Patent DE-19823272-A1 (DE)
Title: Production of nonwoven fabrics with a velvet pile surface character
Inventor: ERTH DIETER
IPC: D04H1/70
Filed: 1998-05-26
Abstract: To produce a nonwoven with a velvet pile surface character, a nonwoven is used which is mostly in a longitudinal orientation containing at least 5 mass% of fusible fibers which melt at a significantly low temperature. To produce a nonwoven with a velvet pile surface character, a nonwoven is used which is mostly in a longitudinal orientation containing at least 5 mass% of fusible fibers which melt at a significantly low temperature. The nonwoven is folded in zigzags to give a serpentine structure (11), and the facing legs of the zigzags are bonded together by their fibers. The bonded package is heated, to melt the fusible fibers at the butting legs of the serpentine material. The bonded package is cut through the center by a conventional pile cutter (F), to be separated into two layers (110,110') each with a velvet pile surface appearance. The nonwoven is folded into a zigzag and the surfaces of the facing legs are bonded together by a row of slide needles for each material surface, to form fiber locking stitches.  Each row of needles has knocking-over and controlled holding-down units.  A laterally-oriented nonwoven and/or a material with a high content of bicomponent fibers is fed into the knocking-over plane, for its fibers to be looped with the fibers of the nonwoven in the serpentine stack. The nonwoven is laid into folds (A) by a folding roller and a pair of take-in rollers near its circumference.  A low-strength pulsed air stream is directed from below the plane of the nonwoven (1) at the surface of the folding roller. After the folding stage (A), the serpentine fabric (11) is compressed within a channel, defined at both sides across the zigzag folds, and the compressed legs of the fabric folds are fixed by heat through heat radiation and/or hot contact surfaces. Directly after the folding (A) and compression (B) stages, the longitudinally oriented nonwoven is initially heat bonded (C) at both surfaces.  The bonded surfaces are rubbed to release surface fibers, which are looped together by a rotary movement, to be heat fixed (D). After cooling (E), the material is cut (F). An Independent claim is also included for a production assembly with at least one carding station (2) to give a carded web (1) where the fibers are mostly in a longitudinal alignment.  A folding station (A) acts across the longitudinal line and the nonwoven (1) plane, followed by a compression station (B) for the serpentine nonwoven (11) in its zigzag folds. The surface fibers at the fold surfaces are locked together (C) and the material is fixed (D) by heat by radiant and/or contact heating, directly followed by cooling (E). The cooled material is cut (F) by a pile cutter, to give two separate layers each with a velvet pile surface. Preferred Features: The folding (A), fold compression (B) and bonding (C) stations are in a single component group. The component group has two slide needle bars under a central fabric feed with feed rollers. The needle bars have an alternating action, at a gap over the two knocking-over planes, intersecting closely below the outlet opening of the web feed. The web feed has inner offset projections, which mesh together and give an offset movement to lay the web (1) fibers into the hooks of the slide needles. Oscillating holding-down units are at the knocking-over plane next to the slide needle bars.  A feed for an inserted material is between the holding-down units and the knocking-over at each needle bar. A row of pulsating air jets is below the pair of take-in rollers, directly under the gap between them, to deliver pulsed compressed air streams at the surface of the folding roller. The folding roller is followed, in succession, by a heat fixing assembly, a surface rubbing station with a rubbing roller (47) acting on the fabric (11) surface, and two heat fixing assemblies (D) with calibrating guides (63) to feed the serpentine-folded nonwoven (11).