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R. M. Nussbaum - One of the best experts on this subject based on the ideXlab platform.

  • Oxidative activation of wood surfaces by Flame Treatment
    Wood Science and Technology, 1993
    Co-Authors: R. M. Nussbaum
    Abstract:

    The effects of an oxidative activation of some different wood surfaces by Flame Treatment has been studied. Flame Treatment markedly increased the wettability and decreased the microbiological activity. No improvement in glue adhesion was discerned for a water-borne PVAc-glue. ESCA measurements showed a considerable increase in oxidation level as a result of the Flame Treatment. The duration of the activation varied between different wood species.

  • Oxidative activation of wood surfaces by Flame Treatment
    Wood Science and Technology, 1993
    Co-Authors: R. M. Nussbaum
    Abstract:

    The effects of an oxidative activation of some different wood surfaces by Flame Treatment has been studied. Flame Treatment markedly increased the wettability and decreased the microbiological activity. No improvement in glue adhesion was discerned for a water-borne PVAc-glue. ESCA measurements showed a considerable increase in oxidation level as a result of the Flame Treatment. The duration of the activation varied between different wood species.

Qitai Eri - One of the best experts on this subject based on the ideXlab platform.

  • Normal spectral emissivity of GH536 (HastelloyX) in three surface conditions
    Applied Thermal Engineering, 2017
    Co-Authors: Bo Kong, Qitai Eri
    Abstract:

    Abstract The normal spectral emissivity of GH536, a nickel-based superalloy, is measured using a FT-IR spectrometer in the wavelength range 1–15 μm at moderate and high temperature (400–1200 K), as well as the samples with partially oxidized and Flame Treatment processed. It is found that the emissivity of GH536 decreases with the increasing of emission wavelength, which is well predicted by the electromagnetic wave theory, and increases linearly when the temperature rises. The emissivity of the other two samples with partially oxidized and Flame Treatment processed is also investigated in details. The results of the partially oxidized sample indicate that oxidation can enhance the emissivity significantly and alter the wavelength dependence trend. And the results of the Flame Treatment processed sample shows that the impurities and defects caused by the fire Treatment process moderately increase the emissivity. The experimental data of GH536 is compared with the results calculated using Hagen-Rubens equation, which shows an inconsistence at high temperature condition. Therefore, a modified emissivity model is proposed, which has a good agreement in measured wavelength range at moderate and high temperature condition.

  • Normal spectral emissivity measurement on five aeronautical alloys
    Journal of Alloys and Compounds, 2017
    Co-Authors: Bo Kong, Ting Li, Qitai Eri
    Abstract:

    Aeronautical alloys have a good performance on resisting oxidization, corrosion and fatigue in high temperature environments. Therefore, they are not only widely employed in aero-engine but also in nuclear and petroleum industries. The normal spectral emissivity of five alloys in the wavelength ranging 1–15��μm�at moderate and high temperature (400–1200�K) is measured. It is found that the emissivity decreases with the increasing of wavelength and increases when temperature rises. The effects of oxidation and Flame Treatment process are also studied. The results of the oxidized samples indicate that oxidation can enhance the emissivity significantly and alter the wavelength dependent trend. The results of the Flame Treatment processed samples show that the impurities and defects caused by the Flame Treatment process moderately increase the emissivity. The experimental data presented in this paper can be used directly to improve the accuracy of radiation computation and other relevant applications.

David J Neivandt - One of the best experts on this subject based on the ideXlab platform.

  • surface Treatments of wood plastic composites wpcs to improve adhesion
    Journal of Adhesion Science and Technology, 2006
    Co-Authors: William M Gramlich, Douglas J. Gardner, David J Neivandt
    Abstract:

    In an effort to improve the adhesive bonding between wood–plastic composites (WPCs) formulated with polypropylene and a commercial epoxy adhesive, surface Treatments were performed to chemically and/or physically modify the surface of WPCs. The Treatments were performed on extruded WPC that had been planed and consisted of chromic acid Treatment, Flame Treatment, water Treatment, Flame then water Treatment and water then Flame Treatment. The strength of the adhesive bonds of the treated samples was tested following ASTM D 905 and the maximum shear stress was calculated for each Treatment. The chromic acid and Flame Treatments increased their respective average shear strengths by 97% and 67% compared to an untreated control group. The increase in bond strength due to these two Treatments is believed to be a result of their oxidative mechanisms. The water Treatment, which consisted of covering the planed surface of a WPC with water for 10 min, resulted in an increase in shear strength of 31% relative to the...

