CA1311889C

CA1311889C - Method for producing consolidated non-woven fabrics and non-woven fabrics

Info

Publication number: CA1311889C
Application number: CA000546143A
Authority: CA
Inventors: Klaus Albien; Gunter Maurer
Original assignee: Rhone Poulenc Rhodia AG
Current assignee: Cerdia Produktions GmbH
Priority date: 1986-09-06
Filing date: 1987-09-04
Publication date: 1992-12-29
Anticipated expiration: 2009-12-29
Also published as: NO162625C; EP0259692A2; EP0259692A3; ATE69073T1; US4818594A; DE3774218D1; NO873713D0; NO873713L; DE3630392C1; EP0259692B1; ES2026501T3; NO162625B

Abstract

ABSTRACT OF THE DISCLOSURE:

Process for the production of consolidated nonwoven fabrics for the absorption of water and/or substances with oleophilic and/or lipophilic properties by blow-spinning a melt or a solution of a spinnable polymeric material to textile fibers and/or filaments, namely those with a diameter of 0.1 to 6 µm, preferably 0.5 to 3 µm, transforming these textile fibers and/or filaments to a nonwoven fabric, consolidating this fabric and applying a wetting agent to the fabric, as well as nonwoven fabrics produced in this manner. According to the process the consolidation is carried out by means of water jets; a zwitterionic or cationic surfactant is applied to the fabric in a wet-in-wet procedure during or immediately after the water-jet consolidation, and the fabric is then dried; these procedures are performed continuously. A polyester or a polyamide is used preferentially as polymeric material. In comparison with known nonwovens of this kind, those accord-ing to the invention have a larger active absorbent surface area, improved strength characteristics and, among other things, an improved textile drape and feel.

Description

~ 31 t 8~q The present invention relates to a process for producing consolidated nonwoven fabrics for the absorption of water and/or substances with olephilic and/or lipophilic properties.
The present invention also relates to consolidated nonwoven fabrics for the absorption of water and/or substances with oleophilic and/or lipophilic properties.
It is known to produce consolidated nonwoven fabrics for the absorption of water and/or oil by blow-spinning molten polypropylene to form fiber webs whose fibers have an average diameter up to lO~m, pattern-binding the fiber webs with pins, and spraying an anionic or nonionic surface-active substance onto the fiber webs.
The known nonwoven fabrics of this kind, however, have the following disadvantages:
- Pattern-binding with pins considerably reduces the surface of the nonwovens that is active in the absorption of water and/or oil.
- Since pattern-binding with pins cannot be performed on the entire surface area, since otherwise the fabric surface active in the absorption of water and/or oil is completely lost, such partially pattern-bound nonwovens have but relatively low strengths, such as maximum tensile strength, initial tearing resistance and tear growth resistance as well as a relatively high raveling loss (i.e. abrasion).
- The pattern-binding cannot change the original bidimensional arrangement of the fibers in the fabric, i.e., the arrangement of the fibers in the lengthwise and transverse directions. Consequently, not only is no improvement of the fabrics possible in regard to the textile drape and feel and the i, softness, but a decided impairment occurs in this regard.
The invention is addressed to the problem of creating a process of the kind described above, whereby nonwoven fabrics can be obtained, which - will have a greater effective surface area than known nonwovens of this kind for the absorption of water and/or oils, fats and the like, - will have improved strengths, such as improved maximum tensile strength, improved initial tearing resistance and improved tear growth resistance as well as a lesser raveling loss (i.e. abrasion), in comparison to the known nonwovens of this kind, - will have a better textile drape and feel and improved softness, in comparison to the known nonwovens of this kind.
According to the present invention, there is provided a process for the production of a consolidated nonwoven water and oil wipe fabric comprising the steps of:
(a) forming a melt or a solution of a spinnable polymeric material;
(b) blow-spinning said spinnable polymeric material through a spinneret means having at least one nozzle orifice to form textile fibrous elements having a diameter in the range of 0.1 to 6 ~m:
(c) depositing said textile fibrous elements on a receiving means;
(d) consolidating said textile fibrous elements on said receiving means by a water-jet means to form a consolidated nonwoven fabric;
(e) concurrently or subsequently applying a zwitter-ionic or cationic surfactant agent to the consolidated nonwoven fabric in a wet-in-wet procedure; and (f) drying the thus treated consolidated nonwoven fabric.
Spinnable polymeric materials preferably employed in the process are polyesters or polyamides and most preferably polyethylene terephthalate is the polyester used and the polyamide used is polyamide-66 (i.e., poly-hexamethyleneadipamide).
Wetting or surfactant agents preferably employed include alkoylamino-3-dimethylamino-propane-3-N-oxide, cocamidopropyl-betaine, or 1-alkoylamino-3-dimethylammoniopropane-3-carboxymethylbetaine,andalkyl-dimethyl-benzylammonium chlorides are used.

