Investigation on the Mechanical Recycling of Carbon Fiber-Reinforced Polymers by Peripheral Down-Milling

Abstract

Carbon fiber-reinforced plastics (CFRPs) are composite materials that play a significant role in the growth of many industrial fields where high performance and lightness of the structures are required. At the same time, the management at the end of their life has required the development of more and more sustainable and efficient recycling solutions. Considering this, the present research work aims to investigate a mechanical recycling method and the cutting strategies able to machine CFRP components in their entirety, using a common milling machine in a job shop scheme, making a shorter supply chain, and leading to economic and environmental benefits. In detail, laminates obtained by unidirectional carbon fiber prepregs were worked through the peripheral down-milling process, by varying the spindle speed and the feed rate. The recording of the cutting forces enabled the evaluation of features such as the cutting power and the specific cutting energy. Moreover, the chips from the milling process were classified as a function of their dimensions. Finally, specimens made of chips and epoxy resin were characterized under bending conditions, to evaluate the effectiveness of using the chips from CFRP peripheral milling as the polymer’s reinforcement and, in addition, to appreciate the goodness of this recycling strategy.

A Review on the Recycling Technologies of Fibre-Reinforced Plastic (FRP) Materials Used in Industrial Fields

“…Durante et al [109] investigated the recycling of CFRP materials using a peripheral down-milling process by adopting different cutting parameters aiming to understand how the process parameters influence the specific cutting energy and dimension of the recovered fibres. At the end of the recycling process, rCFs of different dimensions were obtained, but only fine fibres (with a size smaller than 0.3 mm) and coarse fibres (with a size bigger than 0.3 mm) were used to produce recycled composite materials using an epoxy resin as the matrix.…”

Recycling of Epoxy Resins with Degradable Structures or Dynamic Cross-Linking Networks: A Review

“…It is expected that in the next few years, more and more countries around the world will join this rank. With the development of modern technology, a variety of recycling methods for traditional EPRs have emerged and initially completed industrial applications, which be systematically divided into mechanical recycling, , pyrolysis recycling, − and dissolution recycling. − However, these methods are not ideal recycling methods.…”

Mechanical Recycling of Carbon Fiber-Reinforced Polymer in a Circular Economy

“…It can be applied to the majority of industrial fiber typologies without limitations. The swift industrial scalability, coupled with environmental and economic sustainability in terms of specific energy demand, are compelling features of mechanical recycling that increase its attractiveness [42]. Table 1 provides a summary of the energy consumption rates, environmental impacts, and technology readiness levels of mechanical, chemical, and thermal recycling techniques.…”