Fabric welding
Frequently asked questions about fabric welding
A genuine alternative to the sewing of synthetic textiles, fabric welding enables seams to be made without stitching or assembly marks, and is characterized by its strength, watertightness and high quality.
However, textile welding is not limited to synthetic fibers, as natural fiber fabrics can also be welded in the same way, after a prior coating operation to give them the characteristics required for welding.
What technologies are used for textile welding?
Based on the assembly of fabrics made of synthetic fibers, or on the assembly of fabrics composed of both natural and synthetic fibers, textile welding can be carried out using either ultrasonic or high-frequency technology.
Ultrasonic welding is a rapid joining technique that involves vibrating the fabric strips to be joined at a frequency of between 20 and 70 kHz. The resulting heat causes the thermoplastic fibers to melt, thus joining the fabric elements to be welded. Ultrasonically-coated textile welding makes it possible to join fabric parts made from a mixture of synthetic and natural fibers, with a very clean finish.
High-frequency welding of textiles (RF or HF welding) is based on the generation of a high-frequency electromagnetic field that causes a dielectric effect on the materials. The agitation of molecules in both synthetic fibers and thermoplastic coatings on natural fibers ensures that fabrics are welded together, resulting in very strong assemblies with a high level of finish.
What textile fibers can be coated for welding?
Coating is a technique for modifying the technical characteristics of a textile or fabric, whether made from natural fibers (cotton, linen, wool, etc.), artificial fibers (viscose, lyocell, etc.) or synthetic fibers (polyamide, polyester, acrylic, etc.). Whereas coated textiles are single-layered and undergo a treatment to modify their surface into a uniform coating compound, coated fabrics are composed of at least two layers of material: the fabric layer and the polymer coating layer. Textile substrates most representative of this technique include PVC-coated fabrics, PU (polyurethane) coated fabrics, PVC-coated textiles, etc.
Visit textile polyurethane coating is characterized by its watertightness and low stainability. It protects against chemicals and does not conduct electricity. In general, all woven textile substrates with a high proportion of synthetic fibers can be coated for welding:
- polyamide
- nylon
- polyester
- acrylic or polyacrylonitrile
- polyethylene
- polypropylene
- polytetrafluoroethylene
- elastane…
Non-woven textile substrates and certain natural fibers (cotton, wool, silk, etc.) can also be coated and welded. Textile materials with 40% natural fibers, woven fabrics, elastic fabrics and knitted fabrics can also be welded.
What materials are used for fabric coating?
The production of coated fabrics varies according to the polymers used, the type of coating chosen and the processing methods. The materials used for fabric coating are made up of resins and additives. Coating resins consist of a polymer or polymer-additive blend based on :
- polyurethanes,
- acrylates or polyacrylic acids,
- latex or natural rubber,
- polyvinyl chloride (PVC),
- silicone elastomers…
Additives are softening, hydrophobic or preservative agents, and can represent up to 80% of a coating resin’s composition.
Textile substrates whose initial structure is modified include :
- PVC-coated fabric used for roller doors, floor coverings or waterproof suits…
- Polyurethane-coated fabrics to produce waterproof clothing, mattress pads or hospital mattresses…
- PU-coated textiles for mattress covers, massage table covers, treatment table covers…
Which machines are used for textile welding?
Depending on the type of textile welding to be carried out, Matrelec has several families of high-frequency welding presses to meet very different needs.
For short welds and small production runs, gooseneck presses such as CCM30 are best suited. Allowing manual operation, these high-frequency welding presses are easy to use and meet a wide range of needs. Recommended for finishing products, they are available in 4 power levels.
High-frequency Type C gooseneck welding presses are used to weld large, bulky coated textile products. They can weld fabrics up to 800 mm long.
High-frequency gooseneck presses can be used to weld very bulky textile products, with a passage of 1500 mm behind the welding head. These ECP-type HF presses can produce long welds of up to 1200 mm.
