Method for producing seat core material, and seat core material
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing method of producing seat core materials with foamed molded substrates and embedded frame members experiences deformation issues due to shrinkage, leading to misalignment and dimensional differences, making it difficult to mount the seat core material correctly on vehicles.
Innovation Solution
A method involving the formation of a void cavity adjacent to the frame member within the foamed molded substrate during the molding process, allowing for relative displacement during shrinkage, thereby preventing deformation and ensuring accurate dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If thermoplastic resin expanded beads are heated in a mold cavity with a frame member disposed to fusion-bond the expanded beads and integrally mold a foamed molded substrate with the frame member embedded therein, then productivity is improved and costs are reduced, but deformation of the frame member and warpage of the foamed molded substrate occur due to shrinkage
Solution Approach 1:
The mold cavity is divided into a first mold cavity for molding the foamed molded substrate and a second mold cavity for molding the cushioning layer. This segmentation allows independent control of molding parameters for each component, enabling the frame member to be properly positioned during substrate molding while accommodating shrinkage without deformation.
Solution Approach 2:
The frame member is disposed in the mold cavity before the expanded beads are heated and fusion-bonded. This preliminary positioning ensures the frame member is correctly placed relative to the shrinking substrate, preventing deformation and warpage while maintaining productivity through integral molding.
2Device complexity
If a frame member is embedded in a foamed molded substrate through integral molding, then manufacturing complexity is reduced and costs are lowered, but misalignment of metal fittings and dimensional differences from desired dimensions occur
Solution Approach 1:
A cushioning layer with different material properties is added locally to the foamed molded substrate. This layer has higher elasticity and can deform to compensate for shrinkage, allowing the frame member to maintain correct positioning and alignment while the substrate shrinks, thus preserving dimensional accuracy without increasing overall manufacturing complexity.
Solution Approach 2:
The seat core material is formed as a composite structure combining the foamed molded substrate with a cushioning layer. This composite structure allows the two materials to work together, with the cushioning layer absorbing dimensional changes and preventing misalignment of metal fittings while maintaining the simplicity of integral molding.
3Manufacturing precision
If a void cavity is formed in the foamed molded substrate at a position along and adjacent to the frame member, then deformation is prevented and dimensional accuracy is improved, but device complexity increases
Solution Approach 1:
A void cavity is formed within the foamed molded substrate at a position adjacent to the frame member. This porous structure allows the substrate to shrink into the cavity without deforming the frame member, preventing dimensional inaccuracies. The cavity is integrated into the molding process, so while it adds structural complexity, it does not significantly increase manufacturing 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 method effectively suppresses deformation and ensures the production of seat core materials with excellent dimensional accuracy, facilitating easier and correct mounting on vehicles.
Implementation Method 1
heating thermoplastic resin expanded beads in a mold cavity, in which the frame member has been disposed, to fusion-bond the expanded beads to each other
Implementation Method 2
bending of the frame member and warpage of the foamed molded substrate occur due to the shrinkage of the foamed molded substrate after it has been molded
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A method for producing a seat core material 1 that has a foamed molded substrate 2 and a frame member 3 embedded in a periphery thereof, which includes, as step (a), heating thermoplastic resin expanded beads in a mold cavity, in which the frame member 3 has been disposed, to fusion-bond the expanded beads to each other and to obtain the foamed molded substrate with the frame member 3 being embedded in the periphery thereof; and, as step (b), simultaneously with step (a) or after step (a), forming a void cavity S, S' in the foamed molded substrate 2 at a position along and adjacent to the frame member 3. The void cavity S, S' has a size and shape that allows a relative displacement between the frame member 3 and the foamed molded substrate 2 when the foamed molded substrate shrinks after step (b).