Resin-Filled Purfling Grooves for Stringed Instruments
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Solution Overview
Problem
Conventional methods of forming purfling on stringed instruments, such as violins, either require skilled craftsmanship or result in reduced impact resistance due to the internal structure alignment with the wood grain, leading to potential cracking upon impact.
Innovation Solution
A method involving the formation of grooves in the instrument's top or back plates, filled with a resin that is cured to create the purfling, providing both decorative and impact-resistant features while simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the purfling is formed by traditional inlaying method with three strips, then the impact resistance and durability are improved, but the manufacturing complexity and skill requirement increase
Solution Approach 1:
The patent uses printing technology to create visual copies of the traditional purfling appearance on the top plate and back plate, eliminating the need for physical inlaying while maintaining the decorative effect. This resolves the contradiction by preserving the aesthetic function without the manufacturing complexity.
Solution Approach 2:
The patent changes the manufacturing parameters from mechanical inlaying to printing processes, transforming how the purfling pattern is applied. This allows the decorative function to be achieved through a simpler parameter set (printing coordinates and colors) rather than complex craftsmanship parameters.
2Ease of manufacture
If the purfling is formed only by printing two black lines, then the manufacturing cost and complexity are reduced, but the impact resistance deteriorates due to internal structure alignment with grain
Solution Approach 1:
The patent combines printed patterns with actual purfling members that have different grain orientations. The composite structure includes both the visual printing layer and the physical purfling strips, creating a system that benefits from both the simplicity of printing and the strength of traditional inlaying with cross-grain construction.
Solution Approach 2:
The patent segments the purfling function into two independent parts: the decorative visual pattern (achieved through printing) and the structural reinforcement (achieved through physical purfling members). This segmentation allows each function to be optimized separately, maintaining manufacturing simplicity while preserving impact resistance.
3Productivity
If the purfling is formed by printing method, then the manufacturing time is reduced, but the authenticity and traditional craftsmanship quality are lost
Solution Approach 1:
The patent merges the advantages of modern printing technology (speed and consistency) with traditional purfling craftsmanship (authenticity and quality). By combining both methods, the system achieves high productivity through printing while maintaining craftsmanship quality through the use of traditional purfling members.
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 resin-filled purfling enhances impact resistance, minimizes cracking, and allows for adjustment of acoustic characteristics, enabling a more durable and aesthetically pleasing instrument with improved sound quality.
Implementation Method 1
wherein the resin has a degree of elongation of 20% or more
Data Source
Figure 1
Figure 2~3
Figure 4A~4D
AI summary
A manufacturing method for a board for a stringed instrument that is used as a top plate or a back plate of an acoustic stringed instrument such as a violin, where the board has a purfling, includes forming, for instance, a groove with a depth that is 20% or more and less than 60% of a thickness of the board for a stringed instrument, filling the groove with a resin in which, for instance, colored particles having a diameter of 3 µm or more and less than 70 µm are dispersed and which has a degree of elongation of 20% or more, removing the resin that has flowed out of the groove, and curing the resin.