Types of Plastic Welding Techniques Used Today
Plastic welding is actually welding for the semi-finished plastic materials and is also described as a process to unite softened material surfaces with the use of heat, except for solvent welding. There are three different stages of accomplishing the welding of thermoplastics and these are surface preparation, application of pressure and heat and lastly, cooling.
With the wide applications for welding, there are many methods that are introduced to join semi finished plastic materials. Depending on the mechanism of heat generation at welding interface, welding methods for thermoplastics may be deemed as internal and external heating methods. 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 is using special heat gun that’s called as hot air welder which produces jet of hot air that is softening both end parts that have 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 – plastic welding rod is also called as thermoplastic welding rod which is a rod with a triangular or circular cross section that is used for binding 2 pieces of plastic together. There are different colors for welding rods too so it can match the material’s base color.
Say for example that the plastic welding rod has high porosity, then this can cause air bubbles or voids in the rod. 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 – for this process, it seals one thermoplastic to the other such as thermoplastic using pressure and heat. Direct contact method for heat sealing with the use of constantly heated sealing bar or die in order to apply h eat to a specific path or contact area to either seal or weld the thermoplastic together.
As a matter of fact, there are a number of applications that can be used for heat sealing like thermally activated adhesives and film, heat seal connectors or foil sealing. The common application for heat sealing process is to join PCBs to LCDs in various consumer electronics and even 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.