Polyesters and polyamides are preferably used in the inventive process as spinnable polymeric materials because:
The nonwoven fabrics obtained can be dried at high temperatures, e.g., decidedly above 150C, and are usable even at such high temperatures for the absorption of water and substances with oleophilic and/or lipophilic properties, and The nonwoven fabrics obtained have very high strengths, especially a high maximum tensile strength, initial tearing resistance and tear growth resistance.
The textile fibers and/or filaments obtained in the process preferably have a diameter of 0.5 to 3 ~m because this fineness of the textiles fibers and filaments, i.e., on account of their small diameter and thus great specific surface area, produce nonwovens having a very large active surface for the absorption of water and/or substances with oleophilic and/or lipophilic properties.
The above preferred wetting agents, namely, 1-131 18~q alkoylamino-3-dimethylamino-propane-3-N-oxide, cocamidopropyl-betaine, or . l-alkoylamino-3-dimethylammonio-propane-3-carboxymethylbetaine address special problems, for example in the treatment of metals, where anticorrosive protection and rapid drying are important.
The other preferred wetting agents, namely, alkyl-dimethyl-benryl-ammonium chlorides, offer the advantage that they are biodegradable and tolerant (harmless) to the skin.
It is also the object of the invention to make available consolidated nonwoven fabrics of the kind described, which in comparison to the known nonwovens of this kind, have a larger active area for the absorption of water and/or oils, fats and the like, in comparison to the known nonwovens of this kind, have improved strength characteristics, such as improved maximum tensile strength, initial tearing resistance and tear growth resistance, as well as reduced raveling loss (abrasion), and in comparison to the known nonwovens of this kind, have a better textile drape, feel and an improved softness.
According to the present invention, there is also provided a consolidated nonwoven water and oil wipe fabric, comprising:
- textile fibrous elements having a diameter in the range of ~.1 to 6 ~m, deposited on a receiving means and consolidated to said receiving means by a water-jet means to form a consolidated nonwoven fabric, and - a zwittterionic or cationic surfactant agent contained in said consolidated nonwoven fabric in a 131 18~q final dried form of said fabric.
For the purposes of the invention, any materials can be used as spinnable polymeric materials which can be fabricated by melt spinning or solution spinning (dry spinning); suitable are especially polyesters such as polyethylene terephthalate, and polyamides such as polyamide-66, but also, for example, polyolefins such as polyethylene and polypropylene, cellulose esters such as cellulose-2,5-acetate and -triacetate, and acrylic polymers such as polyacrylonitrile.
By the process according to the invention, a melt or a solution of a spinnable polymeric material is blow-spun to textile fibers and/or filaments. Such blow-spinning is described, for exemple, in "Industrial and Engineering Chemistry", vol. 48, No. 8 (1956), pages 1342 and 1346, and in German Patent 19 64 060.
Substances with oleophilic and/or lipophilic properties are, for example, oils such as mineral oils or silicone oils, and fats or their mixtures.
According to the invention, the consolidation of the nonwoven fabric is performed by water jets. This kind of water jet consolidation is described, for exemple, in german Offenlegungsschrift 17 10 989 and in German _", - 4a -131 188q Auslegeschrift 16 35 577.
Water-jet consolidation produces an entanglement and post-stretching of the spun fibers and/or filaments within the nonwoven fabric, whereby - additional active surface is obtained for the absorption of water and/or substances with oleophilic and/or lipophilic properties, lO- the fabric is given improved strength properties and reduced raveling loss (abrasion), and - the fabric improves in textile drape and feel and in softness.
According to the invention, a zwitterionic or a cationic surfactant is placed on the fabric as wetting ; agent. Suitable zwitterionic surfactants are especially aminoxides and betaines, but also imidazoline carboxylates and aminocarboxylic acids. Suitable cationic surfactants are, for example, primary, secondary, tertiary or quaternary ammonium salts, benzylammonium salts, alkanolammonium salts, pyridinium salts, imidazolinium salts, oxazolinium salts, thiazolinium salts, sulfonium salts, quinolinium salts, salts of aminoxides, tropylium salts, and isoquinolinium salts. If desired, mixtures thereof can also be used.
The nonwoven fabrics according to the invention can be used as roll goods or in pieces cut to measure therefrom, for cleaning purposes in industrial or non-industrial applications; it is important that both water andsubstances with oleophilic and/or lipophilic properties can be absorbed by the nonwoven fabrics.
The invention will now be further explained with the aid of the examples:

