JPH05214694A - Felt for paper manufacturing machine and preparation thereof - Google Patents

Abstract

PURPOSE: To obtain the subject felt having a fleece needle-felted onto a knitted base fabric. CONSTITUTION: This paper machine felt is obtained by needle-felting at least one layer of fleece comprising thermoplastic, melt-spun, three-dimensionally crimped polymer fibers onto a base fabric. The mechanical properties, esp. abrasion resistance, of the three-dimensionally crimped fibers are considerably excellent compared to those of fibers of the identical material origin crimped in a stuffing box.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention comprises a fibrous fleece from a backing and thermoplastic melt-spun polymer fibers, the fleece being sewn onto the backing with a needle. In a paper machine felt consisting of at least one layer, the fiber fleece is characterized in that it consists entirely or in part of three-dimensionally crimped fibers.

In particular, the invention comprises at least one fleece stitched onto a textile fabric surface former, which fleece consists wholly or partly of three-dimensionally crimped synthetic fibers. And a method of making the same and the use of such a fleece for a paper machine felt.

[0003]

2. Description of the Related Art Felts of this kind have improved abrasion resistance and allow the production of papers with smoother surfaces.

In general, a felt for a paper machine is made of a base cloth,
It is manufactured by stitching crimped fibers into a fleece with a needle.
Such a paper machine felt is used for dewatering a paper band in the pressing zone of a paper machine. For this purpose, the felt, together with the stock, must be guided by the arrangement of pressing rolls. In this case, the felt and the paper are subjected to extremely high mechanical loads, which are also chemical and possibly thermal. In particular, the fibers are formed very strongly by the high speeds and pressing pressures in the short process sequences.

According to the state of the art, fibers of this type are
Stabilizers can be used to additionally protect against thermal and chemical damage.

To improve the surface quality of the paper, it is known in the prior art to produce the uppermost cover layer of the felt from fibers of the finest possible fineness. However, the above-mentioned demands are hampered by the slight abrasion resistance of fine-fine fibers.

The abrasion resistance, which is one of the most important properties of the fibers used for paper machine felts, is relatively easy for individual fibers, the so-called abrasion test (Dra).
htscheuertest).

In the above test, the air conditioned fiber is
Initial load (Vorspangewich) 0.44c
It is loaded with N / dtex (0.5 g / den) and is suspended at a certain angle on a precisely defined wire.

The fiber then reciprocates in a certain section along the fiber axis, so that the fiber is abraded by the wire. As a measure of abrasion resistance, the number of abrasion movements of the wire required to break the fiber (abrasion rotation speed (D
Rahtscheuertouren) “DST”).

Gruenewald, K .; H. , Len
zinger Berichte Vol. 26 (1968
Year) The test according to the description on pages 90-109, individual values, at least 44, are used for averaging.

The paper felts used in practice today are mainly made of polyamide 6 fibers or polyamide 6.6 fibers. However, the literature also describes other fiber types for the said intended use. Thus, EP 0287297 A claims patent protection for fibers made of polyamide 12 and EP 372769 A describes patent protection for fibers made of polyamide 11. Are billed as well.

German Patent Application Publication No. 1761
531 describes a paper machine having a surface which is particularly compacted by the use of a fleece consisting of a single yarn that can be expanded or contracted and a mixture of fibers with different fiber thicknesses, (denier) crimps and polymer properties. The felt is described.

The fibers used according to the current state of the art for papermaking felts are industrially two-dimensionally crimped by indentation box processing. However, the mechanical buckling stresses of the abovementioned hardness cause damage to the fiber structure and, compared to uncrimped, but unusable fibers, especially mechanical strength with a clearly deteriorated abrasion resistance. Nature arises.

Tests have shown that the molecular weight of the fiber polymer decreases in the case of compression crimping in the buckled position as a result of mechanical damage.

[0015]

The problem posed by the present invention is that in industrial use, the unsatisfactory working life of paper machine felts is the result of unsatisfactory wear resistance. Is imposed by. In addition, a method of making this type of felt is described.

[0016]

In order to solve the above-mentioned problems, a felt for a paper machine comprising a fiber fleece from a three-dimensionally crimped synthetic fiber according to the characterizing part of claim 1 or claim 10. A method for making a paper machine felt as described in the features and the use of a fiber fleece is proposed.

The dependent claims develop further the invention.

Above all, in the case of filament production, several methods are known by which a three-dimensional crimp can be obtained. However, the method is in principle also suitable for producing staple fibers.

