Today we’ll continue to talk about some reasons of defects on FRP profiles and molds.
1. The fiberglass pultruded profile doesn’t wrapped with fiberglass mat fully. Reasons: fiberglass mat width is too narrow, the positioning device caused by inaccurate mat offset molding mat. Measures: the design of the blanket should be considered when a certain length of lap, felt in the glass fiber reinforced plastic pultrusion mould before the pre molding tool must be more accurate than the mat guide entrance.
2. Surface wrinkles reasons: fiberglass mat is too hard, and wrinkles when going into the pultrusion mold, polyester carpet surface or non-woven mat is soft when going into the mould, pultrusion surfaces of products under the traction force occurred wrinkling aggregation. Measures: choose a kind of soft glass surface mat, polyester surface veil or non-woven fabrics should be careful operation, we can design fixture at the entrance of pultrusion mold for precise positioning when necessary.
3. There is liquid on the surface: the product is not completely cured, the fiber content is too little, the shrinkage is big, the product surface and the mold wall has a large gap. Measures: to increase the temperature or reduce the speed, so that it is fully cured, which is particularly important for the thick wall products, increase the yarn content or add a low shrinkage agent, filler.
4. The surface of the skin, broken reasons: the surface of the rich resin layer is too thick, in the detachment point to produce crawling, gel time and curing time difference is too large, out of the point is too far ahead of curing point. Measures: increase the yarn content in order to increase the internal pressure, adjust the trigger system, adjust the temperature.