No one method of fabric sealing is perfect for every application—in fact, many products are made using more than one method. An RF weld is forged using electromagnetism, while heat sealing melts two fabrics together at the surface using a concentrated application of high heat. Similar to the latter method is solvent bonding, a third type of sealing that also fuses fabrics at a surface level. While this is accomplished by applying a chemical to the surface of the fabrics, it works differently than a simple adhesive, and creates a lasting bond without necessarily relying on a comparable application of heat.
How Solvent Bonding Works
Unlike adhesives, which simply cling to the surface of a material, solvents alter the composition of vinyl or coated fabric materials when applied. Solvent bonding creates a reaction on the surface of the material, causing it to dissolve and break down — when two treated fabrics are pressed together and the solvent dissipates, the molecular breakdown stops and the fabrics fuse to each other. When the process is complete, the solvent is actually gone, leaving a tight and permanent seal behind.
Compared to an RF Weld or Heat Seal
RF welding and heat sealing are completely different processes, both from each other and from solvent bonding, but none of the three processes are always ideal. For example, the flawless bond created by an RF weld is ideal for heavy duty and sensitive applications, like products for the medical industry or the military. While heat sealing is comparably strong for creating airtight seals, its appropriateness may be limited depending on the thickness and type of the fabrics in question. Solvent bonding is ideal for somewhat irregular applications, particularly times when the product is of a shape, size or material that isn’t well-suited for methods like RF welding or heat sealing.
For example, it can be tricky to join two dissimilarly thick fabrics using heat sealing, because they don’t melt the same. Solvent bonding, however, allows you to treat them chemically instead of using temperature, making it easier to create a similarly strong bond without having to worry about variable melting points.