Definitions /Dictionary/Glossary - nptel

Braid/Braider: A narrow tubular or flat fabric produced by intertwining a single set of yarns
according to a definite pattern.
Breakup: see Dispersion
Breathing: Opening and closing a mold so that gas can escape early in the molding cycle. Also
called "degassing"; sometimes called "bumping" in Phenolic molding.
Bridging: It is the condition in which fibers do not move into or conform to radii and corners
during molding, resulting in voids and dimensional control problems.
Broad Strand: see Wides or Matchsticks
Broken Strand: see Broken End
Broken End: In the roving operation, a severed strand (bundle), this causes the forming cake to
stop running.
Broken Fibers: see Fuzz
B-Stage: Intermediate stage in the reaction of certain thermosetting resins in which the material
softens when heated, is plastic and is fusible but may not entirely dissolve or fuse. It is also
called "resistol" or "resitol." Resin in an uncured prepreg or premix is usually in this stage.
Buckling (Composite): It is a failure mode generally characterized by an unstable lateral
material deflection due to compressive action on the structural element involved.
Buildup: Glass bundles or chopper fuzz that collect on the chopper, cot, static bars or machine
frame.
Bulk Molding Composite (BMC): Thermosetting resin mixed with short strand reinforcement,
filler, and other materials to form a viscous compound for compression or injection molding.
Bundle: A discrete collection of many parallel glass filaments. It is a collection of individual
filaments; a sub-strand.
Burst Strength:
• Hydraulic pressure required to burst a vessel of given thickness. It is commonly used in
testing filament-wound composite structures.
• Pressure required to break a fabric by expanding a flexible diaphragm or pushing a
smooth spherical surface against a securely held circular area of fabric. The Mullen
expanding diaphragm and Scott ball burst machine are examples of equipment used for
this purpose.
Bushing: Plate with holes through which molten glass is pulled to produce glass fibers.