FAQs – Ultrasonic Nonwovens/Textiles Bonding

What materials can be bonded by ultrasonic welders for nonwovens/textiles? Can I bond dissimilar materials?

Materials may be 100% synthetic or blends with up to 40% natural fibers.

Acrylics, acetates, polyester, nylon, polypropylene, spandex and PVC are all suitable for bonding or cutting. In general, the higher the synthetic content, the easier it is to cut and seal with ultrasonic energy. Nonwovens including felted filter media are especially suited for ultrasonic bonding.

Yes, many dissimilar materials can be bonded together. Melt temperature difference for dissimilar materials can’t be greater than 50° F.

Will my material still bond ultrasonically if it has a fire retardant treatment?

In many cases, you will not have a problem.  However, some flame retardants do adversely affect bond strength.

What are the advantages/differences between rotary/continuous ultrasonic bonding and stationary/traversing methods?

The rotary method works like a sewing machine and produces a continuous seam or pattern.  The friction between fabric, pattern roller, and ultrasonic horn is greatly reduced if both sides rotate, instead of having the roller rotate on a stationary horn.

What is ultrasonic slitting?

Ultrasonic slitters cleanly cut and seal the edges of synthetic or blended fabrics, eliminating the disadvantages of hot wire or rotating knives. Fraying, unraveling, or beading along the cut edge is eliminated.

What is an acceptable amount of glass content for ultrasonic welding of fabrics?

Fillers such as glass fiber are added to change the physical properties, although glass itself is not weldable.  Glass content of 20% or less may still result in an acceptable bond.