SK280022B6 - Process for decatising a textile fabric - Google Patents

Abstract

Covering fabric decatising on perforated drum for worsted fabric. A textile fabric, optionally with an appreciable portion of wool fibres, is decatised in an autoclave together with a covering fabric while wound round a perforated decatising drum. The covering fabric is a surface structure of non-oriented fibres weighing less than 80 g/m2 and having a water vapour permeability of more than 3500 g/m2/24 hours. The covering fabric may consist of a cheap fibrous web made of synthetic polypropylene or polyethylene fibres. The fibres are connected in accordance with a type of a punched felt or by means of a chemical or thermal adhesing.

Description

Technical field

The invention relates to a method of decatting (a vapor deposition to remove gloss) of a woven fabric of wool fibers or a fabric made using a substantial proportion of wool fibers. Here, the textile thread is wound together with the tread on a perforated decatting roller and the coil thus formed is subjected to an autoclave heat treatment.

BACKGROUND OF THE INVENTION

In generally known decatting processes, the coils are optionally formed outside the decatting autoclave, and then the coil is placed in the autoclave or inside the decatting autoclave, so that the transport of the coil back and forth is discontinued. in an autoclave. For other pressure and dimensional advantages of coil formation and removal within the autoclave, reference is made to DE-AS 17 85 460.

A disadvantage common to all the known decatting method results from the strip material used as the tread, whose width and length dimensions must correspond to the textile fabric to be decatted. In this case, the tread is exposed to high pressures and temperatures, as well as to moisture and residual chemicals, in particular carbon acids, reducing agents, sheet fixatives and the like, which have a detrimental effect on the tread. To maintain its durability for at least a limited period of use, a valuable fabric is used. But it is not only costly, but it is also burdened with other disadvantages. In order to meet the mechanical and chemical requirements, the tread has to be made robustly, so it is relatively thick and has a correspondingly high basis weight. The thickness of the tread promotes undesirable characteristics on the fabric to be coated and also causes overheating, which can cause unevenness in the processing result. Finally, the tread thickness also limits the capacity of the decatting autoclave for the textile fabric to be processed.

SUMMARY OF THE INVENTION The object of the invention is to improve the decatting method of the kind described in such a way that it can be carried out more economically than conventional decatting methods, and also enables qualitatively better processing results.

SUMMARY OF THE INVENTION

The solution to this problem is to use as a tread a flat fabric composed of non-oriented fibers whose basis weight is less than 80 g / m ² and whose water vapor permeability is not less than 3500 g / m ² / 24h.

The web fabric used as a tread by the process of the invention may, for example, consist of a cheap thin fibrous web which is made of synthetic polypropylene or polyethylene fibers or the like, wherein the fibers may be bonded together according to the type of needle felt or also by chemical or thermal bonding. What matters is the low basis weight of the tread used and its good water vapor permeability. On the other hand, the high mechanical strength can be dispensed with, since the small costs required for tread production make it possible to replace the tread with a new one, while maintaining the economy, even after a small application. As a tread suitable, inexpensive, commercially available sheet material is recyclable and can therefore also be reprocessed to a new tread material.

According to one embodiment of the method of the invention, the fabric with a residual moisture content of from 10 to 100 wt. wound on a perforated cylinder and in this state is subjected to a heat treatment.

A particular advantage of this method is that the woven textile fabric to be woven for decatting does not require any intermediate drying after dyeing and before the decatting process, but must only be spun to the desired residual moisture. On the other hand, with conventional treads, intermediate drying is necessary because the high tread thickness causes overheating of the damp textile fabric.

Finally, an embodiment of the method according to the invention assumes that the residual moisture required during the treatment of the textile fabric present in the autoclave is maintained and regulated by external steam supply.

DETAILED DESCRIPTION OF THE INVENTION

In order to emphasize possible qualitative improvements of the method according to the invention over conventional methods, the following experiments were carried out:

1. A 1.6 m wide combed yarn of plain wool yarn weighing 280 g / m and a corresponding basis weight of 280 g / m 2: 1.6 = 175 g / m ² was declared using a conventional tread with a basis weight of 440 g / m ² .

2. It is precisely such a combed yarn fabric that has been decatted under otherwise unchanged conditions using a fiber web of 18 g / m ² .

In both decatting processes, the combed yarn fabric was always stored dry in a decatting autoclave. During the decatting process, both the decatting processes consistently added 100 wt.% Moisture. steam.

