scholarly journals Grinding, Melting and Reshaping of EoL Thermoplastic Polymers Reinforced with Recycled Carbon Fibers

2021 ◽  
Vol 10 (2) ◽  
pp. 53-62
Author(s):  
A. Donatelli ◽  
G. Casciaro ◽  
T. Marcianò ◽  
F. Caretto

This article assesses the technical feasibility of a recycling process based on grinding, melting and re-shaping of carbon fibers (CFs) reinforced thermoplastic polymers, in order to obtain new products that can be introduced in different markets, depending on mechanical properties retained. The idea at the basis of our study is that this kind of recycling process lies at the edge of the stages of recycling and re-use of materials, considering that the latter is preferable when considering the waste management hierarchy. Lower cost and similar mechanical strength of virgin CFs allowed the spread of recycled CFs in the automotive sector in the form of composite materials. Taking into account the Directive 2000/53/EC that sets out measures to prevent and limit waste from end-of-life (EoL) vehicles and their components, and ensures that where possible this is reused, recycled or recovered, we considered worth to investigate the recyclability of composite materials made with recycled CFs when they will reach the state of EoL materials. Considering this premise, an additional scope of this paper is therefore to provide some useful information about the possibility to perform a multiple closed loop recycling of rCF thermoplastic composites. Experiments carried out demonstrated that re-shaping of composites is technically feasible. Some square plates were produced without any setback. The mass balance of the recycling process demonstrated that about 88% of the EoL material can be recovered. Calculation of energy consumption showed that approximately 16 MJ are necessary in the treatment of 1 kg of EoL composites.

2020 ◽  
Vol 21 (3) ◽  
pp. 604-618
Author(s):  
Weihao Liu ◽  
Haihong Huang ◽  
Huanbo Cheng ◽  
Zhifeng Liu

2016 ◽  
Vol 33 (01) ◽  
pp. 1650004 ◽  
Author(s):  
Jianbin Li ◽  
Qifei Wang ◽  
Hong Yan ◽  
Stuart X. Zhu

In this paper, we study recycling, remanufacturing, and pricing strategies of a manufacturer in a closed-loop supply chain. Different from traditional list-price transaction, a name-your-own-price auction is introduced into the recycling process where consumers offer a bid for their own used items and the manufacturer decides whether to accept the bid. We first analyze the consumers’ behavior and find that their bids increase with the dealing cost. Next, we build a newsvendor framework to investigate the manufacturer’s optimal manufacturing with pricing strategies and find that the stocking factor influences the recycling quantity and manufacturing policy. Moreover, we find that a larger salvage value motivates the manufacturer to set a higher stocking factor and thus recycle more as well as manufacture new products. We further investigate the effect of the demand uncertain level and the dealing cost on the system.


2019 ◽  
Vol 254 ◽  
pp. 01018
Author(s):  
František Bárnik ◽  
Milan Vaško ◽  
Milan Sága ◽  
Marián Handrik ◽  
Alžbeta Sapietová

By 3D printing it is possible to create different structures with different fiber-laying directions. These structures can be created depending on the type of 3D printer and its software. The Mark Two printer allows printing Onyx, a material based on nylon in combination with microcarbon fibers. Onyx can be used alone or reinforced with kevlar, glass or carbon fibers. This article deals with 3D printing and evaluation of mechanical properties of printed samples.


1989 ◽  
Vol 170 ◽  
Author(s):  
J. A. Hinkley ◽  
W. D. Bascom ◽  
R. E. Allred

AbstractThe surfaces of commercial carbon fibers are generally chemically cleaned or oxidized and then coated with an oligomeric sizing to optimize their adhesion to epoxy matrix resins. Evidence from fractography, from embedded fiber testing and from fracture energies suggests that these standard treatments are relatively ineffective for thermoplastic matrices. This evidence is reviewed and model thermoplastic composites (polyphenylene oxide/high strain carbon fibers) are used to demonstrate how differences in adhesion can lead to a two-fold change in interlaminar fracture toughness.The potential for improved adhesion via plasma modification of fiber surfaces is discussed. Finally, a surprising case of fiber-catalyzed resin degradation is described.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Kailin Zhou

The need to reduce the overall weight of aeronautical and space structures while preserving or even improving their performances make the research and development in the field of advanced composite materials necessary for the advancement of aerospace technologies. This paper provides an overview of composite materials and their fiber reinforcement technology in aerospace field. We discuss the reasons for aircraft manufacturers and airlines to use composites and illustrate the definition of composite material. Then, we list the advantages and disadvantage of composite materials and cite different fiber reinforcement technologies of carbon fibers, aramid fiber, UHMWPE, etc. At last, we summarize the present and future applications of composites materials in aerospace and other civil fields. A conclusion is drawn that in the future, composite materials are set for their development, while continually decreasing its costs is still an important task.


Author(s):  
D.O. Chervakov ◽  
◽  
O.S. Sverdlikovska ◽  
O.V. Chervakov ◽  
◽  
...  

To improve the physical-mechanical and thermophysical properties of polypropylene-based thermoplastic composite materials, we performed modification of a polymer matrix by reactive extrusion of polypropylene in the presence of benzoyl peroxide and polysiloxane polyols. Modified polypropylene was compounded with basalt, carbon, and para-aramide reinforcing fillers in a screw-disc extruder. It was established that the reinforcement of modified polypropylene by basalt fibers ensured a 110% increase in tensile strength. The reinforcement of modified polypropylene by carbon fibers allowed fabricating thermoplastic composite materials with tensile strength increased by 14%. The maximum reinforcing effect was observed by using para-aramide fibers as reinforcing fibers for modified polypropylene with tensile strength increased by 30% as compared with initial polypropylene. It was determined that the obtained thermoplastic composite materials based on modified polypropylene can be processed into products by the most productive methods (extrusion and injection molding). The developed materials exhibited improved thermal stability. The proposed ways of modification methods provide substantial improvement in physical-mechanical and thermophysical properties of modified polypropylene-based thermoplastic composite materials as compared with initial polypropylene. In addition, they ensure a significant increase in service properties of the products prepared from thermoplastic composite materials based on modified polypropylene.


2021 ◽  
Vol 36 (1) ◽  
pp. 35-43
Author(s):  
M. Längauer ◽  
G. Zitzenbacher ◽  
C. Burgstaller ◽  
C. Hochenauer

Abstract Thermoforming of thermoplastic composites attracts increasing attention in the community due to the mechanical performance of these materials and their recyclability. Yet there are still difficulties concerning the uniformity of the heating and overheating of parts prior to forming. The need for higher energy efficiencies opens new opportunities for research in this field. This is why this study presents a novel experimental method to classify the efficiency of infrared heaters in combination with different thermoplastic composite materials. In order to evaluate this, different organic sheets are heated in a laboratory scale heating station until a steady state condition is reached. This station mimics the heating stage of an industrial composite thermoforming device and allows sheets to slide on top of the pre-heated radiator at a known distance. By applying thermodynamic balances, the efficiency of chosen parameters and setups is tested. The tests show that long heating times are required and the efficiency of the heating is low. Furthermore, the efficiency is strongly dependent on the distance of the heater to the sheet, the heater temperature and also the number of heating elements. Yet, using a full reflector system proves to have a huge effect and the heating time can be decreased by almost 50%.


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