WELDING CHARACTERISTICS: Unlike welding of rigid plastic parts, the ultrasonic welding of textiles and films relies on a pattern or design on the tooling to focus the ultrasonic energy and produce a melt. This geometry can be located on the face of the horn, anvil, rotary drum, or stitching wheel. These patterns are listed in Branson data sheet PW-45. In general, favourable material characteristics that will help to ensure successful ultrasonic welding or bonding are:

• 50% thermoplastic content at a minimum, more preferred
• Uniform thickness

 RELATIVE EASE OF WELDING:

 Additionally, note that certain materials such as foam may weld better in the plunge mode (as on a bench-top welder), than in the continuous mode. This is because there is no hold time in continuous bonding that allows the molten material to cool under pressure and retain its welded shape.
 Code: 1 = Easiest; 5 = Most Difficult
 Note: Categories left blank (—) indicate that the materials are not generally seen in this form.
•Thin polyethylene film is generally considered poor for ultrasonic welding, because it has a low coefficient of friction and tends to break down or degrade during welding. Fast ramp times can improve the weld results with thin films.
• PVC sheet or fibre is difficult to predict due to the broad range of additives used in its manufacture. Plasticizers are often added to PVC to increase flexibility. As the content of plasticizer increases, the ability to ultrasonically bond PVC can be inhibited.
• Acrylics can be ultrasonic allytacked or cut. Continuous bonding is generally unsatisfactory due to embrittlement and low strength.
• Thermoplastic urethane (ester base) coated materials exhibit excellent strength when bonded ultrasonically. Thermosetting urethanes (ether base) will degrade when subjected to ultrasonic energy.
•Cut and seal only.

 TYPICAL APPLICATIONS: Following are some typical textile and film applications that use Ultrasonics:

 Acrylic: Filters, awnings, blankets, knitting yarns, garments.
 Nylon: Carpet, sports gear, food bags, filters, garments, hook and loop material, seat belts.
 Polyester: Conveyor belts, filters, garments, laminates, mattress pads, packaging, quilts.
 Polyethylene: Laminates, packaging film, re-sealable bags.
 Polypropylene: Bags, carpet backing, outdoor furniture, snack food packaging, tents, upholstery, disposable garments.
 PVC: Films, outdoor furniture, shrink packaging, tarpaulins.
 Urethane: Rainwear, coated materials.