Plastic door and window market is different, sealant strips are against the trend.
Release time：2018-08-27 14:42:49
Browse：698
In the past, the quality and service life of plastic doors and windows have been greatly affected by the low performance and poor quality of sealing materials, and many quality problems have appeared, seriously damaging the reputation of businesses. Especially used in building doors and windows, light hardening brittle, loss of elasticity and sealing function, heavy sticky "oil seepage", loss of use function at the same time, pollution of doors and windows, affecting the beauty of doors and windows.
This phenomenon can be attributed to the neglect of the introduction and development of door and window accessories while improving the grade and performance of plastic doors and windows, resulting in the development of sealing materials lagging far behind the development of plastic doors and windows. It is gratifying that high-grade high-quality door and window accessories, especially door and window sealing materials are being accepted by everyone, and gradually into the door and window market.
Material status of plastic door and window sealant strip
At present, the main sealant materials used abroad are NBR, EPDM, TPE, polyurethane elastomer (P), silicone rubber and so on. The use rate of EPDM with excellent aging resistance is higher than 60%.
Analysis of development status of plastic door and window sealing materials in China
In recent years, in the domestic market of door and window sealing materials, the plastic PVC sealing strip occupies more than 90%, and the modified high polymerization PVC and thermoplastic elastomer sealing strip recommended by the relevant departments of the industry occupies a very low market share. Most of them are concentrated in the surrounding areas of Beijing.
Ethylene-propylene-diene-diene rubber (EPDM) was developed by Beijing Institute of Chemical Industry in the 1960s, but its application and development on doors and windows were put on the agenda only in the mid-1990s. It was developed by the rubber and plastic products factory of Capital Aerospace Machinery Company in 2000, and passed the acceptance check and acceptance of relevant experts of Ministry of Construction in the latter ten days of the same year. At present, it has been in mass production stage, but only some domestic high-grade doors and windows manufacturers are using it.
Ethylene-propylene-diene rubber sealant made in China is about 40% lower than that made in other countries, but its development is still slow. The reason is that the majority of users have not realized that the proportion of sealant in the total cost of making doors and windows is small, only considering the cost savings, but not considering the comprehensive effect of using high-price and high-quality sealing materials. Benefit.
Section design and mold making process of sealant strip
Due to the late development of plastic door and window sealant strips in China, the initial cross-section shape is relatively simple, which is limited to the "K" shaped strip used in glass pressure strip sealing, the big spoon strip used in window frame (fan) sealing and the small "0" strip used in screen fan. On the contrary, with the development of plastic doors and windows in foreign countries, the production of sealant strips has reached serialization and scale, and the cross-section design of each product meets the requirements of relevant functions, and the matching between sealant strips and corresponding profiles is almost perfect.
The report shows that in recent years, with the introduction of foreign door and window manufacturing technology, the cross-sectional shape and varieties of domestic sealant strips have also undergone great changes. However, due to the backwardness of domestic mold manufacturing technology and the insufficient attention paid by domestic counterparts to the sealing material as one of the door and window accessories, the final products are produced. Although the shape is close to the design shape, there are still some defects in the use of functions, such as large clearance of the fitting part, the finished product can not meet the relevant requirements of the amount of pressure and lapping, so that in the course of use there will inevitably be some quality problems. This phenomenon is not only affected by the above factors, but also by the raw materials used, such as processability, expansion rate, etc.
Ethylene propylene diene rubber (EPDM) is a kind of sealing material with excellent comprehensive properties. It not only has excellent physical properties, but also has good machinability and small expansion coefficient. The sealing strip made of EPDM is almost the same as the design requirements. This is also an important reason why EPDM has developed rapidly in recent years.
