HF Welding (RF Welding)
High frequency (HF) welding, also known as radio frequency (RF) welding, joins compatible thermoplastics using electromagnetic energy and pressure. The energy generates heat within the material, fusing the layers into a strong seam. Forsstrom HF welding machines operate at 27.12 MHz and are used to manufacture products from PVC and weldable polyurethane films and coated fabrics.
What Materials Can Be HF or RF welded?
PVC (vinyl) and weldable thermoplastic polyurethane (PU/TPU) are common materials for HF welding. They can be used as films or as coatings on reinforced fabrics, including many technical textiles. Suitability depends on the material formulation, coating and thickness. Forsstrom can help assess your material and identify the right machine, electrode and welding settings.
Why use HF welding or RF welding?
Repeatable welding results
Control of HF power, pressure, welding time and cooling time helps manufacturers reproduce the same seam across repeated production cycles. Settings can be adapted to the material and weld design.
Strong, durable seams
HF welding fuses compatible thermoplastic layers into a continuous joint. With the right material, tooling and settings, it produces strong seams for products exposed to repeated use and mechanical loads.
Airtight and watertight joints
Correctly specified and tested HF welds can form airtight and watertight joints. This makes the process suitable for applications such as inflatable products, pool liners and flexible liquid tanks.
Detailed shapes and multiple layers
Shaped electrodes define the weld area, making HF welding useful for detailed geometries, reinforcements and multilayer assemblies. The tooling and layer combination determine which designs can be welded.
Joining without seam adhesives
Compatible thermoplastics can be fused directly without adhesives at the joint. This removes adhesive application and curing steps from the seam-making process.
How does HF welding or RF welding work?
HF welding combines electromagnetic energy, pressure and cooling in five steps.
Position the material
Place the compatible material layers between the electrode and welding table, then align the seam.
Apply pressure
The electrode presses the layers together and defines the shape of the weld.
Generate HF energy
The generator creates an electromagnetic field at 27.12 MHz, heating the material within the weld area.
Fuse the layers
The thermoplastic softens and the layers fuse while the electrode maintains pressure.
Cool under pressure
The HF energy switches off. The joint cools under pressure before the electrode lifts.
Customer cases HF Welding (RF Welding)
All customer cases
30 October 2026
Union Industries
“Forsstrom stood shoulder to shoulder with us in our hour of need. They are not a supplier to Union, they are part of our family.”
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30 October 2026
Järven
“Our impression is that our newest machines give us an even higher quality in the welded seams.”
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30 October 2026
Lanz-Anliker AG
“The Forsstrom machine convinced us, with her design and with the solid construction.”
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Who uses HF welding or RF welding?
Manufacturers use HF welding for truck and boat covers, tarpaulins, tents, pool liners, inflatable products and flexible liquid tanks. It also supports products such as banners, stretch ceilings and oil containment booms. Share your material, seam design and production requirements with Forsstrom to discuss a suitable HF welding solution.