Woven rovingWR

A non woven glass reinforcement made from chopped strands distributed randomly and held with a powder or emulsion binder that dissolves in styrene based resins. It gives roughly equal in plane properties in all directions, wets out readily by hand lay up and is the standard reinforcement in GRP flat roofing laminates. It is specified by areal weight.

A bundle of parallel, untwisted glass fibre strands wound onto a cylindrical package. Direct rovings feed processes such as filament winding, pultrusion and weaving, while assembled (multi end) rovings are designed for chopping in spray up; rovings are specified by tex and by sizing type.

The simplest weave style, in which each warp yarn passes alternately over and under each weft yarn. It is stable and easy to handle but has the highest crimp of the common weave styles, which slightly reduces mechanical performance and limits drape over complex curvature.

An open-mould process in which layers of dry reinforcement are placed in the mould by hand and wetted out with liquid resin using brushes and rollers before curing, usually at ambient temperature. It is the simplest and most widely used method of producing GRP laminates, including site-applied GRP roofing.