Water-Soluble Mandrel for Hollow Composite Filament Winding

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Solution Overview

Problem

Existing methods for producing hollow composite components using filament winding face challenges such as complex and costly mandrel disassembly, potential damage to the component during removal, and high prototyping costs due to mechanical stresses and shape variations.

Innovation Solution

A production method utilizing a winding mandrel with water-soluble portions made via 3D printing, allowing for complex shapes and integration of water-insoluble structural elements, which can be reused or integrated into the component, and a process involving continuous fiber winding and heat treatment followed by water-based dissolution of the mandrel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a metal winding mandrel is used for filament winding, then the structural strength and reusability are improved, but the complexity of disassembly and removal increases

Engineering Contradiction:
Improvemandrel structural strengthVSAvoidmandrel disassembly complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The mandrel material transitions from metal to water-soluble polymer, fundamentally changing the removal mechanism from mechanical disassembly to chemical dissolution. This parameter change eliminates complex coupling systems while maintaining structural integrity during the winding process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The mechanical disassembly system is replaced with a chemical dissolution system. Instead of using mechanical coupling systems that require complex disassembly operations, the mandrel is designed to dissolve in water, substituting mechanical removal with chemical dissolution.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Duration of action of stationary object

If mechanical coupling systems are used to assemble mandrel parts, then the reusability of the mandrel is improved, but the risk of component damage during disassembly increases

Engineering Contradiction:
Improvemandrel reusabilityVSAvoidmechanical stress damage to component
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The mechanical coupling and disassembly system is completely replaced with a water-soluble material system. The mandrel parts are joined without mechanical fasteners, and removal is achieved through water dissolution rather than mechanical unfastening, eliminating stress concentration points.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The mandrel is designed as a disposable component made of water-soluble material that dissolves after use. This eliminates the need for complex reusable mechanical coupling systems, as the mandrel is replaced rather than reused, reducing the risk of component damage.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If traditional metal mandrels are used, then the manufacturing precision is maintained, but the prototyping costs and production time increase

Engineering Contradiction:
Improvecomponent shape precisionVSAvoidproduction speed and cost efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The mandrel material parameter is changed from metal to water-soluble polymer, enabling rapid prototyping and production. The new material allows for faster manufacturing cycles and reduced costs while maintaining the required shape precision through alternative joining methods.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The mandrel parts are pre-assembled using water-soluble joining agents before the winding process. This preliminary assembly eliminates the need for complex mechanical coupling systems and enables rapid disassembly through water dissolution, improving production efficiency.

Inventive Principle:
Principle #10Preliminary action

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

Enables reliable, economical, and rapid production of hollow components with complex shapes by simplifying mandrel removal and reducing mechanical stresses, thereby lowering production costs and improving component integrity.

Implementation Method 1

at least one water-soluble portion (13, 23) of the winding mandrel (12, 13, 14, 23) is made by means of three-dimensional printing

Methodology Applied
Scientific EffectWater solubility: Solvation

Implementation Method 2

the assembly consisting of the winding mandrel and the fibers wound on the latter is heat treated to cure the resin and consolidate the shape of the hollow component

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Data Source

PatentEP4201644B1Method for producing a hollow component made of a composite material
Publication Date: 2025.01.01 MBDA ITAL
  • EP4201644B1 patent drawingFigure 1~2

AI summary

A method (1) for producing a hollow component (11) made of a composite material, comprising the steps of: - producing or providing (S1) a winding mandrel (12, 13, 14, 23) having at least one water-soluble portion (13, 23); - winding (S2) filaments or fibers of the composite material around the winding mandrel (12, 13, 14, 23) to form an assembly comprising the winding mandrel (12, 13, 14, 23) and the hollow component wound around the winding mandrel (12, 13, 14, 23); - subjecting the assembly consisting of the winding mandrel (12, 13, 14, 23) and the hollow component (11) to a heat treatment (S3) to consolidate the shape of the hollow component (11); - dissolving (S4) the at least one water-soluble portion (13, 23) of the winding mandrel (12, 13, 14, 23), by immersing the assembly consisting of the winding mandrel (12, 13, 14, 23) and the hollow component (11) in water or in an aqueous solution.