Definitions /Dictionary/Glossary - nptel

Resin Viscosity: Viscous property of a resin system or solid to liquid transition resistance to
flow, which can be altered by temperature and pressure as necessary to achieve desired flow
characteristics.
Reverse Impact Test: In which one side of a sheet of material is struck by a pendulum or falling
object and the reverse side is inspected for damage.
Reverse Sandwich Lay-Up: A laminate arrangement in which the reinforced mat is laminated
between outer layers of other materials.
RIB: A reinforcing member of a fabricated or molded part.
Ribbon Direction: On a honeycomb core, the way the honeycomb can be separated. The
direction of one continuous ribbon.
Roll-Out: A process used in spray-up and hand lay-up procedures where the resin and glass
reinforcement are compacted to a uniform laminate with rollers.
Room Temperature Curing Adhesives: Adhesives that set (to handling strength) within an
hour at temperatures from 68 to 86 F, and later reach full strength without heating.
Roving: A number of strands, tows, or ends collected into a parallel bundle with little or no
twist. In spun yarn production, it is an intermediate state between sliver and yarn.
Roving (filament winding): The term roving is used to designate a collection of bundles of
continuous filaments either as untwisted strands or as twisted yarns. Roving may be lightly
twisted, but for filament winding they are generally wound as bands or tapes with as little twist
as possible. Glass rovings are predominantly used in filament winding.
Roving Ball: A term used to describe the supply package offered to the winder. It consists of a
number of ends or strands wound to a given outside diameter onto a length of cardboard tube.
RP: Reinforced plastic, polymer, or polyester.
RTA (Room Temperature Ambient): An environmental condition 73(5( (23(3(C) at ambient
laboratory relative humidity; 2) a material condition where, immediately following
consolidation/cure, the material is stored at 73(5( (23(3(C) and at a maximum relative humidity
of 60%.
RTP: Sometimes used to distinguish reinforced thermoplastic from reinforced thermosetting
plastic.
Rubber Plunger Molding: A variation of the matched-die molding process which uses a heated
metal female mold (or outer half) and a rubber plunger male mold. Applicable for relatively
small molds with modest undercuts where low pressures are involved.