Solvent Technology Swells Silicone and Polyurethane

MicroCare Medical is making life easier for design engineers with Swellex and Swellex-P. Design of these solvents is to address the challenge of joining or assembling molded components with rigid parts and barbed fittings.

Swellex, a swelling agent that is absorbed into silicone, and Swellex-P, which is absorbed into polyurethane, expand the materials to a desired dimension, allowing for easy assembly to the fitting or rigid part. The swelling agent then quickly evaporates and returns the silicone or polyurethane component to its original size to create a secure connection without adhesives.

Silicone is an incredibly desirable material, especially in the medical device industry and polyurethane is becoming a more desirable material in the medical device industry as a replacement for PVC, especially in tubing applications for moving fluids. However, the physical properties of silicone and polyurethane can make them a challenge to work with. Swellex and Swellex-P solvents from MicroCare Medical provide an effective and overall low cost solution to those challenges.

Silicone has a tacky surface that is inherently flexible, and polyurethane typically has high tensile strength. These materials do not readily expand without mechanical help, and because of this, design engineers often find difficulty in attaching silicone or polyurethane tubing to barbed fittings or mating molded parts with complex geometries to rigid plastic parts. For designers, knowing that there is an effective solution for joining silicone and polyurethane to rigid parts means they can be more flexible in their specifications and can design without limitations.

Swelling silicone or polyurethane is a cost-effective option because the entire process is extremely quick and involves almost no housekeeping. Other methods, like using oils or alcohol to lubricate the surface, take much longer because of the time necessary for these lubricants to dry. These methods also tend to be very messy, requiring clean up once the part has been joined, which also adds more time to the entire process.

Swellex and Swellex-P are a newer class of solvents that uses proprietary technology to swell more effectively than alternative solutions while meeting today’s strict Environmental Protection Agency regulations.
 

Left: Silicone tubing before and after using Swellex. Right: MicroCare’s Swellex and Swellex P works on silicone tubes requiring fittings.

Historically, the use hexane solvents were for swelling silicone, not solvents, because of silicone’s resistance to solvents, but this class of solvents is extremely aggressive and is subject to environmental air quality regulations.

MicroCare Medical
New Britain, CT
microcaremedical.com