DE3601144A1 - ELASTOMERIC, FIBROUS NON-WOVEN FLEECE AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Description

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description

The invention relates to non-woven fiber materials, in particular made elastic non-woven fiber materials and a method for producing such materials.

\ J The production of elasticized non-woven fiber materials are combined by the method in the conventional textile fibers with elastisierbaren fibers in U.S. Patent 4,426,420 (Likhyani) and the structure to make elastically _around the elastisierbaren fibers, is heat-treated, showed been. This patent discloses the production of non-woven wadding consisting of a so-called "hard fiber" and a "potentially elastic fiber". The hard fibers are described as including any synthetic or natural fiber-forming materials such as polyesters, polyamides, etc., or natural such as cotton, silk, paper, etc. The potentially elastic fibers are considered to be elastomeric compositions of the type which are rendered elastic by heat treatment. The Likhyani patent discloses a method of making a so-called "spunlaced" non-woven structure in which wadding composed of at least two types of staple fibers relieves hydraulic entanglement by fine, high pressure water column streams which disentangle the fibers in order to provide the spunlaced material available. Once tangled, the resulting structure is heat treated to develop elastic properties in the elastomeric fibers. The elastomeric filaments were extruded, cold drawn and cut to the desired fiber length as described in the sole example of the patent.

According to the invention a method for producing a non-woven elasticized fiber material, comprising combining, mixing or blending at least one type of textile fiber with at least one type of a uniaxially oriented elasticizable fiber, bonding the combined fibers to one another to form a nonwoven, a matrix, a Layer, or the like. To bilc'en, and heating the resulting web in order to heat-shrink the oriented fiber, which in this way regains or regains its elastic properties. In this way, the resulting fleece has elastomeric properties.

One aspect of the invention comprises combining from about 1 to 50% by weight, preferably 5 to 35% by weight of the elasticized fiber with about 99 to 50% by weight, preferably 95 to 65% by weight of the textile fiber.

In another aspect of the invention, the elasticizable fiber comprises an extruded synthetic elastomeric polymer and the method comprises the steps of cold drawing an elasticizable filament to uniaxially orient the filament to stretch it by at least about 100 %, preferably about 100 to 500 % of its original length; then the steps of cutting to pre-form filaments of a desired fiber length. This fiber is combined and bonded to the textile fiber while the elasticized fiber is in its oriented state to form a suitable web.

According to the invention, the fleece obtained is heat-shrunk, preferably at a temperature of about 75 to 200 ° C to shrink the oriented fiber to about 10 to 90% of its elongated length.

Another aspect of the invention includes combining at least one Type of textile fiber, at least one type of meltblown fiber and at least one type of elasticizable fiber, around the nonwoven fiber material to build. A certain aspect of the invention is that the elasticizable fiber is selected from the group consisting of styrene-butadiene copolymers, Styrene-butadiene-styrene copolymers and polyurethanes.

According to the invention, an elasticized non-woven fiber material is also used made available comprising at least one type of textile fiber bound to at least one type of elastic fiber obtained by heat treating an oriented preform, wherein the textile fiber is pulled together and folded during the heat shrinkage of the preform, in order to make the elastic fiber elastic, but the textile fiber being released enough to return to about its original state when stretched To expand elongation value.

The fiber material can further include at least one type of meltblown Include fiber.

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Non-woven structures are known and generally include textile fibers, which may be of various lengths from very short fibers to very long or substantially continuous fibers that have been combined are to form a fleece or wadding with a non-woven structure. The term "textile fiber" as used herein and in the claims includes each Fiber that can be used in the manufacture of a non-woven structure. Such fibers can be made from synthetic organic materials Polymer materials, processed natural materials, or a combination from it. Exemplary synthetic fibers usable as textile fibers in the present invention include polyester fibers, Polyamide fibers such as nylon, acrylic polymer and copolymer fibers, glass fibers, polyolefin fibers such as polyethylene and polypropylene fibers, cellulose derivatives, such as rayon and mixed fibers, such as fibers of one material covered with a coating of another material. For example, polypropylene fibers are sheathed with polyethylene, known. Fibers made from pretreated natural materials, e.g. natural fibers that can be used as textile fibers include, but are not limited to, cotton, silk, wool, pulp or paper and the like in the present invention as well Mixtures or combinations of two or more of the foregoing fibers. Such textile fibers are usually made of elastic fibers differentiated, as the textile fibers generally have extremely limited elastic properties, i.e. they can usually not exceed 40% elongate, usually 20 to 40% of their initial length before breaking and generally have a modulus of elasticity on the order of about 18 to 85 grams per denier, or perhaps higher.

