Automated fabrication of corrugated paper products

A method for preparing a paper web for corrugation, comprising the steps of:

• providing a paper web having first and second opposed major surfaces and containing moisture;
• providing heating means with a curved outer heated surface;
• providing a wrap arm for wrapping the paper web across the heating means, with the wrap arm movable between maximum and minimum positions so as to bring greater and lesser portions of the paper web in contact with the heating means;
• moving the wrap arm between a series of different positions, between said maximum and said minimum positions so as to bring a changing amount of the first surface of the paper web in contact with the heating means;
• sensing, for the different positions of the wrap arm, the moisture of the paper web;
• determining a low moisture wrap arm position at which a rate of increase of moisture increases;
• determining a high moisture wrap arm position at which a rate of increase of web moisture is negligible;
• determining an offset comprising one-half of the difference between the low moisture wrap arm position and the high moisture wrap arm position;
• determining a desired operating position of the wrap arm by adjusting the high moisture wrap arm position toward the low moisture wrap arm position by an amount corresponding to the offset;
• and
• moving the wrap arm to the desired operating position.

A method of joining a paper liner to a medium comprising a corrugated paper web, comprising the steps of:

• a) forming the liner from a paper web in preparation for adhesive joinder to the medium, comprising the steps of:
• providing a paper web having first and second opposed major surfaces and containing moisture;
• providing heating means with a curved outer heated surface;
• providing a liner wrap arm for wrapping the paper web across the heating means, with the liner wrap arm movable between first and second positions so as to bring greater and lesser portions of the paper web in contact with the heating means;
• moving the liner wrap arm between said first and said second positions so as to bring a changing amount of the first surface of the paper web in contact with the heating means;
• sensing, for the different positions of the liner wrap arm, the surface moisture carried by the paper web at the first surface and the temperature of the paper web at the first surface;
• determining a low temperature liner wrap arm position at which a rate of increase of surface moisture increases;
• determining a high temperature liner wrap arm position at which a rate of increase of surface temperature is negligible;
• determining an offset comprising the difference between the low temperature liner wrap arm position and the high temperature liner wrap arm position;
• determining a high moisture liner wrap arm position at which a rate of increase of surface moisture is negligible;
• determining a desired operating position of the liner wrap arm by adjusting the high moisture liner wrap arm position toward the low temperature liner wrap arm position by an amount corresponding to the offset;
• and
• moving the liner wrap arm to the desired operating position;
• b) forming the medium from another paper web in preparation for adhesive joinder to the liner, comprising the steps of:
• providing another paper web having first and second opposed major surfaces and containing moisture;
• providing a medium heater with a curved outer heated surface;
• providing a medium wrap arm for wrapping the paper web across the heating means, with the medium wrap arm movable between maximum and minimum positions so as to bring greater and lesser portions of the paper web in contact with the medium heater;
• moving the medium wrap arm between a series of different positions, between said maximum and said minimum positions so as to bring a changing amount of the first surface of the paper web in contact with the medium heater;
• sensing, for the different positions of the medium wrap arm, the moisture of the paper web;
• determining a low moisture medium wrap arm position at which a rate of increase of moisture increases;
• determining a high moisture medium wrap arm position at which a rate of increase of web moisture is negligible;
• determining an offset comprising one-half of the difference between the low moisture medium wrap arm position and the high moisture medium wrap arm position;
• determining a desired operating position of the medium wrap arm by adjusting the high moisture medium wrap arm position toward the low moisture medium wrap arm position by an amount corresponding to the offset;
• and
• moving the medium wrap arm to the desired operating position;
• c) coating one of said liner and said medium with an adhesive;
• and
• pressing said liner and said medium together.

A method of making a double-wall corrugated board, comprising the steps of:

• a) forming the liner from a paper web in preparation for adhesive joinder to the medium, comprising the steps of:
• providing a paper web having first and second opposed major surfaces and containing moisture;
• providing heating means with a curved outer heated surface;
• providing a liner wrap arm for wrapping the paper web across the heating means, with the liner wrap arm movable between first and second positions so as to bring greater and lesser portions of the paper web in contact with the heating means;
• moving the liner wrap arm between said first and said second positions so as to bring a changing amount of the first surface of the paper web in contact with the heating means;
• sensing, for the different positions of the liner wrap arm, the surface moisture carried by the paper web at the first surface and the temperature of the paper web at the first surface;
• determining a low temperature liner wrap arm position at which a rate of increase of surface moisture increases;
• determining a high temperature liner wrap arm position at which a rate of increase of surface temperature is negligible;
• determining an offset comprising the difference between the low temperature liner wrap arm position and the high temperature liner wrap arm position;
• determining a high moisture liner wrap arm position at which a rate of increase of surface moisture is negligible;
• determining a desired operating position of the liner wrap arm by adjusting the high moisture liner wrap arm position toward the low temperature liner wrap arm position by an amount corresponding to the offset;
• and
• moving the liner wrap arm to the desired operating position;
• b) forming the medium from another paper web in preparation for adhesive joinder to the liner, comprising the steps of:
• providing another paper web having first and second opposed major surfaces and containing moisture;
• providing a medium heater with a curved outer heated surface;
• providing a medium wrap arm for wrapping the paper web across the heating means, with the medium wrap arm movable between maximum and minimum positions so as to bring greater and lesser portions of the paper web in contact with the medium heater;
• moving the medium wrap arm between a series of different positions, between said maximum and said minimum positions so as to bring a changing amount of the first surface of the paper web in contact with the medium heater;
• sensing, for the different positions of the medium wrap arm, the moisture of the paper web;
• determining a low moisture medium wrap arm position at which a rate of increase of moisture increases;
• determining a high moisture medium wrap arm position at which a rate of increase of web moisture is negligible;
• determining an offset comprising one-half of the difference between the low moisture medium wrap arm position and the high moisture medium wrap arm position;
• determining a desired operating position of the medium wrap arm by adjusting the high moisture medium wrap arm position toward the low moisture medium wrap arm position by an amount corresponding to the offset;
• and
• moving the medium wrap arm to the desired operating position;
• c) coating one of said liner and said medium with an adhesive;
• d) pressing said liner and said medium together to form a first single-faced board;
• e) repeating said steps a) through d) to form a second single-faced board;
• f) repeating said step a) to form an other liner;
• g) coating said first and said second single-faced boards with an adhesive;
• h) pressing said other liner and said first and said second single-faced boards together to form said double-wall corrugated board.