Filled PTFE Mandrel Assemblies for Clean Thin-Wall Tube Release
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Solution Overview
Problem
Existing methods for producing thin-walled polymeric tubes, particularly PTFE tubes, face challenges in removing the tubes from mandrels and often introduce contaminants during the demolding process, while lacking desirable physical properties such as strength and flexibility.
Innovation Solution
The use of a filled PTFE mandrel with incorporated microparticles, such as glass beads, allows for the production of thin-walled PTFE tubes with patterned inner surfaces and improved physical properties, enabling easy removal without debonding agents and maintaining low coefficient of friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional stainless steel or silver-plated copper wire mandrels are used to draw down PTFE preform, then thin-walled PTFE tubes can be produced, but the tubes are difficult to remove from the mandrels and contaminants are introduced during demolding
Solution Approach 1:
The mandrel is made of PTFE material, which is the same as the tube material being produced. This material homogeneity eliminates the need for debonding agents and prevents contaminant introduction during demolding, while still allowing easy tube removal through controlled adhesion
Solution Approach 2:
The mandrel incorporates fillers (such as glass beads, metal particles, or ceramic particles) within the PTFE matrix to create a composite material. This composite structure provides enhanced surface texture for pattern transfer, improved mechanical properties, and controlled surface energy for optimal tube adhesion and release
2Strength
If thin-walled PTFE tubes with wall thickness less than 0.004 inches are produced, then the tubes achieve desired flexibility and thinness, but the tubes lack sufficient strength and require complex mandrels for support
Solution Approach 1:
The PTFE mandrel incorporates fillers (glass beads, metal particles, or ceramic particles) to create a composite material that provides enhanced mechanical strength and structural support. This allows the mandrel to support thin-walled tubes during manufacturing without requiring complex external support structures
Solution Approach 2:
The fillers are distributed throughout the mandrel material to provide localized reinforcement where needed, particularly at the surface level for pattern transfer and in the bulk material for structural support, enabling the mandrel to support thin-walled tubes without increasing overall device complexity
3Ease of operation
If debonding agents are used to facilitate tube removal from mandrels, then tube removal becomes easier, but contaminants are introduced to the tube surface
Solution Approach 1:
The PTFE mandrel material matches the PTFE tube material, creating compatible surfaces that bond during manufacturing but allow clean separation without requiring debonding agents. This homogeneous material system ensures easy demolding while maintaining tube surface purity
Solution Approach 2:
The invention extracts and eliminates the need for debonding agents from the manufacturing process. By using PTFE as the mandrel material, the system achieves easy tube removal through material compatibility alone, removing the harmful element (debonding agents) that would otherwise be required
Data Source
AI summary
The disclosure relates to assemblies of thin-walled tubes and mandrels for use in thin wall catheter liners. For example, an assembly is provided that includes a thin-walled PTFE tube comprising walls with a thickness of less than 0.004 inches, positioned over a filled mandrel comprising PTFE with one or more fillers incorporated therein. The disclosure further provides, independently, thin-walled tubes and filled mandrels, as well as methods of making and using such components.