  • Surface Treatments of wood–plastic composites (WPCs) to improve adhesion
    Journal of Adhesion Science and Technology, 2006
    Co-Authors: William M Gramlich, Douglas J. Gardner, David J Neivandt
    Abstract:

    In an effort to improve the adhesive bonding between wood–plastic composites (WPCs) formulated with polypropylene and a commercial epoxy adhesive, surface Treatments were performed to chemically and/or physically modify the surface of WPCs. The Treatments were performed on extruded WPC that had been planed and consisted of chromic acid Treatment, Flame Treatment, water Treatment, Flame then water Treatment and water then Flame Treatment. The strength of the adhesive bonds of the treated samples was tested following ASTM D 905 and the maximum shear stress was calculated for each Treatment. The chromic acid and Flame Treatments increased their respective average shear strengths by 97% and 67% compared to an untreated control group. The increase in bond strength due to these two Treatments is believed to be a result of their oxidative mechanisms. The water Treatment, which consisted of covering the planed surface of a WPC with water for 10 min, resulted in an increase in shear strength of 31% relative to the...

Melvyn C. Branch - One of the best experts on this subject based on the ideXlab platform.

  • Application of ribbon burners to the Flame Treatment of polypropylene films
    Progress in Energy and Combustion Science, 2008
    Co-Authors: Colleen Stroud Alexander, Melvyn C. Branch, Mark A. Strobel, Michael J. Ulsh, Neal P. Sullivan, Trina Vian
    Abstract:

    This article focuses on recent advances in the understanding of industrial gas burners. Ribbon burners have been chosen as the focus of the review because of the advantages presented by the burner arrangement and burner performance. The ribbon burner configuration, because of its ability to provide large Flame surface and Flame stabilization, has a large range of stability as flow rate, equivalence ratio and reactant gas composition are varied. Discussed in detail is the application of ribbon burners in the surface modification, or Flame Treatment, of polymer films to increase the wettability of a polymer surface. Optimum Treatment requires a spatially homogeneous post-Flame reaction zone even with burners up to 3 m in length. For methane/air Flames, the optimum equivalence ratio is near 0.93 where the active oxidizing-species concentration near the surface is a maximum. Chemical kinetic models of the impinging Flame and surface oxidation chemistry of a polymer film are also discussed. The model predictions are in good qualitative agreement with the available understanding of the Flame variables affecting surface Treatment and the expected oxidized species on the polymer surface.

  • Surface modification of polypropylene films by exposure to laminar, premixed methane-air Flames
    Symposium (International) on Combustion, 2007
    Co-Authors: Melvyn C. Branch, Michael J. Ulsh, Neal P. Sullivan, Mark A. Strobel
    Abstract:

    The Flame Treatment of polypropylene film was investigated through experimental and numerical studies. Two process parameters, Flame equivalence ratio and burner-to-film separation distance, were varied, and the extent of surface Treatment was quantified through wettability tests and oxygen-to-carbon atomic ratios obtained from X-ray photoelectron spectroscopy. These results were compared with numerical simulations using the nonreacting Fluent fluid-dynamics software and the one-dimensional PREMIX chemical kinetics code. Excellent agreement was found between the experiments and the modeling, with optimal Treatment occurring at a Flame equivalence ratio of 0.93 and a separation distance of 2 mm. A correlation between the film wettability and the concentrations of O and OH radicals was observed. The mechanism of surface oxidation by Flame Treatment probably involves polymer-radical formation by O and OH, followed by rapid reaction of the polymer radicals with O, OH, and O2.

  • The causes of non-uniform Flame Treatment of polypropylene film surfaces
    Journal of Adhesion Science and Technology, 2006
    Co-Authors: Mark A. Strobel, Michael J. Ulsh, Colleen Stroud, Melvyn C. Branch
    Abstract:

    A cross-web non-uniformity ('laning') in the Flame surface modification of polypropylene (PP) film was investigated using Flame temperature measurements and Wilhelmy plate force measurements. To associate the cross-web non-uniformity in the Flame Treatment with specific features of the Flame supported on an industrial 4-port ribbon burner, the temperature and force measurements were registered to a specific burner port. The Wilhelmy force measurements show that the upstream pair of ribbon-burner ports causes a slightly greater Treatment of the PP surface than the corresponding downstream pair of ports. The average temperature experienced by the PP as the film traverses through the Flame is noticeably higher along the down-web line of the upstream burner ports as compared with a line passing through the downstream pair. This greater average temperature correlates to an exposure to a greater concentration of the active species, such as OH radicals, that cause the surface oxidation of the PP.

