RF sealing, also known as RF (high frequency) welding, is the process in which two materials are bonded together using electromagnetic energy. In this process, two different electrodes are used to create an oscillating electric field. This then causes the polar molecules inside to shift and move in accordance with the electromagnetic field. As these molecules move they release energy in the form of heat, which causes the molecules to melt and begin to bond with each other. Pressure is then applied to the area, resulting in a successful seal.
What contributes to a good seal?
There are many different factors that contribute to the formation of a quality seal. This could include tooling layout, weld thickness, material thickness, and machine control. Many welds are subject to pull tests, leak tests, and optical tests to ensure that the correct conditions have been met.
What materials can be RF welded?
When it comes to RF welding, some materials are easier to weld than others. There are some materials that require a special process in order to achieve a successful weld. The following materials can be RF welded:
- Thermoplastic Polyurethanes
- Open Celled Polyurethanes
Why use RF welding?
There are a few different alternatives that can be used in place of RF welding, sewing, gluing or using hot air. So, why would you want to use RF welding?
- RF Welding vs. Sewing: RF welding provides a consistent airtight seal that cannot be achieved from sewing. When under pressure, the sewn threads could break, breaking the seal. RF welding evenly distributes the stress throughout the packaging, creating a stronger seam that is air and moisture tight.
- RF Welding vs. Gluing/Adhesives: Glue can also provide an airtight seal but it is a much longer process that requires hazardous solvents that can potentially be harmful to the environment. Additionally, once the adhesive has worn out, glued seams are likely to fail.
- RF Welding vs. Hot Air: Hot air is applied to the exterior of the material, causing it to melt and seal together. This method is only effective on materials up to a certain thickness. If the material is too thick it will not properly melt and create a weak bond. RF welding works from the inside out, creating an airtight seam that won’t fail.
At SouthPack, we are able to help create custom product packaging that will protect your products. Whether you are looking for RF sealing, blister packaging, or any other type of packing, SouthPack can help you achieve it!