EPDM rubber strip
Why can't we apply sealant?
Structural differences/polarity differences/additive effects
Misunderstandings in application
In the actual operation of door and window sealing, some customers often apply an additional layer of silicone sealant on the surface of the EPDM sealing strip in pursuit of stronger sealing effect. The seemingly "double insurance" operation is actually a "pit". Rongji rubber strip will analyze from a professional perspective, why can't sealant be used on the surface of EPDM rubber strip?
1、 Structural differences lead to 'chemical exclusion'
Although EPDM and silicone sealant each have stable molecular chemical structures, there are significant differences in their chemical structures, such as the "barrier" between species, which affects the compatibility between materials and interferes with the molecular interaction between the two materials, making it difficult for the sealing system to form a stable synergistic effect. This not only fails to achieve the superposition of sealing performance, but may also weaken the basic sealing effect.
2、 Polarity difference blocks' intimate contact '
According to the principle of "similar compatibility" in the field of materials science, the non-polar properties of EPDM are exactly opposite to the polar characteristics of silicone sealant, resulting in the inability of the two materials to achieve molecular level tight bonding when in contact. In practical use, problems such as delamination and peeling are easily caused by environmental changes.
3、 Additives' mutual confrontation 'disrupts the balance of performance
During the production process of EPDM sealing strips, various functional additives are added; Silicone sealant also requires additives to achieve curing and strengthening. However, the interaction between additives often interferes with the sealing performance of the sealing material.
Small tricks for encrypting doors and windows
If you want to achieve a "stacking" sealing effect, Rongji rubber strip suggests replacing the EPDM sealing strip with a silicone sealing strip. Due to the high similarity in molecular structure between silicone and silicone sealant, they have a better "chemical tacit understanding" and can maintain stable sealing performance during long-term use, eliminating hidden dangers such as cracking and peeling.
Rongji rubber strip provides integrated sealing solutions, from rubber strip selection to installation process, to ensure the sealing performance of doors and windows throughout the process, continuously outputting reliable sealing solutions for the industry, and helping every door and window to build a stable sealing defense line.
