Plastic films that are made from polar molecules are used, such as PVC, TPU or PET. These films are loaded into an RF welding tool that consists of an upper and lower die and tray that are made from Aluminum or Brass with the desired weld pattern machined into the Tooling. This weld pattern is welded into the plastic film layers creating the desired 2D shape, but specialty items can be welded into products, such as one way valve, molded components and simple inlet or outlet tubes.

Radio frequency, or High-frequency radio waves, are generated in the Press and broadcasted through the closed tooling. The RF waves cause the polar molecules to rotate at 27.12 MHz, which generates friction between the molecules within the weld area. The RF tools and press applies pressure to the film materials along the weld pattern while they are extremely hot, which welds the materials together under heat. After the RF waves are turned off, the material cools quickly allowing the welded parts to be handled immediately after the weld cycle is complete.

RF welded products have been in use for decades in a variety of application ranging from simple embossing to critical lifesaving medical products. Equipment is fitted with alarms that will trigger if any sort of manufacturing fault occurs during the welding process. The welding process causes the plastic in the welded areas to “flow” into one another, essentially becoming one material, as opposed to two separate film layers. If welded films are loaded onto a tensile tester, it is expected to see the base film material break before the welded are fails, which signifies a functional weld.

The materials being welded need to be comprised on polar Molecules.

Perimeter weld tools are milled flat but allow you to create complex shapes on those 2D planes, resulting in the complex shapes getting welded onto the film layers.

Inlet and outlet tube, one-way valves, or molded parts can be incorporated into the product design (i.e., recreational pool floatation devices.) Inlet or outlet tube welds can be incorporated into the perimeter weld tooling, instead of needing a separate tool.

Select one material that is RF welding compatible for the welded product. This consists of polar molecules like PVC or TPU. PVC or TPU coated fabrics work well and offer exceptional functional properties.

Screen printing or hot stamping can be incorporated into the film layers before welds are completed.

Film layers need to fully cover the tools weld area or weld issues will be created. Typically, the cut pieces are 1/4” larger than the weld pattern, at a minimum, to prevent weld issues. The excess film material can remain after the weld is completed, or it can be trimmed away in an offline operation, if desired.

The welded area will have a higher tensile strength than the adjacent unwelded portion of the product. A large weld width does not increase the product strength.

If your product is intended to be pressurized, any corners should have a large radius to reduce the pressure from concentrating on that specific point, which can cause failures.

Typical testing methods for RF welded products consists of tensile testing, pressure decay testing or burst testing.