Automotive Air Filters Sealing Principle and Leak-Proof Advantage of Integrated PU Foam Frame

Air filter sealing performance directly determines the engine protection effect, and the greatest advantage of PU glue technology lies in its integrated seamless leak-proof structure. Traditional filter products adopt separate frame assembly and manual gluing sealing, which inevitably produce tiny assembly gaps and glue line dead angles. These invisible gaps become hidden dangers for air leakage, making dirty air bypass the filter paper and directly enter the engine.

The PU integral foaming process completely subverts the traditional assembly mode. The filter paper element is fixed in the mold in advance, and the PU liquid material is injected for one-time integral foaming and forming. After curing, the PU frame and the filter paper edge form a molecular fusion state, achieving absolute tight integration without any gap. The foam structure of PU glue has countless tiny elastic pores inside, which can compress and fit tightly with the installation interface during assembly, filling all tiny installation gaps and uneven grooves.

This micro-elastic sealing technology realizes 360-degree full-perimeter leak-proof protection. Whether it is flat filters, curved special-shaped filters, or large truck cylindrical filters, the PU integral frame can achieve perfect fitting. Compared with ordinary glued filters, PU filters have zero air leakage rate, more stable intake efficiency, mor