![]() Depending on the requirements and layup technology, the fibre deposition can be made on plane and on three-dimensional moulds. Therefore, the preform structure can be designed to be load-path oriented and with a near-net-shape. Alternatively, the tows can be placed within a defined area to realize local reinforcements. Bindered and spread fibres can be placed in any orientation within a single ply. According to Gardiner, 80% of the carbon fibres are currently spread before processing. The FAW of a single ply is adjusted by the spreading width of the tows and the web spacing. It is possible to specifically control the required FAW of the individual plies of a laminate. However, the low permeability of the preforms produced is a major disadvantage. The main advantages of DFP are low fibre undulation and low fibre areal weights (FAWs) within the plies. The production of fibre composite structures from spread dry carbon fibre tows, so-called fixed tows, is pursued with the aim of producing homogeneous laminates with a minimum of defects. One of the preforming processes is a dry fibre placement (DFP) process called crosslayer. If the dry fibres are first shaped into a so-called preform and then impregnated with a matrix system, it is called the preforming process. If the fibres are first combined with the matrix and then moulded into shape, this is called a prepreg process. The investigations are performed with carbon fibre tows (24 k), a reactive epoxy-based binder system, and a thermoset infusion resin system.įibre-reinforced plastic composites are created by combining reinforcing fibres with polymers, which serve as matrix. An approach to determine the infusion times as a function of the laminate thickness, the ply structure, and 2 mm wide gaps is demonstrated and analysed using vacuum-assisted process (VAP) infusion tests. The effects on stiffness and strength are compared for several use cases. In this publication, the influences of the process parameters, 2 mm wide gaps and the percentage of 90° plies in the laminate, are investigated with regard to the mechanical properties, the permeability, and the infusion times in the preform z-direction (thickness). Process reliability, low waste rates, and flexible production are demonstrated. ![]() The aim was to automate existing hand lay-up processes, reducing the complexity, increasing robustness, and facilitating the handling of the DFP technology. Within the dry fibre placement (DFP) process, spread and pre-bindered carbon fibre rovings are automatically processed into dry textile preforms using 2-D and 3-D laying systems.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |