Fabrication of High Quality, Large Wet Lay-Up/Vacuum Bag Laminates by Sliding a Magnetic Tool

Abstract

This study presents a novel method to fabricate high-quality, large composite parts which can be used in a wet lay-up/vacuum bag (WLVB) process. The new method utilizes a commercial lifting magnet, which is commonly used for transporting ferrous plates, to apply a magnetic consolidation pressure on the WLVB composite lay-up. The pressure is applied on a large area of the laminate by slowly sliding the magnet over the vacuum bag surface, which leads to an improved laminate quality. When further improvement is desirable, multiple passes of the magnet can be performed, where each pass successively compacts the lay-up. To explore the feasibility of implementing this technique, random mat and plain weave glass/epoxy laminates were fabricated, and their properties compared to conventional WLVB laminates. The effects of the number of moving passes of the lifting magnet on the laminate microstructure and properties are also investigated. As a result of multiple passes, the fiber volume fraction in random mat and plain weave laminates increases to 34% and 53%, representing 80% and 16% improvements, respectively. In addition, the void volume fraction reduces almost by 60% to a very low level of 0.7% and 1.1%, respectively. Consequently, the flexural properties considerably enhance by 20–81%, which demonstrates the potential of the proposed method to produce WLVB parts with substantially higher quality. It is also shown that there exists an optimal number of passes, depending on the fabric type where additional passes induce new voids as a result of excessive resin removal.

Bending Properties of 3d I-Shaped Woven Composites

“…Combining with Figure 5 and Figure 6, the results showed that the increasing fiber volume fraction improved the bending properties of the 3D I-shaped woven composites. This conclusion was consistent with the previous studying results in this aspect by other scholars [16][17].…”

Low-cost fabrication of high-performance composite structures using external compaction pressure

“…FRC structures can be manufactured using a variety of processes including: wet lay-up, vacuum bagging and prepreg moulding [20]. Wet lay-up is a simple and low-cost manufacturing method, but the process tends to produce laminates with lower mechanical properties than either vacuum bagging or prepreg moulding [21, 22]. These advanced methods provide higher fibre volume fractions and lower void content, but require extra equipment, consumables and a higher fabricator skill.…”