Different Plastic Welding Techniques
Plastic welding is about joining semi-finished plastic materials and at the same time, described as the procedure of welding softened material surfaces by using heat. The welding of thermoplastics is also accomplished in 3 phases which include surface preparation, application of pressure and heat and lastly, cooling.
There are various welding methods that have been introduced and developed for joining 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 otherwise referred to as hot air welding, is a type of plastic welding technique that uses 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 a popular fabrication technique in manufacturing smaller items such as water tanks, plumbing fittings, heat exchangers and chemical tanks.
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. 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 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. A common application for heat sealing process is joining PCBs to LCDs in different consumer electronics and sometimes, 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.