No abstract

In modern society, sustainability, resources awareness and energy saving are becoming increasingly important. At the same time, advanced high-tech products are requested by the customers. A promising approach to address these demands is the use of lightweight constructions with a focus on the utilization of mixed materials. Therefore, competitive, economic and producible joining technologies for carbon fiber reinforced plastics are required. This paper firstly discusses the benefits of materials substitution by carbon fiber reinforced plastics (CFRP) by demonstrating two case studies. The applied methods for materials substitution are presented focusing on the weight reduction and the selection of suitable joining technologies.

Often, carbon fiber reinforced plastic (CFRP) manufacturing represents an expensive, time-consuming, small-scale production due to products and components characterized by complex geometric properties. In the field of orthopedic products individual molds, usually made of metal alloys or plaster, are necessary to shape the contour of the components. The presented case study focuses on individually manufactured masks for post-operative treatment of uncomplicated midfacial fractures that are frequent and typical injuries in popular contact sports like football or handball. To improve the costly process of CFRP production of individually manufactured masks, this paper describes the advantages of the combination of optical metrology (i.e. 3D-scanning) and additive manufacturing (i.e. 3D-printing). Therefore, the conventional process chain consisting of the main process steps molding (master pattern), casting (mold), CFRP laminating, curing, cutting and final assembly is replaced by 3D-scanning (instead of master pattern), followed by the revision of the CAD-model (to prevent cutting efforts), 3D-printing (mold), CFRP laminating, curing and final assembly. Summarizing, this case study on manufacturing of carbon fiber reinforced plastic orthopedics shows that the combination of innovative manufacturing technologies opens up new possibilities to increase efficiency in craft based manufacturing.

For the manufacturing of Carbon Fiber Reinforced Plastics (CFRP), more precisely for the curing phase, alternative process technologies are available. These technologies use different types of facilities and forming tools as well as different mechanisms for the heat input and the load application. Thus, the required amount of energy, the needed source materials and the ancillary input of the machines vary widely. Since the resource efficiency of production processes gains in importance, considerations of the inputs, outputs and the ecological impact of CFRP manufacturing processes are essential. In this work, three CFRP manufacturing processes were comparatively investigated with a gate-to-gate analysis following ISO 14044 to reveal the appropriate CO2-emissions and the global warming potential. The curing processes in a vacuum-oven process, a wet pressing process and a prepreg-autoclave process were considered. As a functional unit, an endless reinforced thermosetting CFRP-container served. During the inventory analysis phase all elementary and energy flows of the several process steps of the mentioned technologies were documented. The subsequent impact assessment shows, that for the single piece production in oven and press, the mold exerts the greatest influence on to the global warming potential with a share over 94 %. However, in the autoclave the process energy has the greatest share with over 46 %.