Water-Soluble Polymeric Mandrel for Composite Tubing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing techniques for manufacturing hollow or tubular parts made of composite materials, such as vacuum bagging and rubber mandrel methods, face challenges with complicated geometries, high rejection rates, and increased labor costs, especially when producing parts with nodes, section changes, and small outlet holes.
Innovation Solution
A water-soluble sacrificial mandrel made of polymeric material, specifically comprising polyvinyl alcohol, polyvinyl acetate, latex, and polyurethane rubber, which can be expanded during the polymerization process and is suitable for use on a male mold, allowing for the fabrication of parts with complex geometries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If vacuum bagging technique is used for lamination on male mold, then production speed increases, but fiber sheet overlapping concentration occurs resulting in poor structural strength
Solution Approach 1:
A sacrificial mandrel made of water-soluble material serves as an intermediary between the male mold and the fiber sheets. The mandrel enables proper fiber distribution by preventing overlapping concentration while allowing vacuum bagging to proceed at high speed. After lamination, the mandrel is dissolved in water to leave the desired hollow geometry without compromising structural strength.
Solution Approach 2:
The sacrificial mandrel is a temporary, disposable component made from inexpensive water-soluble materials (such as sugar, salt, or starch). It performs its function during the lamination process and is then discarded by dissolving in water, enabling repeated use of the male mold without fiber accumulation issues.
2Strength
If lamination on female mold is used with rubber mandrel, then structural strength is maintained, but production speed decreases and labor costs increase
Solution Approach 1:
Instead of using a female mold with rubber mandrel (traditional approach), the invention inverts the approach by using a male mold with a water-soluble sacrificial mandrel. This inversion allows maintaining structural strength through proper fiber distribution while achieving faster production speeds and lower labor costs associated with male mold lamination.
3Manufacturing precision
If plaster mandrel is used for complicated hollow parts, then geometric precision is achieved, but production cost and processing time increase significantly
Solution Approach 1:
The invention changes the material parameter of the mandrel from traditional plaster to water-soluble materials. This parameter change allows the mandrel to be easily removed by dissolving in water after lamination, eliminating the need for complex machining or casting operations required with plaster mandrels while maintaining geometric precision for complicated hollow parts.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sacrificial mandrel enables the efficient production of hollow parts with complex geometries, reduces rejection rates, and lowers labor costs by allowing for the use of a male mold and facilitating the removal of the mandrel, resulting in parts with excellent structural integrity and mechanical performance.
Implementation Method 1
The sacrificial mandrel (100) is water-soluble and is made of a polymeric material composition
Implementation Method 2
said sacrificial mandrel being expandable during a polymerization step of the composite material of the part
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The sacrificial mandrel (100) is suitable for being used in the fabrication of tubular parts, preferably of composite material; the mandrel (100) is water-soluble and comprises at least one polymeric material; the sacrificial mandrel (100) comprises at least one wall (1) and one cavity (2) formed inside the mandrel (100) and defined by the wall (1), at least partially; the wall (1) comprises an outer surface (10) and an inner surface (11) facing the cavity (2).