Recyclability and reutilization of carbon fiber fabric/epoxy composites

Abstract

Solid carbon fiber/epoxy laminates manufactured by liquid resin infusion of twill fabric reinforcement are recycled in a bath of boiling sulfuric acid to separate the fibers from the matrix. The recycled reinforcement consists of long fibers arranged in a random, entangled mat. Using the same epoxy matrix and infusion materials and process, the recycled fibers are reutilized to manufacture solid laminates. The physical properties of the recycled laminates are evaluated by means of pulse-echo ultrasound, visual microscopy, and fiber volume content. The average fiber volume content of the recycled laminates is 33%, compared to the 62% of the twill laminates. The mechanical properties of the recycled composite include tension modulus and strength, compression modulus and strength, three-point bend flexure strength, and short beam shear strength. The properties are compared against the values of the twill reinforcement with quasi-isotropic stacking sequence. Results show that the recycled material offers promising elastic properties and strength values, similar to those of advanced carbon fiber sheet molding compounds, and therefore can be used as structural material.

Activating Carbon Fibers and Date Pits for Use in Liver Toxin Adsorption

“…An increasing number of aircraft structures have become highly dependent on the use of these materials. Some of which are the Boeing 787 Dreamliner and Airbus A380 and A350 [20].…”

Resource-friendly carbon fiber composites: combining production waste with virgin feedstock

“…The reclaimed products have lower mechanical properties, with reported strength reductions up Resource-friendly carbon fiber composites: combining production waste with virgin feedstock to 85% and stiffness reductions up to 45%. [12][13][14] The reduction in properties at the laminate level arises from the loss of alignment of reprocessed short fibers, 4,15 larger pieces of reclaimed product acting as a failure initiation site, 7 and low fiber volume fractions. 2,4 Random fiber mats experience less fiber nesting during consolidation due to less alignment within the fiber bed.…”

Round Robin Tests to Determine Fiber Content of Carbon Fiber-Reinforced Thermoplastic Composites by Combustion and Thermogravimetry

“…Methods to determine the carbon fiber content of CFRP are regulated by two international standards: the one set by the International Organization for Standardization (ISO 14127, "Carbon-FibreReinforced Composites-Determination of the Resin, Fibre 2 Journal of Polymers and Void Contents") and the one proposed by the American Society for Testing and Materials (ASTM D3171-15, titled "Standard Test Methods for Constituent Content of Composite Materials"). The fiber content by weight of CFRP is measured after removing the resin part of the CFRP using strong acids according to ISO 14127 and ASTM D3171-15 [7] or by combustion in nitrogen gas according to ISO 14127 [8]. However, methods that do not use combustion or strong acids are safer and eliminate the need to treat liquid wastes arising from the use of the acids.…”

“…However, methods that do not use combustion or strong acids are safer and eliminate the need to treat liquid wastes arising from the use of the acids. Fiber contents of CFRP have been measured in several studies to determine the characteristics of CFRP [7][8][9][10]. The relationship between the fiber contents and thermal diffusivity measured by IR thermography was studied to provide a new method for measuring the fiber content of composites [9,10].…”