JP3440442B2 - Felt for papermaking and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a papermaking felt used in a paper machine, and in particular to a modified papermaking felt.
The present invention relates to a manufacturing method thereof .

[0002]

2. Description of the Related Art In the design of conventional papermaking felts, the required characteristics of papermaking felts have been adjusted by various combinations of material fineness, needle punching conditions, finishing conditions, etc. in accordance with the required properties of paper. . Such required properties include drainage for compressing paper, compression recovery elasticity, surface properties of paper, and abrasion resistance, antifouling property, and flattening resistance for maintaining the properties, but insufficient. Attempts have also been made to address these properties by chemically treating the material and / or felt.

For example, as disclosed in JP-A-3-2218, by treating a felt for papermaking with a phenol / formalin solution, a cross-linking bond is introduced into the inside of the molecule of the nylon material, or the surface of the nylon material is coated with a resin. Therefore, it has been reported that the durability of the felt for papermaking is improved.

[0004]

However, although the conventional chemical treatment is excellent in terms of durability, the nylon material is modified while forming a resin as in the case of treatment with a phenol / formalin solution. In some cases, the nylon material becomes rigid, impairing the required properties of the papermaking felt, such as compression recovery.

On the other hand, the international publication W092 / 1487
As shown in the pamphlet of No. 9, the chemical treatment of the nylon material with the acidic formalin solution does not form a resin unlike the above-mentioned chemical treatment, so that the compression recovery property is not impaired, but a cross-linking bond is formed inside the molecule of the nylon material. As a result, a residue (gel) is left in the 85% formic acid solution. The nylon material having the residue is more rigid than the nylon material having no residue, and thus tends to be embrittled by repeated compression fatigue during use.

In particular, the recent papermaking technology for paper machines involves high temperature, high pressure,
It tends to be faster. For this reason, in conventional chemically treated nylon materials such as the above-mentioned JP-A-3-2218 and the pamphlet according to the international publication W09 / 14879, due to rigidity, repeated compression fatigue during use promptly results. It has a strong tendency to become brittle.

[0007]

SUMMARY OF THE INVENTION In order to improve the required characteristics of felt for papermaking, the present invention fundamentally improves the drawbacks of conventional chemically treated nylon materials, and has various functions for making paper, and We have developed a completely new nylon material that can make the most of the continued function (durability).

That is , the felt for papermaking according to the present invention is a warp,
Nylon element on base fabric made of nylon material with weft
Place a web of wood on it, needle punch it, and
A felt for papermaking obtained by integrating and integrating
Nylon material of Celt is sulfuric acid solution viscosity (0.25g / 5
0 ml, JIS first-class 95% sulfuric acid) is 80 mPa · s or more
And leaves a substantial residue in the 85% formic acid solution.
Nylon molecule as well as material modified to prevent
The phenol / formaldehyde initial condensate is added to
Has been . The nylon materials used in the present invention include nylon 6, nylon 66, nylon 12, nylon 46, nylon 610, nylon 612, copolymerized nylon 6/66, and other aliphatic polyamides, semi-aromatic polyamides, and aromatic polyamides. Any one type or several types of filaments, yarns, or single fibers are adopted. Furthermore
In addition, the method for producing a felt for papermaking according to the present invention is
The material is set on the card machine to make a web,
Set the needle punching machine and make sure the warp and weft threads are
Place the web on a base cloth made of Ron material and need
Lu punching, entanglement and integration to obtain papermaking felt
And then immersing the papermaking felt in an aqueous phenol solution.
Then adsorb formaldehyde gas and
Phenol / formaldehyde initial condensate
Nylon element of the felt for papermaking can be obtained by adding
Sulfuric acid solution viscosity of material (0.25g / 50ml, JIS first grade
95% sulfuric acid) is 80 mPa · s or more, and
Nylon material of paper felt is used in 85% formic acid solution.
It has been qualitatively modified so as not to leave a residue.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
To do. In the present invention, the nylon in card machine
A web punching machine, followed by a needle punching machine
A machine made of nylon with warp and weft threads made of nylon.
Place the web on a cloth, needle punch it, and
After the papermaking felt is integrated and integrated to obtain a papermaking felt,
Dip the solution in a warm 0.1% to 1% by weight resorcinol solution.
After pickling, wash in water, and continue in formaldehyde gas
The resorcinol to the nylon molecule by passing
A le / formaldehyde precondensate is applied. That conclusion
As a result, the papermaking felt has a cross-linking bond in the nylon molecule.
However, it does not form extra resin and has no rigidity.

[0010] The present invention is, as a result of the invention have studied intensively, above
When the felt for papermaking is chemically treated by the means described above, the viscosity of the sulfuric acid solution (0.25 g / 50 ml, JIS Class 1 9
5% sulfuric acid) was 80 mPa · s or more, and the nylon material was found to be a material modified so as not to leave a residue in the 85% formic acid solution. As a result, the above-mentioned
The nylon material of papermaking felt is flexible and durable, and has improved drainage capacity, that is, excellent compression deformability, and its sustainability can be maintained for the life of the felt. Therefore, it has excellent properties for filtering paper, that is, drainage, compression recovery elasticity, surface property of paper, and durability of properties, that is, abrasion resistance, stain resistance, flattening resistance, etc. as will, Extract, which was also matched to a recent paper machine papermaking technology natural
We were able to provide paper felt .

[0011] Here, it is sufficient kinematic viscometer commonly used is a sulfuric acid solution viscosity. In addition, the kinematic viscosity of nylon materials that are generally commercially available is 60 to 70 for clothing.
mPa · s, the range of 70 to 75 mPa · s for industrial materials, the nylon material of 80 mPa · s or more required by the present invention is a commonly used technique, for example, a technique for highly polymerizing nylon resin, nylon. It is not at a level that can be dealt with by post-processing technology of modified resin or nylon material.

