FRP (glass reinforced plastic) not only combines the hardness of glass, but also has the characteristics of hard and unbreakable glass fiber reinforced plastic, and combines the characteristics of the two to create a composite material. FRP uses resin as a matrix, glass fiber as a reinforcing agent, and is bonded together to form a material. Resin-based composite materials were first developed in the United States in 1932. In the first few years, this material was mainly used in the military field. In 1939, low-pressure unsaturated polyester resin came out.
Plastic-steel profiles refer to PVC profiles used to make doors and windows. They appeared in Germany as early as the end of the 1950s. my country only began to introduce them in 1983, and they began to be widely used in the late 1990s. Because the doors and windows made of PVC profiles are not strong enough, steel is usually added to the cavity to enhance the firmness of the doors and windows. Therefore, plastic doors and windows made of steel inside the profiles are usually called plastic steel doors and windows. With the widespread use of plastic-steel doors and windows, the PVC profiles used to make plastic-steel doors and windows are customarily called plastic-steel profiles. Plastic steel is also used as a common material for guardrails.