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Remko Akkerman - One of the best experts on this subject based on the ideXlab platform.
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shredding and sieving thermoplastic composite scrap method development and analyses of the Fibre Length distributions
Composites Part B-engineering, 2019Co-Authors: Guillaume Almire Vincent, Thomas A De Bruijn, Mohammed Iqbal Abdul Rasheed, Sebastiaan Wijskamp, Martin Van Drongelen, Remko AkkermanAbstract:Abstract Recycling of thermoplastic composites has attracted considerable attention in the recent years. Several recycling solutions include shredding scrap to centimetre-sized flakes to retain long Fibres, followed by a remanufacturing step that prevents Fibre breakage. Determining the exact Fibre Length distribution (FLD) for these routes is crucial, as it is of importance for the processibility of the material as well as the mechanical performance of the recycled parts. In this paper, novel analysis methods are introduced to calculate FLDs based on photographs of flakes. The reliability of the method and of the sampling was found to be high. The relation between flake size and FLD was studied, showing that offcut layup barely influences the FLD in comparison to flake size. The effects of shredding settings and sieving were studied, showing a strong correlation between machine parameters and FLD, whereas the offcut size was found to have no effect on FLD.
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Fibre Length distribution of shredded thermoplastic composite scrap
21st International Conference on Composite Materials 2017, 2017Co-Authors: Guillaume Almire Vincent, Thomas A De Bruijn, Mohammed Iqbal Abdul Rasheed, Sebastiaan Wijskamp, Remko AkkermanAbstract:Shredding is a crucial step when recycling thermoplastic composite waste. The outcome of this step can be in the form of flakes or particles of various size, which strongly depend on the chosen shredding solution and the material type. It was shown that the mechanical properties of a part manufactured with these flakes are influenced by the Fibre Length of those. Characterising the Length of Fibres in the flakes is therefore important to link it with mechanical properties [1]–[4]. Literature on characterising FLD in the case of large (a few centimetres) and multi-layered flakes is scarce. However, recycling solutions for these flake sizes exist [5], confirming the interest for this topic. In order to fill this gap, this paper firstly develops a method to determine the FLD of a batch of flakes and secondly investigates the effect of both process parameters and waste size on the FLD. The newly developed method is based on the image processing of flakes. Besides, the sampling process that is linked to the image processing method was found to be both repeatable and reproducible at a high precision, showing that batch-process recycling is robust with respect to the influence of sampling . Following that, ways to tailor the FLD were explored. It seems that the scrap size does not influence the FLD but blade width and screen size of the shredding machine largely govern this FLD.
J L Thomason - One of the best experts on this subject based on the ideXlab platform.
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the influence of Fibre Length diameter and concentration on the impact performance of long glass Fibre reinforced polyamide 6 6
Composites Part A-applied Science and Manufacturing, 2009Co-Authors: J L ThomasonAbstract:Abstract Results of an investigation of the mechanical performance of injection moulded long glass-Fibre reinforced polyamide 6,6 composites are presented. The glass-Fibre content in these composites was varied over the range of 10–50% by weight using Fibres with average diameters of 10, 14 and 17 μm. Impact testing was carried out at −40, 23 and 80 °C on dry-as-moulded and boiling water conditioned samples. The results from these long Fibre composites are compared with standard extrusion compounded short glass-Fibre materials. Data on the influence of Fibre diameter, Fibre concentration, residual Fibre Length, hydrothermal conditioning and testing temperature on the composite performance in notched and unnotched pendulum impact tests and multiaxial instrumented impact tests are presented and discussed. All of the above parameters are shown to have significant influence on impact performance. However, the level of these effects is shown to depend on which type of impact test is being considered.
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the influence of Fibre Length and concentration on the properties of glass Fibre reinforced polypropylene 7 interface strength and Fibre strain in injection moulded long Fibre pp at high Fibre content
Composites Part A-applied Science and Manufacturing, 2007Co-Authors: J L ThomasonAbstract:The mechanical performance of injection moulded long glass Fibre reinforced polypropylene with a glass Fibre content in the range 0-73% by weight has been investigated. The composite modulus exhibited a linear dependence on Fibre content over the full range of the study. Composite strength and impact resistance exhibited a maximum in performance in the 40-50% by weight reinforcement content range. The residual Fibre Length, average Fibre orientation, interfacial shear strength, and Fibre strain at composite failure in the samples have been characterised. These parameters were also found to be Fibre concentration dependent. The interfacial shear strength was found to be influenced by both physical and chemical contributions. Theoretical calculations of the composite strength using the measured micromechanical parameters enabled the observed maximum in tensile strength to be well modelled.
