According to Tom Shoup, New England Regional Sales Manager at LaserLinc, “I've been around extrusion over 38 years and 90% concentricity seemed to be the acceptable goal for tight tolerance medical tubing. American Kuhne has completely shattered those rules. I honestly would not have believed it had I not been there to see it.”
US extrusion equipment builder American Kuhne (www.AmericanKuhne.com) is using die centring technology originally developed and patented by their partner Graham Engineering for parisan sidewall adjustment for die centring technology for medical tubing applications. The new development includes an AK Fixed Center die head (see photo) that is used to eliminate manual die centring and instead the die pin centre location relative to the die bushing is precisely adjusted by touchscreen control of four die pin heaters. These heaters are located in the rear mandrel of the die head where they can be heated in an uneven pattern to “flex” the die pin to control it’s position. American Kuhne has developed the technology further and incorporated closed-loop control of tubing wall thickness concentricity by integrating their control system with an online OD and wall thickness gauge controller. This technology was showcased in a live demonstration with a Zumbach OD and wall system at the MD&M East medical trade show in Philadelphia in June.
For the test, LaserLinc incorporated their trademarked Triton triple-axis micrometer, UltraGauge+ (also trademarked) ultrasonic wall thickness measurement system and Total Vu software with OPC (Object Linking and Embedding for Process Control). Using OPC, the wall thickness data collected by Total Vu was shared with American Kuhne’s PLC where the closed-loop control is performed. LaserLinc is a leading manufacturer of non-contact laser and ultrasonic systems for OD, ID, wall thickness, eccentricity, and concentricity across many industries including wire, cable, medical and other tubing, hose, pipe and fibre.
During the test, the concentricity was intentionally taken out of specification several times and each time the control system recovered to 90% concentricity within a minute and after just five minutes the concentricity was stable at 98%.
According to Tom Shoup, New England Regional Sales Manager at LaserLinc, “I've been around extrusion over 38 years and 90% concentricity seemed to be the acceptable goal for tight tolerance medical tubing. American Kuhne has completely shattered those rules. I honestly would not have believed it had I not been there to see it.”
According to Tyler Ware, American Kuhne Process Engineer, “the LaserLinc system proved to have very robust and fast communications, which allowed our system to quickly and accurately make automatic adjustments to concentricity.”
American Kuhne, Inc is a leading supplier of standard and customised single screw extruders, feed screws, and complete extrusion systems for medical tubing, pipe, and profile.
For more information, contact: American Kuhne, Inc., 401 Main Street, Ashaway, RI 02804, Phone 401-326-6200, Fax 401-326-6201, www.AmericanKuhne.com, email sales@americankuhne.com.