The examination of the textile fabric tested with the conventional tread (test I) and the textile fabric test with the process of the invention (test II) gave the following mean values for the following parameters:

A. Determination of Kowabat feel

1. Flexural stiffness in pNm

exam 1: osnova str. h. x 7.40; Std. variation with 0,298 Attack x 5.89; '* with 0,249 exam II: osnova x 7.01 with 0,346 Attack x 6,23 with 0,277

2. Size of bending hysteresis in mMm / m

test I: osnova str. h. x 0,238; Std. deviation with 0.0444 Attack x 0,181;  with 0,0300 exam II: osnova x 0,230  with 0.0524 Attack x 0,197  with 0.0272

3. Shear stiffness in N / M series

test I: osnova str. h. x 41; Std. deviation with 2.0 attack x 40; '' with 1.4 exam II: warp x 23; '' with 0.7 attack x 22; " with 1.8

4. Size of hysteresis in shear at 0.5 ° in N / M test I: osnova str. h. x 0.6; Std. variation s 0,01 Attack x 0.5; s 0.09 exam II; osnova x 0.4; s 0.04 Attack x 0.4; with 0.03

5. Shear hysteresis at 5 ° in N / m

test I: osnova str. h. X 1.5; Std. variation with 0.02 attack ” x 1.4; with 0.05 exam II: warp x 0.6; with 0.02 attack x 0.6; with 0.02

6. Highest ductility at 500 cN / cm in%

test I: osnova str. h. x 3.7; Std. variation with 0.19 Attack x 5.7; with 0.10 exam II: osnova x 6.7; with 0.28 Attack x 7.9; with 0.50

7. Tensile work in J / m ²

test I: osnova str. h. x 6.6; Std. variation with 0.28 Attack x 9.6; with 0.10 exam II: osnova x 9.6; with 0.22 Attack x 11.4; with 0.47

8. Recovery capacity in%

test I: osnova str. h. x 66; Std. variation with 1.1 Attack x 65; '' with 0.7 exam II: outline ”x 67; with 0.4 attack ”x 67. with 0.3

9. Linearity

test I: osnova str. h. X 0.74; Std. deviation with 0,014 attack x 0.69;  with 0,011 exam II: warp x 0.58;  with 0,012 attack x 0.59; '' with 0,013

B. Drop coefficient test I: p. h. x 0,756; Std. deviation with 0,012 exam II: ¹¹ x 0,690; with 0,026

C. Gloss Factor test I: p. h. x 1.38; Std. deviation with 0.00 exam 11: x 1.25; with 0.03

D. Thickness and compressibility

1. Thickness at 2 cN / cm ² test I:

p. h. x 0.391;

exam II:

x 0.502;

2. The thickness at 20 cN / cm ² Test I:

p. h. x 0.329;

exam II:

x 0.391;

Std. deviation with 0,004 '' with 0,006 Std. deviation with 0,005  with 0,001

3. Absolute compressibility in mm Test I: 0.062 (comparison of the mean value not feasible) Test II: 0.111 (comparison of the mean value not feasible)

4. Relative compressibility in% Test I: 15 (comparison of the mean value not feasible) Test II: 22 (comparison of the mean value not feasible)

E. Aku test of flatness

1. Mark immediately after release test I: 2 test II: 4

2. Mark after 1 hour recovery Test I: 5 Test II: 6-7

3. Sign after 2 hours recovery test 1: 6 test II: 7

4. Examination after 24 hours recovery Test I: 7-8 Test II: 7-8 (assessment grade from 1 to 8: with grade 1 worst and with grade 8 best result)

F. Urea solubility in% (as a measure for chemical changes) Test I: 42.2 Test II: 45.5

Thickness measurements were performed according to DIN 53855 and urea-bisulfite solubility according to IWTO (Intemational Wool Technical Organization) 11-64.

The surface torsion was performed with the support of the Aku-method (cylindrical torsion method) with 3.5 kg weight and 25 min. load time.

All tests were carried out in a normal climatic environment.

The comparison of the mean values of the test results shows. According to the invention, a surprising improvement in the quality of the textile fabric in various directions is achievable by the decatting method of the invention.

Claims (3)

PATENT CLAIMS A method of decatting a woven fabric of wool fibers or a fabric made using a substantial proportion of wool fibers, wherein the textile fabric is wound together with a tread on a perforated decatter roller and the coil so formed is subjected to an autoclave heat treatment characterized in that the optical unit consisting of a non-oriented fibers, the basis weight less than 80 g / m ² and the water vapor permeability of not less than 3500 g / ^m2 / 24h. Method according to claim 1, characterized in that the fabric is wound on a perforated decatting roller with a residual moisture content of 10 - 100% by weight. and in this state it is subjected to heat treatment. Method according to claim 1 or 2, characterized in that the residual moisture of the textile fabric present in the autoclave is always maintained and controlled by the external steam supply during processing.