CHARLTON, MASS. - Mold maker Miniature Tool & Die Inc. of Charlton and custom injection molder Technical Industries Inc. of Canton, Conn., are two companies profiting by thinking smaller.
The companies specialize in micromolding, the art of molding microscopic parts. The companies, which work together on many projects, say micromolding opportunities are growing, especially in the medical and electronics industries.
Miniature Tool & Die, for example, is working on a three-tool contract for a minimally invasive surgical instrument manufacturer. Citing a confidentiality agreement, it will not name the customer.
However, Miniature is building stainless-steel micromolds, which are almost impossible to see without a microscope. They are built with repeatable tolerances of less than a thousandth of an inch, which is about one-third the width of a human hair.
``We are literally mounting microscopes in the equipment to see,'' Donna Tully-Bibber, vice president of sales, said in an Aug. 15 plant visit. The technology to make parts even smaller is advancing quickly.
``People talk plus or minus at the micron level. We are continually updating our equipment [to keep up],'' said Dennis Tully, vice president of engineering.
The future, according to Tully-Bibber, is in nanotechnology, which involves parts measured by molecules. Expect to see that in the next 10 years, she said.
For now, designing molds for a minimally invasive surgical part that will be 0.06 of an inch in length with a 0.0045 subgate takes great detail.
``The trick is to develop techniques to accomplish those things that are not normal. You really have to be creative. Every stage requires a different approach,'' Tully said.
``A lot of care is used just in developing the fixtures [to hold the part],'' Tully-Bibber added.
The continual downsizing of medical parts helped Miniature Tool & Die's business increase 60 percent last year, according to Tully-Bibber. That is why the company, which splits its business evenly between building molds and electrical discharge machining, is pushing to gain more of the micromold market.
Miniature Tool & Die has its roots in miniature electrical connector molds. Current President Richard J. Tully started the company in 1970 in the basement of his home. Two of his five children are now vice presidents and partners in the company.
The firm spent many years in Worcester, Mass., but moved to a new 16,500-square-foot facility in Charlton in 1998. The facility is designed with orderly cells, and a floor system to collect graphite dust, keeping the shop clean. The plant employs 11 and runs its machinery 24 hours a day.
Technical Industries and Miniature Tool are separate entities but find themselves working on many micromolding projects. The companies came together when Technical went to Miniature looking for a micromolder, said Dale Smith, Technical's vice president of engineering.
``We have a good working relationship. Dale works with them on the tool designs and processes,'' said Technical President Susan O. Parent.
Technical started in 1994 as a Tier 2 cartridge ribbon molder. It has evolved into a Tier 1 supplier, and also does work for the mining, medical, dental and defense industries.
One of the parts produced is for an initiation device used in explosives for the mining industry. The parts are small but not microscopic, and the company molds more than 2 million per week.
Smith said that the transition from small miniature parts to the micromolded parts means continual changes. The smaller the part, especially if it is medical, the cleaner the environment has to be. Inspections need to be more frequent, and tolerances are getting tighter.
Technical started using a Nissei table-top injection molding machine back in 1995. It now has 21 machines, 20 of which are Nissei. The presses range from 7.5-240 tons of clamping force.
``As we get micro projects, we situate our work cells, being very flexible to meet our customers' needs,'' said Parent.
In August Technical leased some additional space to push its square footage to 25,000 square feet at three locations around Canton. The company plans to build a 30,000-square-foot facility at a local industrial park within the new few years to consolidate its operations. Technical has 20 employees.
Parent said that overall sales have reached $3.8 million this year and that the micromolding end of the business is about 30 percent of sales.
``You will see more and more micromolding,'' Parent said.