Plastic steel profiles refer to PVC profiles used for making doors and windows. They first appeared in Germany in the late 1950s, and China only started importing them in 1983, with widespread application beginning in the late 1990s. Since doors and windows made solely from PVC profiles lack sufficient strength, steel is usually added inside the profile to enhance the sturdiness of the doors and windows. Therefore, plastic doors and windows that incorporate steel in their profiles are commonly referred to as plastic steel doors and windows. With the widespread use of plastic steel doors and windows, the PVC profiles used to manufacture them are habitually called plastic steel profiles. **Characteristics of Plastic Steel Profiles** 1. **Cost-effective:** The price of plastic is much lower than that of aluminum with equivalent strength and lifespan. This advantage has become increasingly apparent due to the significant rise in metal prices. 2. **Rich in color:** Colored plastic steel profiles add considerable aesthetic appeal to buildings. Previously, wooden doors and windows were used, and to achieve a harmonious appearance with the building, paint was often applied to the surface of the doors and windows. However, paint tends to age and peel when exposed to ultraviolet (UV) light, rendering it unrecognizable within a few years, which is not in sync with the lifespan of the building. Colored aluminum doors and windows were later invented, but they are prohibitively expensive for the average consumer. The use of plastic doors and windows solves this problem, as colored film profiles can even replicate realistic wood grain effects. 3. **Durable:** The addition of reinforced steel inside the profile significantly enhances its strength, providing resistance to earthquakes and wind erosion. Furthermore, the multi-chamber structure of the profiles, with separate drainage chambers, prevents water from entering the reinforced steel chamber, thereby avoiding corrosion and extending the lifespan of the doors and windows. The inclusion of UV-resistant components also improves the weather resistance of plastic steel profiles, allowing for safe use even in tropical regions with strong UV exposure. 4. **Good thermal insulation performance:** The thermal conductivity of plastic steel profiles is far inferior to that of aluminum profiles. Additionally, the design of the multi-chamber structure achieves effective thermal insulation. Research indicates that rooms using plastic steel doors and windows maintain an average indoor temperature that is 5-7°C lower than that of rooms with aluminum doors and windows in the summer, while in winter, temperatures can be higher by 8-15°C in different regions. 5. **Good sound insulation performance:** Plastic steel doors and windows installed with well-sealed hollow glass exhibit outstanding sound insulation performance. Sound insulation has become a primary criterion for choosing doors and windows, especially in residential areas within bustling urban environments. The assembly of plastic steel doors and windows utilizes welding processes, and combined with the enclosed multi-chamber structure, the noise blocking effect is very evident.