  • A Comparison of Corona-Treated and Flame-Treated Polypropylene Films
    Plasmas and Polymers, 2003
    Co-Authors: Markus Strobel, Rajesh Dorai, Christopher S. Lyons, Mark J Kushner, Viv Jones, Michael Ulsh, Melvyn C. Branch
    Abstract:

    The comparison of corona0treated and Flame-treated polypropylene (PP) films provides insight into the mechanism of these surface-oxidation processes. Atomic force microscopy, contact-angle measurements, and X-ray photoelectron spectroscopy were used to characterize surface-treated biacially oriented PP. While both processes oxideze the PP surface, corona Treatment leads to the formation of water-soluble low-molecular-weight oxidized materials (LMWOM), while Flame Treatment does not. Computational modeling of the gas-phase chemistry in an air corona was performed using a zero-dimensional plasma-chemistry model. The modeling results indicate that the ratio of O to OH is much higher in a corona discharge than in a Flame. Chain scission and the formation of LMWOM are associated with reactions involving O atoms. The higher ratios of O to OH in a corona are more conductive to LMWOM production. Surface-oxidized PP exhibits considerable thermodynamic contact-angle hysteresis that is primarily caused by microscopic chemical heterogeneity.

  • Gas-phase modeling of impinging Flames used for the Flame surface modification of polypropylene film
    Journal of Adhesion Science and Technology, 2001
    Co-Authors: Mark A. Strobel, Melvyn C. Branch, Viv Jones, Michael J. Ulsh, Neal P. Sullivan, John Park, Joan M. Strobel, Christopher S. Lyons
    Abstract:

    Contact-angle measurements, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS or ESCA) were used to characterize Flame-treated biaxially oriented polypropylene (PP) films. While the surface of PP treated in a fuel-lean Flame is highly oxidized, no watersoluble low-molecular-weight oxidized material (LMWOM) is formed by the Flame Treatment. A new computational model, SPIN, was used to determine the chemical composition of the impinging Flames used to modify the PP. The SPIN model indicates that the species primarily responsible for the surface oxidation of the PP are OH, HO2, H2O2, and O2. Because the concentration of atomic O in the Flame is low, there is little scission of the PP chains and no formation of LMWOM. AFM indicates that a 'nodular' surface topography is generated during the Flame oxidation of the PP. The surface topographical features generated by Flame Treatment are probably the result of the agglomeration of intermediate-molecular-weight materials.

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

  • Application of ribbon burners to the Flame Treatment of polypropylene films
    Progress in Energy and Combustion Science, 2008
    Co-Authors: Colleen Stroud Alexander, Melvyn C. Branch, Mark A. Strobel, Michael J. Ulsh, Neal P. Sullivan, Trina Vian
    Abstract:

    This article focuses on recent advances in the understanding of industrial gas burners. Ribbon burners have been chosen as the focus of the review because of the advantages presented by the burner arrangement and burner performance. The ribbon burner configuration, because of its ability to provide large Flame surface and Flame stabilization, has a large range of stability as flow rate, equivalence ratio and reactant gas composition are varied. Discussed in detail is the application of ribbon burners in the surface modification, or Flame Treatment, of polymer films to increase the wettability of a polymer surface. Optimum Treatment requires a spatially homogeneous post-Flame reaction zone even with burners up to 3 m in length. For methane/air Flames, the optimum equivalence ratio is near 0.93 where the active oxidizing-species concentration near the surface is a maximum. Chemical kinetic models of the impinging Flame and surface oxidation chemistry of a polymer film are also discussed. The model predictions are in good qualitative agreement with the available understanding of the Flame variables affecting surface Treatment and the expected oxidized species on the polymer surface.

