Vacuum Infusion

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Rohit Shenoi - One of the best experts on this subject based on the ideXlab platform.

  • a cure modelling study of an unsaturated polyester resin system for the simulation of curing of fibre reinforced composites during the Vacuum Infusion process
    Journal of Composite Materials, 2015
    Co-Authors: A Aktas, S W Boyd, Latha Krishnan, Baljinder K Kandola, Rohit Shenoi
    Abstract:

    This study presents the cure kinetics and cure modelling of an ambient curing unsaturated polyester (UP) resin system for its cure simulation in the Vacuum Infusion (VI) process. The curing of the UP resin system was investigated using differential scanning calorimetry (DSC). The dynamic DSC test measurements were conducted to find out the ultimate heat of reaction and enable experimental conversion determination for the isothermal curing. The empirical autocatalytic cure kinetics model incorporating the Arrhenius law represented the cure behaviour. The results of the cure kinetics study, the cure model, the material properties and the boundary conditions were the inputs in PAM-RTM software for the simulation of the degree of cure and the exothermic temperature during the Infusion and the room temperature curing stages. The simulation results were compared with experimentally measured data. A Vacuum Infusion (VI) experiment involving a non-crimp glass fibre preform was performed in order to monitor the curing using thermocouples and validate the temperature simulation result. It was shown that the degree of cure and the exothermic temperature of a room temperature curing thermoset resin system during the VI process could be predicted through the steps of this study.

  • cure and strain monitoring of novel unsaturated polyester phenolic resin blends in the Vacuum Infusion process using fibre bragg gratings
    Journal of Composite Materials, 2015
    Co-Authors: A Aktas, S W Boyd, Rohit Shenoi
    Abstract:

    In recent years, a few research studies have been published on the blending of unsaturated polyester and phenolic resins for the purpose of improving the fire properties of unsaturated polyester resins. However, there has been no published study on the cure and strain monitoring of unsaturated polyester/phenolic blends during composite manufacturing. In this study, non-crimp triaxial glass fabric preforms were infused with the unsaturated polyester/phenolic blends, and the strain developments inside the composites were monitored using fibre Bragg grating sensors, as the long and complex curing stages were progressing at different temperatures. Strain-free fibre Bragg grating sensors and also thermocouples were utilised for temperature monitoring and compensation in order to obtain true strain developments and residual strains. The results were associated with a study presenting the cure analyses of unsaturated polyester/phenolic blends. The unsaturated polyester and the phenolics were found to be incompatible and exhibited different curing mechanisms in the blends, which were also observable in the strain development results. This paper has been the first attempt to (i) process these novel resin systems in the Vacuum Infusion process and (ii) monitor the long, complex and high-temperature cure cycles and the strain developments in the Vacuum Infusion process using fibre Bragg gratings.

  • Cure and strain monitoring of novel unsaturated polyester/phenolic resin blends in the Vacuum Infusion process using fibre Bragg gratings
    Journal of Composite Materials, 2015
    Co-Authors: Abdurrazzak Aktas, S. Boyd, Rohit Shenoi
    Abstract:

    In recent years, a few research studies have been published on the blending of unsaturated polyester and phenolic resins for the purpose of improving the fire properties of unsaturated polyester resins. However, there has been no published study on the cure and strain monitoring of unsaturated polyester/phenolic blends during composite manufacturing. In this study, non-crimp triaxial glass fabric preforms were infused with the unsaturated polyester/phenolic blends, and the strain developments inside the composites were monitored using fibre Bragg grating sensors, as the long and complex curing stages were progressing at different temperatures. Strain-free fibre Bragg grating sensors and also thermocouples were utilised for temperature monitoring and compensation in order to obtain true strain developments and residual strains. The results were associated with a study presenting the cure analyses of unsaturated polyester/phenolic blends. The unsaturated polyester and the phenolics were found to be incompatible and exhibited different curing mechanisms in the blends, which were also observable in the strain development results. This paper has been the first attempt to (i) process these novel resin systems in the Vacuum Infusion process and (ii) monitor the long, complex and high-temperature cure cycles and the strain developments in the Vacuum Infusion process using fibre Bragg gratings.

