Common Plastic for Welding

• Plastics are known for their malleability, or plasticity. Compared to iron, steel and other metals for welding, plastic welding is not as complicated. Many of the most common plastics are easily welded through processes requiring little equipment. However, it is good to know the most common plastics used for welding. Although this is not a comprehensive list, the most common plastics include PVC, or polyvinyl chloride; polystyrene; polyurethane; polypropylene; polycarbonate; nylon and acrylic.
  
  

Hot Air Welding

• The most common way of welding plastic is through "hot air welding" or "hot gas welding." To perform this technique, a specifically designed implement named a "hot air welder" is needed. The implement produces hot air that causes the plastic to soften and allows for two pieces to conjoin into each other. A limitation to this process is the two materials must be similar or identical plastic. PVC and acrylic welding are not recommended.
  
  

High-Frequency Welding

• This type of welding involves electromagnetic waves that loosen the molecular bond of the plastic, making it easy to join the two pieces. It is referred to as high frequency welding, but it is radio frequency that is often used. The normal plastics used in radio frequency welding are polyurethane, nylon and PVC.
  
  

Laser Welding

• For this technique, one plastic must be susceptible to the laser and the other plastic must have a coating that is absorbent to the laser beam. A great amount of pressure is applied while the laser beam runs along the conjoining line. Polypropylene, polycarbonate and acrylic are commonly welded through this process.
  
  

Tools

• Plastic welding tools are available online and in many home improvement and construction department stores. Consumers can purchase hot gas welding tools, hand-held extrusion welding tools, sheet butt welding and bending machines. These tools are mainly used for the hot air welding process, as that is the most accessible and commonly performed method of plastic welding.
  
  

Other Techniques

• There are other techniques for welding plastic, such as friction, ultrasonic, solvent, spot, speed and contact welding. Hot air, high-frequency and laser are the more modern and accessible techniques. While the other processes may require different tools and applications, they are still used for many of the same common plastics.