The term "elasticizable fiber" as used here and in the claims refers to such materials, usually synthetic polymeric elastomeric materials, that (a) can be extruded into filaments,

(b) can be drawn, usually at room temperature (cold drawn), to elongate, stretch or orient the filaments that want to maintain their stretched state while relaxing by loosening them tension and (c) when heated, the tensioned material shrinks significantly in order to regain its elastomeric properties or to resume.

By "elasticizing" it is meant that the heat-shrunk fibers are in are able to apply to all or almost all of their relaxed, preheated,

elongated lengths to be stretched and roughly their heat-shrunk Regain length when the stretching force is released.

The drawn filament is preferably cut to a desired fiber length 5

cut, the length depending on such factors as the definite processes used or the end use of the material. Before being elasticized, the elasticizable fibers can be airlaid, carded or otherwise in non-woven fleeces in essentially the same way

The way textile fibers are shaped.
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With the term "cold drawing" as used here and in the claims is meant a process in which the elastomeric fiber or preform is drawn or stretched when it is substantially below its extrusion temperature is cooled, usually when it has cooled to room temperature. This pulling is conventionally used to remove the Strengthen and decrease the diameter of the extruded fiber. The cold drawing, as used in the present invention, at a temperature below the extrusion temperature, preferably at room temperature, and the cold drawing is preferably carried out to the extent that the fiber is about 100 to 500% or less elongate more, for example 1000%, but usually by about 100 to 400% of their original length.

In the present invention, the elasticizable fiber is made with the textile fiber and can optionally be combined with other materials such as meltblown fibers using any suitable Processes such as drying, wet laying or carding processes, and the combined fibers are then prepared using any suitable Process bound that the elongated elasticizable fibers are not heated to shrinkage, since according to the invention the heat shrinkage of the elasticizable fibers after they are bonded to the textile fibers or the textile and meltblown fibers. Thus can bonding, e.g. latex spray binding, sound wave binding or any combination of suitable methods, as long as the shrinkage temperatures, until the binding process is complete.

The result is a shrinkable, more precisely a heat-shrinkable fiber material, whereby the shrinkage of the elasticizable fibers makes the fleece from

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* bound elasticizable fibers and textile fibers shrink. In a preferred Embodiment of the bonding, a thin coating of a suitable adhesive, such as a latex, for example a urethane latex, is sprayed onto the fleece of the combined fibers. The fibers can be combined in any suitable manner and the term "adhesive" as used herein and in the claims becomes used broadly to include any material which binds the combined fibers together is intended and suitable for the purposes of the invention is. Adhesive or sonic binding is preferred because it physically binds the fibers connects, not only through frictional entanglement, so that the heat treatment to shrink the elasticizable fibers and thereby become elastic to make the textile fibers relaxed so that they do not hinder the stretching of the elasticized fibers. The length and width of the fleece Fiber material is reduced after the heat treatment.

After the combined fibers have been bonded together, will the resulting nonwoven fiber material is heated by suitable means, such as passing through by an oven, urtfr Heizismpen, infrared radiation or the like, to heat the elasticizable fibers enough to shrink them to give them the desired elastic properties. The fibrous material containing the elasticizable fibers is in one during the step of heating to allow contraction relaxed state.

A significant advantage available through the method according to the invention is that, since the elasticizable fibers, when bound to the textile fibers, are oriented, as the former shrinks the textile fibers bound to it contract and form loops or fold when the elasticizable fibers contract. Thus when the finished structure is stretched, even when it is stretched to the extent that the now elasticized fibers are returned to their original Return pre-shrunk length ^ there is sufficient slack in the textile fibers that they do not restrict stretching of the structure.

In other words, the maximum stretching of the elasticized fibers, even to their pre-shrunk length, the textile fibers only stretch to the level they were at when they were not shrunk elasticizable fibers were bonded. This contributes extremely to the comfort and the ability of the non-woven structure of the fabric to stretch.