131 18~q Example 1 Polyethylene teraphthalate with an intrinsic viscosity of 0.67 (measured in tetrachloroethane-phenol 1:1), a melt viscosity of 2,4000 dPa.s and a moisture content of 0.1 weight-percent was melted at 323C and melt-blow-spun by means of a spinning head (spinneret) similar to the one according to German Patent 2S 50 463 to textile fibers and filaments having an average diameter of 1.8 ,um.
The textile fibers and filaments were made into a nonwoven fabric with a basis weight of 100 g/m2 by deposition onto a receiving means which consisted of a rotating drum. The spinneret was situated above the rotating drum and the spinning was performed vertically downwardly.
The nonwoven fabric, which had a width of 200 mm was guided over rollers onto a circulating endless screen belt which was part of a water jet consolidating apparatus based on the principle of the one described in German Auslegeschrift 16 35 577.
The water jet consolidating apparatus had eight rows of water jets disposed above the fabric at an angle of 90 to the direction of movement of the fabric. Each row of water jets had a length (effective jet width) of 200 mm and had 100 nozzle holes. The distance of the nozzles from the fabric was 100 mm and a water pressure of 120 bar prevailed ahead of each nozzle. The water jets formed an angle of 90 with the fabric.
By then passing the fabric through wringer rolls the process water was removed down to a residual moisture content in the fabric of 100%.
This was immediately followed by the application of the wetting agent by passing the fabric over a patterned wetting roll. The wetting agent was 1-alkoylamino-3-dimethylaminopropane-3-N-oxide. The liquid absorption of 1 3 1 1 88q the fabric amounted to 100~ of the initial dry weight of this fabric. The bath of the wetting agent had a concentra-tion of 0.5 weight-percent of the above-named wetting agent;
the fabric thus received a content of 0.5 weight-percent of S wetting agent, with respect to the dry weight of the fabric.
From the wetting roll the fabric was carried through a drying oven where it was dried down to a residual moisture content of about 1% and then wound on tubes.
The process speed, i.e., the speed with which the fabric ran continuously through the above-described steps, amounted to 2 meters per minute. The consolidated fabric obtained had a maximum tensile strength (measured according to DIN 53857) in the lengthwise direction of 8.3 daN and of 4.5 daN in the transverse direction.
lS The specific textile fiber and filament surface area of this fabric that was active for the absorption of water and/or oils and/or fats and the like amounted to 1.6 m2/g (measured by the BET method), corresponding to 160 m2 of surface per square meter of fabric. The oil absorption of this fabric (measured according to the oil binder guideline of the Federal Ministry of the Interior in the text of 31 December 1985) amounted to 4.3 grams of oil per gram of fabric.
The ability of this fabric to absorb water (measured by adapting the oil binder guideline mentioned above) amounted to 5.8 g of water per gram of fabric.
Purthermore, the consolidated~ fabric obtained had a pleasant, soft textile feel and good draping quality.

Example 2 Example l was repeated except that - the application of the wetting agent was performed not by guiding the fabric over a patterned wetting roll but by applying to the fabric this agent, con-tained in an 0.3 weight-percent solution in the process water, through the water-jet consolidating apparatus, - instead of the wetting agent named in Example 1, a mixture of alkyl-dimethylbenzylammonium chlorides was used, which is sold by Hoechst AG, Frankfurt-on-the Main, Federal Republic of Germany, under the mark Dodigen 226*

- the process water was removed after the water-jet consolidation by passing the fabric through wringer rolls to a residual moisture content in the fabric of 200~, the fabric thus receiving a content of 0.6 weight-percent of wetting agent, with respect to the - dry weight of the fabric, - immediately after removal of the process water the fabric was dried by passing it through a drying oven down to a residual moisture content of about 1%.

