Fiberglass pultruded window and door profiles are not the same as many general FRP products, they have multi-cavity and very thin wall thickness. Today we’ll talk about the basic requirements of the pultrusion resin for the multi-cavity and thin-walled profile in high-speed production:
(1) high reactivity;
(2) high glass temperature;
(3) the speed of saturation should be as high as possible;
(4) the proper viscosity characteristic.
Low reactive resin has slow speed reaction, even in the pultrusion mold for very short residence time and is unable to complete curing reaction, the cementitious area will be too long, production difficulties: to regulate the reaction activity of the matrix resin, selection of appropriate initiator or choose a variety of initiator trigger.
Isophthalic resin glass transition temperature is high, the gelation time is short and the gel strength is higher, easily impregnated fiber and moderate viscosity (500 ~ 600 centipoises), packing is not easy to sink, very suitable for the production of multi-cavity thin wall material with a special shape.
In order to improve the pultrusion speed and shorten the time of gelation, we should use the multi-level initiating system caused by low temperature, medium-temperature and high temperature so that the resin matrix can be initiated at a lower temperature. In order to guarantee the inner and outer resin matrix can simultaneously cure, eliminate the crack and the profile bending phenomenon due to the curing time of the inside and outside resin matrix, adopt this system. It can also shorten the time of gelation. To improve the strength of the gel, and reduce the occurrence of the accident rate. The surface quality of the profiles can be improved by improving the tension speed and increasing the degree of curing.