In Tests by Eldon James Corp. of Tubing Made with Medalist® TPE from Teknor Apex, Connection Withstood More than Double the Force Specified in Customer Requirements

DENVER, CO, U.S.A., April 2, 2014: Tests by Eldon James Corporation, a manufacturer and custom assembler of medical tubing and fittings, have demonstrated the toughness of tubing produced from Medalist® thermoplastic elastomers (TPEs), and the durability of connections between this tubing and single-barb luer fittings, it was announced today by Teknor Apex Company.

Teknor Apex, which manufactures the Medalist range of medical elastomers, will present the results of the tests at its exhibit during MD&M East (Booth 1551), along with sample kits provided by Eldon James.

In pull-apart tests of more than 1,000 assemblies (see photo), the connections typically did not fail until forces greater than 8 lb. were applied—more than double the requirement set by Eldon James’ customer, according to Mark Timbrook, director of marketing. In burst tests, the TPE tubing withstood average pressures of 500 psi before failure.

“The elasticity of the TPE has proved to be an advantage in two ways,” said Mr. Timbrook. “It enhances the bond between tubing and fitting, in much the same way that the grip of a finger-trap toy tightens as you pull your fingers outward. At the same time, within the parameters of our burst test, the resilience of the TPE prevents the tubing from rupturing. While PVC tubing would burst under similar pressures, the failure of the TPE tubing took the form of bulging.”

Seeking an alternative from PVC tubing as well as from the adhesives typically used for bonding it with connectors, Eldon James produced a new range of tubing from Teknor Apex’s Medalist MD-585 compound and paired it with USP Class VI-compliant single-barb connectors, which it also manufactures. “We’ve found that single-barb fittings make a better seal with TPE tubing than multi-barb connectors, one that is at least comparable in strength to that of adhesive assemblies with PVC tubing,” Mr. Timbrook said.

While exceeding customer requirements based on adhesive-bonded fittings, single-barb fittings save time and cost in comparison with adhesive assembly, according to Eldon James, while avoiding issues involving volatile organic compounds, material incompatibility, cross-contamination, workplace ventilation, concerns related to aging, thermal cycling, and chemical attack, and documentation of expiration dates and lot numbers.

“From the outset in developing the Medalist MD-500 Series of medical tubing compounds, Teknor Apex has had the goal of establishing these innovative TPEs as truly practical alternatives to PVC,” said Ross Van Royen, senior medical market manager for the company’s Thermoplastic Elastomer Division. “To that end we have worked with Eldon James and other companies that have real-world expertise in the design, production, assembly, or clinical use of medical tubing.”

Compared with PVC, the tubing compounds in the Medalist MD-500 Series exhibit comparable crystal clarity and mechanical properties; provide similar clamp resilience and resistance to kinking and necking; have a similar “feel”; and are substantially more flexible and significantly less dense than PVC. At the same time they undergo minimal color shift upon heat aging after exposure to gamma irradiation, the most severe type of sterilization. A typical compound in the series, Medalist MD-575, actually exhibits 70% less heat-aged color shift than a gamma-stabilized PVC compound of comparable hardness.

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