Press Moulding Method for Composite Panels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current press moulding methods for fibre-reinforced resin matrix composite materials face challenges such as high manufacturing costs, poor surface finish, and excessive resin bleed-out, particularly when using prepregs, which require high pressure and are difficult to conform to complex geometries.
Innovation Solution
A method involving a multilaminar panel with dry fibres and resin layers, where the mould tool is closed in stages with controlled vacuum pressure and closure speed to achieve full impregnation without excessive resin bleed, and the use of a surface resin layer to enhance surface quality and reduce fibre print-through.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high pressure is applied to achieve full impregnation of fibres by resin, then resin impregnation is improved, but resin bleed-out increases excessively
Solution Approach 1:
The moulding process uses periodic action by implementing a multi-stage closing sequence with distinct phases: a first closing stage at higher speed to initially position the moulding material, followed by a second closing stage at reduced speed to achieve complete impregnation while controlling resin flow. This periodic variation in closing speed allows full fibre impregnation without excessive resin bleed-out
Solution Approach 2:
The invention applies parameter changes by dynamically adjusting the closing speed parameter during the moulding process. The closure speed is reduced in the second closing stage compared to the first stage, and the mould temperature is controlled within a specific range (150-200°C) to optimize resin viscosity and flow characteristics, thereby achieving complete impregnation with minimal resin bleed-out
2Shape
If high pressure is applied to conform prepreg to complex geometries, then shape conformity is improved, but manufacturing cost increases
Solution Approach 1:
The invention uses parameter changes by controlling the mould temperature within a specific range (150-200°C) and adjusting the closing speed in two stages. This optimized parameter control allows the moulding material to conform to complex geometries through controlled resin flow rather than relying on high pressure, thereby reducing manufacturing costs while achieving good shape conformity
Solution Approach 2:
The first closing stage performs a preliminary action by quickly positioning the moulding material and initiating resin flow before the second stage completes the impregnation. This preliminary closing action helps the material conform to the mould geometry early in the process, reducing the need for excessive pressure in subsequent stages
3Manufacturing precision
If high pressure is applied to mould prepreg, then impregnation is improved, but cycle time increases
Solution Approach 1:
The multi-stage closing process uses periodic action with a first stage at higher speed for initial positioning and a second stage at lower speed for complete impregnation. This periodic variation in closing speed achieves full fibre impregnation more efficiently than sustained high pressure, reducing overall cycle time while maintaining manufacturing precision
Solution Approach 2:
By controlling the mould temperature (150-200°C) and using a two-stage closing speed profile, the invention optimizes resin viscosity and flow characteristics. This parameter control enables complete impregnation to occur more rapidly than under high pressure conditions, thereby reducing cycle time while maintaining thorough fibre impregnation
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 results in high-quality surface finishes with reduced fibre print-through and minimal resin bleed, enabling the production of lightweight, low-cost automotive body panels with minimal post-moulding finishing requirements, and allows for higher tool temperatures to reduce cycle time.
Implementation Method 1
the mould tool being closed in stages with controlled vacuum pressure
Implementation Method 2
a hydraulic pressure within the resin material of the moulding material is needed to achieve full impregnation of the fibres by the resin and cause resin flow to fill the geometrical details within the mould cavity
Implementation Method 3
substantially fully curing the resin to form a moulded part from the moulding material
Data Source
Figure 1a
Figure 1b
Figure 1c
AI summary
A method of press moulding a moulding material to form a moulded part of fibre-reinforced resin matrix composite material, the method comprising the steps of: i. providing a mould tool having a lower mould part (58) and an upper mould part (60), the upper mould part (60) having a first moulding surface (62) for moulding a first moulded surface of the moulded part and the lower mould part (58) having a second moulding surface (64) for moulding a second moulded surface of the moulded part; ii. providing a multilaminar panel of moulding material (66) comprising at least one layer of dry fibres and at least one layer of resin, the multilaminar panel having first and second opposite major surfaces (68, 70); iii. locating the moulding material (66) in the mould tool; iv. progressively closing the mould tool to define a substantially closed mould cavity containing the moulding material (66), the closing step having: I. a first stage prior to both the first moulding surface (62) contacting the first major surface (68) and the second moulding surface (64) contacting the second major surface (70) and II. a second compression stage after both the first moulding surface (62) has contacted the first major surface (68) and the second moulding surface (64) has contacted the second major surface (70), the second compression stage causing resin impregnation of the dry fibres,the closure speed of relative movement between the lower and upper mould parts (58, 60) being higher in the first stage than in the second compression stage;v. applying pressure to the moulding material (66) in the mould cavity to configure the moulding material (66) in a fully moulded shape; and vi. substantially fully curing the resin to form a moulded part from the moulding material (66).