The core around which paper-, fabric-, or resin-impregnated glass is wound to form pipes, tubes, or vessels; in extrusion, the central finger of a pipe or tubing die.
A fibrous reinforcing material comprised of chopped filaments (for chopped-strand mat) or swirled filaments (for continuous-strand mat) with a binder to maintain form; available in blankets of various widths, weights, and lengths.
Resin applied to glass fiber and cured during the manufacture of mat, to hold the fibers in place and maintain the shape of the mat.
Ability of the mat to resist being pulled apart under tension during impregnation and molding.
Matched Metal Molding
A reinforced plastics manufacturing process in which matching male and female metal molds are used (such as compression molding) to form the part, as opposed to low pressure laminating or spray-up.
The material in which the fiber reinforcements of a composite system are embedded. Thermoplastic and thermoset resin systems can be used, as well as metal and ceramic.
Metal-Matrix Composites (MMC)
Materials in which continuous carbon, silicon carbide, or ceramic fibers are embedded in a metallic matrix material.
Continuous glass strands hammer milled into very short glass fibers. Useful as inexpensive filler or anticrazing reinforcing fillers for adhesives.
The cavity or matrix into or on which the plastic composition is placed and from which it takes form. To shape plastic parts or finished articles by heat and pressure. The assembly of all the parts that function collectively in the molding process.
The immediate shrinkage which a molded part undergoes when it is removed from a mold and cooled to room temperature; the difference in dimensions, expressed in inches per inch between a molding and the mold cavity in which it was molded (at normal temperature measurement); the incremental difference between the dimensions of the molding and the mold from which it was made, expressed as a percentage of the dimensions of the mold.
The side of a laminate that faced the mold (tool) during cure.
The forming of a polymer or composite into a solid mass of prescribed shape and size by the application of pressure and heat for given times. Sometimes used to denote the finished part.
Plastics in a wide range of forms to meet specific processing requirements. Granules or pellets are popular forms.
The period of time occupied by the complete sequence of operations on a molding press requisite for the production of one set of moldings; the operations necessary to produce a set of moldings without reference to the time taken.
Molding Pressure, Compression
The unit pressure applied to the molding material in the mold. The area is calculated from the projected area taken at right angles to the direction of applied force and includes all areas under pressure during complete closing of the mold. The unit pressure is calculated by dividing the total force applied by this projected area, and is expressed in pounds per square inch.
A lubricant, liquid, or powder (often silicone oils and waxes), used to prevent sticking of molded articles in the cavity.
A simple molecule which is capable of reacting with like or unlike molecules to form a polymer; the smallest repeating structure of a polymer; for addition polymers, this represents the original unpolymerized compound.
A yarn consisting of many continuous filaments.
A mold with two or more mold impressions; that is, a mold which produces more than one molding per molding cycle.