Murat E Sozer - One of the best experts on this subject based on the ideXlab platform.

  • effect of permeability characterization at different boundary and flow conditions on Vacuum Infusion process modeling
    Journal of Reinforced Plastics and Composites, 2017
    Co-Authors: Akif M Yalcinkaya, Baris Caglar, Murat E Sozer
    Abstract:

    Permeability characterization of a fabric preform is a key factor that affects the accuracy of process modeling of Vacuum Infusion. There are various flow types and boundary conditions (such as one...

  • modeling of post filling stage in Vacuum Infusion using compaction characterization
    Journal of Composite Materials, 2015
    Co-Authors: Baris Caglar, Bekir Yenilmez, Murat E Sozer
    Abstract:

    Two-dimensional finite-element method solution of the post-filling stage of Vacuum Infusion was studied based on mass conservation in an infinitesimal control volume. First, resin pressure distribution at the instant of mold filling was calculated and then used as the initial condition for the transient post-filling stage. Explicit time-marching algorithm was used for the evolution of resin pressure and part thickness, and its stability was ensured by selecting the time step adaptively. Finite-element method solution was verified analytically for one-dimensional case and numerically for two-dimensional cases using global mass conservation. The time that it took for the settlement of pressure and thickness was investigated to compare the effectiveness of different resin-bleeding scenarios where different number and locations of gates were used. It was shown that the settlement time increased exponentially as the dimensions of the mold increased, which proved that process simulation fed with correctly desig...

  • effect of part thickness variation on the mold filling time in Vacuum Infusion process
    Journal of Reinforced Plastics and Composites, 2014
    Co-Authors: Akif M Yalcinkaya, Murat E Sozer
    Abstract:

    An experimental setup was used to fairly compare mold filling times in Vacuum Infusion and resin transfer molding, and a 9.5% shorter mold filling time in Vacuum Infusion was observed than in resin transfer molding. The setup was also used to conduct compaction and permeability characterization experiments, and the results were used in a simplified Vacuum Infusion model, which is more straightforward to solve than the conventional full and coupled models in the literature. Simulated filling time in Vacuum Infusion was 31% shorter than in resin transfer molding. The faster resin flow in Vacuum Infusion is explained by the fact that the thickness in the wetted upstream region increases with time, and thus the effective permeability in that region increases.

  • variation of part thickness and compaction pressure in Vacuum Infusion process
    Composites Science and Technology, 2009
    Co-Authors: Bekir Yenilmez, Murat Senan, Murat E Sozer
    Abstract:

    Abstract In Vacuum Infusion (VI), it is difficult to manufacture a composite part with small dimensional tolerances, since the thickness of the part changes during resin injection. This change of thickness is due to the effect of varying compaction pressure on the upper mold part, a Vacuum bag. In this study, random fabric layers with an embedded core distribution medium is used. The thickness of the composite part and resin pressure are monitored using multiple dial gages and pressure transducers; the results are compared with the model developed by Correia et al. [Correia NC, Robitaille F, Long AC, Rudd CD, Simacek P, Advani SG. Analysis of the Vacuum Infusion molding process: I. Analytical formulation. Composites Part A: Applied Science and Manufacturing 26, 2005. p. 1645–1656]. To use this model, two material characteristics databases are constructed based on the process parameters: (i) the thickness of a dry/wet fabric preform at different compaction pressures, and (ii) the permeability of the preform at different thicknesses. The dry-compacted preform under Vacuum is further compacted due to fiber settling in wet form after resin reaches there; the part thickens afterwards as the resin pressure increases locally. The realistic model solution can be achieved only if the compaction characterization experiments are performed in such a way that the fabric is dry during loading, and wet during unloading, as in the actual resin Infusion process. The model results can be used to design the process parameters such as Vacuum pressure and locations of injection and ventilation tubes so that the dimensional tolerances can be kept small.

