What is high strength fiberglass felt
Glass fiber felt is a sheet-like product made of continuous precursor or chopped precursor which is non directionally combined by chemical binder or mechanical action. Hand lay up forming: hand lay up forming process is the main mode of FRP production in China. Glass fiber chopped felt, continuous felt and stitched felt can be used for hand lay up forming process. The use of stitched felt can reduce the number of layers and improve the efficiency of hand lay up. However, the stitched felt contains more chemical fiber stitched threads, so the bubbles are not easy to drive away. The FRP products have more needle bubbles, and the surface feels rough and not smooth. In addition, the sewn felt is a heavy fabric, which has poor mold coverage compared with short cut felt and continuous felt. When making products with complex shapes, it is easy to form holes at the bends. The hand lay up process requires that the felt has the characteristics of fast resin penetration rate, easy elimination of bubbles and good mold coverage.
Pultrusion process is one of the main applications of continuous felt and stitched felt. Generally, it is used in combination with untwisted roving. Using continuous felt and stitched felt as pultruded products can significantly improve the circumferential and transverse strength of products and prevent products from cracking. The pultrusion process requires that the felt has the characteristics of uniform fiber distribution, high tensile strength, fast resin penetration rate, good flexibility and mold filling, and a certain continuous length. Resin transfer molding (RTM) is a closed mold process. The utility model is composed of a female mold and a male mold, two half molds, a pressure pump and an injection gun, without a press. The RTM process usually uses continuous felt and stitched felt instead of chopped felt. It is required that the felt shall be easily saturated by resin, with good air permeability, good resin scouring resistance and good mold covering performance. Winding process: short cut felt and continuous felt are generally used for winding and forming, mainly used as the resin rich layer of products, including the inner layer and outer surface layer. The requirements of winding process for glass fiber felt are basically similar to those of hand lay up method. Centrifugally cast: chopped felt is usually used as raw material. Lay the chopped felt in the mold in advance, then add the resin into the rotating open mold cavity, and discharge the bubbles through centrifugation to make the product dense. The felt is required to have the characteristics of easy infiltration and good air permeability.
