PAWTUCKET (TIP): Welding isn’t just for aircraft carriers anymore.
The US Navy could be turning to ultrasonic welding to make its uniforms lighter, stronger and cheaper. And if the project by a Rhode Island company and the Navy Clothing and Textile Research Facility is a success, it could help bring manufacturing back from overseas.
Welded seams — created when two pieces of fabric are essentially melted together by sound waves — are already used in some clothing that some Americans have in their closets. Patagonia and North Face both sell models of jackets with welded seams. But so far, most, if not all, of that manufacturing is done overseas.
Propel LLC is trying to figure out how to make one of the Navy’s more expensive and challenging garments to assemble — the Navy parka, which it buys for $190.50 each — without stitches. It has spent the past year testing welded seams, adhesive techniques and other bonds using a federal grant from the Navy.
“This was a good way for us to start to get an understanding of what the current state of the art is,” said Cleveland Heath, the technical program manager at the Navy facility in Natick, Massachusetts.
Current garment assembly methods can be cumbersome and costly, Heath said. Different kinds of stitches are used and garments have to be moved from sewing machine to sewing machine as they are formed. One welded seam could replace several stitch types and the sewing machines associated with them, he said.
The seam is a garment’s weak point, said Propel president Clare King. Using a needle and thread creates tiny holes that air and water can permeate, taping a seam to cover the holes adds weight.
The welded seams have proven to be lightweight, flexible and waterproof, King said.
“We have a lot of opportunity to improve the garments and also effect change at the factory level,” King said. “Some of these technologies have been used in factories overseas but we have no knowledge base here of how to do them or how to implement them.”
Seams are welded on some large tents, liners and other specialty industrial fabrics, but not on typical, casual clothing. For the Navy project, King consulted Patagonia, whose M10 jacket has welded seams and is made in Vietnam. Joe Vernachio, a vice president at The North Face, said he knows of only four or five factories overseas that weld seams for apparel. The military is required by law to manufacture all uniforms in the United States.