Fiber-thermoplastic Leaf Spring Manufacturing with Inert Gas
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Solution Overview
Problem
The processing of thermoplastics for fiber composite leaf springs is hindered by oxidation reactions with ambient air, leading to suboptimal production and quality issues, particularly in ensuring uniform fiber alignment and adequate thermoplastic impregnation without excess material.
Innovation Solution
A method involving the production of a fiber-thermoplastic strand by alternately arranging fibers and thermoplastic films, followed by heating in a molding press under inert gas conditions to melt and evenly distribute the thermoplastic, ensuring complete coverage of fibers and minimizing oxidation, with subsequent cooling and finishing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thermoplastic is used for fiber composite leaf springs, then production costs are reduced and processing is simplified, but oxidation reactions with ambient air occur leading to quality issues
Solution Approach 1:
The patent applies an inert gas atmosphere (nitrogen or argon) during the thermoplastic processing steps to prevent oxidation reactions. The inert gas is introduced into the processing chamber during heating and molding operations, creating an oxygen-free environment that eliminates oxidation of the thermoplastic material while maintaining the benefits of thermoplastic processing such as lower costs and simplified manufacturing compared to duroplastic alternatives.
2Manufacturing precision
If thermoplastic films are used to impregnate fibers, then adequate coverage is achieved, but excess material and uneven distribution occur
Solution Approach 1:
The patent controls the thickness and dimensions of thermoplastic films as input parameters, and precisely controls heating temperature and pressure parameters during processing. By optimizing these parameters, the thermoplastic material melts and distributes uniformly among the fibers without excessive material accumulation, achieving complete fiber impregnation while minimizing waste material.
Solution Approach 2:
The patent utilizes the phase transition of thermoplastic material from solid to liquid state through controlled heating. The thermoplastic films are heated above their melting point to become molten, allowing them to flow and penetrate uniformly among the fibers. After impregnation, cooling solidifies the material, creating a uniform composite structure without excess material.
3Manufacturing precision
If fibers are alternately arranged with thermoplastic films, then complete fiber coverage is achieved, but production process complexity increases
Solution Approach 1:
The patent performs preliminary arrangement of fibers and thermoplastic films in an alternating sequence before the actual molding process. This pre-arranged structure ensures that when heating and pressure are applied, the molten thermoplastic automatically distributes uniformly among the fibers without requiring complex real-time control mechanisms during processing, thus maintaining manufacturing precision while reducing process 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
This method allows for the production of high-quality fiber composite leaf springs with desired fiber alignment and efficient thermoplastic distribution, meeting automotive standards while reducing production costs and preventing oxidation, resulting in a durable and cost-effective product.
Implementation Method 1
applying a predetermined force and a predetermined first temperature to the at least one fiber-thermoplastic strand in the molding press in such a way that the thermoplastic melts
Implementation Method 2
cooling it to a second temperature which is below the melting temperature of the thermoplastic
Implementation Method 3
heating in a molding press under inert gas conditions to melt and evenly distribute the thermoplastic, ensuring complete coverage of fibers and minimizing oxidation
Data Source
Figure 1~5
AI summary
The method involves alternatingly positioning unidirectionally aligned fibers (9) and thermoplastic resin to manufacture fiber thermoplastic strands (10c). The strands of predetermined length are introduced into a molding machine (11). A predetermined force and a predetermined temperature are exerted on the fiber thermoplastic strand to melt thermoplastic resin and fill the spaces between the fibers and to completely cover the fibers at the outside surface of a manufactured raw leaf spring. The raw spring is molded from the molding machine and the spring is cooled at a specific temperature. An independent claim is also included for a leaf spring formed from a fibrous composite, which consists of a thermoplastic resin and unidirectional aligned fibers.