At MD&M West/Plastec West 2023, Conair Group, together with technology partners Davis-Standard and Zumbach Electronics, is demonstrating the extrusion of medical-grade, ¼-inch polycarbonate tube, cleanly and continuously cut into 5-inch pipettes that need no secondary cleaning or finishing operations. Four new Conair products* will make their operational debut on the extrusion line, which is operating in Booth 3911 of the MD&M West tradeshow being held at the Anaheim Convention Center in Anaheim, CA, Feb. 7-9, 2023.
The polycarbonate material will be pre-conditioned using a Conair dX25 Carousel Plus desiccant dryer equipped with a premium 7-inch DC-B color touchscreen control. The DC-B “common” control not only regulates critical drying setpoints and resin moisture with an in-hopper Drying Monitor, but also automatically regulates material movement through the dryer to the extruder, via automatic controls for hopper and extruder loading. Polycarbonate moving from the hopper to the extruder also passes through Conair’s new Moisture Minder*, an in-line device that reads the moisture content of moving resin, enabling rapid identification and notification of out-of-spec moisture levels.
The polycarbonate material will be processed in a Davis-Standard 1.25-inch HPE Horizontal Extruder. This versatile extruder features a compact, energy-efficient design with increased torque capacity to handle high-viscosity resins and is available in sizes from ¾-inch (20 mm) to 1-3/4-inch (45 mm). Also, on static display, is the Davis-Standard Super Blue extruder with the advanced XEL process control, which offers security, multi-language, safety, alarm-logging, trending, and other features.
From the extruder, the polycarbonate melt passes through sizing inserts as it enters a water-filled, non-contact calibration head mounted at the front end of a Conair MedLine® MedVac 235 vacuum sizing tank. Like all Conair MedLine auxiliaries, this compact, single-pass vacuum tank is specially configured, documented, and supported for cleanroom applications, and is equipped with a PAVC Plus automatic vacuum control and touchscreen HMI. Temperature-controlled water for the calibration head and vacuum tank is delivered by two more touchscreen-controlled auxiliaries making their operational debut: a Conair TW-T Series Thermolator® temperature control unit* and a Conair EP-1A Series two-ton, air-cooled chiller*.
The vacuum chamber in the MedVac sizing tank creates a differential in air pressure that exerts slight outward pressure in the extruded tube, stabilizing its dimensions. Within the chamber, ultrasonic wall-thickness gauges from Zumbach measure the OD and wall thickness of the tube, first as the hot extrudate enters the tank and further along as it cools. These measurements are used to calculate the ID of the tube, the dimension most critical for medical fluid delivery, and are displayed on a color screen in real-time. Then, downstream from the tank, a Zumbach 3-axis OD laser gauge uses patent-pending technology to precisely calculate and display the concentricity of the tube profile while providing feedback used for closed-loop dimensional control. Together, data from the ultrasonic and laser gauges are used to regulate puller speed and cooling-tank vacuum to maintain critical tube dimensions over the production run.
After exiting the vacuum tank through a water-seal chamber and air-wipe assembly, the polycarbonate tube is drawn through a Conair 2-12 Precision Series servo puller, whose digital control continuously receives dimensional input from the upstream sensors and makes precise adjustments in line speed to keep tube dimensions consistent.
The rigid polycarbonate tube then enters the Conair MedLine M-TPC-1 planetary cutter*, which continuously and precisely cuts the moving tube into short pipettes. Specially designed for particle-free cutting of rigid or flexible medical-grade plastics, the MTPC planetary cutter employs a rotating cutter head in a servo-controlled traveling carriage. Using precise line speed information from the extrusion line control, the carriage travels with the moving tube, clamping on long enough to cut the tube using a rotating blade that increases depth until the cut is complete. This planetary cut neatly displaces the material on either side, resulting in smooth cuts without dust or particulates.
“The M-TPC-1 planetary cutter is specially designed for making clean, continuous, medical-grade cuts on relatively small tubes made of rigid materials, such as polycarbonate or crystal styrene. You can’t use a typical medical fly-knife cutter on these materials without cracking them, while a saw-blade cutter creates undesirable dust,” says Ernie Preiato, Conair’s VP of extrusion. Until the compact M-TPC planetary cutter became available, he says that processors had to “rough cut” sections of rigid tube from the extrusion line, then put them through secondary saw-cutting operations that generated dust, required secondary cleaning operations, and created significant scrap. “The M-TPC planetary cutter eliminates all that.”
The Conair Group (www.conairgroup.com) offers innovative auxiliary equipment solutions to plastics processors around the world. With 32 degreed engineers, including 16 senior team members with an average of over 23 years of experience, Conair brings unparalleled technical expertise and support to its customers, guaranteeing its products will deliver maximum productive uptime. Twenty parts and service team members respond to tens of thousands of calls each year, answering in an average of about 15 seconds. Over 450 individual products include resin drying systems, blenders, feeders and material-conveying systems, temperature-control equipment, and granulators. Extrusion solutions include line-control systems, film, and sheet scrap-reclaim systems, and downstream equipment for pipe and profile extrusion. Conair also has specialized expertise in every major end market – such as packaging, medical, transportation, building and construction, and many others – and strives to ensure plastics processors succeed in today’s competitive global marketplace.
The MedLine M-TPC-1 planetary cutter from Conair is designed for cleanroom use. It makes precise, continuous cuts in medical-grade rigid or flexible tube up to 1-in (25.4 mm). Download a high-resolution file
The new Moisture Minder™ from Conair offers an in-line solution for real-time moisture analysis. It accurately detects residual moisture in a broad range of materials at rates of 20-5000 lbs/hr. Download a high-resolution file