Method and apparatus for longitudinal compressive treatment of webs
AssigneeRichard R. Walton
InventorsRichard R. Walton, George E. Munchbach
Life of this patent
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Abstract
A machine and method for treating a web by longitudinal compressive action, by pressing a web against a driven roll to drive it into a treatment cavity bounded by the roll and an overlying surface, followed by application of retarding forces by extrusion in which the extrusion orifice is arranged with its axis substantially parallel to the roll at the web-drive point, and in which resilient self-adjustment of the extrusion orifice is achieved by employing a plate-form member parallel to the web which is resiliently urged toward the drive nip in the direction of extent of the plate-form member.
Claims12
A machine for microcreping a running length of web comprising
- a driven roll,
- a stationary primary pressing surface for pressing the web against the surface of said roll to drive the web forward at a drive nip, and
- first and second generally stationary downstream web-contacting surfaces on sides of the web corresponding to said roll and primary surface, respectively, adapted to define an extrusion orifice to provide an extrusion retarding effect to the oncoming web, said second generally stationary downstream web-contacting surface being an extension of said stationary primary pressing surface,
- the driving and retarding of said web being adapted to cause its longitudinal compressive treatment in a cavity defined in the region of transition of the web from said roll to said downstream surfaces,
- that improvement wherein:
- the machine is adapted to treat the web in response to retarding forces produced by tangential extrusion,
- said first and second generally stationary downstream web-contacting surfaces defining an extrusion orifice (TEO) the axis X of which extends at an angle substantially parallel, i.e., at an angle less than 20.degree., to the tangent to the roll at the final point P of positive drive of the web, the extrusion resistance force R provided solely by the surfaces defining said orifice, serving to maintain a substantially straight retarded column of treated web material capable of resisting forward movement of material freshly driven by said roll, to cause said longitudinal compressive treatment of the web, said first web-contacting surface being defined by a generally plate-form blade member, said plate-form member being resiliently urged toward the driven nip by a force acting generally parallel to the tangent to the roll in the manner to enable resilient self adjusting movement of said plate member in its plane in response to operating conditions of said machine.
A method for microcreping a running length of web comprising pressing the web between the surface of a driven roll and a stationary primary pressing surface to drive the web forward at a drive nip, and
- providing an extrusion retarding effect to the oncoming web by employing first and second generally stationary web-contacting surfaces on sides of the web corresponding to said roll surface and primary surface, respectively,
- the driving and retarding of said web causing its longitudinal compressive treatment in a cavity defined in the region of transition of the web from said roll to said downstream surfaces,
- that improvement wherein:
- the web is treated by an extrusion resistance force formed solely by tangential extrusion between web-contacting surfaces comprising first and second generally stationary surfaces that define an extrusion orifice the axis of which extends substantially parallel, i.e., at an angle less than 20.degree., to the tangent to the roll at the final point P of positive drive of the web to maintain a substantially straight retarded column of treated web material capable of resisting forward movement of material freshly driven by said roll,
- the extrusion retarding effect is resiliently maintained by providing a plate-form member to provide said first web-contacting surface, and resiliently urging said plate-form member toward the drive nip by a force acting generally parallel to the tangent to the roll in the manner to enable resilient self-adjusting movement of said plate-form member in the direction of its plane in response to operating conditions of said process.
Dependencies are inferred from the claim text.