By way of example, the following method has been selected herein: Manufacture of bicomponent fibers having a non-concentric distribution of components, for example a side-by-side distribution. Different physical properties of the two components (expansion rate, shrinkage behavior, water absorption capacity)
On the basis of the above, a three-dimensional crimp is inevitably generated in the fiber. The production of fibers of this type has been known in the art for some time (eg Koch, PA: Chem.
iefasern / Textilind. (1979
Year), pp. 431-438).

It is advantageous if the two polymer components are as similar as possible in their chemical structure and thus compatible with one another. This is because otherwise there is the risk of splicing. Particular preference is given to using exactly the same polymer for the two components, but with different viscosities or using the same polymer, in which case one component is
It has been modified by additives.

2. Asymmetric cooling of the yarn in the case of melt spinning. This can be achieved by a liquid, a strong stream of air, or even by a solid, cooled member that is in contact with the hot thread on one side.

The structure of the polymer is affected by the asymmetric cooling. This results in different physical properties of the polymer within the filament, as in the case of bicomponent fibers.

3. Air jet or steam jet textured. H. Schellenberg;
3. Reutlinger Texture-Ko
According to Lloquium (1984), the production of crimps in the case of the air (steam) jet method can be described as follows: Single yarns are drawn, at a temperature near their softening point, at a textured spinneret. Enter Here, it is additionally heated by the hot gas jet under pressure and stays (St
It is transported to the autoil). In the above case, the existing pressure is abruptly reduced by the decompression opening, so that the fiber bundle is released and accumulates to form a plug. However, this pressure cannot be reduced completely, so that the plug is gradually formed by the retention part. The strength of dwell and plug transport can be controlled by the type of pressure relief.

Surprisingly, the three-dimensionally crimped synthetic fibers have a much better abrasion resistance than the two-dimensionally crimped fibers of the same starting material. It became clear that there is. This crimp is essential for processing the fibers into a fleece and gives the felt a favorable capacity for carrying water.

The advantages of a paper machine felt made entirely or in part of three-dimensionally crimped synthetic fibers are that it has a longer life and a finer life than conventionally used two-dimensional indentation box crimped fibers. There is a method of using fibers of fineness.
Thus, it is also possible to use preferably a fineness of less than 10 dtex and particularly preferably a fineness of 4.5 to 6.5 dtex.

The felt for a paper machine according to the present invention is manufactured in whole or in part by a method known per se by sewing in the three-dimensionally crimped synthetic fibers described in the method according to the present invention with a needle.

In principle, the invention is not limited to fibers of a particular polymer type or of a particular polymer combination, but rather advantageously to a paper machine jacket (Papiermastine).
It is possible to influence the fiber properties of all polymer types to be used for Nbespannungen).

Preference is given to three-dimensionally crimped synthetic fibers of polyamide. In this case, PA6, PA1
1, PA12, PA4.6, PA6.6, PA6.1
0, PA6.12, PA10. T, PA12. T, PA
Copolyamides consisting of 12.12 or aliphatic monomers having 4 to 12 C atoms and / or aromatic monomers having 6 to 12 C atoms are particularly advantageous. Preferred monomers of this type of copolyamide are caprolactam, laurinlactam, tetraphthalic acid and linear α, Ω-diamines having 4 to 12 C atoms.

The three-dimensionally crimped synthetic fibers according to the invention can be used outstandingly in the production of fiber needled fleece which can be used as felt for paper machines. This is because the fibers show a significantly improved abrasion resistance compared to the state of the art.

[0030]

【Example】

Example 1 An air jet textured fiber was prepared using suitable spinning equipment using dry PA6 granules rolled and carried with 0.7% Irganox 1098. .. This granule has a relative viscosity (96% sulfuric acid (23 ° C.), 1 g / 1
Η rel. = 3.65.

The granules were completely melted in the extruder and subsequently spun.

The spinneret has a diameter of 0.6 mm.
It had holes. The total throughput was 154 g / min at a spinning speed of 600 m / min. After leaving the spinneret, the fiber bundle is cooled by blowing air,
It was continuously prepared and then placed in a can with the spinning wheel.

The spinning substance was prepared by
air jet textured processing machine J0
/ 10 stretched, textured, then 16 per minute
It was wound up at a speed of 70 m.

Subsequently, the filament was unwound from the spool, fixed without tension at about 165 ° C. and cut.

