An investigation into the performance of aligned, discontinuous carbon fibre produced with the scaled-up HiPerDiF process

纤维增强聚合物复合材料为生产更轻、更便宜、更耐用的产品提供了机会，与金属材料相比，这些产品具有更高的机械性能。然而，这带来了与复杂的制造工艺和复合废物相关的挑战。废纤维以不连续和随机取向的形式存在，为了创造出有价值的产品，有必要重新排列它们以获得高体积分数。布里斯托尔大学发明的HiPerDiF技术可以加工各种类型的纤维，以生产高度排列的不连续纤维预制件。使用不连续纤维的优点是它们提供了更好的处理和成形能力，并有可能减少缺陷。固化后的复合材料还可以达到与连续复合材料相当的力学性能。虽然在优化使用HiPerDiF技术生产的定向不连续纤维预浸料的机械性能方面取得了重大进展，但这些预浸料大多是基于实验室的，产量较低。因此，这允许对所生产的材料进行有限的表征。最近安装了新一代机器HiPerDiF 3G，能够以每小时1000公斤的速度生产排列整齐的不连续纤维预浸料。这将使HiPerDiF技术产业化，使其适用于广泛的复合应用。随着生产率的提高，可以生产足够的材料，以充分表征所生产的材料在各种加载条件下的质量控制和机械性能。该项目将专注于从生产废物中提取原始的不连续纤维。任何新技术的扩大都会带来新的挑战。因此，该项目的目的是确定与将该工艺改造成更大规模相关的风险，并调查对所生产材料的性能和质量的影响。为了实现这一目标，该项目将：-使用HiPerDiF 3G的材料生产面板，与使用相同组成材料的连续纤维预浸料生产的面板进行比较。-设计和进行一项测试活动，分析机械性能、故障特性和纤维物理性能，以确定材料的极限。-通过实验确定通过改变关键工艺参数来优化工艺以实现性能最大化的可行性。-探索可用于对HiPerDiF 3G制造工艺实施质量控制的适当测量技术。基于这个项目的结果，可以进行进一步的研究，以建立有效的控制策略，更好地了解过程参数的相互作用及其影响。

Fibre reinforced polymer composites provide the opportunity to produce lighter, cheaper and, durable products with increased mechanical performance compared with metallics. However, this creates challenges related to the complex manufacturing processes, and composite waste. Waste fibres are in a discontinuous and randomly oriented form and to create a valuable product it is necessary to realign them to achieve high volume fractions. The HiPerDiF technology, invented at the University of Bristol, can process a variety of fibre types to produce a highly aligned discontinuous fibre preforms. The advantages of using discontinuous fibres are that they provide better handling and forming capabilities with the potential to reduce defects. The cured composite material can also achieve mechanical properties comparable to that of its continuous counterparts. While significant progress has been made to optimize the mechanical performance of aligned discontinuous fibre prepregs produced using HiPerDiF technology, it has mostly been lab-based with a low throughput. As a result, this has allowed a limited characterisation of the produced material. A new generation machine, HiPerDiF 3G, capable of producing kg/hr quantities of aligned discontinuous fibre prepregs has been recently installed. This will industrialise the HiPerDiF technology, making it suitable to a wide range of composite applications. With the increased production rate, enough material can be produced to allow a full characterisation of the produced material both in terms of quality control and its mechanical performance under various loading conditions. The project will concentrate on virgin discontinuous fibres sourced from production waste.The scale-up of any new technology brings with it new challenges. Therefore, this project will aim to identify risks associated with transforming the process into a larger scale and investigating the effects on the performance and quality of the produced material. To achieve this, the project will:- Produce panels using material from HiPerDiF 3G to compare with panels produced with continuous fibre prepreg of the same constituent materials.- Design and conduct a testing campaign that will analyse mechanical performance, failure properties, and fibre physical properties to determine the material's limits.- Experimentally determine the feasibility of optimising the process to maximise performance by varying the key process parameters.- Explore suitable measurement techniques which can be used to implement quality control into the HiPerDiF 3G manufacturing process. Based on the results of this project, further research can be conducted to establish an efficient control strategy with a better understanding of the process parameters interactions and their effects.This project will be supported by Solvay.