Radio Frequency Welding vs. Hot Air Plastic Welding

Radio Frequency Sealed Green Bag

What is plastic welding? Plastic welding is the process of joining two plastic materials typically through heat. Plastic welding has many applications from medical and manufacturing to retail. Many of these we produce right here at SealTech using Radio Frequency Welding. The two most popular ways to generate heat for plastic welding are through the use of hot air and radio frequency current.

Hot Air Welding

Hot air welding, like its name implies, uses hot air to heat the plastics to a temperature in which the layers will fuse. This process in which the hot air heats the plastic is convection. Convection transfers heat using a fluid flow. In the case of hot air welding, air flows across the surface area of the plastic you are welding. In turn, this transfers heat through the plastic.

However, this puts a limit on the thickness of the material that is being welded. Because convection heats from the outside, this causes the surface to burn before the inner layers that are being welded to reach the necessary temperature. This is where Radio Frequency Welding comes in.

Radio Frequency Welding

Rf welding uses radio frequency electric current to generate heat within the plastic itself to fuse the layers. Rf welding heats through a process known as radiation. This happens when an object is heated from the energy of electromagnetic waves. The Rf current that passes through the plastic and generates an electromagnetic field.

It works in a similar way to a kitchen microwave. The electromagnetic field causes the molecules within this plastic to oscillate. This generates high heat within the material, causing the layers to fuse. This process creates heat throughout the material rather than from just the surface.

Because of this, we are able to weld much thicker material than hot air welding allows. In turn, we at SealTech can even weld plastic coated fabrics too!

Which one is better?

Using radio frequency welding means you can remove some sewing and gluing out of the manufacturing process. Rf welding has a ton of versatility. It enables plastic manufacturing for both low and high-volume production. Here at SealTech, we are always ready to bring RF welding to your product.