What is Plastic Welding? 3 Steps to Welding Plastics

Welding plastics is a process applicable to plastic part manufacturing , used to join two compatible thermoplastic parts. It involves preparing two thermoplastic parts, pressing them together to form a joint, and then heating them using a variety of heating techniques. Furthermore, the heating technique used depends mainly on the plastic material. For example, Laser plastic welding is commonly used for PVC, which produces dangerous toxic gases in an unpressurized environment.

The continuous application of pressure during the heating and cooling process forms a molecular bond between the two parts. Therefore, unlike other plastic joining processes such as adhesives and riveting, plastic welding joints are very strong. Plastic welding has been widely used in medicine, electronics, construction and other fields.  

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Welding two semi-finished plastic resins made by injection molding or other processes can be challenging. Therefore, this time we will show you the steps on how to weld plastics regardless of welding technique.

• Step 1: Set Up Your Workspace and Clean the Plastic

The first thing to do is to set up a workspace. The workplace needs to be properly ventilated, as most heating techniques emit dangerous fumes, or a powerful fume extraction and fume extraction device should be added.

Clean thermoplastics to ensure high weld joints. Cleaning methods are washing with soap and warm water, then wiping the plastic dry with a clean, lint-free cloth. In addition, it is recommended that you use a liquid solvent such as methyl ethyl ketone (MEK), 80 grit sandpaper or a paint scraper to remove stains.

• Step 2: Joining Plastics

Clamp and stick the two plastic pieces together to form and secure the desired joint. Also, place the plastic pieces on the workbench and secure them using C-clamps. The way you connect the plastics depends on your welding technique.

• Step 3: Finish the Weld

Repair the weld before cooling to address issues such as smoothness. Allow the welded plastic to cool for about 5 minutes or to reach room temperature. Additionally, grind or use other surface treatment processes to smooth the weld joint after cooling.