The hot wedge welding process effectively creates a strong air- and watertight seal for a variety of products. The resulting bond is permanent, durable and at least as strong, or stronger than the original materials.
How Hot Wedge Welding is Accomplished
During the hot wedge sealing process a rotary press is used to press two layers of material, which causes them to melt slightly. A heated wedge further heats the materials prior to passing through rollers, and the combination of pressure and heat forms a hermetic seal that is permanent and tear-resistant.
Materials That Work Best with Hot Wedge Sealing
There are several different coated materials that hot wedge welding can seal together. These material combinations can be similar, such as two vinyl surfaces, or dissimilar, like polyester and polypropylene, provided the materials have equal thickness. The materials that are most appropriate for the hot wedge sealing process have thermoplastic coatings, including polyurethane (PU), polypropylene (PP), polyvinylchloride (PVC) and polyethylene (PE). This method is a good alternative to other common sealing processes that aren’t as reliable, such as taping, adhesive bonding and sewing, although those methods are useful for other materials.
Thinner materials are also sealable with hot wedge welding. This method is often used to fuse thin layers of PVC or vinyl coated materials with thicknesses of 10 to 80 mils (.020 to .080), along with other plastic fabrics like nylon and polyester.
Fabricating Three-Dimensional Products
Hot wedge bonding is an efficient process for producing straight or rounded welding patterns for many different product configurations. It is ideal for longer lengths of materials as well, and many industries can use this process to connect large pieces of coated fabrics because of its reliability. Two previously sealed pieces of material can use hot wedge welding to fuse to a third layer, but this process cannot fuse more than two surfaces at a time. Hot air welding is another heat sealing process that works under similar rules.
Using a rotary hot wedge press, hot wedge welding can fabricate three-dimensional products of various lengths, widths, patterns and seam types. Many industries use this process to create containment products, including:
- Pillow tanks
- Air and liquid containment bags
- Water storage tanks
- Fuel storage bags
- Pneumatic pillows
The width of seams in all products is typically around the same measurement as the rollers, anywhere from about 1/4″ to 1″. It is possible for the wedge to be wider than the rollers.
For additional information about this service and others that we provide, reach out to SealWerks. We will also help you determine if this process is right for your product.