The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform

G.a. Dumont - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive basis weight control in paper Machines
    Proceedings of IEEE International Conference on Control and Applications, 1993
    Co-Authors: X.g. Wang, G.a. Dumont
    Abstract:

    A dynamic model for basis weight variations in paper Machines has been developed. The model is identified recursively from scanned measurements, and so provides an online estimation of basis weight variations in both cross-Machine Direction and Machine Direction, as well as estimates of the dynamic parameters and noise characteristics of the process. Here the approach is extended to include the adaptive generalized prediction control (GPC) algorithm for Machine Direction variations of the basis weight process. The adaptive controller is designed to overcome shortcomings of the nonadaptive traditional controllers being used.

  • Modelling and identifications of basis weight variations in paper Machines
    IEEE Transactions on Control Systems Technology, 1993
    Co-Authors: X.g. Wang, G.a. Dumont
    Abstract:

    A dynamic model for basis weight variations in paper Machines is established and estimated recursively from scanned measurements using a combination of an exponential forgetting and resetting least squares estimator and an extended Kalman filter. The algorithm provides online estimation of basis weight variations in both cross-Machine Direction and Machine Direction, as well as estimates of the dynamic parameters and noise characteristics of the process.

  • On-line estimation of a dynamic model for basis weight variations in paper Machines
    [Proceedings 1992] The First IEEE Conference on Control Applications, 1992
    Co-Authors: X.g. Wang, G.a. Dumont
    Abstract:

    A dynamic model for basis weight variations in paper Machines is established and estimated recursively from scanned measurements using a combination of an exponential forgetting and resetting least squares estimator and an extended Kalman filter. The algorithm provides online estimation of basis weight variations in cross-Machine Direction and Machine Direction, as well as estimates of the dynamic parameters and noise characteristics of the process.

  • An improved algorithm for estimating paper Machine moisture profiles using scanned data
    [1991] Proceedings of the 30th IEEE Conference on Decision and Control, 1991
    Co-Authors: G.a. Dumont, K. Natarajan, C. Lindeborg, F. Ordubadi, Y. Fu, K. Kristinsson, I. Jonsson
    Abstract:

    An improved estimation algorithm for use in processing data generated online by a scanning sensor is described. The algorithm is to be used as part of a paper Machine control system to maintain the moisture content of the sheet at a target value. The algorithm rapidly estimates, in the presence of noise, cross and Machine Direction moisture profiles. The basic algorithm consists of a modified least-squares parameter identifier for estimating cross Direction profile deviations and a Kalman filter for estimating Machine Direction disturbances. Simulation results showing the effectiveness of the algorithm in estimating known profiles are given. Results of the offline application of the algorithm to industrial data are also given. Online tests have been performed to demonstrate the improvements in accuracy and speed of detection of process upsets.

X.g. Wang - One of the best experts on this subject based on the ideXlab platform.

  • Basis Weight Estimation from Array Measurements
    IFAC Proceedings Volumes, 1993
    Co-Authors: X.g. Wang, Guy A. Dumont, M.s. Davies
    Abstract:

    Abstract This paper proposes a new on-line estimation scheme that fully utilizes a new generation of basis weight sensors—non-scanning array sensors—to give improved estimation of basis weight variations in paper Machines. A dynamic model is established for the Machine Direction (MD) variations and identified on-line with an extended Kalman filter. Cross Machine Direction (CD) variations are estimated by a matrix exponential forgetting and resetting recursive least squares algorithm which is able to give faster and more accurate CD profile estimation.

  • Adaptive basis weight control in paper Machines
    Proceedings of IEEE International Conference on Control and Applications, 1993
    Co-Authors: X.g. Wang, G.a. Dumont
    Abstract:

    A dynamic model for basis weight variations in paper Machines has been developed. The model is identified recursively from scanned measurements, and so provides an online estimation of basis weight variations in both cross-Machine Direction and Machine Direction, as well as estimates of the dynamic parameters and noise characteristics of the process. Here the approach is extended to include the adaptive generalized prediction control (GPC) algorithm for Machine Direction variations of the basis weight process. The adaptive controller is designed to overcome shortcomings of the nonadaptive traditional controllers being used.

  • Modelling and identifications of basis weight variations in paper Machines
    IEEE Transactions on Control Systems Technology, 1993
    Co-Authors: X.g. Wang, G.a. Dumont
    Abstract:

    A dynamic model for basis weight variations in paper Machines is established and estimated recursively from scanned measurements using a combination of an exponential forgetting and resetting least squares estimator and an extended Kalman filter. The algorithm provides online estimation of basis weight variations in both cross-Machine Direction and Machine Direction, as well as estimates of the dynamic parameters and noise characteristics of the process.

  • On-line estimation of a dynamic model for basis weight variations in paper Machines
    [Proceedings 1992] The First IEEE Conference on Control Applications, 1992
    Co-Authors: X.g. Wang, G.a. Dumont
    Abstract:

    A dynamic model for basis weight variations in paper Machines is established and estimated recursively from scanned measurements using a combination of an exponential forgetting and resetting least squares estimator and an extended Kalman filter. The algorithm provides online estimation of basis weight variations in cross-Machine Direction and Machine Direction, as well as estimates of the dynamic parameters and noise characteristics of the process.

