Release of Respirable Fibrous Dust from Carbon Fibers Due to Splitting along the Fiber Axis

Kehren, Dominic; Simonow, Barbara Katrin; Bäger, Daphne; Dziurowitz, Nico; Wenzlaff, Daniela; Thim, Carmen; Neuhoff, Judith; Meyer‐Plath, Asmus; Plitzko, Sabine

doi:10.4209/aaqr.2019.03.0149

Cited by 16 publications

(18 citation statements)

References 20 publications

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“…in den vergangenen zwei Jahrzehnten wurden mit metho den der Nanotechnologie große Fortschritte bei der entwick lung neuer materialien erzielt. eine neue und vielfäl tige materialgruppe sind die auf Fulleren und Graphenstrukturen basierenden Kohlenstoffmaterialien, speziell die ein und mehrwandigen Kohlenstoff nanoröhren (Carbon Nanotubes, CNT [16,17]. ein solches Bruchverhalten entlang Faserrichtung zeigten bisher vornehmlich die kristallinen pechbasierten Carbonfasern.…”

Section: Neue Materialien -Neue Erkenntnisse In Der Risikoforschungunclassified

Bloß kein zweites Asbest

Packroff

Broßell²,

Meyer‐Plath³

et al. 2021

Chemie in nserer Zeit

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ZusammenfassungDie Verwendung von Asbest wurde, obwohl die gefährlichen Eigenschaften bereits vor mehr als 120 Jahren erkannt wurden, viel zu spät durch gesetzliche Regelungen eingeschränkt. Mit dem Toxikologischen Faserprinzip wurden die gesundheitlichen Auswirkungen auch wissenschaftlich plausibel und konnten auf Morphologie und Biobeständigkeit eingeatmeter Faserstäube zurückgeführt werden. Damit wurden nicht nur andere Fasermaterialien als potenzielle Kanzerogene identifiziert, sondern auch Ansatzpunkte für ein sicheres Design neuer Fasermaterialien abgeleitet. Die Risikoforschung zu Nanomaterialien hat diese Kenntnisse weiter vertieft und differenziert. Sie müssen nun Grundlage für eine Weiterentwicklung des europäischen Chemikalienrechts werden, um kein zweites Asbest auf dem Binnenmarkt zuzulassen.

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Section: Neue Materialien -Neue Erkenntnisse In Der Risikoforschungunclassified

Bloß kein zweites Asbest

Packroff

Broßell²,

Meyer‐Plath³

et al. 2021

Chemie in nserer Zeit

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“…In Germany, according to the “Technical Rules for hazardous Substances” 905 18 all inorganic fibers with insufficient toxicological data but WHO dimensions are object of the carcinogenicity class 2 of the European CLP Regulation 19 . As a consequence they are governed by an occupational exposure limit of 50,000 WHO Fibers/m 3 20 . It is obvious, that there is a lack of data in order to draw specific conclusions on how to handle fiber dust.…”

Section: Introductionmentioning

confidence: 99%

“…19 As a consequence they are governed by an occupational exposure limit of 50,000 WHO Fibers/m 3 . 20 It is obvious, that there is a lack of data in order to draw specific conclusions on how to handle fiber dust. Therefore, it is necessary to gain know-how about alveolar fiber dust formation during shredding as a part of the mechanical recycling process.…”

Section: Introductionmentioning

confidence: 99%

Influence of process parameters on the formation of inhalable fiber dust during shredding for mechanical recycling of fiber‐reinforced organo sheets

Tölle

Hopp

2022

J of Applied Polymer Sci

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Shredding is a major process step in mechanical recycling, as the plastic scrap needs to be cut into small pieces for further processing. It will be melted and finally injection‐molded to form new plastic parts. Also for fiber‐reinforced thermoplastics, the mechanical recycling process is an ecofriendly process because all resources are reused. One challenge during the shredding of fiber‐reinforced plastics is the fiber dust formation. The fiber dust disturbs the following production processes, and the fiber fragments can be alveolar and thus potentially toxic. Therefore, it is a major aim of this research to optimize the cutting process by investigating the effect of different shredding parameters on the alveolar fiber dust formation. Three different continuous fiber‐reinforced thermoplastic organo sheets (PP with glass fibers, PA6 with glass fibers, PA66 with carbon fibers) are shredded while the parameters of throughput, rotational speed, screen size and feedstock size are varied. The results show no clear effect of the throughput either on the amount of fine particles nor on the number of short fibers after removal of the plastic matrix for all materials. Reducing the screen size in the cutting mill leads to a large increase in the amount of fine particles and on the number of short fiber fragments. Additionally, the rotational speed has a large impact on the amount of fine particles. With increasing rotational speed, the number of fine particles rises, whereas there is no major effect on the fiber length distribution. The investigations relating the rotational speed are valid for all materials, throughput, screen sizes and feedstock sizes. Decreasing the feedstock size leads to an increasing amount of fine particles with no change in fiber length distribution for the glass fiber‐reinforced organo sheets. For the carbon fiber‐reinforced materials, it does not lead to any change in the amount of fiber dust but to an increase in shorter fibers. Thus this parameter seems to be material dependent. Images taken by a scanning electron microscope show alveolar fiber dust fragments in the ground material of all samples.

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“…Whether these fibres are a health hazard to humans is currently under research. In the past, the research was focused mainly on fibres that have been treated mechanically ( Holt and Horne, 1978 ; Kehren et al, 2019 ; Martin et al, 1989 ; Mattenklott and Van Gelder, 2019 ; Mazumder et al, 1982 ; Schlagenhauf et al, 2015 ; Thomson et al, 1990 ; Wang et al, 2017 ). It is recommended for further investigations to focus on thermally treated fibre residues ( Kehren et al, 2019 ; Stapf, 2019 ).…”

Section: Introductionmentioning

confidence: 99%

Thermal treatment of carbon-fibre-reinforced polymers (Part 2: Energy recovery and feedstock recycling)

et al. 2021

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The use of carbon fibre (CF)-reinforced plastics has grown significantly in recent years, and new areas of application have been and are being developed. As a result, the amount of non-recyclable waste containing CF is also rising. There are currently no treatment methods for this type of waste. Within this project different approaches for the treatment of waste containing CF were investigated. Main subject of the research project were large-scale investigations on treatment possibilities and limits of waste containing CF in high temperature processes, with focus on the investigation of process-specific residues and possible fibre emission. The results showed that the two conventional thermal waste treatment concepts with grate and rotary kiln firing systems are not suitable for a complete oxidation of CFs due to the insufficient process conditions (temperature and dwell time). The CFs were mainly discharged via the bottom ash/slag. Due to the partial decomposition during thermal treatment, World Health Organization (WHO) fibres occurred in low concentrations. The tests run in the cement kiln plant have shown the necessity of comminution for waste containing CF. With respect to the short testing times and moderate quantities of inserted CF, a final evaluation of the suitability of this disposal path was not possible. The use of specially processed waste containing CF (carbon-fibre-reinforced plastic (CFRP) pellets) as a carbon substitute in calcium carbide production led to high carbon conversion rates. In the unburned furnace dust, which is marketed as a by-product of the process, CFs in relevant quantities could be detected.

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Release of Respirable Fibrous Dust from Carbon Fibers Due to Splitting along the Fiber Axis

Cited by 16 publications

References 20 publications

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Bloß kein zweites Asbest

Influence of process parameters on the formation of inhalable fiber dust during shredding for mechanical recycling of fiber‐reinforced organo sheets

Thermal treatment of carbon-fibre-reinforced polymers (Part 2: Energy recovery and feedstock recycling)

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