Abstract A method for forming a low basis weight nonwoven web of randomly arranged, intermingled fibers including a major proportion by weight of short cellulosic fibers of a papermaking length less than one-quarter inch, and a minor proportion by weight of longer reinforcing fibers having an average length greater than onequarter inch. The method includes the steps of: (1) forming separate batts of the short cellulosic fibers and the longer reinforcing fibers; (2) blending together the fibers in the batts in a randomly arranged and intermingled fashion; (3) conveying the blended fibers in a gaseous carrier medium to a foraminous support member; (4) passing the gaseous medium through the support member to condense the fibers on the support member into a fibrous feed mat having an average basis weight which is the greater of 12 oz/yd2 and at least three times the average basis weight of the low basis weight fibrous web to be formed; (5) separating the fibers from the feed mat; (6) conveying the separated fibers in a gaseous carrier medium to a second foraminous support member; and (7) passing the gaseous medium through the second support member to condense the blended fibers on the second support member into the low basis weight nonwoven fibrous web.
A METHOD FOR FORMING A LOW BASIS WEIGHT NONWOVEN FIBROUS WEB INCLUDING A MAJOR PROPORTION BY WEIGHT OF SHORT CELLULOSIC FIBERS OF A PAPERMAKING LENGTH LESS HAN ONE-QUARTER INCH AND A MINOR PROPORTION BY WEIGHT OF LONGER REINFORCING FIBERS HAVING AN AVERAGE FIBER LENGTH OF OVER ONE-QUARTER INCH, SAID METHOD COMPRISING THE STEPS OF: A. FORMING A LOOSELY COMPACTED BATT OF SUBSTANTIALLY INDIVIDUALIZED SHORT CELLULOSIC FIBERS OF A PAPERMAKING LENGTH LESS THAN ONE-QUARTER INCH; B. FORMING A LOOSELY COMPACTED BATT OF REINFORCING FIBERS HAVING AN AVERAGE FIBER LENGTH OF OVER ONE-QUARTER INCH; C. SEPARATING AND BLENDING THE FIBERS IN THE BATTS OF SHORT CELLULOSIC FIBERS AND LONGER REINFORCING FIBERS TO FORM A GASEOUS SUSPENSION OF RANDOMLY ARRANGED AND INTERMINGLED FIBERS IN WHICH A MAJOR PROPORTION OF THE FIBERS BY WEIGHT ARE THE SHORT CELLULOSIC FIBERS, AND A MINOR PROPORTION OF THE FIBERS BY WEIGHT ARE THE LONGER REINFORCING FIBERS; D. CONVEYING THE GASEOUS SUSPENSION OF RANDOMLY ARRANGED AND INTERMINGLED SHORT AND LONGER FIBERS TOWARD A FORAMINOUS SUPPORT MEMBER THROUGH WHICH THE GASEOUS CARRIER MEDIUM PASSES, AND UPON WHICH THE FIBERS ARE DEPOSITED IN A FIBROUS FEED MAT OF RANDOMLY ARRANGED AND INTERMINGLED SHORT AND LONGER FIBERS, SAID FEED MAT COMPRISING A MAJOR PROPORTION BY WEIGHT OF THE SHORT CELLULOSIC FIBERS AND A MINOR PROPORTION BY WEIGHT OF THE LONGER REINFORCING FIBERS, SAID FEED MAT HAVING AN AVERAGE BASIS WEIGHT WHICH IS THE GREATER OF 12 OZ./YD.2 AND AT LEAST THREE TIMES THE AVERAGE BASIS WEIGHT OF THE LOW BASIC WEIGHT NONWOVEN FIBROUS WEB TO BE FORMED; AND E. SEPARATING FIBERS FROM THE FEED MAT AND CONVEYING THEM IN A GASEOUS CARRIER MEDIUM TO A SECOND FORAMINOUS SUPPORT MEMBER WHEREAT THE GASEOUS MEDIUM-PASSES THROUGH THE FORAMINOUS SUPPORT MEMBER AND THE FIBERS ARE DEPOSITED ON SAID SUPPORT MEMBER TO FORM THE LOW BASIS WEIGHT NONWOVEN FIBROUS WEB.
Claim 2
Independent Claim
305 words
A METHOD FOR FORMING A LOW BASIS WEIGHT NONWOVEN FIBROUS WEB INCLUDING A MAJOR PROPORTION BY WEIGHT OF SHORT CELLULOSIC FIBERS OF A PAPERMAKING LENGTH LESS HAN ONE-QUARTER INCH AND A MINOR PROPORTION BY WEIGHT OF LONGER REINFORCING FIBERS HAVING AN AVERAGE FIBER LENGTH OF OVER ONE-QUARTER INCH, SAID METHOD COMPRISING THE STEPS OF: A. FORMING A LOOSELY COMPACTED BATT OF SUBSTANTIALLY INDIVIDUALIZED SHORT CELLULOSIC FIBERS OF A PAPERMAKING LENGTH LESS THAN ONE-QUARTER INCH; B. FORMING A LOOSELY COMPACTED BATT OF REINFORCING FIBERS HAVING AN AVERAGE FIBER LENGTH OF OVER ONE-QUARTER INCH; C. SEPARATING AND BLENDING THE FIBERS IN THE BATTS OF SHORT CELLULOSIC FIBERS AND LONGER REINFORCING FIBERS TO FORM A GASEOUS SUSPENSION OF RANDOMLY ARRANGED AND INTERMINGLED FIBERS IN WHICH A MAJOR PROPORTION OF THE FIBERS BY WEIGHT ARE THE SHORT CELLULOSIC FIBERS, AND A MINOR PROPORTION OF THE FIBERS BY WEIGHT ARE THE LONGER REINFORCING FIBERS; D. CONVEYING THE GASEOUS SUSPENSION OF RANDOMLY ARRANGED AND INTERMINGLED SHORT AND LONGER FIBERS TOWARD A FORAMINOUS SUPPORT MEMBER THROUGH WHICH THE GASEOUS CARRIER MEDIUM PASSES, AND UPON WHICH THE FIBERS ARE DEPOSITED IN A FIBROUS FEED MAT OF RANDOMLY ARRANGED AND INTERMINGLED SHORT AND LONGER FIBERS, SAID FEED MAT COMPRISING A MAJOR PROPORTION BY WEIGHT OF THE SHORT CELLULOSIC FIBERS AND A MINOR PROPORTION BY WEIGHT OF THE LONGER REINFORCING FIBERS, SAID FEED MAT HAVING AN AVERAGE BASIS WEIGHT WHICH IS THE GREATER OF 12 OZ./YD.2 AND AT LEAST THREE TIMES THE AVERAGE BASIS WEIGHT OF THE LOW BASIC WEIGHT NONWOVEN FIBROUS WEB TO BE FORMED; AND E. SEPARATING FIBERS FROM THE FEED MAT AND CONVEYING THEM IN A GASEOUS CARRIER MEDIUM TO A SECOND FORAMINOUS SUPPORT MEMBER WHEREAT THE GASEOUS MEDIUM-PASSES THROUGH THE FORAMINOUS SUPPORT MEMBER AND THE FIBERS ARE DEPOSITED ON SAID SUPPORT MEMBER TO FORM THE LOW BASIS WEIGHT NONWOVEN FIBROUS WEB.
Claim 3
Dependent Claim
14 words
The method according to claim 1, wherein said short cellulosic fibers are wood pulp.
Claim 4
Dependent Claim
13 words
The method according to claim 2, wherein the reinforcing fibers are rayon fibers.