Nik Shah - One of the best experts on this subject based on the ideXlab platform.

  • Machine Direction orientation of high density polyethylene hdpe barrier and optical properties
    Polymer, 2014
    Co-Authors: Tirtha Chatterjee, Rajen M Patel, John W Garnett, Rajesh Paradkar, Shouren Ge, Kenneth T Forziati, Nik Shah
    Abstract:

    Abstract In this study, blown films were produced from three different high density polyethylene (HDPE) resins. Further, these blown films were oriented along the Machine Direction using either traditional Machine Direction orientation (MDO) or compression roll drawing (CRD MDO) technology. The stretched/oriented films were compared for their water vapor transport and optical properties as a function of the extent of orientation (i.e., draw ratio, DR). In addition to that, these properties were directly compared between the oriented and unoriented (blown) films of the same thickness. The present study revealed that the water vapor transmission rate (WVTR) as a function of draw ratio (DR) went through a maxima. Detailed morphological characterization showed that initially, at low DR, stretching resulted in lamellar organization (along the MD). Consequently, the tortuosity in the diffusion path decreased and the overall WVTR increased. However, beyond a critical DR, lamellar crystals transformed to microfibrillar crystals. During this process the amorphous content of the HDPE chains decreased and geometric redistribution of the amorphous phase occurred along with some orientation. As a combination of all these effects, the WVTR was found to decrease beyond the critical DR. Unlike transport properties, optical properties monotonically improved as a function of DR. Further, for both, the barrier and optical properties, the absolute values were found to be a strong function of the resin physical properties. Finally, compression roll drawing technology (CRD MDO) utilizes a patented process that simultaneously applies a stretching and compressive force to orient polymer chains homogeneously without any tiger striping (uneven deformation). Consequently, CRD MDO stretched samples showed a lower surface roughness compared to their traditional MDO stretched counterpart. Therefore, for the same resin and DR, CRD MDO stretched samples displayed markedly better barrier properties and optics, especially lower total haze and higher gloss.

I. Jonsson - One of the best experts on this subject based on the ideXlab platform.

  • An improved algorithm for estimating paper Machine moisture profiles using scanned data
    [1991] Proceedings of the 30th IEEE Conference on Decision and Control, 1991
    Co-Authors: G.a. Dumont, K. Natarajan, C. Lindeborg, F. Ordubadi, Y. Fu, K. Kristinsson, I. Jonsson
    Abstract:

    An improved estimation algorithm for use in processing data generated online by a scanning sensor is described. The algorithm is to be used as part of a paper Machine control system to maintain the moisture content of the sheet at a target value. The algorithm rapidly estimates, in the presence of noise, cross and Machine Direction moisture profiles. The basic algorithm consists of a modified least-squares parameter identifier for estimating cross Direction profile deviations and a Kalman filter for estimating Machine Direction disturbances. Simulation results showing the effectiveness of the algorithm in estimating known profiles are given. Results of the offline application of the algorithm to industrial data are also given. Online tests have been performed to demonstrate the improvements in accuracy and speed of detection of process upsets.

Eric Hatfield - One of the best experts on this subject based on the ideXlab platform.

  • Machine Direction oriented film technology
    Multilayer Flexible Packaging, 2020
    Co-Authors: Eric Hatfield
    Abstract:

    Abstract Machine Direction orientation of films has been studied for decades. In the 1950s and 1960s, the academics studied property improvements when a film is stretched in the Machine Direction. It has taken many years for the industry to begin to commercialize the technology. This chapter looks at the hardware to produce MDO film, the process used and properties obtained.

  • Chapter 10 – Machine Direction oriented film technology
    Multilayer Flexible Packaging, 2020
    Co-Authors: Eric Hatfield
    Abstract:

    Publisher Summary This chapter focuses on Machine Direction oriented film technology. An MDO Machine is a stack of usually separately driven rolls mounted in side frames for support, where the rolls are heated and/or cooled in separate temperature zones. When a film is correctly Machine Direction oriented, many of its physical and barrier properties are greatly improved. Barrier properties, both water and oxygen, can be doubled with the right orientation and annealing conditions whereas film stiffness, measured by secant Modulus, can be increased by two to three times and, in some cases, four times. Optical properties such as haze, gloss, and clarity can also be enhanced, as well as tensile properties and films can also be made with controlled shrink levels and temperature. The four sections in the MDO Machine and process are the preheat section, the draw section, the annealing section, and the cooling section. The preheat section heats the incoming film to the desired temperature for orientating the film and in the draw section, the film is oriented, or drawn or stretched, between a set of rolls with a narrow gap between them. The annealing section heat sets or anneals the film to prevent it from shrinking back to its pre-oriented state and the cooling section cools the film down from the annealing temperature to ambient and sends the film on downstream to the next process.