Molded capillary tubing used in a range of medical and diagnostic applications, including drug delivery, is typically fabricated from thermoplastics. The Institute of Plastics Processing (IKV) in Industry and the Skilled Crafts at RWTH Aachen University, both located in Aachen, Germany, are exploring a process that would optimize the micromolding of tubing with integrated functional features using liquid silicone rubber (LSR). The technology could offer a better alternative to thermoplastics, say researchers.
The biocompatibility of LSR, along with its sterilizability and chemical resistance, make it a highly desirable material for medical applications. By combining gas-assist injection molding (GAIM) and projectile injection technology (PIT) with LSR micromolding, researchers believe that they can improve upon existing products. In particular, the technology will allow molders to form elastic micro-sized hollow tubing that won't buckle as easily as its straight elastic counterparts, explains Daniel Kaltbeitzel, Dipl.-Ing., Medical Engineering, at IKV. Other advantages over thermoplastics include the material's lower viscosity and the aforementioned biocompatibility, he adds.