A Cool Technology

These days, mention the words “cryogenic technology” to the average man or woman on the street and they’re likely to roll their eyes and mumble something about Ted Williams, before offering a dismissive wave.

“Cryogenics—as a science—gets a bad rap,” says Robin Rhodes. “A lot of people don’t understand it, and they’re not willing to invest the time or resources in order to learn more about it.”

Rhodes is the president of the Cryogenic Institute of New England, Inc., a Worcester, MA-based outfit that offers cryogenic deburring and deflashing, as well as cryogenic tempering of steel and other metals (see sidebar on page 56). For the record, his business has nothing to do with preserving the bodies of dead baseball legends.

Rhodes points out that the reality of cryogenics is that various aspects of it have been around for hundreds of years. “Swiss and German watchmakers used a process called ‘seasoning’ where they would take their steel and put it outside over the winter season in order to make the metal more stable and easier to work with.”

Rhodes—who left a high-level job with an electronics corporation in order to pursue his dream of owning a company of his own—formed the Cryogenic Institute in March, 2002. Initially, he intended to focus solely on cryogenic tempering, but realizing the possibilities afforded by cryogenics, added deflashing and deburring to his company’s repertoire of services a year later. He has since added cryogenic material separation (rubber debonding), shrink fitting and cryogenic grinding as well. “My goal is to make the company into a boutique of cryogenic services,” he says.

Cryogenic Deburring

Cryogenic deburring—an offshoot of cryogenic deflashing—uses a system whereby parts are placed in a chamber, exposed to extremely cold temperatures (achieved with the use of liquid nitrogen) and then tumbled and blasted with a polycarbonate media. Because the burrs have a high surface area relative to their mass, they “freeze” very quickly and become brittle. The tumbling action—combined with the impact of the media—removes the burrs without damaging the part itself.

After the process is complete, parts are returned to room temperature. Rhodes says that cryogenic deburring leaves a clean part—with no dust or other residue remaining—with 100% burr removal. “It's an incredibly efficient process,” he says.

Rhodes and his team use a computer controlled system from Cryogenic Deflashing & Deburring Systems, Inc. “One of the benefits of using an automated system is that it gives us a process that is repeatable and extremely reliable,” he says. The system allows the technician to create and store thousands of recipes using different combinations of temperature, time, tumble speed and media velocity.

The size of the polycarbonate media ranges—depending on the shape, size and material of the part being deburred—from tiny pellets the size of a grain of sand to some that are as much as an eighth of an inch in diameter. Rhodes’ staff uses a special grade of media designed by Abrasive Warehouse specifically for use in cryogenic applications.

Cryogenic deburring and deflashing are ideal for die cast metal parts, complex rubber parts, precision electrometric parts, medical parts and micro electronic parts.

For his part, Rhodes sees cryogenic deburring as a technology that holds tremendous potential, but which has yet to be accepted by many industries. However, he remains optimistic that as companies continue to explore leaner, more cost-effective ways of deburring, cryogenics will receive the attention it deserves.

About The Cryogenic Institute Of New England, Inc.

The Worcester, MA-based Cryogenic Institute of New England offers cryogenic tempering, deburring and deflashing. Other services include cryogenic material separation, rubber debonding, shrink fitting and cryogenic grinding.

Cryogenic Institute of New England, Inc.
90 Ellsworth St.
Worcester, MA 01610
Phone: (800) 739-7949
Fax: (508) 459-7426
Web: www.nitrofreeze.com

Cool Tempered

Cryogenic deburring is just one of the services offered by the Cryogenic Institute of New England. The company was actually founded as a service provider of cryogenic tempering of steel and other metals.

Cryogenic tempering—a process that uses sub-zero temperatures to modify the microstructure of metal—is a product of NASA research in the 1960s. Commercialized in the 1980s with the introduction of process controls, the technology continues to gain acceptance in a variety of industries and regions.

Viewed as an extension of heat treating, cryogenic tempering uses sub-zero temperatures to modify the microstructure of metal, resulting in a more stable, wear-resistant part with fewer residual stresses.

At the Cryogenic Institute of New England, technicians employ a process dubbed NITROFREEZE® in which parts are placed in a computer-controlled chamber and very precisely dropped in temperature to 300°F below zero. After being held at that temperature for 24 hours, the parts are then slowly allowed to return to room temperature. They are then tempered with heat to finish the process.

Rhodes says that cryogenically treated parts enjoy a number of benefits, including increased resistance to wear, easier machining, enhanced thermal properties and fewer failures due to cracking along stress lines. The Cryogenic Institute performs the process on a variety of parts including machine tools, saw blades, brake rotors, gun barrels, softball bats, carbide tools, knives and golf clubs.

PPG