Nitrofreeze Cryogenic Solutions working more with LSR

WORCESTER, Mass.—Liquid silicone rubber has emerged as a preferred material for many of the parts being serviced by the Cryogenic Institute of New England, which brands itself as Nitrofreeze Cryogenic Solutions.

The Worcester-based firm provides a wide range of cryogenic services for the manufacturing, molding, medical device and aerospace industries. It also provides cryogenic deflashing and deburring services to remove flash and burrs from molded and machined parts with as little as a two-business day turnaround.

That move to LSR rather than more standard rubber materials has necessitated the continual "finessing" of ways to become more efficient, said Assistant General Manager Ryan Taylor. With the latest improvement, Nitrofreeze provides LSR molders with a faster and more efficient way to get flash-free parts without waste.

Previously, it was difficult to process on LSR, but over time—and with the lessons learned from countless hours of testing—deflashing has become simpler, allowing LSRs to run on a wider spectrum of end products.

"Now we can run anything that flashes," Taylor said. "We typically are running samples at least once every business day over the course of a month."

That is important, he said, because Nitrofreeze works on LSR for as much as 25 percent of its work. Traditional rubber was more dominant five to 10 years ago, but the versatility of LSR continues to improve in various elements, including outdoors in areas of high ultraviolet light.

Nitrofreeze cryogenic deflashing uses fine blast media that won't damage LSR parts, Taylor said. Molders are not forced to run more parts than required to account for scrap from the deflashing process. The goal is to help molders save time and money during production, while getting back every part they send to Nitrofreeze, Taylor said. Improved processes allow molders to receive parts that look the same as when molded but without any flash.

These ongoing improvements have allowed the company to grow its business particularly in the defense and health care sectors, with medical device companies being among the fastest growing. Taylor said demand for defense work has grown further since the start of the war between Russia and Ukraine, while the health care sector has been a "mainstay" for a while. Cryogenic Institute of New England had revenues of roughly $2 million in 2022 with sales expected to grow another 10-15 percent this year.

During the cryogenic flashing, batches of molded parts are cooled below LSR's glass transition temperature so that the flash hardens, becomes brittle and thus is easy to remove. The parts are then blasted with a specified cryogenic-grade polycarbonate media that comes in different diameters to finish part features without impacting critical surface tolerances or altering part geometry.

It is an especially efficient way to remove flash from cross-holes, blind holes and other geometries that are hard to reach with hand tools. Taylor believes this sets Nitrofreeze apart from other similar providers because the company can achieve thorough wheel speeds of up to 20,000 RPMs. At a higher speed, it allows the company to address the needs for smaller, fine parts that often are considered highly valued components by customers.

"We have three machines that can do this work, which is another advantage," Taylor said, adding that his team of 10 employees will often run samples for clients at no charge. "We've been able to remove mold flash from liquid silicone rubber products in (numerous applications)."

Cryogenic deflashing is an automated, computer-controlled batch process that can remove flash from tens to thousands of molded LSR parts all at the same time. It provides more consistent results compared to other options and is considered safe as well, according to the company.

Future improvements are possible as well, to both the speed and consistency of the automated deflashing process. Other improvements could help lower end costs by reducing cycle times, and finding other efficiencies, Taylor said. Future processes may be developed for fixturing or using different media to achieve desired results.

"We'll continue to test and tinker," said Taylor. "There's a wide array of variables we can play with."