The fibers consist of a corresponding polymer and have an abrasion resistance (DST value) at least 100% higher than the crimped fibers in the indentation box.

From this fiber a needle-sewn fleece having a surface weight of 500 g / m ² was produced on a base fabric. Test felts of this kind are at least 30% longer than the corresponding felts made of fibers crimped in the indentation box (Comparative Example 1) when the test according to the behavior in the paper machine is adopted. Showed a lifespan.

Example 2: As in Example 1, fibers were prepared and processed into felt, but the fibers were spun and drawn. This fiber likewise has a very good abrasion resistance (DST value).

The life of the felt was about 30% better than that of the crimped fibers in the indentation box described in Comparative Example 1.

Example 3: As in Example 1, the fibers were
Manufactured from 12 and processed into felt. Abrasion resistance and felt life were essentially better than for the comparative fiber crimped in the corresponding indentation box (Comparative Example 2).

Example 4: As in Example 1, the fibers were
Produced from 6.6 (granule of ηrel.3.4) and tested.

Example 5: Bicomponent fiber. Using suitable spinning equipment, 0.7% Irganox (Irgano)
x) Dried PA6 rolled with 1098
Manufactured using the granules of The granules were distinguished by relative viscosity (96% sulfuric acid (23 ° C.), measured in 1 g / 100 ml). Granule A: ηrel. = 3.4 and granules B: ηrel. = 3.65. The granules were completely melted in two different extruders and subsequently spun in a spinneret pack, in which the two melt fluids were first combined just before leaving the spinneret and the two components lined up. The resulting placement resulted. This spinneret has a diameter of 0.
It had 200 holes with 4 mm. The total passing amount is
At a spinning speed of 770 m / min, it was 550 g / min. After leaving the spinneret, the fiber bundles were cooled by blowing air, subsequently prepared and then placed in a can with the spinning wheel.

The spun material was processed using the usual structural type drawing section to a Galett temperature of 60-65 ° C.
It was stretched with an entemperature, provided with a beam, dried and cut. The fiber properties are listed in Table 1.

This fiber has an abrasion resistance (DST value) which is at least 100% higher than the crimped fiber in the indentation box made of the corresponding polymer.

From this fiber, a needle-sewn fleece having a surface weight of 500 g / m ² was produced on a base fabric. Test felts of this kind are at least 30% longer than the corresponding felts made of fibers crimped in the indentation box (Comparative Example 1) when the test according to the behavior in the paper machine is adopted. Showed a lifespan.

Example 6: As in Example 5, the fibers were treated with different viscosities (eg m-cresol, 25 ° C., 0.
Ηrel. Measured in 5 g / 100 ml. 2.0 and 2.2) made from PA12 granules and processed into felt. This fiber also has a very good abrasion resistance (DS).
T value).

The life of the felt is 2. 25% better than the comparative fiber described in.

Example 7: As in Example 1, prepared from PA6 and a copolyamide based on caprolactam / laurinlactam and processed into felts.

Example 8: As in Example 1, the fibers were
6 granules (ηrel.3.4) and PA66 granules (ηrel.3.4) and processed into felts.

COMPARATIVE EXAMPLE 1 Polyamide 6 fibers crimped in an indentation box were tested as a comparative variant. The test results are listed in Table 1.

Comparative Example 2: Polyamide 12 fibers crimped in an indentation box were tested as a comparative variant.

The characteristic values measured for the fibers of the examples are given in table 1.

[0052]

[Table 1]

* Twinkle-type crimp measuring scale (Zwei
It was measured using a gle Kraeuselwaage) S 160 (for the test method, see the instruction manual of the apparatus).

** Measured in m-cresol.

# In the case of three-dimensionally crimped fibers,
All the turning points of the fiber are counted as bending (in a relaxed state), while in the case of a two-dimensionally crimped fiber,
All buckling positions were counted as bends.

Table 1 shows that the three-dimensionally crimped synthetic fibers are essentially abrasion resistant as compared to the corresponding indentation box crimped fibers. Is shown in.

With respect to Example 4, it was pointed out that it was known from the description in the trade journal "Grilon" for paper machines that PA6.6 had only about 60-70% of the abrasion resistance of PA6. Has been done.

