As design engineers continue to seek ways to shrink medical devices while increasing functionality, micro extrusion is seen as a key enabling technology. But, as Bill Kramer, President of extrusion equipment supplier American Kuhne (Ashaway, RI), explains in an article published by PlasticsToday sister brand Qmed, it's not a simple process and requires expertise. For starters, simply scaling down a larger machine to extrude miniature tubing is not a workable solution.
Using a conventional extruder for micro-extrusion applications would require running the machine at speeds that fall below its typical comfort zone of 5 to 50 rpm. That may lead to material residence times that could compromise the properties of the polymer being processed. Kramer recommends using purpose-built small extruders to avoid material degradation. This is especially critical when processing bioresorbable materials, which are sensitive to high temperatures.
Read more about micro extruding medical parts in the article, "How to Get the Most Out of Microextrusion" published in Qmed.
American Kuhne introduced its first micro extruder for the North American market at the 2013 MD&M West show in Anaheim, CA. Reporting on the machine launch at the time, PlasticsToday noted that slow output rates are critical for production of micro catheters using medical plastics such as Pebax elastomers, nylon, polyurethane, PEEK, FEP fluoropolymers and bioresorbable plastics such as polylactic acid.
The company returns to MD&M West in 2015, which will be held in Anaheim, CA, from Feb. 10 to 12, where it will feature its Modular Quick-Change technology for medical extrusion. This system slashes changeover time in the cleanroom and removes the dirty activity from the clean environment by hot-swapping the barrel, screw, and die head. The modular extruder design allows the removal of the barrel and its replacement by a preheated barrel with pre-mounted tooling, all within a few minutes.
To learn more about this technology and the ins and outs of micro extrusion, visit the company at booth 2431.