Types of Plastic Welding Techniques Used Today
Actually, plastic welding is welding semi-finished plastic materials and described as the process of uniting softened material surfaces by using heat, except for solvent welding. Welding thermoplastics can be accomplished in 3 different stages and these are surface preparation, application of pressure and heat and lastly, cooling.
There are many different welding methods that are introduced and developed to join semi finished plastic materials. Welding methods for thermoplastics are actually considered as internal and external heating methods because it depends on the generated heat mechanism at the welding interface. As a matter of fact, there are now various welding techniques used for semi-plastic products and these are:
Hot gas welding – this is also called as hot air welding which is a kind of plastic welding technique that is using heat. It utilizes a special heat gun that is called as hot air welder that is producing jet of hot air which softens both end parts to be joined and plastic filler rod.
Hot gas/air welding is very popular fabrication technique to manufacture smaller items similar to water tanks, chemical tanks, plumbing fittings and heat exchangers.
Welding rod – this is also called as thermoplastic welding rod that has a triangular or circular cross section which is used by welders when they need to bind 2 pieces of plastic together. They come in different colors in an effort to match the base color of the material.
Air bubbles or voids in the rod will come up if the plastic welding rod has high porosity. At all cost, this should be avoided as it is decreasing the welding quality. For this reason, it is highly recommended to use plastic welding rods that have zero porosity or known to be voidless.
Heat sealing – in this process, it is sealing one thermoplastic to another similar to thermoplastic with the use of pressure and heat. Direct contact method for heat sealing using constantly heated sealing bar or die to apply heat to specific path or contact area to weld or seal the thermoplastics together.
There are various applications for heat sealing whether you believe it or not similar to foil sealing, heat seal connectors, thermally activated adhesives and film. Joining the PCBs to LCDs in countless of consumer electronics is the most popular application for the process of heat sealing but it can be used as well in telecommunications and medical devices. Heat sealing of products is using thermal adhesives to be able to hold clear display screens to consumer electronic products, for other sealed thermo plastic devices or assemblies in which ultrasonic or heat staking welding is not a viable option as a result of part design requirements or other assembly consideration.