TORONTO - Putting a stainless steel shutter on a plastic computer diskette doesn't make much sense to Tosh Kitagawa, who injection molds a plastic shutter that is cheaper and more durable. ``To this day, diskette manufacturers still say customers won't accept the plastic shutter,'' Kitagawa said. ``They think that if they use plastic, they will have to lower the price of their diskettes because customers will think the diskettes are lower quality.''
Kitagawa had no plastics experience three years ago when he noticed a company in Japan developing a plastic shutter.
``I recognized that this had to be the material of the future,'' he said.
Virtually all of the world's annual production of 3 billion to 4 billion diskettes still use metal shutters.
So Kitagawa negotiated North American rights to the Japanese company's new process and started a company called Malaka Manufacturing Inc. in Surrey, British Columbia.
Malaka's plant is highly automated and can be run by a shift of just two employees, said David R. Bennett, vice president of production. It contains five Nissei presses with 80 tons of clamping force. Japanese-made molds are all multicavity.
Kitagawa and Bennett were interviewed May 1 at Plast-Ex '95 in Toronto.
The polyacetal diskette shutter weighs 1.2 grams. Walls are 0.013-inch thick. Bennett said the resin must have a high melt flow index rate - 50 or higher works best - and sometimes has been difficult to obtain. He is currently using a Hoechst Celanese resin with a melt flow of about 40.
The acetal shutters are lighter, 30-40 percent cheaper and experience less static build up than steel shutters, Kitagawa said. They can be taken off and put back on a diskette with no damage. So why do only about 1 percent of diskettes have plastic shutters?
``Diskette manufacturers have done a terrible job of marketing,'' he said. ``For years, they couldn't keep up with demand. Then China came on strong and in less than a year the market was glutted.
``Now prices are dropping and the only way to compete with the Chinese is on quality and service,'' he said. ``Plastics sells itself as a high-tech material, so diskette manufacturers need to market plastic shutters as a better-quality product.''
Malaka sells its plastic shutters primarily to distributors, who resell them to diskette makers around the world.