Transverse flow processes in continuous fibre-reinforced thermoplastic composites

Barnes, J.A.; Cogswell, F.N.

doi:10.1016/0010-4361(89)90680-0

Cited by 80 publications

(26 citation statements)

References 2 publications

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“…Initially, only layers of fibres closest to the moving platen displace, with resistance coming primarily from fibre-fibre friction between this and the next layer. However, as the applied strain increases, fibre twisting and entanglement, as depicted by Barnes and Cogswell, [23] leads to successive layers being forced into motion, resulting in increased frictional resistance.…”

Section: Introductionmentioning

confidence: 99%

Insights into complex rheological behaviour of carbon fibre/PEEK from a novel numerical methodology incorporating fibre friction and melt viscosity

Deignan

Figiel

McCarthy

2018

Composite Structures

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Section: Introductionmentioning

confidence: 99%

Insights into complex rheological behaviour of carbon fibre/PEEK from a novel numerical methodology incorporating fibre friction and melt viscosity

Deignan

Figiel

McCarthy

2018

Composite Structures

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“…Initially, only layers of fibres closest to the moving platen displace, with resistance coming primarily from fibre-to-fibre friction between this and the next layer. However, as the applied strain increased, fibre twisting and entanglement, as depicted by Barnes and Cogswell, 25 would have led to successive layers being forced into motion, leading to increasing frictional resistance. This translates into the increase in viscosity with strain magnitude, observed in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Insights into wide variations in carbon fibre/polyetheretherketone rheology data under automated tape placement processing conditions

Deignan

Stanley

McCarthy

2017

Journal of Composite Materials

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Although carbon fibre/polyetheretherketone has been extensively characterised, literature reveals large variations in reported values of melt viscosity. Partly due to this lack of clarity, process models of carbon fibre/polyetheretherketone during automated tape placement tend to be overly simplistic, often assuming Newtonian behaviour, even though this is completely at odds with experimental data. This paper seeks to provide insight into why these wide variations exist, via rheological characterisation, utilising a novel single-ply test method to eliminate inter-ply slip. Several previously unreported and non-intuitive trends are found, e.g. shear viscosity increases with temperature, depends significantly on applied pressure, and increases substantially with time, even in an inert atmosphere. The results here, and in the literature, are explainable if carbon fibre/polyetheretherketone melt is regarded as a yield-stress fluid in which boundary-lubricated, fibre-to-fibre friction determines the viscosity at low strain rates. Additionally, shear banding can occur at low strain rates, if pressure and strain magnitude are low, significantly affecting the results obtained.

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“…8 Poly(aryl-ether-ether-ketone) (PEEK) is a thermoplastic polymer widely used in automobile and aerospace industries and has an increasing number of applications. 9 The pyrolysis mechanism of PEEK has been extensively studied using techniques such as thermal gravimetric analysis (TGA), [10][11][12] TGA/MS/ MS, 13 Py/FTIR 14,15 and recently TGA/MS and Py/GC/ MS 16 for the purpose of evaluating their thermal stability at high temperatures. The detailed degradation mechanism of PEEK is not yet clear owing to the complexity of the pyrogram, although comprehensive reviews of the thermal degradation mechanism were reported previously.…”

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confidence: 99%

A study of thermal degradation of poly(aryl-ether-ether-ketone) using stepwise pyrolysis/gas chromatography/mass spectrometry

Tsai

Perng

Ling

1997

Rapid Commun. Mass Spectrom.

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Thermal degradation of poly(aryl-ether-ether-ketone) (PEEK) was investigated using stepwise pyrolysis/gas chromatography/mass spectrometry (Py/GC/MS) by consecutively heating the sample at fixed temperature intervals to achieve narrow temperature pyrolysis conditions. The individual mass chromatograms of the various pyrolysis products were correlated with the pyrolysis temperature in order to elucidate the pyrolysis mechanism. 4-Phenoxyphenol and 1,4-diphenoxybenzene were detected at 450°C, indicating that the degradation of PEEK was initiated by selective cleavage at chain ends and chain branches. Phenol was detected as the major pyrolysis product by further pyrolysis to 650 °C, which was attributed to the random main chain cleavage of ether groups. At temperatures above 650 °C, chain cleavage at carbonyl ends became the dominant pyrolysis pathway. The high char yield suggested that random main chain scission was accompanied by carbonization. Carbonization was presumably the dominant pyrolysis mechanism at temperatures above 750°C. Results obtained with the new method indicate the interesting potentials of the technique for the investigation of polymeric materials. © 1997 John Wiley & Sons, Ltd. Received 15 August 1997; Revised 17 October 1997; Accepted 20 October 1997 Rapid Commun. Mass Spectrom. 11, 1987-1995(1997 Pyrolysis uses heat alone to break down large molecules into molecules of lower mass due to thermal fission and, occasionally, of higher mass due to intermolecular reaction. The nature of the fragmentation and recombination products is determined largely by the heating parameters and ambient conditions. The analysis of pyrolysis products (pyrolysates) thus provides an alternative means to study polymeric and complex materials that are not suitable for direct analysis by popular techniques such as chromatography and mass spectrometry. From an analytical viewpoint, the applications of analytical pyrolysis are limited by the complexity of the pyrolysates. As a result, the integration of pyrolysis with Fourier transform infrared spectroscopy (Py/FTIR), mass spectrometry (Py/MS), and gas chromatography (Py/GC) is necessary for the routine analysis of polymeric and complex materials. Py/MS offers the advantages of the speed of analysis, the ease of automated data processing, and the richness in chemical information. Py/GC is capable of separating isomers and is a useful tool for quantitative analysis. The integration of pyrolysis with GC/MS (Py/GC/MS) could therefore provide additional sensitivity and selectivity, and extend the application fields of pyrolysis.

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Transverse flow processes in continuous fibre-reinforced thermoplastic composites

Cited by 80 publications

References 2 publications

Insights into complex rheological behaviour of carbon fibre/PEEK from a novel numerical methodology incorporating fibre friction and melt viscosity

Insights into complex rheological behaviour of carbon fibre/PEEK from a novel numerical methodology incorporating fibre friction and melt viscosity

Insights into wide variations in carbon fibre/polyetheretherketone rheology data under automated tape placement processing conditions

A study of thermal degradation of poly(aryl-ether-ether-ketone) using stepwise pyrolysis/gas chromatography/mass spectrometry

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