  • compaction of e glass fabric preforms in the Vacuum Infusion process a characterization experiments
    Composites Part A-applied Science and Manufacturing, 2009
    Co-Authors: Bekir Yenilmez, Murat E Sozer
    Abstract:

    An experimental procedure was designed to realistically characterize the compaction behavior of e-glass fabric preforms during initial application of Vacuum and mold filling stages of Vacuum Infusion (VI). To mimic VI, the loading (compaction) was done on a dry preform, and the unloading (decompaction) was done after the preform was saturated with resin. When fabrics were wetted at constant full compaction pressure, a significant decrease in thickness was observed for the random fabric, but not for woven and biaxial fabrics. The rate of change of thickness, ∂h/∂t had different signs and order of magnitudes when various constant compaction pressures were applied during fiber relaxation stage. Thus, previous compaction-mold filling models based on static relationship between thickness and compaction pressure do not appropriately simulate the compaction physics of VI. Time-dependent database of this study is a useful and straightforward tool to model VI, as demonstrated in Part B of this study.

A Aktas - One of the best experts on this subject based on the ideXlab platform.

  • a cure modelling study of an unsaturated polyester resin system for the simulation of curing of fibre reinforced composites during the Vacuum Infusion process
    Journal of Composite Materials, 2015
    Co-Authors: A Aktas, S W Boyd, Latha Krishnan, Baljinder K Kandola, Rohit Shenoi
    Abstract:

    This study presents the cure kinetics and cure modelling of an ambient curing unsaturated polyester (UP) resin system for its cure simulation in the Vacuum Infusion (VI) process. The curing of the UP resin system was investigated using differential scanning calorimetry (DSC). The dynamic DSC test measurements were conducted to find out the ultimate heat of reaction and enable experimental conversion determination for the isothermal curing. The empirical autocatalytic cure kinetics model incorporating the Arrhenius law represented the cure behaviour. The results of the cure kinetics study, the cure model, the material properties and the boundary conditions were the inputs in PAM-RTM software for the simulation of the degree of cure and the exothermic temperature during the Infusion and the room temperature curing stages. The simulation results were compared with experimentally measured data. A Vacuum Infusion (VI) experiment involving a non-crimp glass fibre preform was performed in order to monitor the curing using thermocouples and validate the temperature simulation result. It was shown that the degree of cure and the exothermic temperature of a room temperature curing thermoset resin system during the VI process could be predicted through the steps of this study.

  • cure and strain monitoring of novel unsaturated polyester phenolic resin blends in the Vacuum Infusion process using fibre bragg gratings
    Journal of Composite Materials, 2015
    Co-Authors: A Aktas, S W Boyd, Rohit Shenoi
    Abstract:

    In recent years, a few research studies have been published on the blending of unsaturated polyester and phenolic resins for the purpose of improving the fire properties of unsaturated polyester resins. However, there has been no published study on the cure and strain monitoring of unsaturated polyester/phenolic blends during composite manufacturing. In this study, non-crimp triaxial glass fabric preforms were infused with the unsaturated polyester/phenolic blends, and the strain developments inside the composites were monitored using fibre Bragg grating sensors, as the long and complex curing stages were progressing at different temperatures. Strain-free fibre Bragg grating sensors and also thermocouples were utilised for temperature monitoring and compensation in order to obtain true strain developments and residual strains. The results were associated with a study presenting the cure analyses of unsaturated polyester/phenolic blends. The unsaturated polyester and the phenolics were found to be incompatible and exhibited different curing mechanisms in the blends, which were also observable in the strain development results. This paper has been the first attempt to (i) process these novel resin systems in the Vacuum Infusion process and (ii) monitor the long, complex and high-temperature cure cycles and the strain developments in the Vacuum Infusion process using fibre Bragg gratings.