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Influence of Fibre Length and concentration on the properties of glass Fibre-reinforced polypropylene: 1. Tensile and flexural modulus
Composites Part A: Applied Science and Manufacturing, 1996Co-Authors: J L Thomason, M. A. VlugAbstract:In this report we present the results from the first part of a study on the influence of Fibre Length (0.1-50 mm) and concentration (3 60% w/w) on the properties of glass-reinforced polypropylene laminates. These laminates were prepared in the laboratory using a wet deposition method, and are compared with samples prepared on a commercial melt-impregnation GMT line. We found that laminate stiffness increased linearly with Fibre concentration up to 40% w/w. However, stiffness was virtually independent of Fibre Length above 0.5mm. Predictions of tensile modulus using the Cox model correlated well with the experimental data. High concentrations of long Fibres (>40% w/w) resulted in Fibre packing problems and an increase in void content which lead to a reduction in modulus. The matrix molecular weight and the Fibre-sizing compatibility had little effect on the laminate stiffness.
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influence of Fibre Length and concentration on the properties of glass Fibre reinforced polypropylene part 3 strength and strain at failure
Composites Part A-applied Science and Manufacturing, 1996Co-Authors: J L Thomason, M. A. Vlug, G Schipper, H G L T KrikorAbstract:Abstract In this report we present the results from the third part of a study on the influence of Fibre Length (0.1–50 mm) and concentration (3–60% w/w) on the properties of glass Fibre-reinforced polypropylene laminates. These laminates were prepared in the laboratory using a wet deposition method and compared with samples prepared on a commercial melt impregnation GMT line. We found that laminate tensile strength increased linearly with Fibre concentration up to 60% w/w. Laminate strength was also found to increase with increasing Fibre Length. At high values of Fibre Length (> 3–6 mm) the strength reached a plateau level which was directly dependent on Fibre content. The matrix molecular weight appeared to have little direct influence on the level of laminate strength. However, the glass Fibre sizing compatibility was found to have a strong effect on the tensile strength of both laboratory made wet deposited laminates and commercially prepared GMTs. The tensile strength of the GMT samples also showed a clear correlation with the measured Fibre strength. A modified version of the Kelly-Tyson model gave calculated values of laminate strength which correlated well with the experimental data. We propose that the tensile strength of these laminates is governed by the properties of the Fibres which have an orientation close to parallel with the loading direction.
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the influence of Fibre Length and concentration on the properties of glass Fibre reinforced polypropylene 2 thermal properties
Composites Part A-applied Science and Manufacturing, 1996Co-Authors: J L Thomason, W M GroenewoudAbstract:Abstract In this report we present the results from the second part of a study on the influence of Fibre Length and concentration on the properties of glass reinforced polypropylene laminates. The heat deflection temperature of these laminates is dependent on both Fibre Length and concentration. A maximum plateau level close to the polypropylene melting point was observed, longer Fibres require a lower concentration to attain this plateau value. Elevated temperature stiffness retention was also enhanced by higher Fibre concentration and longer Fibres. The Cox—Krenchel equations gave a good prediction of the laminate stiffness over the temperature range —50 to 100°C. Both the in-plane and out-of-plane linear coefficients of thermal expansion were strongly dependent on Fibre concentration but relatively insensitive to the Fibre Length. We obtained excellent correlation between experimental values of the in-plane linear coefficients of thermal expansion and theoretical predictions based on the shear lag theory. Out-of-plane linear coefficients of thermal expansion were found to be much larger than predicted by the equations used for continuous Fibre reinforced composites. An approach based on the in-plane compression of the matrix due to the restriction of the matrix expansion by the reinforcing Fibres was found to give good agreement with the experimental data. Good correlation of the experimental and predicted data was only obtained when the effect of voids was included in the calculations
Guillaume Almire Vincent - One of the best experts on this subject based on the ideXlab platform.
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shredding and sieving thermoplastic composite scrap method development and analyses of the Fibre Length distributions
Composites Part B-engineering, 2019Co-Authors: Guillaume Almire Vincent, Thomas A De Bruijn, Mohammed Iqbal Abdul Rasheed, Sebastiaan Wijskamp, Martin Van Drongelen, Remko AkkermanAbstract:Abstract Recycling of thermoplastic composites has attracted considerable attention in the recent years. Several recycling solutions include shredding scrap to centimetre-sized flakes to retain long Fibres, followed by a remanufacturing step that prevents Fibre breakage. Determining the exact Fibre Length distribution (FLD) for these routes is crucial, as it is of importance for the processibility of the material as well as the mechanical performance of the recycled parts. In this paper, novel analysis methods are introduced to calculate FLDs based on photographs of flakes. The reliability of the method and of the sampling was found to be high. The relation between flake size and FLD was studied, showing that offcut layup barely influences the FLD in comparison to flake size. The effects of shredding settings and sieving were studied, showing a strong correlation between machine parameters and FLD, whereas the offcut size was found to have no effect on FLD.
