An automatic fitting inserter developed by Clean Room Devices, based in Westminster, CO, US, enables medical product manufacturers to obtain the advantages of Medalist elastomers over PVC while increasing productivity in the assembly of tubing and connectors.
The CRD 600 Automatic Fitting carries out high-speed assembly of tapered-barb connectors and tubing produced from Medalist MD-500 Series thermoplastic elastomers (TPEs).
"Tapered-barb connectors fit into the Medalist TPE tubing with a retention strength that exceeds the 35.6 N (8.0 lbf) level specified by most global OEMs for infusion systems and is greater than levels achieved with either adhesive or solvent bonding," said Richard Faulkner, medical market manager for the Thermoplastic Elastomer Division of Teknor Apex. "The automatic fitting inserter developed by Clean Room Devices enables medical product manufacturers to obtain strong, secure connections even at very high assembly speeds."
The CRD 600 unit cycles at a rate of 2,300 per hour and, with the addition of a feeder bowl, enables an operator to make 1,800 insertions per hour, including time for handling the tubing and inspecting the results, according to Ronald Del Valle, president of Clean Room Devices.
"Because the CRD 600 allows for insertion of over-sized barbs into tubing with a smaller internal diameter, it ensures a stronger fit than solvent bonding," Mr. Del Valle said. "A big advantage of our system is that it eliminates the presence of solvent chemicals and odours in the cleanroom."
Solvent bonding is the standard assembly technique for PVC tubing. Several assembly options are now available for tubing based on Medalist MD-500 TPEs. In addition to the insertion of barbed fittings, these include patent-pending, TPE-specific technologies developed by Teknor Apex for solvent bonding and for room temperature and light-cured adhesive bonding.
Medalist MD-500 elastomers are in commercial use as alternatives to PVC in tubing applications. Compared with PVC, Medalist MD-500 compounds 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 colour shift upon heat aging after exposure to gamma irradiation, the most severe type of sterilisation. A typical compound in the series, Medalist MD-575, actually exhibits 70% less heat-aged colour shift than a gamma-stabilized PVC compound of comparable hardness.
