Polymer solution casting

Polymer Solution Casting is a manufacturing process used to make flexible plastic components which are typically in the shape of a single or multi-lumen tube commonly utilized in the Medical device industry. This manufacturing technology is unique in that the process does not require conventional extrusion or injection molding technologies, yet it readily incorporates components and features traditionally produced by these processes.

The Polymer Solution Casting process utilizes a mandrel, or inner diameter mold, that is immersed in a tank of polymer solution or liquid plastic that has been specifically engineered for the process. Due to a combination of thermal and frictional properties, the polymer solution then forms a thin film around the mold. The mold is then extracted from the tank in a precisely controlled manner, followed by a curing or drying process. Once the first layer of thin film is appropriately solidified, secondary features can be added to the product such as braided or coiled wire, laser-cut hypotubes or engineered metal reinforcements to prevent kinking, or imaging targets specific to the intended medical application. Multiple casting steps can then be repeated to encapsulate the reinforcements, build up wall thickness, add additional lumens and optimize column strength. The part is then removed from the mold after it is cured or solidified.

The most notable attribute of this thin-film process technology is the ability to alternate the material properties (i.e. strength, durometer, color, lubricity) amongst the individual layers or even down the length of the part, resulting in a feature-rich single-piece construction. This process also allows other components to be incorporated into the structure of the part during the layering processes, such as injection molded components and extruded tubes made of high performance polymers such as PTFE, PEBAX, and polyimide.

Another notable advantage of polymer solution casting technology is that the total manufacturing cost for both prototyping and production volumes are frequently less than the conventional technologies. This cost benefit results from the use of inexpensive molds coupled with the scalability and adaptability of the manufacturing line. As a result, new products and processes are readily developed and implemented, facilitating cost-effective creation of very feature rich and complex catheters. Since the 1990s, Avalon Laboratories and Piper Plastics Corp. have aggressively pioneered polymer solution casting technology, focusing on complex medical devices. The history of these technologies dates back to many highly regarded names in the medical industry including Medtronic, BioMedicus, Bard, Terumo, Research Medical Inc., Shiley, Polaris Plastics, and Caplugs.

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