Innovative Production of Composites with Through Plane Alignment of Fi-bers

短纤维复合材料(SFC)依靠增强纤维相的特殊性能来提高基体的性能。根据所需的产品应用，纤维必须以特定的方向排列，可以是平面内的，也可以是直通平面的，等等。出于成本和大规模生产的考虑，通常不采用直通平面的纤维取向。这项建议旨在开发具有穿透平面取向(TPA)纤维的复合材料，因为它们可以显著改善用于许多现有应用的SFCs的性能。此外，如果能够适当地控制光纤的穿透平面排列，则可以设想许多新的和创新的应用。控制平面内对齐的最常见方法是应用剪切流场，该流场可以在挤出或注塑成型过程中固有地产生。垂直于平面(穿过平面)对齐纤维更加困难，因为在控制剪切流场方面存在挑战。许多技术都是基于对液体悬浮液中的颗粒施加电磁力，然后使其凝固。机械法不适合大规模生产。可能的应用包括导电和导热涂层、耐磨表面、渗透膜、散热片和创新传感器等。 因此，这项研究计划的目标是开发创新的制造技术，以实现TPA SFCs的高通量生产，比随机SFCs更适合某些应用。成功地这样做将产生巨大的影响，打开一些申请，而这些申请目前甚至没有被考虑为安全和可持续发展中心。 将研究两种不同的方法来实现光纤的穿透平面对准。A)在SFC薄板中发泡，其中基质中的气泡被迫经历双向拉伸、破裂并形成开放的气孔，从而使大量纤维横向排列。B)挤压，然后进行后处理、折叠和固化。这项研究建议首先使用挤出将纤维在平面方向上对齐，然后进行类似折叠的操作和固化，以改善折叠层的表面与表面的结合。这两种方法都需要广泛的设计和开发工作，并需要应用创新的方法来解决设计挑战。初始阶段将侧重于上文提出的第一种方法。 穿透平面纤维对准的工作很少，而在SFCS中通过平面对准实现高产量的技术有可能显著提高复合材料的可用性，并产生许多新颖和创新的应用，这将有利于加拿大的塑料制造业。它也将是HQP在该行业培训和创新经验的来源。

Short-fiber composites (SFC) rely on the exceptional properties of the reinforcing fiber phase to enhance the properties of the matrix. Depending on the product application required, the fibers must be arranged in a particular orientation, either in-plane, through-plane, etc. Due to cost and mass-production concerns, through-plane fiber orientation is usually not pursued. This proposal seeks to develop composites with through-plane aligned (TPA) fibers, as they can significantly improve properties of SFCs for use in a number of existing applications. Moreover, many new and innovative applications can be envisaged if through-plane alignment of fibers can be properly controlled. The most common way of controlling the in-plane alignments is by applying a shear flow field, which can be inherently generated in extrusion or injection molding processes. Aligning fibers perpendicular to the plane (through-plane) is more difficult because of the challenges in controlling the shear flow field. Many techniques are based on utilizing electromagnetic forces on particles in fluid suspensions and then solidification. Mechanical methods are not suitable for large scale production. Possible applications include electrically and thermally conductive coatings, wear resistant surfaces, permeable membranes, heat sinks, and innovative sensors etc. Therefore, the objective of this research program is to develop innovative manufacturing techniques for high throughput production of TPA SFCs, which are more suited for certain applications than random SFCs. Success in doing so will have a dramatic effect in opening up a number of applications which are not even being considered at present for SFCs. Two distinct methodologies will be investigated for through plane alignment of fibers. A) Foaming in SFC thin sheets, where the bubbles in matrix are forced to undergo biaxial stretching, rupture and form open pores which will align large number of fibers laterally. B) Extrusion followed by post-processing folding and curing. This research proposes to first align the fibers in the planer direction using extrusion and followed by folding like operations and curing to improve the surface to surface bonding of the folded layers. Both the methods require extensive design and development efforts and application of innovative approaches to solve design challenges. The initial phase will focus on the first methodology proposed above. Work on through-plane fiber alignment is sparse and achieving technology for high throughput through plane alignment in SFCs has the potential to dramatically increase the usefulness of composite materials and generate many novel and innovative applications, which will be beneficial for the plastics manufacturing industry of Canada. It will also be a source of training and innovation experience for HQP in this industry.