Definitions /Dictionary/Glossary - nptel

Roving Doff or "Doff": The final product sold to the customer. It is made by roving or pulling
together a group of forming cakes (the number of which depends upon the product being made).
RP: Reinforced plastic, polymer or polyester.
RRIM: see Reinforced Reaction Injection Molding
RTM: see Resin Transfer Molding
RTM Light: see Vacuum Molding
RTP: Sometimes used to distinguish reinforced thermoplastic from reinforced thermosetting
plastic.
Rule-of-Mixtures: A composite’s properties are the combination of properties in its two
constituent materials. The composite property equals the amount of fiber property multiplied by
the volume percentage of fiber, plus the amount of matrix property multiplied by the volume
percentage of matrix.
Run-Out: The process of pulling glass from doff to the chopper.
Runner: The channel through which thermoplastic material moves through a mold.
SAN: Styrene Acrylonitrile (Thermoplastic Resin).
S Glass: A family of magnesium-alumina-silicate glasses with a certified chemical composition
that conforms to an applicable material specification and produces high mechanical strength.
Sandwich Constructions: Panels composed of a lightweight core material, such as honeycomb
or foamed plastic, to which two relatively thin, dense, high-strength or high-stiffness faces or
skins are adhered.
Scrim: Light woven or non-woven fabric with relatively large openings between the yarns, used
to reinforce paper and other products.
Section Beam: Flanged cylinder onto which yarn is drawn and accumulated from yarn bobbins
or packages.
Serving: Wrapping of yarn around a product in one or more layers to form a protective covering.
Set-Up: To harden, as in curing.
Sewing Thread: Flexible small diameter yarn or strand, usually treated with a surface coating
and/or lubricant, used to stitch one or more pieces of material together or stitch an object to a
material.