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 mechanism of heat generation at welding interface, the welding methods for the thermoplastics could be considered as internal and external heating methods. In reality, there are countless of welding techniques that are being used for semi-plastic products which include the following:
Hot gas welding – this is otherwise referred to as hot air welding, is a type of plastic welding technique that uses heat. This is making use of a special heat gun that’s called as hot air welder that produces a jet of hot air; this as a result softens the end parts that should 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.
High porosity in plastic welding rod will lead to air bubbles or also known as voids in the rod. The welding quality greatly diminished if this happens. With this in mind, voidless or zero porosity rods are the best plastic welding rods that can be used.
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 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. 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 with the use of thermal adhesives is for holding clear display screens to consumer electronic products and at the same time, for other sealed thermo plastic devices or assemblies where heat staking or even ultrasonic welding is not a recommended option.