Claims (21)

[Claims] 1. A fiber fleece comprising a backing and a thermoplastic melt-spun polymer fiber, the fibrous fleece being sewn onto the backing with a needle.
A paper machine felt consisting of three layers, characterized in that the fiber fleece consists of three-dimensionally crimped fibers in whole or in part. 2. The felt for a paper machine according to claim 1, wherein the three-dimensionally crimped fiber is a bicomponent fiber. 3. The felt for a paper machine according to claim 1, wherein the three-dimensionally crimped fiber is an asymmetrically cooled polymer fiber. 4. The felt for a paper machine according to claim 1, wherein the three-dimensionally crimped fibers are crimped by an air jet method. 5. The felt for a paper machine according to claim 1, wherein the three-dimensionally crimped fibers are crimped by a steam jet method. 6. At least one three-dimensionally crimped fiber
A felt for a paper machine according to any one of claims 1 to 5, which comprises one polyamide component. 7. The three-dimensionally crimped fiber comprises at least two polyamide components having different properties.
The felt for a paper machine according to claim 1. 8. A polyamide component comprising polyamide 6, polyamide 11, polyamide 12, polyamide 4.6, polyamide 6.6, polyamide 6.10 and polyamide 6.1.
2, polyamide 10. T, polyamide 12. T, a polyamide selected from the group of polyamide 12.12 and C
Aliphatic monomer having 4 to 12 atoms and / or C
The paper machine felt according to claim 6, which is a copolyamide composed of an aromatic monomer having 6 to 12 atoms. 9. At least one polyamide component comprises polyamide 6, polyamide 11, polyamide 12, polyamide 4.6, polyamide 6.6, polyamide 6.10,
Polyamide 6.12, polyamide 10. T, polyamide 12. T, a polyamide selected from the group of polyamide 12.12 and a copolyamide consisting of an aliphatic monomer having 4 to 12 C atoms and / or an aromatic monomer having 6 to 12 C atoms, The felt for a paper machine according to claim 7. 10. The copolyamide is composed of a monomer selected from the group of caprolactam, laurinlactam, terephthalic acid and linear α, Ω-diamines having 4 to 12 C atoms. Or the felt for a paper machine described in 9. 11. In a manner known per se, it consists of a base fabric and a fiber fleece from thermoplastically melt-spun polymer fibers, which is sewn onto the base fabric with a needle. A method for producing a needle felt for a paper machine, which comprises at least one layer, characterized in that the felt is produced by sewing a whole or a part of a three-dimensionally crimped fiber with a needle. Needle felt manufacturing method. 12. The method according to claim 10, wherein a bicomponent fiber is used as the three-dimensionally crimped fiber. 13. The method according to claim 10, wherein asymmetrically cooled polymer fibers are used as the three-dimensionally crimped fibers. 14. The method according to claim 10, wherein a fiber crimped by an air jet method is used as the three-dimensionally crimped fiber. 15. The method according to claim 10, wherein fibers crimped by a steam jet method are used as the three-dimensionally crimped fibers. 16. The method according to claim 10, wherein the three-dimensionally crimped fiber consists of one polyamide component. 17. The method according to claim 10, wherein the three-dimensionally crimped fiber is composed of more polyamide components with different properties. 18. The polyamide component comprises polyamide 6, polyamide 11, polyamide 12, polyamide 4.6, polyamide 6.6, polyamide 6.10, polyamide 6.
12, polyamide 10. T, polyamide 12. T, a polyamide selected from the group of polyamide 12.12 and a copolyamide consisting of an aliphatic monomer having 4 to 12 C atoms and / or an aromatic monomer having 6 to 12 C atoms, The method according to claim 16. 19. At least one polyamide component comprises:
Polyamide 6, Polyamide 11, Polyamide 12, Polyamide 4.6, Polyamide 6.6, Polyamide 6.1
0, polyamide 6.12, polyamide 10. T, polyamide 12. T, a polyamide selected from the group of polyamide 12.12 and a copolyamide consisting of an aliphatic monomer having 4 to 12 C atoms and / or an aromatic monomer having 6 to 12 C atoms, The method according to claim 17. 20. The copolyamide is composed of a monomer selected from the group of caprolactam, laurinlactam, terephthalic acid and a linear α, Ω-diamine having 4 to 12 C atoms. Or the method according to 19. 21. A method of making a paper machine felt, at least partially from the group of bicomponent fibers, asymmetrically cooled fibers, air jet crimped fibers and steam jet crimped fibers. A method for producing a felt for a paper machine, which comprises using a fiber fleece made of a three-dimensionally crimped polymer fiber that is thermoplastically melt-spun.