In the rest of its properties the consolidated fabric obtained was the same as the fabric of Example 1.
The invention has the following advantages:
The consolidated nonwoven fabrics produced accord-ing to the invention have - a greater active surface for the absorption of water and/or oils, fats and the like, - improved strength characteristics and less loss by raveling (abrasion), and * Dodigen 226 is a trade mark, 1 31 1 8~q - a better textile drape and feel and improved softness in comparison to known consolidated nonwoven fabrics for the absorption of water and substances with oleophilic and/or lipophilic properties.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for the production of a consolidated nonwoven water and oil wipe fabric, comprising the steps of:
(a) forming a melt or a solution of a spinnable polymeric material;
(b) blow-spinning said spinnable polymeric material through a spinneret means having at least one nozzle orifice to form textile fibrous elements having a diameter in the range of 0.1 to 6 µm;
(c) depositing said textile fibrous elements on a receiving means;
(d) consolidating said textile fibrous elements on said receiving means by a water-jet means to form a consolidated nonwoven fabric (e) concurrently or subsequently applying a zwitterionic or cationic surfactant agent to the consolidated nonwoven fabric in a wet-in-wet procedure; and (f) drying the thus treated consolidated nonwoven fabric.

2. A process according to claim 1, where said spinnable polymeric material in step (a) is a polyester or polyamide.

3. A process according to claim 2, where said polyester in polyethylene terephthalate and said polyamide is polyamide-66.

4. A process according to claim 1, where said textile fibrous elements in steps (a) and (b) have a diameter in the range of 0.5 to 3 µm.

5. A process according to claim 1, where said surfactant agent in step (e) is selected from the group consisting of aminoxides, betaines, imidazoline carboxylates, aminocarboxylic acids, primary ammonium salts, secondary ammonium salts, tertiary ammonium salts, quaternary ammonium salts, benzylanmmonium salts, alkanolammonium salts, pyridinium salts, imidazolinium salts, oxanolinium salts, thianolithium salts, sulfonium salts, quinolinium salts, salts of aminoxides, tropylium salts, isoquinolinium salts, and mixtures thereof.

6. A process acording to claim 5, where said surfactant agent is 1-alkoylamino-3-dimethylaminopropane-3-N-oxide, cocamidopropyl-betaine or 1-alkoylamino-3-dimethylammonio,propane-3-carboxymethylbetaine.

7. A process according to claim 5, where said surfactant agent is an alkyl-dimethyl-benzylammonium chloride.

8. A process according to claim 1, where step (e) is performed concurrently with step (d).

9. A process according to claim 1, where step (e) is performed subsequent to step (d).

10. A consolidated nonwoven water and oil wipe fabric, comprising:
- textile fibrous elements having a diameter in the range of 0.1 to 6 µm, deposited on a receiving means and consolidated to said receiving means by a water-jet means to form a consolidated nonwoven fabric, and - a zwitterionic or cationic surfactant agent contained in said consolidated nonwoven fabric in a final dried form of said fabric.

11. A consolidated nonwoven water and oil wipe fabric according to claim 10, wherein said fibrous elements comprise spinnable polymeric material.

12. A nonwoven water and oil wipe fabric of claim 11, where said spinnable polymeric material is a polyester or polyamide.

13. A nonwoven water and oil wipe fabric of claim 12, where said polyester is polyethylene terephthalate and said polyamide is polyamide-66.

14. A nonwoven water and oil wipe fabric of claim 10, 11, 12 or 13, where said textile fibrous elements have a diameter in the range of 0.5 to 3 µm.

15. A nonwoven water and oil wipe fabric of claim 10.
where said surfactant agent is selected from the group consisting of aminoxides, betaines, imidazoline carboxylates, aminocarboxylic acids, primary ammonium salts, secondary ammonium salts, tertiary ammonium salts, quaternary ammonium salts, benzylammonium salts, alkanolammonium salts, pyridinium salts, imidazolinium salts, oxanolinium salts, thianolithium salts, sulfonium salts, quinolinium salts, salts of aminoxides, tropylium salts, isoquinolinium salts, and mixtures thereof.

16. A nonwoven water and oil wipe fabric of claim 15, where said surfactant agent is 1-alkoylamino-3-dimethylaminopropane-3-N-oxide,cocamidopropyl-betaineor 1-alkoylamino-3-dimethylammonio-propane-3-carboxymethylbetaine.

17. A nonwoven water and oil wipe fabric of claim 15, where said surfactant agent is an alkyl-dimethyl-benzylammonium chloride.