Hot Wedge Welding: Applications, Functionality, Materials, and Safety
Introduction: Hot Wedge Welding (HW) is a versatile and efficient welding technique widely employed in various industries. This ultimate guide aims to provide comprehensive insights into the uses, functionality, materials, and safety considerations associated with Hot Wedge Welding.
Overview of Hot Wedge Welding
Hot wedge welding, also known as bar welding, utilizes a heated metal wedge to melt thermoplastics effectively. The process involves precisely positioning the wedge at the weld point while pulling two sheets of fabric or film across it. The controlled temperature of the wedge, ranging from 370°C to 493°C (700°F to 920°F), ensures optimal welding conditions.
Functionality of Hot Wedge Welding
- Welding Process:
- The material is moved across the heated wedge from above and below.
- Pinch rollers or manual pressure are applied to create a smooth-seamed weld.
- HW welding excels in straight seams, offering one of the fastest welding methods, with variable weld times from 0.5 to 42 m/min.
- Equipment Characteristics:
- Unlike other welding methods, HW machines are silent and nearly smokeless.
- Lack of high-frequency generators or high-speed air flow fans ensures a quiet and safe work environment.
Applications of Hot Wedge Welding
- HW welders can simultaneously create multiple seams, making them suitable for various applications.
- Ideal for portable apparatuses used in field applications with soft or uneven welding surfaces.
- Material Compatibility:
- Preferred for welding more than two layers or films with a thickness from 0.2 – 2mm (usually less than 0.5mm).
- Particularly suited for PVC parts and TPU– and PVC-coated materials.
- Common Uses:
- Manufacture of smaller tents, temporary inflatable structures.
- Application of tape onto sewn seams.
- Flexible storage tanks, geomembrane works, tunneling, and roofing.
- Specialized Applications:
- Geothermal membranes – HW welding is the technique of choice for assembling large-area geothermal membranes in the field.
- Thick HDPE-coated industrial materials are dual-track welded for consistent welding speeds and seam integrity testing.