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Fibre Length distribution of shredded thermoplastic composite scrap
21st International Conference on Composite Materials 2017, 2017Co-Authors: Guillaume Almire Vincent, Thomas A De Bruijn, Mohammed Iqbal Abdul Rasheed, Sebastiaan Wijskamp, Remko AkkermanAbstract:Shredding is a crucial step when recycling thermoplastic composite waste. The outcome of this step can be in the form of flakes or particles of various size, which strongly depend on the chosen shredding solution and the material type. It was shown that the mechanical properties of a part manufactured with these flakes are influenced by the Fibre Length of those. Characterising the Length of Fibres in the flakes is therefore important to link it with mechanical properties [1]–[4]. Literature on characterising FLD in the case of large (a few centimetres) and multi-layered flakes is scarce. However, recycling solutions for these flake sizes exist [5], confirming the interest for this topic. In order to fill this gap, this paper firstly develops a method to determine the FLD of a batch of flakes and secondly investigates the effect of both process parameters and waste size on the FLD. The newly developed method is based on the image processing of flakes. Besides, the sampling process that is linked to the image processing method was found to be both repeatable and reproducible at a high precision, showing that batch-process recycling is robust with respect to the influence of sampling . Following that, ways to tailor the FLD were explored. It seems that the scrap size does not influence the FLD but blade width and screen size of the shredding machine largely govern this FLD.
Susanne H Wolf - One of the best experts on this subject based on the ideXlab platform.
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asbestos Fibre dimensions and lung cancer mortality among workers exposed to chrysotile
Occupational and Environmental Medicine, 2010Co-Authors: Dana Loomis, John M. Dement, David B Richardson, Susanne H WolfAbstract:Objectives To estimate exposures to asbestos Fibres of specific sizes among asbestos textile manufacturing workers exposed to chrysotile using data from transmission electron microscopy (TEM) and to evaluate the extent to which the risk of lung cancer varies with Fibre Length and diameter. Methods 3803 workers employed for at least 1 day between 1 January 1950 and 31 December 1973 in any of three plants in North Carolina, USA that produced asbestos textile products and followed for vital status through 31 December 2003 were included. Historical exposures to asbestos Fibres were estimated from work histories and 3578 industrial hygiene measurements taken in 1935–1986. Exposure–response relationships for lung cancer were examined within the cohort using Poisson regression. Results Indicators of Fibre Length and diameter obtained by TEM were positively and significantly associated with increasing risk of lung cancer. Exposures to longer and thinner Fibres tended to be most strongly associated with lung cancer, and models for these Fibres fit the data best. Simultaneously modelling indicators of cumulative mean Fibre Length and diameter yielded a positive coefficient for Fibre Length and a negative coefficient for Fibre diameter. Conclusions The results support the hypothesis that the risk of lung cancer among workers exposed to chrysotile asbestos increases with exposure to longer Fibres. More research is needed to improve the characterisation of exposures by Fibre size and number and to analyse the associated risks in a variety of industries and populations.
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asbestos Fibre dimensions and lung cancer mortality among workers exposed to chrysotile
Occupational and Environmental Medicine, 2010Co-Authors: Dana Loomis, John M. Dement, David B Richardson, Susanne H WolfAbstract:Objectives To estimate exposures to asbestos Fibres of specific sizes among asbestos textile manufacturing workers exposed to chrysotile using data from transmission electron microscopy (TEM) and to evaluate the extent to which the risk of lung cancer varies with Fibre Length and diameter. Methods 3803 workers employed for at least 1 day between 1 January 1950 and 31 December 1973 in any of three plants in North Carolina, USA that produced asbestos textile products and followed for vital status through 31 December 2003 were included. Historical exposures to asbestos Fibres were estimated from work histories and 3578 industrial hygiene measurements taken in 1935–1986. Exposure–response relationships for lung cancer were examined within the cohort using Poisson regression. Results Indicators of Fibre Length and diameter obtained by TEM were positively and significantly associated with increasing risk of lung cancer. Exposures to longer and thinner Fibres tended to be most strongly associated with lung cancer, and models for these Fibres fit the data best. Simultaneously modelling indicators of cumulative mean Fibre Length and diameter yielded a positive coefficient for Fibre Length and a negative coefficient for Fibre diameter. Conclusions The results support the hypothesis that the risk of lung cancer among workers exposed to chrysotile asbestos increases with exposure to longer Fibres. More research is needed to improve the characterisation of exposures by Fibre size and number and to analyse the associated risks in a variety of industries and populations.
N Horiba - One of the best experts on this subject based on the ideXlab platform.
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effects of Fibre Length on tensile strength of carbon glass Fibre hybrid composites
Journal of Materials Science, 1994Co-Authors: Minoru Miwa, N HoribaAbstract:The tensile strength of epoxy resin reinforced with random-planar orientation of short carbon and glass Fibres increased as the Length of the reinforcing Fibres increased, and the increase in tensile strength remained almost unchanged after the Fibre Length reached a certain level. The tensile strength of composites at any Fibre Length could be estimated by taking the strain rate and temperature dependence of both the yield shear strength at the Fibre-matrix interphase and the mean critical Fibre Length into consideration. The tensile strength of the hybrid composite could be estimated by the additive rule of hybrid mixtures, using the tensile strength of both composites.