One of the many challenges of producing medical tubing is the use of flexible materials. Improve diameter stability and concentricity coming from extrusion without sacrifice.
One of the many challenges faced by the medical device industry is the production of plastic tubing employing flexible materials such as PVC or polyurethane (PU). The dimensional characteristics and mechanical properties needed for these tubes can be quite demanding, meaning that specific knowhow and equipment are required for their respective processing.
Improving stability
For medical lines producing intravenous (IV) tubing or tubing for peristaltic pumps, Maillefer’s complete extrusion lines employ two extruder models from the MXC series. The MXC 60-30D and the 80-30D are proven machines designed with medical tube extrusion excellence in mind.
Our solutions focus on improving diameter stability and concentricity given by the extrusion group without sacrificing overall line performance. The machines are equipped with the most recent screw designs developed specifically for soft materials, as well as with a precise extruder temperature control system at the feeding section. These two techniques allow us to guarantee dimensional stability of the tube and improve its mechanical properties.
The calibration process that follows extrusion is of critical importance. Indeed, the extruder may ensure optimum plasticization with a constant and stable output, but it’s vacuum calibration and cooling that guarantee the dimensional stability. Maillefer know-how and experience in vacuum calibration is coupled with more than 50 years of expertise in extrusion screw design. The quality product results in increased performance, less waste and ultimately higher OEE.
The innovative screw has a well calculated geometry which improves the stability of the extruder flow. This has a direct effect on the diameter stability. In addition, shear rate is reduced noticeably.
The graph above shows an example of the diameter stability obtained on a 5.9 mm PVC pipe base.
These screw and temperature control improvements were brought to light on the MXC generation of extruders, proven in medical manufacturing environments. The most recent methods for optimizing flexible tubing are now proposed for complete medical extrusion lines. They are also available as a Value Package for existing machines.
Pascal Scaramuzzino, PhD
Product Manager, Automotive and Elastomer Systems
pascal.scaramuzzino@maillefer.net
Topics: Medical tube, Extruder, pipe & tube, House of Experts, stability, PVC, experience