Effect of extrusion process melt temperature on polyurethane catheter surfaces

• Published in: Materials and manufacturing processes 2018-01, Vol.33 (2), p.180-185
• Main Authors: Bovas, B. Clemend, Karunamoorthy, L., Chuan, Foo Boon
• Format: Article
• Language: English
• Subjects: Catheter; extrusion; hydrophilic; hydrophobic; melt; polyurethane; roughness; surface; temperature; wetting
• ISSN: 1042-6914; 1532-2475
• DOI: 10.1080/10426914.2017.1292036

Determination of optimum process melt temperature of medical-grade polyurethane (PU) is an indispensable challenge witnessed during the catheter manufacturing process. This resin does not contain a uniform crystal structure but exists in an amorphous state. The lower shore hardness PU material, used in catheter manufacture, has just a "melt temperature range" instead of a definite melt temperature. This temperature plays a significant role in shaping the catheter surfaces, which directly interact with human tissues and cause health-care-associated issues. The objective of this work is to evaluate the effects of variations in the melt temperature during the extrusion process of medical catheters on their outer surfaces. Medical PU, Pellethane, was used for this study and 12 Fr (4.0 mm) catheters were manufactured with optimal validated parameters, excluding melt temperature. The manufactured catheters were examined under Optical Microscopy and Atomic Force Microscopy (AFM) for surface topography studies. Wettability studies were carried out using a Goniometer for evaluating the water contact angles. The effects of melt temperature on the surface roughness (R a ) and wettability of the catheter surfaces were analyzed through analysis of variance (ANOVA). The conclusion was that the process melt temperature variations have a significant effect on catheter R a and its wettability characteristics.