Anti-rewet transfer belt
OwnerLeonard R. Lefkowitzinventor
Life of this patent
Estimating the term…
Abstract
An endless belt for a press section forces a controlled amount of air into a sheet to relieve a vacuum in the sheet during dewatering of the sheet. The first surface of the belt is impermeable to water and permeable to air and the second surface of the belt is impermeable to water and air. Between the first and second surfaces is a body that is resiliently compressible and that has a plurality of air pockets that communicate vertically with the first surface. The air pockets are arranged to essentially stop passage of air through the belt in machine and cross machine directions. Air is compressed in the air pockets as the belt enters the nip, and the compressed air leaves the air pockets to relieve the vacuum in the sheet as the belt passes beyond mid-nip, preventing water from reentering the sheet.
Claims17
An endless belt for a press section, the belt extending in machine and cross machine directions and having a vertical thickness, the belt comprising:
- a first layer that is substantially impermeable to water and permeable to air;
- a second layer that is impermeable to water and air and that includes a dimensionally stable substrate;
- and
- between said first and second layers, a compressibly resilient body having a plurality of air pockets that are arranged to intake and exhaust air vertically through said first layer and that are arranged to essentially bar movement of air through said body in the machine and cross machine directions.
An endless belt for a press section, the belt extending in machine and cross machine directions and having a vertical thickness, the belt comprising:
- a barrier layer adapted to engage a sheet passing through a nip of the press section, said barrier layer being substantially impermeable to water and permeable to air;
- a roll-engaging layer that is opposite said barrier layer and that is adapted to engage a roller in the nip of the press section, said roll-engaging layer being impermeable to water and air and including a substantially incompressible belt-supporting substrate for providing dimensional stability to the belt;
- and
- between said barrier and roll-engaging layers and immediately adjacent to said barrier layer, a void space layer that is resiliently compressible and that has a plurality of internal air pockets, said air pockets communicating vertically with said barrier layer to intake and exhaust air vertically through said barrier layer and not communicating in the machine and cross machine directions so that air in said air pockets moves vertically and not in the machine and cross machine directions when said void space layer is compressed and decompressed as the belt moves through a nip of the press section material.
Dependencies are inferred from the claim text.