By Bruce Geiselman
Photoluminescent tubing put collaboration in the spotlight, as Conair, Davis-Standard and Zumbach Electronics teamed up to exhibit their collective capabilities at MD&M/Plastec West.
In a demonstration in Conair’s booth, equipment from the three companies produced tapered medical tubing made from a photoluminescent blend of thermoplastic elastomer. Attendees could join the tube segments into souvenir loops they were invited to take with them.
Davis-Standard provided the extrusion equipment; Conair, the auxiliary equipment; and Zumbach Electronics, the online gauging systems.
The photoluminescent segments were reminiscent of glow sticks popular as party novelties and sold at fairs and festivals. However, similar extrusion lines have serious applications.
“We’re making what we call a bump or taper tube,” said Kevin Dipollino, senior product manager of Davis-Standard’s Pipe, Profile and Tubing Systems. “It’s used in the medical field. Typically, the smaller end is in the body, and the larger end is for insertion into an instrument.”
Tapered tubing can be used for applications involving site-specific chemotherapy and with medical pumps. The photoluminescent quality was added as curiosity to attract visitors to the tradeshow booth.
Conair, Davis-Standard and Zumbach have worked together for about 30 years, company representatives said.
Conair provided a written description of various pieces of equipment used in the process and their functions. The company’s description follows.
The tube extrusion process began upstream where virgin Teknor Medalist TPE was delivered through a Conair AL-2 Access Loader, while photoluminescent masterbatch arrived through a TLM Tube Loader. Both loaders were mounted atop a TrueBlend TB45 blender, which created the material mix. The blender rested on a new TBBS blender stand that featured bolted construction that is lower-cost, lighter-weight and easier to move than all-welded models.
A second TLM Tube Loader, mounted on the extruder hopper, drew the blended material from the hopper to the feed throat of a Davis-Standard 1-inch HPE (high-performance) medical extruder. A 10-inch HMI touch-screen control on a downstream Conair Medline 1-12 Puller/Cutter unit regulated the speed of the extrudate.
“Bump tube” software in the Medline puller control managed rapid changes in tube taper and sizing, and a Zumbach SPV-1 digital airbox produced air-pressure changes. The equipment together produced tubing that tapered from a maximum of 0.22-inch outer diameter to a minimum outer diameter of 0.175 inch over a length of about 12 inches. After exiting the extruder, melt passed through an extrusion die and was skinned by a non-contact tube calibrator at the entrance to a Conair MedVac 238 single-pass vacuum sizing/cooling tank.
A 10-inch Medvac touch-screen control regulated the vacuum tank. A Conair Thermolator temperature control unit and a 2-ton Conair EP1A-02 portable air-cooled chiller managed the vacuum tank temperature. A Zumbach ultrasonic tube gauge near the entrance of the tank measured wall thickness of the hot tube, displaying real-time tube dimensions on an HMI and communicating the dimensions back to the extrusion control.
A Zumbach ODAC gauge checked the final cold outer diameter of the tapered tubing after it emerged from the cooling tank. The tubing then entered the Conair Medline 1-12 puller/cutter unit that can run at speeds from 2.5 feet to 250 feet per minute. A servo-controlled rotating-blade cutter produced the 12-inch tubing segments.
Cut tube segments moved onto a 6-foot-long Conair MTAC automated take-away conveyor for sorting of good segments from out-of-spec segments. A compressed-air sortation system blew the good segments off the side of the conveyor into a collection tray, while out-of-spec segments flowed off the end of the conveyor into a scrap bin.
Contact:
Conair Group, Cranberry Township, Pa., 724-584-5500, www.conairgroup.com
Davis-Standard LLC, Pawcatuck, Conn., 860-407-6177, www.davis-standard.com
Zumbach Electronics Corp., Mount Kisco, N.Y., 914-241-7080, www.zumbach.com
