Different Plastic Welding Techniques
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.
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. In reality, there are countless of welding techniques that are being used for semi-plastic products which include the following:
Hot gas welding – this welding technique is making use of heat which is why it is also called as hot air welding. 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 – the plastic welding rod is being called as thermoplastic welding rod; a rod that has a triangular or circular cross section used to bind 2 pieces of plastic together. There are different colors for welding rods too so it can match the material’s base color.
High porosity in plastic welding rod will lead to air bubbles or also known as voids in the rod. At all cost, this should be avoided as it is decreasing the welding quality. With this in mind, voidless or zero porosity rods are the best plastic welding rods that can be used.
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 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.