Furthermore, the present invention is a mandatory requirement that a material nylon <br/> down material papermaking felt is modified to avoid leaving residue on the 85% formic acid solution. To leave no residue means that 1 g of nylon material sample is put into 100 ml of JIS-grade 85% formic acid and left at room temperature for one day and then 50
It means that no residue (in many cases, viscous liquid or gel-like substance) is left on the filtration surface when filtered with a μm Millipore filter, but substantially the weight residue ratio before and after formic acid dissolution. Means not to exceed 1%.

The nylon material of the papermaking felt that can be used in the present invention is nylon 6, nylon 66, nylon 6/6.
It is a filament, a yarn, or a monofilament made of any one or several kinds of 6 copolymers. These nylon materials are in the range of the viscosity of the sulfuric acid solution described above, and each of them has a characteristic that no residue remains in the 85% formic acid solution. That is, it is soluble in 85% formic acid.

The base fabric fabric used in the practice of the present invention is made of warp yarns, weft yarns, spun yarns, mixed twisted yarns, monofilaments, multifilaments, or monofilament twisted yarns. It is most effective to use any one or several of nylon 6, nylon 66, and nylon 6/66 copolymer, but nylon that has excellent dimensional stability in monofilaments used in some base fabrics. 610, nylon 61
Nylon materials such as 2, nylon 11 and nylon 12 can also be used.

[0015] Nylon 66 commercially available examples monofilament "Toray type 49
01: Sulfuric acid solution viscosity 74 mPa · s (0.25 g / 50
ml, JIS first-class 95% sulfuric acid) " to a card machine to make a web, and then a needle punching machine to make a monofilament twist of nylon 6 for warp and weft.
A web was placed on a base fabric made of yarn, needle punching was performed, and entanglement and integration were performed to obtain a papermaking felt. Then 1
The above papermaking felt was immersed in a warm wt% aqueous resorcinol solution and then washed with water, and then formaldehyde gas was adsorbed in a closed room to give a resorcinol / formaldehyde initial condensate to the nylon molecule . After that, the felt was rinsed with warm water and then dried and heat-treated in a hot air dryer at 150 ° C.

[0016] Comparative Example A commercially available nylon 66 resin (Toray type 490
1) and a commercially available nylon 6 resin (Toray type CM1041) were melt-spun to obtain a single fiber, which was applied to a card machine to make a web, and subsequently to a needle punching machine to obtain the same base fabric as in Example 1. A web was placed on the top, needle punching was performed, and entanglement and integration were performed to obtain a papermaking felt. Then the after needle punching
1% papermaking felt with 0.2% by weight resorcinol
The papermaking felt was immersed in a mixed aqueous solution of wt% formalin, chemically treated for a sufficient time and temperature, rinsed with warm water, and then dried and heat-treated in a hot air dryer at 150 ° C.

As an evaluation, Table 1 shows a comparison between a single fiber and a web.

[Table 1] Comparison of monofilament and web

As an evaluation, Table 2 shows a comparison of the functions of felts for making paper.

[Table 2] Function comparison of felt for filtering paper * Smoothness of paper: Calculated from stylus type surface roughness profile measurement
Parameter (10-point average roughness)

As an evaluation, the durability of the papermaking felt is shown in Table 3.

[Table 3] Durability of felt for papermaking * Flattening resistance: Felt density ratio after press fatigue test

[0020]

INDUSTRIAL APPLICABILITY The papermaking felt of the present invention has flexibility and durability in the nylon material itself as compared with the conventional chemically treated felt, and has an improved drainage capacity, that is, excellent compression deformability, and its durability. The felt can be used for a long period of time. Therefore, the characteristics for filtering the paper, that is, the drainage and compression recovery of the felt were good, and the surface property of the paper was also improved. Further, the durability of the felt for papermaking, that is, the abrasion resistance, antifouling property, flattening resistance, etc. has been improved, so that the life of the felt has been remarkably improved.

Further , as an excellent additional function which the conventional chemically treated felt does not have, vibration due to the felt, which is likely to occur in the press section of the paper machine, can be suppressed, and as a result, a soft felt can be obtained. The ability to put felt on the machine has been improved.

[0022] According to the production method of the present invention, the modified papermaking felt obtained may simply and easily yield.

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Claims (2)

(57) [Claims] 1. A felt for papermaking has both warp and weft yarns.
Nylon material on the base cloth made of iron material
Put the web on, needle punch, and entangle and integrate.
The felt for papermaking obtained, wherein the felt of the papermaking is
Ron material is sulfuric acid solution viscosity (0.25g / 50ml, JI
S Primary 95% sulfuric acid) is not less 80 mPa · s or more and 85% formic acid solution substantially material der Rutotomoni that has been modified so as not to leave residues during the phenol nylon molecule
A papermaking felt which s / formaldehyde initial condensation product is characterized that you have been granted. 2. A nylon machine is mounted on a card machine to
Web and continue to work on the needle punching machine
Koke, warp and weft are placed on a base fabric made of nylon material
The web is put on and needle punching is performed to integrate the entanglement.
To obtain the papermaking felt,
Dip in an aqueous solution of enols, then formaldehyde gas
Adsorbs phenol and forms phenols / form on nylon molecules
By adding the aldehyde initial condensation product, the papermaking paper
Viscosity of sulfuric acid solution of Nert's nylon material (0.25g / 5
0 ml, JIS first-class 95% sulfuric acid) is 80 mPa · s or more
And the nylon material of the papermaking felt is 85
% Formic acid solution modified to leave virtually no residue
A method for producing a felt for papermaking, characterized in that