Computational Fluid Dynamics Study and Experimental Verification of the Proposed Procedure for Luer Fitting to Catheter Shaft Attachment

The objective of this study is to develop and design an efficient procedure for molding luer fittings and joining luer with an extruded catheter shaft. Unlike overmolding, this technology involves the process of injection molding the luer fittings separately from the catheter and their subsequent attachment to the extruded catheter shaft using adhesives and UV curing. The proposed methodology is empirically evaluated using an injection molding machine and manual assembly with an emphasis on evaluating the quality of the final product and manufacturing efficiency. As a result, unlike the traditional method of manufacturing fittings and connecting to catheters (via overmolding), luer fittings obtained using the proposed methodology have a low probability of short shots during the manufacturing process, do not compress the catheter lumen since they are not subject to shrinkage, and reduce labor costs by 4.9%, which makes this technology attractive. When designing the luer fitting, 3D modeling tools such as Solidworks were used, and calculations of the pressure and speed of the polymer melt inside the mold were analyzed using the finite element method in the Ansys Polyflow software. The absence of shrinkage, efficiency in labor costs, and compliance of the final product with the standards of ISO 10555-1 (2021) for intravascular catheters were experimentally verified.