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finding at.

The elasticizable fibers useful in the present invention can be any suitable fiber as described above. A suitable elastic ° matable fiber is under the trademark KRATON (Shell Chemical Company) and another is commercially available under the trademark ESTANE (BFGoodrich Company). Other suitable compositions are disclosed in U.S. Patents 3,007,227, 3,651,014, 3,766,143, and 3,763,109, the disclosures of which are incorporated herein by reference. The ESTANE elasticizable fiber is a urethane polymer and the KRATON elasticizable fiber is a styrene-butadiene-styrene copolymer.

The examples illustrate the invention. 15th

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example 1

Various types of elasticizable urethane polymers available at

the trademark ESTANE by B.F. Goodrich Chemical Company and ver-5

Various types of elasticizable styrene-butadiene-styrene polymer are available under the trademark KRATON from Shell Chemical Company were extruded into filaments. The extruder has four along the screw Heat zones, which are typically at temperatures of 148.9 C, 168.3 C, 176.7 C and 182.2 C in the direction of extrusion. The tool includes 8 openings, each 0.254 mm (10 mil) in diameter, and a mold pressure of 241300 to 379200 hPa was used. To Cooling to room temperature, the filaments were extruded over rollers with the following typical results, depending on the specific

Extrusion conditions, cold drawn.
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Table 1

Elasticized

Polymer (a) (b) (c) (d)

ESTANE 57Ο7 551600 122.11 0.616 308

ESTANE 5710 482600 135.18 0.341 254

KRATON 11Ο2 317 200 39Ο.3 Ο.198 1OS5

KPATON 3200 117200 139.8 0.0 ~ 6 268

(a) = nominal tensile strength (hecto-Pascal hPa)

(b) = denier per filament

(c) = tensile strength, grams per denier

(d) =% elongation at break

The percentage values of the elongation at break show highly elastic fibers that after are shrinkable to a portion of their elongated length upon heat treatment and are resilient between their heat-shrunk and elongated lengths.

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Example 2

A four-strand, super-crimped Nyon fiber was made into a carded batt shaped and stretched; the elastic fibers made from KRATON 3200 copolymer extruded as described above was airlaid onto the carded nylon. The elasticizable fibers had one Denier of 139.8 0.076 grams per denier and an elongation at break of 268%. The fiber content of the finished web comprised 60% by weight of the elasticizable fiber and 40% by weight nylon. The fleece made of fiber material showed the following shrinkage upon heating and the corresponding

Elasticity: C.
i % Shrinkage of the fleece Heating
temperature
15th 8O ⁰ C 12O ⁰ C 150 ⁰ C sample 29 35 44 1 3O 37 45 2 29 33 43 3
20th Example 3

A bonded nonwoven was made from 1.5 parts by weight of Enka Rayon 700 staple fibers (14,224 mm long), 1.5 parts by weight of polypropylene staple fibers (14,224 mm long) and 12 parts by weight of the elasticizable KRATON 5200 fiber from Example 2. A urethane bonding liquid was sprayed onto the batt using a spray template in a pattern of dots 3.17 mm in diameter that were almost touching. The urethane binder contains 80% by weight of the finished bonded fleece. The non-woven of fibrous material held on heating at 120 to 13O ⁰ C 38% shrinkage from.

Example 4

A bonded non-woven fabric was made from 4 parts by weight of polypropylene staple fibers (14.224 mm length), 9 parts by weight of KRATON 32OO fibers from Example 2, cut to 14.224 mm staple length, and the combined

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Fibers were bonded with a pattern of 5 points of a urethane tie, so that the finished fleece contained 70 wt .-% urethane binder. When heated to 120 to 130 C, the nonwoven made of fiber material showed a 65% shrinkage.

the.

fiber webs according to the invention show excellent elasticity as Extensibility, which is unhindered by the limited extensibility of the textile fibers. This follows from the method described above, in which the elasticizable fibers in their elongated, pre-shrunk state are bound to the textile fibers to form a shrinkable fleece

Claims (14)

