UPVC windows and doors are made of polyethylene resin as the main raw material, coupled with a certain degree of stability of agents, modifiers, coloring agents, fillers, UV absorbers and other additives processed by extrusion profiles, and then cutting, welding approach produced window frames, fan, fitted with rubber sealing strip, top, hardware and other accessories which made windows and doors, call for increased rigidity of products, within the prescribed length, profiles cavity need to add steel (rebar), So called PVC doors and windows. The types of steel doors and windows: fixed windows, casement window, sliding sash, combination windows. Performance and Characteristics 1. Thermal insulation properties Plastic profiles for the multi-cavity structure, with good insulation properties, the heat transfer performance is very small, only steel l/357, aluminum 1 / 250, showing that plastic steel door and window insulation, thermal insulation results are obvious, especially with the Heating air conditioning equipment is more applicable to modern buildings. Comparing the relevant departments to investigate, namely: the use of plastic doors and windows of the room than the use of wood doors and windows in winter indoor temperature can be 4-5 degrees higher; the northern region the use of double-glazed better effect. 2. Physical properties UPVC windows and doors of physical properties mainly refer to: PVC plastic doors and windows of the air permeability (air tightness), rain water permeability (water tightness), wind resistance and thermal insulation and sound insulation properties. As the plastic window and door profile has a unique multi-chamber structure, and formed by the welding process windows, doors and windows installed in all the gaps are sealed with plastic tape and rubber top, and therefore has a good physical. 3. Corrosion Plastic profile because of its unique formula which has good corrosion resistance, followed by the corrosion resistance depends on the hardware to be used, under normal circumstances pieces of metal hardware products, while the corrosive environment of the industry, such as food, medicine, health, chemical industry and coastal areas, wet and humid areas, use corrosion of metal parts (plastic), which is 10 times the life of a steel window. 4. Weatherability UPVC windows with special formulations, raw materials to add UV absorbers, and low temperature impact resistance agent, thereby enhancing its weather resistance. Long-term use in the temperature climate, the environment, in a 30 degree to 70 degrees, sun, heavy rain, dry, wet the changes, no discoloration, degeneration, aging, embrittlement and so on. UPVC windows of the examples in Western Europe for three decades, its materials are well preserved. 5. Fire Performance UPVC windows and doors are not spontaneous, non-combustion from the fire self-extinguishing, safe and reliable, in line with fire safety requirements, this performance also expanded the use of plastic doors and windows. 6. Insulation The use of plastic doors and windows profiles excellent electrical insulator, non-conductive, high safety factor. 7. Density of Dense smooth plastic-type material, quality inside and outside the consensus, without surface exceptional handling, easy processing, after cutting, welding process, the doors and windows finished length, width and diagonal are able to within plus or minus 2MM, processing accuracy, angular intensity up to more than 3000N.