Foster’s New Radiopaque Filler Delivers Improved Value for Medical Devices

Putnam, CT, USA – (September 29, 2009) – Foster Corporation, a PolyMedex Discovery Group company, introduces a new radiopaque polymer enhancement technology that offers a superior value option for the medical device industry. Marketed under the name Foster Bismuth Subcarbonate, this new radiopaque filler offers superior quality that translates to improved performance at the extrusion step of the supply chain. According to Brian LaBrec, Director of Engineering at Foster, “This is the next generation filler that will allow improved yields and thinner wall thicknesses, thereby pushing the limits of product design. Not only does it improve performance, it costs less than standard bismuth subcarbonate radiopaque fillers.”

Radiopaque fillers are added to polymers to make catheters and other medical devices visible under fluoroscopy or X-ray imaging. The filler affects the degree of contrast and the sharpness of the image to the extent that it influences the attenuation of X-rays passing through the body and the device. Standard bismuth subcarbonate radiopaque fillers, however, have historically caused problems for OEM and small extrusion operations due to rough surfaces and unstable extrusion processes. “Dispersion of fillers into plastics in the medical industry has been an ongoing challenge,” explained LaBrec. “Poor dispersion is the result of agglomeration of fillers in the extruded plastics and this makes for bumpy areas on the surface of catheters. These bumps are unacceptable to the industry because this results in discomfort to the patient or mechanical stress points that may cause premature failure of the device.”

“Foster listened to its customers and began working with bismuth subcarbonate manufacturers to optimize the new filler for medical devices. We focused on the morphology, density, crystallinity, surface area and particle size,” LaBrec said. “Our Bismuth Subcarbonate allows for a much smoother surface, which means improved yields to the OEMs and happier customers throughout the supply chain. We’ve had input from customers that this new filler is actually more stable in the extrusion process. This is believed to be related to the particle morphology and dispersion characteristics.”

Foster Bismuth Subcarbonate compounds are the newest addition to Foster’s family of Lo-Pro™ radiopaque compounds designed to meet the increasing challenges of the medical device market. They can be used in several different polymer families, such as TPE, TPU, PVC, EVA and polyolefins. Medical markets include cardiology, radiology, oncology, neurology, urology and gastroenterology. Applications include catheter tubes, balloons, stents, catheter tips and injection molded parts.

For more information, please call 860-928-4102 or visit the Foster website at

Foster Corporation, a PolyMedex Discovery Group company, supplies custom biomedical polymers for the medical device industry, including custom compounds for minimally invasive devices, polymers blends for implants, and drug/polymer blends for combination products. For more information, please visit