Reusable Sand-Based Tooling for Rapid Prototyping
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Solution Overview
Problem
Existing prototype tooling for making sand castings, sheet metal dies, and vacuum-formed parts is costly and not reusable, leading to high expenses and inefficiencies due to the need for extensive machining and assembly, with rapid casting technologies resulting in durable but single-use three-dimensional patterns that suffer from breakage and loss of surface finish when reused.
Innovation Solution
A reusable tool is created by forming a base and pattern with layers of foundry sand and applying a resin binder, followed by a low viscosity resin coating that penetrates and hardens, allowing for durable and cost-effective production of sand casting tools, stamping dies, and vacuum-formed parts without extensive machining or assembly, using a process that involves sequential layering and vacuum-assisted resin infiltration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rapid casting technology is used to produce three-dimensional patterns, then the pattern can be manufactured quickly, but the pattern is not durable and suffers from breakage or wear resulting in loss of surface finish and dimensional accuracy if used multiple times
Solution Approach 1:
The invention combines rapid casting three-dimensional patterns with traditional wooden patterns and REN board structures to create a composite prototype tooling system. The rapid casting pattern is embedded within and supported by the more durable wooden pattern structure, allowing the benefits of rapid manufacturing while gaining the durability and reusability of traditional materials.
2Ease of manufacture
If conventional prototype tooling is used for cope and drag dump boxes, then the tooling can be assembled, but the per piece cost is relatively expensive due to the low number of parts over which the cost of the tooling may be amortized
Solution Approach 1:
The invention creates prototype tooling that can be reused multiple times for producing prototype parts. By embedding the rapid casting pattern within a durable wooden structure, the tooling can serve multiple production cycles, amortizing the tooling cost across more parts and reducing the cost per piece while maintaining the ability to manufacture prototypes efficiently.
3Ease of manufacture
If rapid casting three-dimensional patterns are assembled to REN board box, then the pattern can be formed, but substantial expense and delay are incurred relating to the assembly
Solution Approach 1:
The invention merges the rapid casting pattern directly into the wooden pattern structure during the pattern creation phase, rather than assembling them separately. The rapid casting pattern is embedded within the wooden structure, eliminating the need for separate assembly operations and reducing both time and expense while maintaining the functional benefits of rapid casting technology.
4Ease of manufacture
If machined vacuum form tools are used to manufacture plastic prototype trim parts, then the parts can be produced, but extensive machining or assembly to REN supporting structures is required
Solution Approach 1:
The invention creates a composite vacuum form tool by combining the rapid casting pattern with wooden pattern structures. This composite tool provides the necessary rigidity and support for vacuum forming operations while eliminating the need for extensive machining and assembly to REN supporting structures, simplifying the overall tool complexity.
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 solution enables the creation of durable, cost-effective reusable tools for prototype and limited-production parts, reducing material costs and extending tool life by providing a strong, rigid shell that withstands multiple uses and maintains dimensional accuracy, while also allowing for efficient production of sand castings and vacuum-formed parts.
Implementation Method 1
A coating that forms a low viscosity resin shell is applied to and penetrates substantially all of the surfaces of the base wall and the pattern
Implementation Method 2
A sheet of thermoplastic material may be heated and placed on the pattern with a vacuum being drawn through the layers of sand and printed resin and through the holes in the forming surface of the pattern
Data Source
AI summary
A reusable, low investment tool for making parts is made by a process in which a mixture of sand and an activator is applied as a layer onto which a printed resin is deposited to form a base and a pattern. A plurality of sidewalls may also be provided on the base using the same process. The tool is coated with a curable resin to form a protective shell. The reusable tool may be used as a dump box or as a vacuum forming tool for forming parts. A stamping die may be formed by drawing a vacuum through the sand layer as the resin coating is applied to more fully permeate the stamping die.