American Kuhne says it has now completed testing of its new “Automatic Die Centering Technology” using LaserLinc’s laser and ultrasonic measurement system.
The group is using die centering technology originally developed and patented by its partner Graham Engineering for parison sidewall adjustment, for die centering technology for medical tubing applications. The new development includes an AK Fixed Center die head (see image) where the die pin center location (relative to the die bushing) is adjusted via touchscreen control of four die pin heaters — as opposed to manual die centering. The 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 added to the system with the incorpororation of closed-loop control of tubing wall thickness concentricity. The group integrated its control system with an online OD and wall thickness gauge controller.
For the test, LaserLinc incorporated its Triton triple-axis micrometer, UltraGauge+ 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.
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 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 supplier of standard and customised single screw extruders, feed screws, and complete extrusion systems for medical tubing, pipe, and profile.
LaserLinc is a 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.