Fabric (woven – knitted – or nonwoven textile or cloth – etc.) – Nonwoven fabric – Spun-bonded nonwoven fabric
Reexamination Certificate
2000-03-07
2001-08-14
Morris, Terrel (Department: 1771)
Fabric (woven, knitted, or nonwoven textile or cloth, etc.)
Nonwoven fabric
Spun-bonded nonwoven fabric
C442S327000, C442S334000, C442S335000, C442S362000, C442S363000, C442S409000, C442S415000
Reexamination Certificate
active
06274521
ABSTRACT:
FIELD OF THE INVENTION
The invention concerns a spun nonwoven fabric which has different proportions of bicomponent filaments along its cross section. The remaining filaments are polyethylene terephthalate monofilaments.
BACKGROUND OF THE INVENTION
A spun nonwoven fabric of this kind is known from JP A Patent 435 28 61, as a material for bags. The spun nonwoven fabric includes two types, A and B, of long conjugated multicomponent filaments. Filament type A comprises the polymer components (a
1
) and (a
2
), the latter having a melting point 30 degrees C. higher than (a
1
). Filament type B comprises the polymer components (b
1
) and (b
2
), component (b
1
) having a melting point 20 degrees C. higher than component (a
1
), and component (b
2
) having a melting point more than 30 degrees C. higher than component (b
1
).
The nonwoven fabric of JP A Patent 435 28 61 further possesses a four-layer structure in cross section, the individual layers differing in that the first contains only filaments of type A; the second layer and third layers contain filament types A and B, with a higher proportion of filament type A in the second and a higher proportion of filament type B in the third layer; while the subsequent fourth layer consists only of filaments of type B.
The different melting points on the two surfaces of the nonwoven fabric and the different melting points in the cross section of the nonwoven fabric which result from this configuration prevent delamination of the individual layers.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the invention to provide a spun nonwoven fabric, made up of monofilaments and bicomponent filaments. Because of the different distribution of the filaments in the cross section of the nonwoven fabric, the interior of the nonwoven fabric may be configured harder or softer than at least one of its outward-facing surfaces. The different distributions of filaments are preferably achieved through a smooth transition to thereby avoid a layered structure with distinct phase boundaries. Avoiding distinct phase boundaries reduces the risk of delamination of individual layers, for example following high-temperature treatment during dyeing and steaming, or as a result of mechanical stress, for example during shaping.
The invention further provides an apparatus suitable for manufacturing a spun nonwoven fabric of the kind described above. In the existing art, multiple process steps, proceeding separately from one another, are necessary for manufacturing and for joining the individual layers of the nonwoven fabric. Each of the steps requires a separate, adjusted arrangement of the spinneret beam. In contrast, according to the present invention, a single apparatus with correspondingly arranged spinneret beams is sufficient for manufacturing the spun nonwoven fabric. This arrangement is similar to conventional apparatuses for manufacturing monofilaments.
It is an object of the present invention to provide a spun nonwoven fabric comprising monofilaments made of polyethylene terephthalate and bicomponent filaments made of polyethylene terephthalate and a polymeric binding component. The bicomponent filaments may have at least two outward-facing segments of the binding component. The bicomponent filaments, taken over cross sectional planes of the spun nonwoven fabric, are present in different weight proportions having a range from approximately 1% by weight to 100% by weight. The cross sectional planes of the spun nonwoven fabric, which have different proportions of bicomponent filaments, transition into one another without detectable phase boundaries.
It is a further object of the invention to provide an apparatus for manufacturing a spun nonwoven fabric comprising at least one spinneret device having a plurality of spinning orifices, the at least one spinneret device arranged above a stretching device adapted to receive filaments leaving the plurality of spinning orifices, and a transport device located beneath the stretching device for receiving the filaments, the transport device having a horizontally and linearly moving collector belt defining a transport direction. The plurality of spinning orifices of the at least one spinneret device face toward the collector belt. At least a first portion of the plurality of spinning orifices discharge a monofilament from a melt, and at least a second portion of the plurality of spinning orifices discharge a bicomponent filament from a melt, such that when viewed in a direction of motion of the collector belt a projection of the plurality of spinning orifices onto the plane of the collector belt corresponds to the concentration profile of the filaments in a vertical cross section of the nonwoven fabric. Viewed in the direction of motion of the collector belt, the filaments which impact the collector belt first are the filaments intended to constitute an outward-facing surface of the nonwoven fabric. Then, in continuous transition from the filaments deposited first, the filaments constituting inner regions of the nonwoven fabric are deposited. Finally, and in the same way, the filaments constituting a second outward facing surface of the nonwoven fabric are deposited in continuous transition from the filaments deposited before them. The filaments constituting any given cross section of the spun nonwoven fabric may include monofilaments, bicomponent filaments, or a mixture thereof.
REFERENCES:
patent: 4555430 (1985-11-01), Mays
patent: 5660910 (1997-08-01), Hoyt et al.
patent: 435 28 61 (1992-12-01), None
Barbier Detlef
Emirze Ararad
Goffing Norbert
Locher Engelbert
Firma Carl Freudenberg
Kenyon & Kenyon
Morris Terrel
Torres Norca L.
LandOfFree
Spun nonwoven fabric and apparatus for the manufacture thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spun nonwoven fabric and apparatus for the manufacture thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spun nonwoven fabric and apparatus for the manufacture thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2441651