Anybody who's taken care of a baby for even an afternoon knows the importance of keeping wet wipes on hand — for those ever-messy faces and hands, not to mention those poopy bottoms. There was a time when the wet-wipe market catered almost exclusively to the parental set. But these days, the disposable wipes are in demand for everything from cleaning countertops to removing makeup to disinfecting wounds.
This change has had some key effects on the market, and in turn on the machines that serve the market. For one, the market for non-woven wipes has seen explosive growth over the past 10 years. It has become a highly competitive space, making price a key differentiator in production. This places more demands on the production tools to increase throughput, and to do so at an affordable price. Also, with the diversity now present in the market comes the need for increased flexibility in the machinery. Such changes in the competitive landscape called for innovation in machine design. And it's that innovation that we recognize this month.
Paper Converting Machine Company (PCMC) in Green Bay, Wis., makes the converting machines used by leading wet-wipe manufacturers. The company is always looking at upcoming trends in the market to find new ways to provide more value for its customers. It has been particularly innovative with its patented rotary saw cutting technology, and it is PCMC's latest saw, the Mako, that earns the 2011 Innovator Award. It's a cutting-edge, two-bladed, high-speed rotary saw application that increases throughput, and provides flexibility for wet-wipe converting processes.The Web of Innovation
Non-woven fabrics, such as wet wipes, are made by a process that creates a single sheet of materials from a tangled web of separate fibers such as cotton or rayon. Fibers are made into liquid slurries with water and other chemicals, and the resultant paste is pressed into flat sheets by rollers and then dried to form long rolls of fabric.
A converting machine folds the individual webs into various shapes that will "pop up" from the wet-wipe container when they're packaged (Figure 1). Once folded, the webs form a ribbon that is essentially a long stack of wipes that haven't been cut. The machine then cuts the ribbon to individual lengths that get wrapped into a conventional package.
Traditionally, adjusting the cut length of the stacks required changing mechanical parts followed by manual re-timing of those parts. PCMC wanted to improve throughput on its wet-wipe machine by designing a faster saw cutting application that would allow operators to adjust cut lengths with the push of a button. The challenge for PCMC was that this capability didn't exist at the time. Making this change represented a step forward for the non-wovens industry, and required PCMC to tap into some of the newest automation technologies.
"PCMC is an established industry leader, and we believe that's because we're constantly looking for ways to provide more value for our customers," says Rodney Pennings, product line engineering leader at PCMC. "With the Mako saw application, we wanted to think about how we could continue to improve the value customers gain from our machines, while designing technological improvements that would move the industry forward."
Because PCMC was seeking a significant step forward in its saw cutting technology, the company decided to take a mechatronic approach early during machine design in order to validate the performance of new concepts and save testing time in the future. Mechatronics — a combination of mechanical, electrical and control engineering—offers a collaborative, interdisciplinary approach to machine design that helps machine builders bring engineering processes closer together to achieve faster time to market, and reduce design and development costs. This was the first time that PCMC had applied some of the latest mechatronic design tools, so again it was faced with the challenge of applying new technology to provide greater customer value.A Cut Above
PCMC set out to design a saw cutting technology that would significantly increase the speed and throughput of its wipes converting machine. The high-speed rotary Mako saw cuts wipes at speeds of 500 per minute with a two-bladed, servo-driven head and drum. It is 67% faster than its predecessor, and is said to be the highest-speed saw cutting application on the market today.