“One of the most technically difficult demonstrations ever at a tradeshow”

At MD&M West/Plastec West 2025, Conair Group, together with technology partners Davis Standard and Zumbach Electronics, will demonstrate one of the most technically difficult production processes ever shown at a trade show – the extrusion of extremely small, tapered, three-lumen medical/surgical catheters made of thermoplastic elastomer. This demonstration – which replicates the extraordinary precision and minute scale required to produce multi-lumen tubing used for minimally invasive surgeries and medical procedures – will be ongoing in Booth 4320 during the tradeshow held in Anaheim, CA, February 4-6, 2025.

The Conair booth is also featuring the new SmartFLX mini conveying control, introduced at NPE2024, which is sized for the needs of small medical processing operations or work cells that require powerful central conveying features, easy installation, and an economical cost. Based on the system architecture, logic, and field-proven components developed for Conair’s full-sized SmartFLX conveying control, the SmartFLX mini supports vacuum conveying systems with up to three vacuum pumps and a maximum of up to 12 receivers.

Precision, Multi-Lumen “Bump” Tube Extrusion – Live Demonstration

The multi-lumen catheter segments being produced live at the Conair booth are an engineering feat: Each requires continuous and precise dimensional control not only of a constantly changing and tapering tube profile, but of each of three internal lumen profiles. Over a segment length of about 24 inches, the external tube profile tapers from a maximum of 0.140 in. (catheter body) to a minimum of just 0.110 in. (catheter tip). Inside each tapered catheter segment are three

lumens: two outer, crescent-shaped lumens surround a central lumen with an ID of just 0.005 in. The internal dimensions of the three lumens vary along with the taper of the tube OD, while the dimensions of the outer wall of the tube remain consistent. Together, the three lumens provide passageways that allow surgical tools, cameras, air injection, drug delivery, irrigation, fluid evacuation, or other interventions.

The bump tubing demonstration starts with materials, including medical-grade thermoplastic elastomer (TPE) and additive masterbatch delivered by Conair AL-2 and TLM loaders, and blended in a Conair TrueBlend TB45 blender for delivery into a Davis-Standard 1-inch High Performance HPE medical extruder. Process cooling and temperature control for the extruder, die, and downstream equipment are provided by a Conair EP1A portable chiller and a Thermolator TW-T temperature control unit.

In operation, the 1-inch Davis Standard extruder drives TPE-based extrudate at a constant speed through a Guill cross-head die. Within the die, precise air inputs from three Zumbach SPV-1 digital airboxes are injected into the extrudate to inflate and maintain each lumen and pressurize the inside of the hot tube.

Upon exiting the die, the melt passes into a water-filled pre-skinner sizing/calibration tool, which uses a wafer-thin, vacuum-controlled layer of water atop a sizing ring to lubricate, pre-skin, and shape the tube OD. Such “non-contact” sizing prevents frictional damage to the sticky TPE tube.

The extrudate then continues into a Conair MedVac 238 vacuum cooling tank, equipped with a PAVC vacuum control that uses multi-step pressure regulation to ensure a laminar flow of cooling water over the tube OD. The MedVac tank is optimized for medical production, including electropolished stainless steel surfaces, UV light water purification, and a 5-micron filter system. Inside, a Zumbach UMAC ultrasonic device measures the external tube wall thickness, while at the tank exit, a Zumbach ODAC laser device measures tube OD. Together, the two devices feed real-time measurements to the line control and display in the puller/cutter.

At the center of the downstream extrusion line, a Conair Medline MLD1-12S puller/cutter unit draws the extruded tube forward using a 1 x 12-in. belt drive. Within its control system, sophisticated bump tubing software regulates the sudden, precise variations in line speed and air pressure that create the bump, or change, in tube dimensions. Conair’s industry-leading software offers presets that support bump tube designs with up to 16 lumens. A 10-inch color touchscreen HMI mounted on the puller/cutter unit provides users with programming access, as well as real-time displays of critical product and dimensional data. The cutter assembly is equipped with air-assisted cutter bushings that create a gentle venturi around the sticky TPE tube prior to the cut. The venturi effect eliminates friction and hang-ups within the bushing and ensures consistent, accurate segments of catheter tubing. After cutting, the finished catheters drop onto a six-foot-long Conair Medline MTAC 406 conveyor for offloading.

Note that each finished, tapered tube results in a small segment of scrap – a transition segment that falls out-of-spec due to a slight change in line speed when catheter tips or bodies are cut. These scrap segments will be collected throughout the demonstration, then granulated and conveyed to a blender, from which the regrind will be introduced at a 10-20 percent ratio into the ongoing extrusion process, resulting in a zero-waste production process.

The Conair Group (www.conairgroup.com) is a world-leading supplier of plastics auxiliary equipment and systems. Our equipment line includes more than 450 innovative auxiliary products for plastics molders and extruders around the world. Our product range features resin drying systems, blenders, feeders and material-conveying systems, temperature-control equipment, and granulation and recycling products. Extrusion solutions include line-control systems, film and sheet scrap-reclaim systems, and downstream equipment for pipe and profile extrusion. Conair also combines specialized expertise in every major end market – such as automotive, packaging, medical, transportation, building and construction, and many others – with the technical and engineering resources needed to deliver sustainable, fully-integrated system solutions that Make Every Pellet Count.

    

 

 

 

 

 

 

 

Two views of the same small, multi-lumen catheter in clear and green thermoplastic elastomer. Photo at left, taken with a special lens, enhances the cross-sectional detail of the catheter and highlights the small center lumen (0.005 in. ID). Photo at right shows the same catheter in actual scale, with a tip end OD of 0.110 in. and a body end of 0.140 in. This tiny surgical catheter will be produced at the Conair booth (4320) at the MD&M 2025 show.