PU Foam Sealant for Doors & Windows

Many purchasers and installers have encountered this strange phenomenon: The foam sealant looks full and solid right after application, but the next day after curing, it has sunk inward and even deformed lightweight door frames. Most people's first reaction is "I didn't apply enough foam." But the real root cause lies in the formulation's initial post-expansion rate. Technical Breakdown: The curing process of foam sealant is essentially the reaction between isocyanate (MDI) and moisture in the air, releasing CO₂ and forming a polyurea backbone. If the free NCO content in the formulation is too high, or if the catalyst activity is too strong, a critical problem occurs – excessive initial expansion followed by post-cure shrinkage. Our lab conducted comparative tests (see data in the attached image): · Standard foam sealant: Initial expansion to 300% of original volume, dropping to 220% after 6 hours – a shrinkage rate as high as 26%· Our optimized formulation: Strictly control the NCO index to XX±1, using a gradient catalysis system. Initial expansion is controlled at 260%, stabilizing at 250% after 24 hours – volume loss <4% What does this mean for contractors? 1. No structural damage – No secondary expansion during high summer temperatures that could crack hollow door frames2. No gaping seams – No through-holes between door/window frames and walls, so waterproofing and sound insulation remain effective3. Labor savings – No need for secondary application; a single cut leaves a smooth, flat surface How do we achieve this? · Key raw material MDI is sourced from high-quality suppliers, with batch variation <0.5%· Each batch undergoes dual testing: "free foam density" + "restricted foam pressure"· Separate summer/winter formulas with adjusted blowing agent boiling points Want to dive deeper into our quality control logic? DM me "Foam Sealant" for the complete test report.

Typhoon season is here. Can your windows still hold up?  Last typhoon season, did any of this happen to you?Water seeping in through window edges, soaking your floorOld sealant cracked and turned black — an eyesore you can't unseeGlass rattling, feeling like the whole frame might fall off when the wind picks up The problem isn't your windows. It's the sealant. Regular sealant fails after just 1–2 years:Powdering under UV exposureLosing adhesion after rain soakingCracking wide open with temperature swings But our MS Sealant (Modified Silane) is different:Waterproof – 72-hour water immersion, no debonding. Typhoon rain won't get through.UV-resistant – 2,000 hours of UV aging test. No cracking, no yellowing.Flexible – ±25% movement capability. Keeps up with building vibration, expansion, and contraction.Eco-friendly & odorless – No solvents, no smell. Safe for indoor and outdoor use. One cartridge lasts 5–8 years. That's a lot cheaper than fixing water damage even once. Comment "SAMPLE" belowGet a trial sample + application guideCustom colors available (white/gray/black/clear) A window that doesn't leak lets you sleep through a typhoon.

XMC Sealant — 20 Years of Dedicated Sealant Industry, Providing Durable Protection for Buildings Worldwide.Founded in 2004, XMC Sealant Factory has been deeply rooted in the industry for two decades, continuously developing its core advantages of integrated manufacturing and trading. By 2025, it had achieved annual sales of 300 million RMB.We specialize in silicone sealants, particularly in window and door sealants, where we possess profound technology and an outstanding reputation. Our comprehensive product line covers silicone sealants, window and door sealants, curtain wall sealants, large-panel glass sealants, aquarium sealants, anti-mildew sealants, fire-retardant sealants, polyurethane sealants, MS sealants, and expanding foam sealants, meeting the diverse needs of building and industrial applications.Adhering to the principles of "Integrity, Craftsmanship, Altruism, and Win-Win," we sell our high-quality, highly stable products both domestically and internationally, providing safe, durable, and worry-free sealing solutions for various projects. XMC is committed to working with global partners to build an international platform for resource sharing and win-win cooperation.Choosing XMC means choosing professionalism and trust—let's join hands to build a more solid and safer future for buildings!

Reliable Sealant Products for Construction, Industrial, and Automotive Applications  XMC provides professional sealant and adhesive solutions for multiple industries. With high-performance products and reliable manufacturing, we help customers achieve durable sealing and bonding performance in various applications.