Flexible Tube Extrusion Mold Layout for Shorter Resin Transition Zones
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catheter molding technologies face challenges in shortening the length of the mixed resin portion when switching between soft and hard resins, leading to difficulty in producing catheters that can bend sharply at the boundary between flexible and rigid sections.
Innovation Solution
A mold design with linear resin supply paths orthogonal to the central axis of a through hole, combined with controlled resin extrusion using valves, allows for precise control over resin switching, reducing the mixed resin length and enabling sharp bends.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conical mold with large resin flow path volume is used, then resin can be supplied to the entire circumference of the mesh layer, but the length of the mixed resin portion increases making it difficult to produce catheters with sharp bends
Solution Approach 1:
The resin supply system is segmented into multiple independent flow paths (first resin flow path and second resin flow path) that connect to different regions of the mold. This allows selective supply of different resins to different circumferential regions, enabling precise control over where and how resin mixing occurs, thereby reducing the length of the mixed resin portion while still supplying resin to the entire circumference.
Solution Approach 2:
Different regions of the mold are provided with different resin supply characteristics through the segmented flow paths. The first resin flow path supplies resin to one region while the second resin flow path supplies resin to another region, allowing local control over resin type and mixing ratio. This enables sharp transitions between different resin types at specific locations, reducing the mixed resin portion length.
2Adaptability or versatility
If resin supply is switched from first resin to second resin, then different resin types can be extruded, but the first resin continues to be extruded due to residual pressure in the flow path
Solution Approach 1:
The resin supply system is divided into separate flow paths for different resins, each with its own control valve. This segmentation allows independent control of each resin supply, enabling precise switching between resin types by closing the valve of the resin being discontinued and opening the valve of the resin to be introduced, without the residual pressure of one resin affecting the other.
Solution Approach 2:
Control valves are introduced as intermediary devices between the resin sources and the mold. These valves act as mediators that can precisely control the timing and amount of resin supply, allowing complete cutoff of the first resin before the second resin is supplied, thereby eliminating the mixing caused by residual pressure and improving resin switching precision.
3Stability of the object's composition
If the first resin remains in the flow path after switching, then resin continuity is maintained, but the mixed resin portion length increases reducing catheter flexibility
Solution Approach 1:
The flow paths are segmented into separate channels for different resins, allowing the first resin to be completely stopped in its designated flow path while the second resin is supplied through a different flow path. This prevents the first resin from being pulled out into the mold cavity and mixing with the second resin, maintaining resin supply stability to different regions while minimizing mixed resin portion length.
Solution Approach 2:
Control valves serve as intermediary devices that can completely close off the first resin flow path before the second resin is supplied. This ensures that the first resin does not continue to be extruded into the mold due to residual pressure, eliminating the source of mixing while maintaining overall resin supply continuity through the valve-controlled switching mechanism.
Data Source
AI summary
Provided is a mold capable of shortening the length of a part mixed with resin before and after switching when switching the resin to be extruded onto the surface of a braided wire, and a flexible tube producing apparatus using the same. The mold for extruding the flexible tube includes a linear through hole through which a braided wire inserted from one end is drawn out from the other end, a first resin supply path connected to the through hole and having a flow path parallel to a plane orthogonal to the central axis of the through hole, and a second resin supply path connected to the through hole on the one end side of the through hole relative to the connection point between the first resin supply path and the through hole, and having a flow path parallel to the plane.