Method and apparatus for making nonwoven from continuous filaments

Abstract

An apparatus for making nonwoven has a spinning device for spinning continuous filaments and moving the spun filaments in a vertical travel direction along a vertical travel path and a mesh belt below the spinning device, traveling in a horizontal direction, and having a multiplicity of vertically throughgoing openings distributed generally uniformly over its surface and of which a portion are plugged. A cooler and a stretcher are provided along the path downstream of the spinning device and above the belt for cooling and stretching the filaments and depositing the cooled and stretched filaments at a predetermined deposition location on the belt. A blower underneath the belt at the deposition location aspirates air through the openings and thereby holds the deposited filaments down on the belt.

Description

FIELD OF THE INVENTION[0001]The present invention relates to making a nonwoven. More particularly this invention concerns making nonwoven from continuous filaments.BACKGROUND OF THE INVENTION[0002]An apparatus for making nonwoven from continuous filaments, in particular thermoplastic monofilament, typically has at least one spinning device for spinning the filaments being provided, a device for cooling and stretching the spun filaments, and a device for depositing the drawn filaments to form the nonwoven. Continuous filaments differ because of their quasi-endless length from staple fibers that have much lesser lengths, for instance of 10 mm to 60 mm.[0003]An apparatus and method for making nonwoven of the type described above are known in practice in various embodiments. It is often desirable to produce structured nonwoven or spun nonwoven with a “3D structure” with varying local thicknesses or porosities. Various provisions for this purpose are also known in practice. For instance,...

AI Technical Summary

Benefits of technology

[0008]In addition, an object of the invention is to provide an apparatus of the type defined above with which a nonwoven with a 3D structure can be produced in a simple and efficient way, and this nonwoven is distinguished by an aesthetically perfect, replicable 3D structure and furthermore has a sufficiently soft hand.

[0023]It has been explained above that the plugged openings effect a lateral air motion in the air flowing through the mesh belt, and that, because of this lateral motion, the filaments in the air stream follow the stream and are thus deposited preferably onto the open mesh belt areas. The invention is based on the recognition that this shift in location can be effectively intensified if the sealing compound of the plugged openings projects upward past the mesh belt surface. Because of the crest created as a result, the deposited filaments can slide into the adjacent open mesh belt area, and the differences in the filament density or weight per unit of surface area can as a result be even more markedly pronounced. The invention is further based on the recognition that limits are set on the height of the area projecting from the mesh belt, since an area projecting too high is associated with reduced stability of the filament deposition.

[0038]The invention is based on the discovery that with the apparatus and the method of the invention, a structured spun-nonwoven with locally varying weights per unit of surface area can be made in a simple and cost-effective way. Within the scope of the invention it is possible, in a functionally safe and secure and relatively uncomplicated way, to produce nonwoven without having to sacrifice additional favorable properties. In particular, in comparison to the prior art, 3D-structured nonwoven with a soft hand can be produced in a simple and replicable way. The properties of the nonwoven can be varied to meet requirements in a targeted and problem-free way. As a result, the apparatus and the method of the invention are distinguished by low material and labor costs and functional safety and security.

Problems solved by technology

The deformation then also causes compacting; the overall strip of nonwoven becomes flatter, which impairs the desired soft hand of the strip of nonwoven.

However, this limits the choice of material for the strip of nonwoven, since many kinds of polymer fibers cannot be hot-air-consolidated without problems.

In the case of continuous filaments, these provisions have furthermore not proven themselves over time.

These provisions are disruptive and likely to produce flaws and have not proven themselves in practice.

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