Sheet Stabilizer With Dual Inline Machine Direction Air Clamps and Backsteps

A method of non-contact support of a flexible continuous web that is moving in a downstream machine direction (MD) along a path that comprises the steps of:

• (a) positioning an air stabilizer below the continuous web along the path wherein the stabilizer comprises:
• (i) a body having an operative surface facing the web wherein the operative surface has a web entry end and a web exit end that is downstream from the web entry end;
• (ii) a first nozzle, positioned at the web entry end, that defines a first slot that extends across the surface of the operative surface along a first direction that is substantially transverse to the MD, wherein the first nozzle is fluid communication with a first source of gas;
• and
• (iii) a second nozzle, positioned at the web exit end, that defines a second slot that extends across the surface of the operative surface along a second direction that is substantially transverse to the MD wherein the second nozzle is fluid communication with a second source of gas;
• (b) directing a first jet of gas from the first slot toward a downstream MD to impart a first force on the continuous web;
• and
• (c) simultaneously directing a second jet of gas from the second slot toward a downstream MD to impart a second force on the continuous web, whereby the first force and the second force maintain at least a portion of the moving web, that is located between the web entry end and the web exit end, at a substantially fixed distance to the operative surface.

A system for monitoring a continuous web that is moving in a downstream machine direction (MD) that comprises:

• (a) an air stabilization system for non-contact support of the flexible continuous web, which has a first surface and a second surface, that comprises:
• (i) a body having an operative surface facing the web wherein the operative surface has a web entry end and a web exit end that is downstream from the web entry end;
• (ii) a first nozzle, positioned on the operative face at the web entry end, that defines a first slot that extends across the surface of the operative surface along a first direction that is substantially transverse to the MD and wherein a first elongated jet of pressurized gas is exhausted through the first slot and moves toward a downstream MD to impart a first controlled force on the web;
• and
• (iii) a second nozzle, positioned on the operative face at the web exit end, that defines a second slot that extends across the surface of the operative surface along a second direction that is substantially transverse to the MD, wherein a second elongated jet of pressurized gas is simultaneously exhausted through the second slot and moves toward a downstream machine direction to impart a second controlled force on the web and whereby the first force and the second force maintain at least a portion of the moving web, that is located between the web entry end and the web exit end, at a substantially fixed distance to the operative surface;
• (b) a first sensor head that is disposed adjacent the first surface of the web;
• and
• (c) means for regulating the first jet of gas and the second jet of gas to control the web's profile along the process path over the operative surface.