| abstract |
Apertured fibrous webs are disclosed which are formed by a wet laying process, as on a papermaking machine, which webs have from about 100 to about 1,300 apertures per square inch of the web, the apertures being arranged in a predetermined pattern. A method is disclosed for forming the above-described apertured fibrous webs involving the step of removing fibers from predetermined areas of a layer of a stock mixture of liquid and fibers disposed upon a drainage member during removal of liquid from the stock mixture by drainage through the drainage member and formation of a fibrous web upon the drainage member, whereby an apertured fibrous web is formed upon the drainage member which is removable from the drainage member by a couch roll or other conventional papermaking techniques. A foraminous belt-like structure is disclosed for use as a drainage member in the method and apparatus for forming apertured fibrous webs. The foraminous belt-like structure comprises a drainage member having a plurality of apertures substantially uniformly disbursed throughout, and flow control means, which in some instances comprise bodies of settable material, connected to the drainage member in a manner which prevents flow of liquid through the apertures in predetermined areas of the drainage member, the number of these predetermined areas being from about 100 to about 1,300 per square inch of said member. A method is disclosed for preparing the above-described foraminous belt-like structure including inserting filling material into apertures in the drainage member which will ultimately be open for drainage after which a settable material is inserted into the remaining apertures of the drainage member in the predetermined areas in which flow of liquid through the drainage member is to be prevented. The settable material is fixed or cured depending upon its composition, after which the filling material is removed from the drainage member, leaving the desired foraminous belt-like structure. |