Lightweight Glass Fiber Mat Successfully Used in Fiber-Metal Laminates

  A recent study of vacuum-infusion molded fiber-metal laminates at the University of Edinburgh, UK, has highlighted the performance benefits of Technical Fiber Products' (TFP) 6g/m2 glass fiber mats as an adhesive carrier within fiber-metal laminates.

  Fiber metal laminates combine composite and metal layers to create a unique set of material properties that balance the strengths and weaknesses of the two constituent materials. Originally developed for the aerospace industry, fiber-metal laminates are lightweight, have a high damage tolerance, and exhibit good fatigue, corrosion, and impact resistance.TFP says the versatility and mechanical properties of fiber-metal laminates have the potential to allow them to be expanded into other areas, such as wind energy and marine transportation, especially when combined with new reactive thermoplastics.

  However, there are challenges in combining these technologies, particularly the need to optimize the metal-composite interface for good adhesion. Differences in the constituent materials may result in a weak bond at the interface, leading to delamination and poor integrity.

  This study evaluates the role of thin felts as adhesive carriers used to improve adhesive layer uniformity and interfacial bonding, which is characterized by the interlayer shear strength.TFP produces high-quality, lightweight nonwovens (thin felts) that are widely used in the aerospace industry. They contribute to uniform adhesive penetration, consolidate the adhesive layer to ensure consistent film thickness, and improve the handling properties of the final product.

  This study investigated the bond strength within fiber metal laminates, evaluating the effect of using three different glass fiber mats with unit area weights of 6, 17, and 34 g/m2, respectively. The fiber-metal laminates were fabricated using a standard vacuum infusion process with an adhesive layer (consisting of a glass fiber mat of TFP and a methacrylate adhesive) between the composite layer and the aluminum layer.

Short beam shear tests were performed on the laminates to assess the interlaminar shear strength and to determine which carrier provided the most effective bond. The results showed that TFP's 6 g/m2 lightweight fiberglass mat was the most effective; the thin, porous mat structure allowed the adhesive to impregnate quickly and consistently, resulting in a thin, uniform adhesive layer.

  This study demonstrates the importance of using TFP thin felts in this area, enabling fiber metal laminates to be used in new sectors and applications. Key takeaways from the use of TFP fiberglass mats include:

- Ensuring a consistent and uniform adhesive layer is important for the successful transition of fiber metal laminates to industrial scale.TFP's lightweight fiberglass mats used as an adhesive carrier achieved the necessary control over the thickness of the adhesive layer and maintained uniformity.

- The use of thin glass fiber mats as an adhesive carrier improves the homogeneity of the adhesive layer without compromising the interfacial bond by reducing the interlayer shear strength. Measurements of interlayer shear strength have shown that optimum results are obtained with TFP's 6 g/m2 glass fiber mats.-----Glass Fiber Intelligence