Abstract

This work presents ionically vulcanized carboxylated nitrile rubber (XNBR) compounds reinforced with conventional and sustainable fillers. The impact of adding traditional fillers, such as carbon black and silica, as well as sustainable options, such as cellulose and ground tire rubber from end-of-life tires (GTR), on the rubber's mechanical, thermal, self-healing, and recyclability properties is carefully analyzed. The results demonstrate that the incorporation of sustainable fillers achieves a favorable balance between repairability, recyclability, and mechanical performance. In particular, the compound with GTR exhibits reinforcement levels comparable to those of silica-based compounds, while maintaining full reprocessing and repairability. This study highlights the potential of using sustainable and recycled materials in the rubber industry, significantly contributing to the development of environmentally friendly elastomeric compounds.

Abstract

This PART 2 is the continuation of the project: “PART 1: recyclability and revalorisation of railway components made of composite materials”. Following the successful development of the recycling process for the Lightweight Running Gear Frame prototype and the formulation of a 3R epoxy resin suitable for use in the railway sector, the project advances with the following challenges:

1. Revalorisation of Recycled Carbon Fibre (rCF) into new fabrics, by obtaining hybrid rCF and polyamide 6 (PA 6) yarns by adapting and optimising textile processes to incorporate recycled fibres into new intermediate products.
2. Production of a new prepreg and its laminates. The new prepreg and its laminates will be produced using the dry fabric obtained in the previous objective and the 3R epoxy resin, developed in PART 1 of the project.

The overall conclusions of the project are that: the recycling process is suitable for post-consumer components, the spinning and weaving methods are effective for dealing with this type of fibres and the 3R laminates manufactured are of high quality and ready to be evaluated in terms of their properties.

Abstract

In the railway sector, represented by TALGO, there is growing concern about the recyclability and reusability of composite parts at the end of their useful life. To address this concern and comply with Spanish and European directives and legislation, an innovation project (divided into "PART 1" and "PART 2") has been carried out in which AITEX, CIDETEC, iTREE, and TALGO have collaborated. The main results of the first part are as follows:

1. Recycling process of the composite material of the first prototype of the Lightweight Running Gear Frame: This process focuses on recovering the carbon fiber contained in the material by combining several chemical-physical steps.
2. Development of a 3R (recyclable) epoxy resin formulation: This resin meets the thermal, mechanical, and FST (Fire, Smoke, and Toxicity) requirements of the railway sector and is suitable for use with prepreg technology.

The results indicate that the recycling process is suitable for producing post-consumer parts and that the formulated resin meets the required standards. The overall conclusions of the project will be revealed in PART 2 of this study.