Polyurethane Adhesive
Besides working as an
adhesive, this polyurethane substance acts as a sealant to close off gaps, fill holes and level surfaces. It often replaces fasteners like nails and screws as a cleaner and less obtrusive option, is very effective in the construction industry for applications like installing wood floors and thread locking. Polyurethane is also the adhesive of choice in book binding. Woodworkers use it to make furniture and architectural components like window frames and doors. Polyurethane adhesives, along with
acrylic adhesives and
silicone adhesives, are used in the automotive, conveyor belt, footwear, packaging and plumbing industries. It is resistant to chemicals, oil and moisture and provides sound and vibration support. At room temperature, this adhesive is very pliable and has a low viscosity. Using it is easier than other adhesives because it has a low odor, is nonflammable and won't spill easily. Its color can range from a rich amber shade to a clear liquid. It adheres to almost any surface, including concrete, ceramic, marble, plywood, paper, plastics and wood.
Polyurethane adhesives come in two different ways: two-part formulas or pre-mixed. If it is mixed, the adhesive must be completely homogenous in order to work appropriately. The result is a tough yet bendable bond that is more flexible than
epoxy. In order to cure, it uses the moisture in the air or a bonding substrate to form a cured polymer layer. To start the curing process, it requires either heat or air evaporation. Unlike some adhesives, polyurethane takes many hours to cure, usually overnight. Because it takes such a long time to cure, the two surfaces being bonded together are tightly clamped together to ensure a tight seal. Once the adhesive has cured, it provides a tight, reliable bond that is durable and impact resistant. The bond is permanent and can last for decades. Because of its resistant properties, all polyurethane adhesives may be used indoor or out. Today, polyurethane adhesive is sold in hardware stores for general use by consumers. It has a short shelf life and many different varieties. Different chemical compositions result in varying attributes and applications.
