High-Frequency Welding (HFW)
In high-frequency welding, high-frequency electromagnetic waves are used to fuse two pieces of thermoplastic materials together.
The chemical structure of some plastics is used in HFW. A distinction is made between neutral types of plastic (without dipoles) and polar plastics (with dipoles). Neutral plastics include plastics such as polyethylene (PE), polypropylene (PP), and polystyrene (PS). Polar plastics include polyvinyl chloride (PVC), polyamide (PA), and acetate.
Dipoles are two opposing electrical or magnetic poles. In this process, the foils to be welded are exposed to a hig-frequency electromagnetic alternating field, which excites the dipoles of the plastics. The excitation causes heating, and the subsequent application of pressure welds the thermoplastic films to one another.
How HFW Works
High-frequency welding involves an alternating current (AC), which is passed through an induction coil made of copper. This current generates an electromagentic field.
The thermoplastic to be welded is placed between two coils. The electromagnetic field then causes the molecules that are contained within the material to rapidly vaibrate. This rapid vibration generates heat, and thus melts and fuses, or welds, the two pieces of plastic together.
This form of welding process is a continuous one, where larger areas can be processed without having to set the welding device down.
You can also work very precisely with this process, because only the areas that are actually to be connected are heated.
Advantages of High-Frequency Welding
- Consistent Welds
- Fast and efficient
HFW is able to produce very strong, consistent welds. This method is able to do so without creating materials that are damaged or distorted.
Welding time with this process typically lasts anywhere between seconds to minutes to create, depending on the material and product. This fact makes high-frequency welding a fast and efficient welding method.
Check out our Price Holders, which are high-frequency welded. Thanks to our HFW machine, we have many different styles of price holders depending on how you want to advertise your product.