Spray Forming Silicone Prosthetic Shells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional dip casting methods for forming silicone shells for implantable prostheses and tissue expanders result in inconsistent thickness, significant waste, and limitations in creating complex shapes due to the dependence on mandrel shape and solvent evaporation.
Innovation Solution
The method involves spraying a silicone dispersion onto a mandrel using high volume, low pressure (HVLP) or rotary atomization techniques, allowing for controlled thickness and complex shape formation, with multiple coats and solvent evaporation between applications to achieve uniform and varied thicknesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional dip casting method is used to form silicone shells, then the shell can be formed with relatively simple equipment, but the shell thickness becomes inconsistent and varies substantially
Solution Approach 1:
The patent replaces the mechanical dip casting process with a spray application process. Instead of dipping the mandrel into silicone dispersion and relying on gravity-driven flow and solvent evaporation, the invention uses a spray device to atomize and deposit silicone dispersion onto the mandrel. This substitution of mechanical action with spray technology enables precise control over shell thickness while maintaining ease of manufacture.
2Ease of manufacture
If dip casting method is used, then the process is simple to implement, but considerable silicone dispersion waste is created during the casting process
Solution Approach 1:
The patent changes the fundamental parameters of the application process from bulk immersion to atomized spray deposition. By controlling spray distance, spray rate, and atomization patterns, the process achieves precise material utilization with minimal waste, while the overall process remains simple to implement using standard spray equipment.
3Ease of manufacture
If traditional dip casting is used to form shells, then the method is straightforward, but shells with complex shapes cannot be efficiently formed
Solution Approach 1:
The spray application process is inherently more adaptable to complex geometries than dip casting. The spray device can be positioned and maneuvered to apply silicone dispersion to intricate shapes, recesses, and protrusions on the mandrel, enabling efficient formation of complex shell geometries while maintaining ease of manufacture through the flexibility of the spray process.
4Ease of manufacture
If dip casting method is used, then the process requires relatively large vat of silicone dispersion, but solvent evaporation during casting creates further waste
Solution Approach 1:
The patent extracts the essential function of shell formation from the bulk silicone dispersion vat system. By using spray application, only the precise amount of silicone dispersion needed for the shell is applied to the mandrel, eliminating the need for large vats and minimizing solvent evaporation losses while maintaining process feasibility.
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
This approach produces shells with consistent and controlled thickness, smoother surfaces, and the ability to form complex geometries, reducing waste and improving the efficiency of shell production compared to traditional dip casting.
Implementation Method 1
spraying a silicone dispersion onto a mandrel or other object using, for example, a high volume, low pressure (HVLP) spray device or a rotary atomizer
Implementation Method 2
After the excess dispersion has drained from the mandrel at least a portion of the solvent is allowed to evaporate to stabilize the silicone coating
Data Source
AI summary
Shells for mammary prostheses and other devices are created by spraying a silicone dispersion onto a mandrel. Several coats of dispersion are applied with an interval for evaporation of solvent from the dispersion between application of coats. The shells created are uniform in thickness and have a desirably defect-free surface.