  • Surface modification of polypropylene films by exposure to laminar, premixed methane-air Flames
    Symposium (International) on Combustion, 2007
    Co-Authors: Melvyn C. Branch, Michael J. Ulsh, Neal P. Sullivan, Mark A. Strobel
    Abstract:

    The Flame Treatment of polypropylene film was investigated through experimental and numerical studies. Two process parameters, Flame equivalence ratio and burner-to-film separation distance, were varied, and the extent of surface Treatment was quantified through wettability tests and oxygen-to-carbon atomic ratios obtained from X-ray photoelectron spectroscopy. These results were compared with numerical simulations using the nonreacting Fluent fluid-dynamics software and the one-dimensional PREMIX chemical kinetics code. Excellent agreement was found between the experiments and the modeling, with optimal Treatment occurring at a Flame equivalence ratio of 0.93 and a separation distance of 2 mm. A correlation between the film wettability and the concentrations of O and OH radicals was observed. The mechanism of surface oxidation by Flame Treatment probably involves polymer-radical formation by O and OH, followed by rapid reaction of the polymer radicals with O, OH, and O2.

  • Time-of-flight SIMS analysis of polypropylene films modified by Flame Treatments using isotopically labeled methane fuel
    Journal of Adhesion Science and Technology, 2007
    Co-Authors: Steven J. Pachuta, Mark A. Strobel
    Abstract:

    The surface of polypropylene (PP) film was oxidized by exposure to a Flame fueled by isotopically labeled methane (CD4). The isotopic sensitivity of static secondary ion mass spectrometry (SIMS) was then used to gain new insights into the mechanism of Flame Treatment. SIMS analysis indicated that much of the oxidation of PP occurring in fuel-lean Flames is not deuterated, while for PP treated in fuel-rich Flames, some of the affixed oxygen is deuterated. These observations imply that O2 is the primary source of affixed surface oxygen in fuel-lean Flame Treatments, but that OH may be a significant source of affixed oxygen in fuel-rich Flame Treatments. Hydroxyl radicals are primarily responsible for hydrogen abstraction in fuel-lean Flames, while H is the primary active gasphase species in fuel-rich Flames. SIMS also detected trace quantities of oxidized nitrogen groups affixed to the Flame-treated PP.

  • The causes of non-uniform Flame Treatment of polypropylene film surfaces
    Journal of Adhesion Science and Technology, 2006
    Co-Authors: Mark A. Strobel, Michael J. Ulsh, Colleen Stroud, Melvyn C. Branch
    Abstract:

    A cross-web non-uniformity ('laning') in the Flame surface modification of polypropylene (PP) film was investigated using Flame temperature measurements and Wilhelmy plate force measurements. To associate the cross-web non-uniformity in the Flame Treatment with specific features of the Flame supported on an industrial 4-port ribbon burner, the temperature and force measurements were registered to a specific burner port. The Wilhelmy force measurements show that the upstream pair of ribbon-burner ports causes a slightly greater Treatment of the PP surface than the corresponding downstream pair of ports. The average temperature experienced by the PP as the film traverses through the Flame is noticeably higher along the down-web line of the upstream burner ports as compared with a line passing through the downstream pair. This greater average temperature correlates to an exposure to a greater concentration of the active species, such as OH radicals, that cause the surface oxidation of the PP.

  • Characterization of non-uniform wettability on Flame-treated polypropylene-film surfaces
    Journal of Adhesion Science and Technology, 2003
    Co-Authors: John Park, Christopher S. Lyons, Mark A. Strobel, Michael J. Ulsh, Michael I. Kinsinger, Michael J. Prokosch
    Abstract:

    The Flame Treatment of polypropylene (PP) film involves the use of impinging, conical Flames to oxidize the surface of the PP.Depending on Treatment conditions, the PP film can be exposed to an inhomogeneous environment because of the conical shape of the Flames. This environment can lead to cross-web variations, or 'lanes', in the wettability of the film. We have developed a simple method to quantify these non-uniformities using the information provided by the Wilhelmy plate technique of dynamic contact angle measurement. Both surface-averaged and spatially resolved surface-energy data can be obtained by this technique. In the case of our PP film, the spatial nonuniformities were found to be caused by variations in surface chemistry, not topography. These nonuniformities are not observed on untreated PP. Use of this method enables a quantitative evaluation of the effects of Flame-Treatment process variables on Treatment uniformity.