Method for controlling edge uniformity in nonwoven fabrics

摘要

An improved method of manufacture of a nonwoven fabric wherein a nonwoven fabric web is passed through a needle punching zone wherein the nonwoven fabric web is needle punched in such a manner that the number of needle punches per unit area in the edge portions of the nonwoven fabric web is less than the number of needle punches per unit area in the medial portion of the nonwoven fabric web, and the thus needled nonwoven fabric web is passed through a tentering zone wherein it is stretched transversely relative to its direction of movement to thereby reduce the weight per unit area of the edge portions to approximately the weight per unit area of the medical portion so that a nonwoven fabric or substantially uniform thickness and weight per unit area is produced. Also disclosed is apparatus comprising a needle punching machine with a needle board having a plurality of needles extending outwardly therefrom toward the nonwoven fabric web and arranged such that there are more needles per unit area adjacent the medial portion of the nonwoven fabric web than there are needles per unit area adjacent the edge portions of the nonwoven fabric web, and further including a tenter frame.