PVDF medical tubing clamps target stainless steel

Twin Bay Medical (Williamsburg, MI) was awarded two U.S. patents yesterday for disposable plastic sanitary clamps designed to replace stainless steel. The clamps are used to connect ends of plastic or liquid silicone rubber tubing.

"Stainless steel connectors or clamps have the advantage of being capable of sterilization and therefore

being reusable," states one of the patents. "However, stainless steel connectors are expensive to manufacture and do not completely protect against cross contamination."

The sanitary clamp is designed so that first and second semi-circular sections receive funnel shaped ends of connectors. The circular sections also have second ends that lock after the pair of barb connectors is removed.

The locking device is molded with a ratchet that has external teeth and a housing that extends from one circular section. The housing has side walls with an internally molded rocker lock.

The clamps are molded in high-molecular weight plastics, such as Kynar polyvinylidene difluoride (PVDF) supplied by Elf Atochem North America.  According to the patent, PVDF is used in applications requiring the highest purity, strength, and resistance to solvents, acids, bases and heat. Polysulfone may also be used.

The two patents cover variations in the design of the clamp. The inventor is Albert A. Werth, a tool and die maker by trade who in 1999 invented a tubing retainer called BarbLock that has become a gold standard in the biotech industry. Werth is the founder and president of Twin Bay Medical.

Werth describes BarbLock as the only retainer system that joins flexible tubing and barb fittings with a full 360 degrees of radial compression and seal. The system took off in part because it eliminated adhesives and solvents from the joint between tubing and medical devices.

Various geometries and other fluid handling products have been developed to solve specific problems in recent years. Twin Bay Medical operates nine Arburg electric molding machines in three clean room suites.  The company recently became part of Saint-Gobain Performance Plastics.