Elastomeric, fibrous non-woven fleece and process for its production. Patent claims 1. Elastomeric non-woven fleece, characterized by a large number of textile fibers that are gathered and folded., a plurality of heat-shrunk elasticized fibers, combined with the aforementioned textile fibers, with at least some of the elasticized fibers being bound to at least some of the textile fibers, the gathering and folding of the textile fibers being formed by the shrinkage of the heat-shrunk elasticized fibers. 2. Non-woven fleece, characterized by a large number of textile fibers and a plurality of heat-shrunk elasticizable fibers, wherein at least some of the elasticizable fibers to at least some of the textile fibers ₂ 36011U are bound, the aforementioned elasticizable fibers to Shrinking and gathering and folding of the textile fibers when using Apply heat to the fleece. 3. Fleece according to claim 1 or 2, characterized in that that it further comprises a plurality of meltblown fibers. 4. Process for making an elastomeric fibrous non-woven Fleece, characterized in that it has the following stages includes: Combining a plurality of at least one type of textile fiber with at least one type of uniaxially oriented elasticizable Fiber;
15th and bonding at least some of the textile fibers to at least some of the elasticizable fibers to form a fleece and Heating the nonwoven to shrink and shrink the elasticizable fibers to make elastic. 5. A method for producing an elastomeric non-woven fleece, thereby characterized in that it comprises the following stages: Extruding a synthetic elastomeric polymer as an elasticizable one Filament; uniaxial orientation of the elasticizable filament by stretching the Filaments by at least 100%;
30th Cutting the uniaxially oriented filament to make a variety uniaxially to provide oriented fibers; Combining a plurality of the aforementioned uniaxially oriented Fibers comprising a plurality of at least one type of textile fiber; Bind at least some of the textile fibers to at least some of the elastic convertible fibers to form a non-woven fleece and Heating of the non-woven fleece to the elasticizable fibers to shrink and make elastic.
5 6. A method for producing an elastomeric non-woven fleece, thereby characterized in that it comprises the following stages: Extruding a synthetic elastomeric polymer as an elasticizable one Filament; Cold drawing the elasticizable filament to make the filament uniaxial orientate; Cutting the uniaxially oriented filament to make a variety uniaxially to provide oriented elasticizable fibers; Combining the aforesaid plurality of uniaxially oriented elasticizable fibers with a plurality of textile fibers;
20th Bonding at least some of the textile fibers to at least some of the elasticizable ones Fibers to form a non-woven fleece and Heating the non-woven fleece in order to shrink the elastic fibers and make them elastic. 7. Process for the production of an elastomeric non-woven fleece, characterized by the following stages: Combining a variety of textile fibers with a variety uniaxial oriented elasticizable fibers; Bonding at least some of the textile fibers to at least some of the elasticizable ones Fibers to form a non-woven fleece and Heating of the non-woven fleece in order to shrink and make the elasticizable fibers elastic, whereby at least some of the textile 36011U 4 fibers can be gathered and folded. 8. The method according to any one of claims 4 to 7, characterized in that the combining stage is carried out so that the Nonwoven comprises about 1 to about 50 percent by weight of the elasticizable fiber and about 99 to about 50 percent by weight of the textile fiber. 9. The method according to any one of claims 1 to 8, characterized in that that the combining stage is carried out so that the ■ "■ ^ nonwoven about 5 to about 35 wt .-% of the elasticizable fiber and about Comprises from 95 to about 65 percent by weight of the textile fiber. 10. The method according to any one of claims 4 to 9, characterized in that the textile fibers to the elasticizable fibers ■ * - ° be connected by applying an adhesive to it. 11. The method according to any one of claims 4 to 10, characterized in that at least one type of meltblown fiber is combined with the textile fibers and the uniaxially oriented elasticizable fibers. 12. The method according to any one of claims 4 to 11, characterized in that the step of heating on heating the fleece comprises a temperature of from about 75 to about 200.degree. 25th 13. The method according to any one of claims 4 to 12, characterized in that a discrete object is formed from the fleece before the fleece is heated, around the elasticizable fibers to shrink and make elastic.
30th 14. The method according to any one of claims 4 to 13, characterized in that the elasticizable fibers are formed from a material selected from the group of styrene-butadiene copolymers, Styrene-butadiene-styrene copolymers and polyurethanes. 35