by Mary C. Gannon, Senior Editor
Two years ago, Trelleborg Sealing Solutions purchased a liquid silicone company headquartered in Switzerland, which provided silicone extrusion and silicone molding, all in a clean room facility. The facility in Stein am Rhein, Switzerland and another in Northborough, Mass., allows the company to manufacture and design two-part Liquid Silicone Rubber (LSR) devices and components for the medical, biotech, pharmaceutical, and food and beverage industries.
The facilities specialize in finishing, washing and packing products and processes, manufacturing high-precision, miniature silicone parts.
Silicone is best suited to life sciences applications because it features matchless inertness and biocompatibility, which should be considered when factoring in potential bacteria growth and alleviating contamination. It is also the most widely tested and proven material related to human compatibility. In addition, silicone‘s mechanical properties prove to be excellent in dynamic applications where accuracy, consistency and longevity are important performance determining factors.
When medical devices require two types of material — silicone and rubber — to be manufactured into one piece, Trelleborg’s Liquid Silicone Rubber manufacturing allows for seamless, one-piece designs that eliminate waste and simplify production.
The key to LSR injection molding, said Jerry Zawada, Life Sciences Segment Manager, is a two-shot, two-component technology, which allows Trelleborg to mold plastic and silicone into one piece, such as a pushbutton on an IV machine.
“The advantage of this is usually when you injection mold something, you then have to transfer it and hand assemble it into the new mold and do the rubber mold that way,” Zawada said. “With the finished part, there is no plastic trimming needed and no waste.”
In addition to meeting the needs of high-precision applications, the wasteless and flashless design of LSR injection molding is ideal for complicated geometrical features, especially in situations where thin wall thicknesses (as low as 0.10 mm / 0.004 in.) are needed.
Finally, unlike most compression molded components, LSR technology allows for undercutting. “Because it’s fully cured, there is no need to cure it, so you can undercut it,” Zawada added.
The technology is much faster and can be accomplished with much less labor, Zawada said.
The facilities operate from low to high volume production, ranging from 100 to 100 million pieces. Fully closed-loop, automated production ensures high product purity and cleanliness. In addition, sophisticated robot technology, and high-precision tool design and manufacture eliminate secondary parts handling operations.
Trelleborg Sealing Solutions
www.tss.trelleborg.com
Northborough Life Sciences
www.trelleborg-lifesciences.com
![A photo of the Northwestern University pacemaker surrounded by grains of rice for scale [Photo courtesy of Northwestern]](https://www.medicaldesignandoutsourcing.com/wp-content/uploads/2025/04/Worlds-smallest-pacemaker-Northwestern-wearable-268x170.jpg)