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Investigations on the Manufacturing and Mechanical Properties of Spun Yarns Made from Staple CF for Thermoset Composites

Hasan M. M. B., Hengstermann M., Dilo R., Abdkader A., Cherif C.

Autex Research Journal

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2017

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Vol. 17, no. 4

395--404

EN

This article reports the results of investigations carried out to produce yarns consisting of staple carbon fiber (CF) obtained from process waste for the manufacturing of composites suitable especially for thermoset applications. For this purpose, a comparative analysis is done on processability between 100% staple CF and 60 weight% staple CF mixed with 40 weight% PVA fibers in carding, drawing and spinning process. The hybrid yarns are produced by varying twist level. The PVA fibers of the hybrid yarn are then dissolved using hot water treatment. The mechanical properties of yarns consisting of 100% staple CF and hybrid yarns consisting of staple CF and PVA before and after hot water treatment are investigated. Furthermore, test specimen is also prepared by impregnating 100% staple CF yarn and the hybrid yarns (after the dissolving of PVA) with epoxy resin. The results of the tensile test of the yarns in consolidated state reveals that the hybrid yarn produced with 80 T/m after hot water treatment exhibits approximately 75% of the tensile strength of virgin filament tow, and it is expected that the hybrid yarns can be applied for the manufacturing of thermoset based composites for load bearing structures.

2

Influence of Fibre Length and Preparation on Mechanical Properties of Carbon Fibre/Polyamide 6 Hybrid Yarns and Composites

Hengstermann M., Hasan M. M. B., Abdkader A., Cherif C.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 5 (119)

55--62

EN

The aim of this paper was to investigate the effect of carbon fibre (CF) length and preparation prior to carding on the mechanical properties of hybrid yarns as well as composites consisting of CF and polyamide 6 (PA 6). The hybrid yarns are manufactured using an optimised process route of carding and drawing with a flyer machine from virgin staple CF (40/60/80/100 mm) and PA 6. In order to explore the effect of fibre preparation on the mechanical properties of hybrid yarns as well as composites, virgin staple CF and PA 6 fibres were prepared by varying the mixing type prior to the carding process. For this purpose, the fibres were mixed either by a fibre-opening device or supplied directly to the carding machine without prior mixing. The CF content of the card webs produced is kept at 50 volume %. Hybrid yarns were produced with a twist of 102 twist/m and then thermoplastic uni-directional (UD) composites were manufactured from them. The investigations revealed the influence of the input CF length and mixing type on the mechanical properties of hybrid yarns and thermoplastic UD composites.

PL

Celem badań było stwierdzenie wpływu długości włókien węglowych i ich obróbki przed zgrzebleniem na mechaniczne właściwości przędz hybrydowych/włókno węglowe /poliamid 6/ jak również kompozytów z nich wykonanych. Zmieniano skład mieszanki przed zgrzebleniem. Włókna mieszano lub dostarczano bezpośrednio do zgrzeblenia. Zastosowano zoptymalizowany proces zgrzeblenia i rozciągania z użyciem niedoprzędzarki. Przędze hybrydowe posiadały skręt 102 skręty/m. Z przędz hybrydowych produkowano termoplastyczne kompozyty „jednokierunkowe”. Badania wykazały wpływ parametrów wejściowych na końcowe właściwości kompozytów.

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Development of a Method for Characterization of the Fibre Length of Long Staple Carbon Fibres Based on Image Analysis

Hengstermann M., Bardl G., Rao H., Abdkader A., Badrul Hasan M. M., Cherif C.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 4 (118)

39--44

EN

For the manufacturing of load-bearing carbon fibre reinforced plastics (CFRP) made from staple carbon fibres (CF) , statements of the CF fibre length in the composite are essential. However, no suitable fibre length measuring method is currently available for long staple CF over 60 mm. The aim of this study is the development of an effective method for characterization of the fibre length distribution of long staple CF. For this method, a fibre beard specimen is extracted from a sliver manufactured from 80 mm staple CF, which is then scanned. Greyscale values densities (GD) of the individual length classes are determined from the scanned images, which correspond to the number of fibres per length class. From the proportion of all length classes, a span length diagram and staple fibre length diagram can be compiled. The results show the good potential of the method developed for the fibre length measurement of long staple CF.

PL

Dla wytwarzania kompozytów ze wzmocnieniem włókien węglowych bardzo ważna jest znajomość rozkładu długości tych włókien. Niestety, jak dotychczas nie istniały odpowiednie metody pomiarowe pozwalające charakteryzować włókna odcinkowe o długościach powyżej 60 mm. Celem pracy była analiza istniejących metod pomiarowych oraz opracowanie metody, która umożliwiłaby satysfakcjonujące rozwiązanie tego zagadnienia. Zostały przedstawione zasady działania tej metody oraz uzyskana dokładność pomiarów.