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. Welding thermoplastics can be accomplished in 3 different stages 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 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 a popular fabrication technique in manufacturing smaller items such as water tanks, plumbing fittings, heat exchangers and chemical tanks.
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. They come in different colors in an effort to match the base color of the material.
Say for example that the plastic welding rod has high porosity, then this can cause air bubbles or voids in the rod. The welding quality greatly diminished if this happens. For this reason, it is highly recommended to use plastic welding rods that have zero porosity or known to be voidless.
Heat sealing – when it comes to this process, this seals thermoplastics to another like thermoplastic using heat and pressure. 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. 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.