Industry Glossary - F

The portion of the glass fiber production process where the forming cakes are put into creels and “roved” or fabricated onto doffs.

Manufacturer of reinforced plastic products.

The shape of the pattern of chopped fibers as they drop from the chopper to the bed.

The chopped bundles which fall or are thrown off the chopper and cot.

The failure or decay of mechanical properties after repeated applications of stress. Fatigue tests give information on the ability of a material to resist the development of cracks, which eventually bring about failure as a result of a large number of cycles.

The number of cycles of deformation required to bring about failures of the test specimen under a given set of oscillating conditions (stresses and strains).

The stress level below which a material can be stress cyclically for an infinite number of times without failure.

The maximum cyclical stress a material can withstand for a given number of cycles before failure occurs. The residual strength after being subjected to fatigue.

Reinforcement material which is a major component in a composite matrix. Often, fiber is used synonymously with filament.

The amount of fiber present in a composite. This is usually expressed as a percentage volume fraction or weight fraction of the composite.

The orientation or alignment of the longitudinal axis of the fiber with respect to a stated reference axis.

Primarily means glass in fiber form. However, “fiber glass” is also used to describe composite processing and applications. Examples of usage: fiber glass molding plant, fiber glass car.

Visible fibers on the surface laminates or molding. The thread size and weave of glass cloth.

A general term for a composite that is reinforced with cloth, mat, strands, or any other fiber form.

Major material used to reinforce plastic. Available as mat, roving, fabric, and so forth, it is incorporated into both thermosets and thermoplastics.

A single, threadlike fiber of glass.

Process, which involves winding a resin-saturated strand of glass filament around a rotating mandrel.

A yarn composed of continuous filaments assembled with or without twist.

The system of yarns running crosswise in a fabric (short for filling). Also known as weft.

An inexpensive substance which is added to plastic resins to extend volume, improve properties, and lower cost.

Bundles that have been split apart into smaller bundles which are composed of only a few or single filaments. Fuzz is usually made of fines.

Certain chemicals that are used to reduce the tendency of a resin to burn.

Effect of surface contamination, which causes a circular separation of a paint or gel coat.

This property describes how fast a plastic material will burn when subjected to a particular ASTM test. In this test, a flame is applied to one end of a strip of material. When the material starts burning the flame is removed and the time to consume a given amount of material is measured. Units – inches per minute (in/min.). Higher numbers indicate that the material will burn faster under conditions of this particular test. S.E. means self extinguishing. If a material is classified as S.E., the specimen stops burning when the flame is taken away.

That portion of the charge, which flows from or is extruded from the mold cavity during the molding. Extra plastic attached to a molding along the parting line, which must be removed before the part is considered finished.

Lowest temperature at which a substance gives off enough vapors to form a flammable mixture.

Molds made of rubber or elastomeric plastics, used for casting plastics. They can be stretched to remove cured pieces with undercuts.

This is a number associated with the stiffness of materials. It is used to calculate how far a bar will bend when a bending load is applied to it. Units are normally millions of pounds per square inch. (106 psi) – Giga Pascals (gPa). Higher numbers for materials mean that they are more resistant to deflection when equal thickness are being compared.

This is also known as bending strength. It describes how much of a nonmoving load can be applied before a bar yields or breaks. Units are normally thousands of pounds per square inch. (103 psi) – Mega Pascals (mPa). Higher numbers mean that material is stronger and can withstand a heavier load.

The movement of resin under pressure, allowing it to fill all parts of a mold. The gradual but continuous distortion of a material under continued load, usually at high temperatures; also called creep.

A mark on a molded piece made by the meeting of two flow fronts during molding. Also called striae, weld mark, or weld line.

Wavy surface appearance of an object molded from thermoplastic resins, cased by improper flow of the resin into the mold.

Fibers which fly out into the atmosphere during handling and processing.

Lightweight, cellular plastic material containing glass-filled voids. Typical foams include urethane, PVC, and polyester.

The male half of the mold that enters the cavity, exerting pressure on the resin and causing it to flow. Also called punch.

The portion of the glass fiber production process where the fibers are drawn, attenuated from molten glass, and collected in forming cakes.

The package of glass fibers which is produced in forming. This package is generally on a tube and is placed on a forming carrier and sent through a drying/curing oven. These “cakes” are subsequently put into a roving creel and collected together into a roving doff.

The separation of a body. Defined both as rupture of the surface without complete separation of laminate and as complete separation of a body because of external or internal forces.

The true, normal stress on the minimum cross-sectional area at the beginning of fracture.

A measure of the damage tolerance of a material containing initial flaws or cracks. Used in aircraft structural design and analysis.

Creel Fuzz – In glass fiber manufacturing, the broken filaments found around and on a roving creel. Chopper Fuzz – In Composite Fabrication, the broken filaments found around the glass cutter or chopper. In the field, the broken filaments found around a roving pallet.

Small, broken, compacted filaments of glass which collect inside the guide eye tubes which feed the chopper and cause the glass to stop running through it.