Abstract: A system for applying a suspension of uncooked starch particles in water to a web on a forming wire includes a source of such suspension and a source of dilution water, an application die positioned transversely of the web with an internal manifold opening into a downwardly opening die slot through which material flows from the manifold as a falling curtain onto the web. The die has a plurality of transversely spaced inlets leading into the manifold to define transversely spaced application zones across the web. The suspended starch and water are applied from the manifolds through control valves into the inlets by means of which the consistency or concentration of the starch may be varied at positions representing the application zones across the web to provide a desired strength profile to the dried web.

Abstract: A method of applying a starch sizing to a forming web on a paper machine, such as in the form of a curtain on a fourdrinier machine, employs a suspension of uncooked particulate starch and water which is applied, as a suspension, to the inlet of a downwardly opening die positioned over the forming web and applied at a consistency of between about 2 to 10% onto the surface of the web as a free falling curtain, the impact velocity of which is controlled to a rate sufficiently low to prevent distortion of the web on impact. Improved drainage is achieved by heating the suspension to a temperature less than about 150.degree., to prevent the cooking of the starched particles. The curtain may be applied to the web at fourdrinier table consistencies as low as about 2% and still obtain starch retention rates of about 80%.

Abstract: A method of applying a starch sizing to a forming web on a paper machine, such as in the form of a curtain on a fourdrinier machine, employs a suspension of uncooked particulate starch and water which is applied, as a suspension, to the inlet of a downwardly opening die positioned over the forming web and applied at a consistency of between about 2 to 10% onto the surface of the web as a free falling curtain, the impact velocity of which is controlled to a rate sufficiently low to prevent distortion of the web on impact. Improved drainage is achieved by heating the suspension to a temperature less than about 150.degree., to prevent the cooking of the starched particles. The curtain may be applied to the web at fourdrinier table consistencies as low as about 2% and still obtain starch retention rates of about 80%.