Fibre-Composite Impregnation via Spreading and Deflection
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Solution Overview
Problem
Existing methods for impregnating fibre bundles with a melt suffer from high fibre damage, restricted processing velocities, and poor impregnation quality, especially with high-viscosity systems, due to high take-off forces, mechanical friction, and long residence times, which limit the use of heat-sensitive and thermally degradable materials.
Innovation Solution
A process involving a combination of fibre spreading, cross-section narrowing, deflection, and relaxation zones to achieve uniform fibre distribution and high impregnation quality, allowing for high take-off velocities and low residence times, with a device comprising a spreader device, applicator nozzles, cross-section narrowing system, deflection point, and take-off die, ensuring complete matrix penetration and minimal fibre damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple spreader devices are used to spread fibre bundles, then the spreading effectiveness is improved, but the take-off forces increase greatly and mechanical friction damages the reinforcement fibre
Solution Approach 1:
The fibre bundle spreading process is divided into multiple stages: initial spreading in the inlet zone, further spreading through cross-section narrowing, and final distribution through deflection points. This segmented approach achieves effective spreading without requiring multiple heavy spreader devices that would increase take-off forces and fibre damage.
Solution Approach 2:
Instead of using multiple spreader devices acting in the same dimension (horizontal spreading), the invention utilizes dimensional transitions by narrowing the cross-section and introducing deflection points that spread fibres through spatial reconfiguration, achieving effective distribution with minimal mechanical force.
2Productivity
If take-off velocity is increased to improve productivity, then production speed is improved, but the quality of impregnation decreases and fibre damage increases
Solution Approach 1:
The fibre bundles are pre-spread and pre-positioned in the inlet zone before the actual impregnation process. This preliminary spreading action ensures that fibres are properly distributed and ready for rapid impregnation at high take-off velocities without compromising impregnation quality.
Solution Approach 2:
The invention replaces traditional mechanical spreading devices with a flow-based system where the melt itself, guided by cross-section narrowing and deflection points, performs the spreading and distribution function, enabling high-velocity processing without mechanical fibre damage.
3Reliability
If residence time of the polymer is reduced to prevent degradation of heat-sensitive materials, then material integrity is improved, but the effectiveness of impregnation decreases
Solution Approach 1:
The impregnation process is designed as a continuous flow through the mould cross-section, with the melt continuously advancing through cross-section narrowing and deflection points. This continuous action ensures complete impregnation occurs rapidly during the short residence time, preventing polymer degradation while maintaining impregnation effectiveness.
Solution Approach 2:
The mould cross-section is designed to dynamically narrow and deflect the melt flow, creating a dynamic impregnation process that adapts to the flow velocity. At high take-off velocities, the dynamic cross-section narrowing ensures the melt remains in contact with fibres long enough for complete impregnation despite reduced residence time.
4Adaptability or versatility
If melt viscosity is increased to process higher viscosity systems, then material selection flexibility is improved, but the quality of impregnation and take-off velocity are reduced
Solution Approach 1:
The invention changes the geometric parameters of the mould cross-section (narrowing and deflection angles) to compensate for increased melt viscosity. By adjusting these geometric parameters, the system can process high-viscosity materials at high take-off velocities, maintaining both material versatility and productivity.
Solution Approach 2:
The use of curved deflection points and rounded cross-section transitions creates smooth flow paths that reduce turbulence and pressure losses for high-viscosity melts, enabling these materials to be processed at high velocities without compromising impregnation quality.
Data Source
AI summary
Very good impregnation quality is achieved by a process for production of a fiber-composite material, with introducing a fiber layer by a spreader device and thus spreading to a width greater than that of the final product, at least by a factor of 1.2, where the extent of spreading of the fiber layer is such that its average thickness is 1 to 50 times the filament diameter; applying a melt by at least one applicator nozzle to the spread material; by virtue of cross-section-narrowing, the mould brings the width of the wetted fiber layer at least to the cross section with which the product leaves the take-off die; a radius then deflects the wetted fibers by an angle of 5 to 60°; a relaxation zone renders the fiber distribution more uniform to give a uniform height; achieving the first shaping by a take-off die at the end of the mould.