Nonwoven fiber-sheet process
AssigneeE. I. Du Pont de Nemours and Company
InventorJohn Farago
Life of this patent
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Abstract
A process is provided for reducing the size and number of undesirable gauge bands in wound-up rolls of wide nonwoven sheet that is produced by a plurality of oscillating fiber streams depositing fiber on a moving receiver. The desired effect is accomplished by varying the oscillation frequency of the fiber streams by more than .+-.5% of the average oscillation frequency.
Claims4
In a process for making a wide nonwoven fiber sheet wherein a fiber stream issues from each of a plurality of positions located above a moving receiver and along a line that makes an angle with the direction of receiver movement, each fiber stream being oscillated as it is forwarded to the receiver whereon it deposits fiber to form a ribbon which is lapped with ribbons from preceding and succeeding positions along the line, the improvement comprising varying the oscillation frequency of every other fiber stream along the line by more than .+-.5%, but less than .+-.50%, of the average oscillation frequency, the variation in oscillation frequency having a period in the range of 1 to 120 seconds.
Dependencies are inferred from the claim text.