Conestoga news

July 29, 2007 1:02 PM

Painful production for a practical pair: Researcher finds effective way of closing leather gloves

By Leanne Mountford
(Kitchener, July 19, 2007)

An electrician's hands need to be protected from dealing with exposed wiring all day long. Rubber gloves wear down over time, so electricians require leather gloves to wear over top of the rubber ones.

Brian Morriss, a professor in the School of Engineering and Information Technology, says the production of leather gloves is very difficult. Currently, the process of sewing the glove is a manual one. The top of the leather glove is wider than the bottom to allow space for a human hand. Sewing this three-dimensional shape makes it difficult to match the sides evenly during the sewing process, and even more challenging to automate. To get the three-dimensional shape, human operators have to constantly be pinching the leather together as it’s running under the sewing machine. It takes a fair amount of training on the part of the operators to get it right, he says.

"It’s a health issue and a cost of production issue,” says Morriss. After dealing with fine work like this all day long, the sewing machine operators can suffer from repetitive strain injury (RSI) problems. In addition, some glove manufacturers are outsourcing the production to overseas markets due to cheaper labour costs.

If the process of sewing a leather glove together could be automated, there would be fewer health issues and a faster production rate. Working with Marzo Glove of Rockwood, Ontario, Morriss decided to figure out a way of automating the closing (holding the leather together at the right points) of a leather glove.

"There have been a number of researchers who have tried to solve this problem of closing the leather glove so it can be sewn automatically, no one has found an automatic way of closing the glove,” says Morriss. Knowing the basic information, that the glove had to be formed over a three-dimensional shape, the leather was flat and the shape of the leather could not be changed, Morriss got to work.

Working on several different prototypes, Morriss developed a solution whereby operators place a lower clamp on to a metal fixture base and place the palm (bottom) part of the glove on the base. They then place a vacuum form on top of the glove and fold the glove top over the vacuum form. The vacuum form is a solid 3-D imprint of a human hand featuring a vacuum tube inserted in the end with holes on top of the form. A vacuum is attached to the tube and the air is sucked from the form. With a little operator help, this results in the top of the glove being "closed” (pulled down onto the bottom of the glove) leaving a perfect match for the operators to perform the stitching. At this point, the top fixture would be brought in and the glove would be clamped down around the outside edges of the glove. Once the clamps were in place, it could be lifted off the base, the vacuum form could be taken out and the glove could then be sewn around the edges. Prof. Brad Smith, of Conestoga’s Machine Tool Builder and Integrator (MTIB) program assisted Morriss in the project by building the metal base fixtures.

There are still some dimensional problems that need to be worked out, but Morriss says the pilot work has enabled them to get glove 75 per cent closed.

The final steps to completing this project will be to optimize the dimensional problems, to get the glove 100 per cent closed. Modifications will need to be made to the sewing machines to automate the process, but Morriss says he doesn’t see that as a big problem. A numerical control machine would be programmed to move the glove under the sewing machine, making the process automatic.

This research was funded by Marzo Glove and the Ontario Centres of Excellence.