Foamed Plastic Sandwich Component Manufacturing
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Solution Overview
Problem
Current methods for producing sandwich components for motor vehicles are inefficient, often resulting in brittle components that can break under mechanical stress and create sharp edges, and they have high production costs and cycle times.
Innovation Solution
A method involving a core layer of foamed plastic and a cover layer with reinforcing fibers, where the core layer has a higher melting temperature than the cover layer, allowing for a mechanical connection without chemical bonding, enabling flexible and cost-effective production of sandwich components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sandwich components are made using conventional hot pressing processes with thermoplastic foam and thermoplastic facing layers, then the components achieve high strength and stiffness, but they become brittle and can break under mechanical stress creating sharp edges
Solution Approach 1:
The patent uses a composite material system consisting of a foam core layer and a non-foam plastic layer with different melting temperatures. This layered composite structure combines the high strength and stiffness of the foam core with the ductility and safety of the non-foam plastic skin, resolving the contradiction between structural performance and safety.
Solution Approach 2:
The patent changes the thermal parameters of the material layers by selecting materials with different melting temperatures. The foam core layer has a higher melting temperature while the non-foam plastic layer has a lower melting temperature, allowing selective melting and bonding during processing while maintaining the foam's structural integrity and the plastic's safety characteristics.
2Strength
If sandwich components are produced using polyurethane materials, then high strength is achieved, but production costs and cycle times increase significantly
Solution Approach 1:
The patent changes the material selection parameters by using common thermoplastics like polypropylene or polyethylene for the non-foam plastic layer instead of expensive polyurethane. These materials can be processed at lower temperatures and have shorter cycle times, reducing production costs while maintaining adequate strength through the composite structure.
Solution Approach 2:
The patent discards the conventional single-material polyurethane approach and recovers cost efficiency by using cheaper thermoplastics in a composite configuration, achieving the required performance through structural design rather than material cost.
3Strength
If the core layer and cover layer are bonded using chemical bonding, then strong adhesion is achieved, but the manufacturing process becomes more complex and costly
Solution Approach 1:
The patent replaces chemical bonding methods with a thermal-mechanical bonding process. By heating the non-foam plastic layer above its melting temperature and then pressing it against the foam core layer, the molten plastic flows into the foam structure and bonds upon cooling, achieving strong adhesion through physical interlocking and crystallization rather than chemical reactions.
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 allows for the production of flexible sandwich components with reduced manufacturing effort, lower weight, and improved safety, while maintaining dimensional stability and reducing production costs and cycle times.
Implementation Method 1
The plastic of the core layer has a (first) melting temperature that is higher than the (second) melting temperature of the plastic fibers of the cover layer
Implementation Method 2
heating the multilayer composite or the semi-finished product manufactured from it in a heating device to a temperature that is lower than the first melting temperature but higher than the second melting temperature
Implementation Method 3
an adhesive, form-fitting, or mechanical connection is established between the core layer and the cover layer
Implementation Method 4
The foam of the core layer can partially melted
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~4b
AI summary
The invention relates to a method for producing a sandwich component (10), particularly an interior trim component for a motor vehicle. The method proceeds from a core layer (12) made of a foamed plastic and a cover layer (14), which comprises reinforcing fibers and plastic fibers. The plastic of the core layer has a (first) melting temperature that is higher than the (second) melting temperature of the plastic fibers of the cover layer. A multi-layer composite (20) is created by arranging the core layer on the cover layer. Said multi-layer composite can be further processed into a semi-finished product (30, 30') by further process steps. The multi-layer composite or the semi-finished product (30, 30') produced therefrom is then heated in a heating device (52) to a temperature that is lower than the first melting temperature but higher than the second melting temperature. The multi-layer composite heated in this manner or the semi-finished product (30, 30') heated in this manner is then shaped in a shaping tool in order to produce the sandwich component.