Hot plate welding
Its most common use is for welding the ends of plastic tubes used in the distribution of gas and water, wastewater and effluent evacuation. It is also common in housings of vacuum cleaners, parts of washing machines or automobiles and in the chemical industry.
The technique is the most common to join plastics, since it consists of the use of a plate, previously heated, that is interposed between the surfaces to be joined until they soften. To know the temperature, the time and the pressures necessary for each pipe, depending on the diameter, we will have the reference of the DVS2207-1 standard.
Hot air welding
Its use is very common in domestic repairs in which an object has been broken in two pieces, or also to bend a pipe of conventional PVC material if we do not have the piece or the elbow at the moment. It can also be used for small changes in thermoplastic sheets . Welding is achieved thanks to a stream of hot air, a welding rod and a nozzle. Although it is simple, its effectiveness depends on the skill of the operator who performs it.
Sealed by heat
Sealing bags and films hermetically, as well as sterilized medical devices is the most common use of heat sealing. The plastics in which they are used are polypropylene or high density polyethylene , which stand out for their resistance.
Extrusion welding
The repair of tanks and containers, as well as the joining of plates, is usually done with extrusion welding. It is a type of union for the contribution of material and, among its main characteristics, it stands out that, in a single step, it allows to apply large welds . With it it is possible to make welds on sheets with a thickness between 3 / 4mm to 35 / 40mm. The regulation that regulates this type of welding is the DVS 2209-1.
Injection welding
It is similar to extrusion welding, although it offers the added advantage of allowing the tip to be inserted into holes of plastic defects of different sizes.
Ultrasound welding
The applications of this type of welds, which are used for components of short length, are varied, from valves and filters used in medical equipment to automotive components and appliances housings. The joining method is high frequency mechanical vibrations.
High frequency welding
It is one of the techniques with the greatest number of uses, including the case of large surfaces. The plastic tarps, inflatable products, movie screens or tanks for liquid items are just a few examples. The materials are soldered thanks to the energy caused by an electromagnetic field (27.12 MHz) and the pressure exerted on the surfaces to be joined
Laser welding
Plastic parts and films can be welded easily with this technique. Its use is common in, for example, the union of parts of the headlight of a car, since they are transparent thermoplastics. It does not generate vibrations in the structure or require contact of any kind, which makes it clean and hygienic.
Vibration welding
Appliances and automobiles are usually soldiers with this technique. Almost all thermoplastics admit their use. Applying a pressure at a correct frequency and amplitude to two pieces that are rubbed together, we generate the heat necessary to melt the plastic. When this is achieved, the vibration stops, the parts are aligned and the polymer, already melted, is allowed to solidify.
Friction welding
Also called rotational, it is used for plastic wheels or shopping carts . Its use is common because it is not expensive, although it is essential that at least one of the components that we are going to weld have a circular shape. With one of the fixed components, the other is rotated at a controlled speed until the heat of the friction causes the melting of the polymer and, already cold, the welding.
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