ASTM International Committee F04 on Medical and Surgical Materials and Devices is now developing a proposed new standard, WK8619, Test Method for the Measurement of Crystallinity and Melting Point of Ultra High Molecular Weight Polyethylene via Differential Scanning Calorimetry. The proposed test method, under the jurisdiction of Subcommittee F04.15 on Material Test Methods, will focus on the measurement of the heat of fusion and the melting point of ultra high molecular weight polyethylene (UHMWPE), and the subsequent calculation of the percentage of crystallinity.

"The crystallinity of UHMWPE is a commonly used parameter in the orthopedic industry as both an indication of mechanical properties and the method of processing used on the UHMWPE," says Stephen Spiegelberg, president, Cambridge Polymer Group, Inc. "Lacking a standardized method of characterization of the crystallinity, the crystallinity of an identical UHMWPE tested at two different labs can vary by as much as 5 to 8 per cent."

Spiegelberg notes that WK8619 will be used for quality control of raw stock, process stock and for implant retrievals to assess any chemical changes in the materials. In addition, the standard will be used for research and development of advanced generations of highly crosslinked UHMWPE.

UHMWPE consolidators, end users of UHMWPE, regulatory staff and independent testing labs are all invited to participate in the ongoing development of WK8619.

For further technical information, contact Stephen Spiegelberg, Cambridge Polymer Group, Inc., Boston, Mass. (phone: 617/629-4400, ext. 12; steve@compoly.com). Committee F04 will meet Nov. 8-11, in Dallas, Texas. For membership or meeting details, contact Dan Schultz, ASTM International (phone: 610/832-9716; dschultz@astm.org).

Release #7198