The amount of material volume or weight required for the injection unit to plasticize for each molding cycle.
Chemical resistance - Ability of a material to retain utility and appearance following contact with chemical agents.
Child resistant closure (CRC) - A closure that requires dissimilar motions which may make removal by a child difficult. Subject to government regulations.
Clamp speed - Speed at which the mold platens will open and close; controlled by operator settings.
Clamp tonnage - Amount of force, in tons, that a machine is capable of exerting on the mold. Insufficient tonnage will allow the mold to flash at the parting line when the mold is filled under high pressure.
Clamp plate - A plate fitted with the mold and used to fasten the mold to the molding machine's platens. The outermost plates on an injection mold.
Clarifier - An additive that increases transparency of a plastic material.
Clearance - Controlled distance by which one part of an object is kept separated from another part.
Closure - A device used to seal off the opening of a container, so as to prevent loss of contents.
Coefficient of expansion - The fractional change in length of a material for a unit change in temperature
Cold slug well - A void located directly beneath the sprue, designed to collect unmelted plastic and to provide a means of positive ejection.
Color concentrate - A measured amount of dye or pigment incorporated into a pre-determined amount of plastic. This pigment is then mixed into larger quantities of plastic material to be used in molding.
Colorant - Any substance that imparts color to another material or mixture. Colorants can be either dyes or pigments
Compression ratio - In a helical extruder screw, the ratio of volume available in the first flight at the hopper versus that available in the last flight at the end of the screw.
Conditioning - Subjecting a material to standard environmental and/or stress history prior testing.
Control chart - A graphical method for evaluating whether a process is or is not in a state of statistical control (stable). The decisions are made through a comparison of the values of some statistical measurement calculated from the data with control limits.
Control limits - Limits on a control chart that serve as a basis for judging whether or not a process is in a state of statistical control (stable)
Core (core pin) - Mold component which forms internal surface of the molded part.
Cooling channels - Channels or passageways located within the body of the mold through which cooling medium can be circulated to control temperature on the mold surface.
Crazing - Fine cracks which may extend in a network on or under the surface or through a layer of a plastic material.
Creep - The dimensional change with time of a material under load, following the initial instantaneous elastic deformation.
Crystalline polymer - Plastic whose state of molecular chains are in a uniform, regular arrangement.
Crystallinity - A state of molecular orientation which denotes an orderly compact structure of the molecular chains forming the polymer.
Cushion - Volume of plastic in-between screw end of barrel when shot is injected into mold.
Cut-off - Point at which the injection unit goes from filling to packing. Cut-off point can be based on screw position, time, or pressure.
Cycle - The complete sequence of operations in an injection molding process to complete a set of parts.
Cycle time - Time during which one molding cycle is completed.