The advantages and disadvantages of the performance of the sealing strip affect the airtightness, water resistance, heat loss and other important performance indicators of the doors and windows of the building doors and windows to a large extent, as well as the firmness of the doors and windows. For this reason, the country has formulated the national standard GB12002-89 “Plastic door and window seal” for a long time to standardize the production and inspection of seals.
However, the current quality and price of rubber and plastic sealing strips for doors and windows in the building materials market are very confusing. It is expensive at 15,600 yuan per ton, but cheap at only 6,000 yuan per ton. The price difference is nearly 10,000 yuan, and the quality varies greatly. Everyone knows what to do. Many manufacturers have stated that their seal is the implementation of the GB12002-89 national standard, and a qualified test report can be issued by an authorized agency. According to the rubber seals of well-known manufacturers that our company is currently using in the industry, as well as the samples of sealing strips issued by the manufacturers, the hot air aging performance of this project has a surprising effect in the heating weight loss index: more than 10 samples, in fact, none people qualified.
According to the GB12002-89 standard, the hot air aging performance item of the sealing strip should be 3% in the heating weight loss index. However, the heating weight loss of the actual test results is 7.17%~22.54%, which is far beyond the scope of the national standard.
For such sealing strips, a large amount of low-boiling plasticizers or plasticizer substitutes are added to the formula. This kind of seal is still very flexible in the new era. However, as time goes by, the plasticizer is more volatile, the sealing elasticity is good, and it softens and deteriorates, which affects the sealing performance from the impact force of the door and window, and also affects the firmness of the door and window assembly.
In addition, the plasticizer content of the sealant is too high, and it is in contact with the migration phenomenon of the PVC resin during the use of the plasticizer. Causes local fan frame shadowing and swelling. That is to say: in contact with the seal on the sealing surface, there is a wide and narrow, non-rubbing, black stain, and the white body forms a strong contrast, which greatly affects the appearance. The color in the plasticizer is due to emigration, and local swelling. (Sliding doors and windows are not exposed due to the contact with the profiles of the parts, and the profiles are partially colored and swollen. Generally, the opened doors and windows cannot be observed in the open state. The seal and the corresponding profiles have been exhausted from the contact.) Although local Coloring and swelling profiles do not have serious consequences for the failure of frames and fan profiles, but seriously affect the appearance of plastic doors and windows. After all, this is a defect, after all, the image effect of plastic doors and windows is extremely poor.
In order to maintain the image of plastic doors and windows and care about the healthy and strong growth of this emerging industry, sealing strip manufacturers should actually produce truly qualified seals, and plastic door and window assembly plants should use truly qualified high-quality seals.
Post time: Aug-29-2023