What is RF (High Frequency) Welding?

Our Medical Instrument Packaging Pouches Made From FlexShield Thermoplastic Polyurethane Film (TPU)

Radio frequency welding or (high frequency welding) is the process of bonding together materials through the use of electromagnetic energy. Two electrodes create an oscillating electric field that begins to shift and move polar molecules within the materials in order to orient themselves in accordance with the electromagnetic field. The movement of these molecules releases energy in the form of heat. When enough energy is applied, the molecules begin to melt and bond to one another. No external heat is applied. The weld is completed by applying pressure to the bonded area, ensuring a successful seal.



Many factors affect the strength and seal quality in RF welding. Tooling layout, weld thickness, material thickness, and machine control are some of the most important factors in creating a good seal. The appeal of RF welding is in the completeness of the weld. Using this method can create very robust hermetic seals. Many welds are subject to pull tests, leak tests, and optical tests to determine that the correct conditions have been achieved.


Some materials are more of a challenge to RF weld than others and may even require a special process. No matter the level of difficulty, UFP Technologies is confident in its ability to expertly perform RF welding on the following materials:


There are several alternatives to RF welding including sewing, gluing, or using hot air. Why use RF welding?

RF welding provides a consistent air tight seal unlike sewing. When sewn seams are stressed, the thread takes the pressure and could break. RF welds evenly distribute stresses throughout the material providing a much stronger seam while preventing any air, moisture, or debris getting in.

Gluing can provide an air tight solution, but gluing takes much longer than RF welding and often uses hazardous solvents that are harmful to the environment. Glued seams are also subject to failure once the adhesive has worn out.

Hot air is a method that applies heat to the outside of the material to melt it and create a bond. This method is only effective up to certain thicknesses. Materials that are too thick will not bond in the middle as the core will struggle to melt, while the outside layers are over heated or burned. RF welding heats from the inside out and is the best method for forming air tight seams.


Our RF Welded Packaging Pouch Made From FlexShield TPU For Medical Instruments

Our packaging pouch made from FlexShield® thermoplastic polyurethane film (TPU) is one of our newest innovations for the medical device industry. The FlexShield® TPU pouch is manufactured via RF welding and provides puncture and abrasion resistance in order to safely ship medical instruments without incurring damage to external packaging. Utilizing FlexShield pouches within your packaging systems will ensure the integrity of the sterile barrier between your instruments and outside contaminates.

It is crucial to the functionality of the product that the RF welds on the FlexShield pouch maintains integrity throughout the supply-chain. RF welding is also used in a number of wound care applications that assist patients through the healing process. For safe storage of defibulators, UFP Technologies manufacturers a three chamber reusable pouch storage system that is sealed using RF welding. We also utilize these capabilities to produce industrial cleaning products.


In February 2018, UFP Technologies acquired Dielectrics, Inc., a leader in the design, development, and manufacture of medical devices using RF welded thermoplastic materials. Our combined capabilities and expertise allow us to provide improved patient outcomes by minimizing the chance for infection, improving patient comfort, and promoting faster healing. To learn more about Dielectrics visit their website at

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Contact UFP

To contact UFP Technologies, please call the number below or complete the following form so that we may route your request to the proper contact.

  • 100 Hale Street Newburyport, MA 01950 USA
  • 800-372-3172