  • monitoring and simulation of the Vacuum Infusion process
    2013
    Co-Authors: A Aktas, Stephen Boyd, Ajit Shenoi
    Abstract:

    The Vacuum Infusion (VI) is a relatively cheap composite manufacturing process which is widely used for the manufacturing of large scale structures in a number of industries, in particular the aerospace, marine and wind turbine industries. The process has to be monitored in order to ensure the quality of the final products. In this study, a monitoring setup involving relatively cheap thermocouples is utilised for the purpose of monitoring of the novel fire retardant resin systems in the VI process. The setup provides a number of variables to be used in the simulation of the Vacuum Infusion process using PAM-RTM software

Ica Manaszloczower - One of the best experts on this subject based on the ideXlab platform.

  • a sustainable alternative to current epoxy resin matrices for Vacuum Infusion molding
    Composites Part A-applied Science and Manufacturing, 2017
    Co-Authors: Anthony Maiorana, Ammar Patel, Richard A Gross, Ica Manaszloczower
    Abstract:

    Abstract Biobased diglycidyl ethers of diphenolate (DGEDP) and monoglycidyl ether of eugenol (GE) were synthesized and formulated as new type of biobased epoxy resins for Vacuum Infusion processing with glass fiber mats. The processability of these new biobased formulations were benchmarked against two diglycidyl ether bisphenol A (DGEBA) petroleum based resins. Compositions with 15 wt% GE and 85 wt% of either DGEDP-ethyl or pentyl esters resulted in suitably viscosity and gelation time for composite Vacuum Infusion processing whilst maintaining and in some cases exceeding the mechanical and thermal properties of the petroleum based systems. This work indicates the excellent potential of using biobased epoxy resins as sustainable alternatives to the traditional petroleum based epoxy resins for engineering applications.

Santina Romani - One of the best experts on this subject based on the ideXlab platform.

  • effect of pulsed electric field coupled with Vacuum Infusion on quality parameters of frozen thawed strawberries
    Journal of Food Engineering, 2018
    Co-Authors: Elena Velickova, Urszula Tylewicz, Marco Dalla Rosa, Eleonora Winkelhausen, Slobodanka Kuzmanova, Santina Romani
    Abstract:

    Abstract In this study, pulsed electric field (PEF) was coupled with Vacuum Infusion (VI) to impregnate strawberries with cryoprotectants. Electroporation of fruits was reached with 5 bi-polar, rectangular pulses of 100 μs width with a nominal electric field strength of 850 V/cm. After PEF treatment, the strawberries were Vacuum infused with a cryoprotective solution (12 g/100 g trehalose and 0.2 g/100 g acclimated winter wheat extract containing antifreeze proteins) for 14 min. The strawberries were frozen in liquid nitrogen and thawed in air at 20 °C. Cell survival, texture and color were evaluated before and after freezing and thawing cycle. The fruit pre-treated with PEF prior to VI exhibited higher cell viability in epidermal layer and 30% more red color retention compared to just VI samples. However, no further improvement on strawberry quality in terms of drip loss and texture was observed upon the application of PEF.

  • Effect of pulsed electric field coupled with Vacuum Infusion on quality parameters of frozen/thawed strawberries
    Journal of Food Engineering, 2018
    Co-Authors: Elena Velickova, Urszula Tylewicz, Marco Dalla Rosa, Eleonora Winkelhausen, Slobodanka Kuzmanova, Santina Romani
    Abstract:

    Abstract In this study, pulsed electric field (PEF) was coupled with Vacuum Infusion (VI) to impregnate strawberries with cryoprotectants. Electroporation of fruits was reached with 5 bi-polar, rectangular pulses of 100 μs width with a nominal electric field strength of 850 V/cm. After PEF treatment, the strawberries were Vacuum infused with a cryoprotective solution (12 g/100 g trehalose and 0.2 g/100 g acclimated winter wheat extract containing antifreeze proteins) for 14 min. The strawberries were frozen in liquid nitrogen and thawed in air at 20 °C. Cell survival, texture and color were evaluated before and after freezing and thawing cycle. The fruit pre-treated with PEF prior to VI exhibited higher cell viability in epidermal layer and 30% more red color retention compared to just VI samples. However, no further improvement on strawberry quality in terms of drip loss and texture was observed upon the application of PEF.