JPH1181181A - Needle felt for papermaking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a needle felt for papermaking having a suitable compressibility, in other words, made so as not to generate neither excess nor shortage of the compressed density to the felt just under the pressing part. SOLUTION: This needle felt 1 for papermaking is obtained by laminating a pad 3 obtained by the mixed spinning of a polyester elastic fiber and a low- elastic film on a base fabric 2, and integrally entertaining the fabric 2 and the pad 3 by their needling. The needle felt 1 has a characteristic of having 0.600-0.850 g/cm<3> substantial compressed felt density range under 30 kg/cm<2> wet pressure, and is constituted by controlling the compressed felt density in a suitable range so as to obtain the stable operation of a papermaking machine and a uniform quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle for papermaking, and more particularly to a needle for papermaking which is used in a wet press part of a papermaking machine, withstands high pressure and high speed and is useful for forming the best paper quality. Things.

[0002]

2. Description of the Related Art In recent years, the performance of a paper machine has been remarkably improved. Therefore, a function is required for a papermaking needle felt that withstands high pressure and high speed and that is useful for forming the best paper quality.

[0003] Conventionally, a papermaking needle felt obtained by laminating a wool bat which is a natural fiber on a base cloth and needling it has been used. When wool is used for a papermaking needle felt, there is no report that discusses the relationship between the density of the felt immediately below the press section (hereinafter referred to as “density under pressure”) and paper quality formation.

[0004] Next, a papermaking needle felt appeared in which a bat made of only low-elastic fibers such as nylon 6.66 was laminated on a base cloth and entangled and integrated by needling.
The low-elasticity fiber such as nylon 6, 66 used as the bat has toughness, but it becomes a bulky felt, the density under pressure is not so high, and the amount of dewatering from the paper machine is small. It was something.

Recently, it has been proposed to use polyelastomeric elastic fibers as a bat. This polyelastomeric elastic fiber has attracted attention as a technique for imparting a high degree of compression recovery to a needle felt for papermaking.

The present inventor has also proposed a papermaking needle felt utilizing a polyelastomeric elastic fiber. This is because the rubber-like elasticity, flexibility and durability inherent of the polyelastomeric elastic fiber have been emphasized in terms of the properties of the needle felt for papermaking that effectively function against repeated compression fatigue. .

[0007]

However, when a bat containing polyelastomer elastic fibers is used for some paper machines, the press roll is excessively compressible in the press section, in other words, the density under pressure is too high. As a result, there is a problem that vibration occurs, and the pattern of the base fabric structure is transferred to the paper, thereby deteriorating the paper quality.

[0008] The present invention relates to a problem of poor water squeezing caused by low density under pressure and an increase in heat energy required for drying of a needle felt for papermaking using a bat made of only low elasticity fibers such as nylon 6.66. And, at once, it solves the problem of press roll vibration, the problem of transferring the pattern of the base fabric structure to the paper, which occurs because the density under pressure is too high, for the papermaking needle felt using a bat containing polyelastomer elastic fiber, It is an object of the present invention to provide a papermaking needle felt in which moderate compressibility, in other words, the density under pressure of the felt immediately below the press section is not excessive or insufficient.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a base cloth, in which a bat obtained by blending a polyelastomer elastic fiber and a low elastic fiber is laminated and entangled and integrated by needling. Needle felt
The needle felt has a substantial felt press density under a wet press of 30 kg / cm ² of 0.600 to 0.850.
g / cm ³ , and the density under felt pressure was controlled in an appropriate range so that stable paper machine operation and uniform paper quality could be obtained.

Further, the invention according to claim 2 is characterized in that a blending ratio of the polyelastomeric elastic fiber and the low elastic fiber is 40% or less by weight of the polyelastomeric elastic fiber, and the low elasticity is mainly reduced. The polyelastomeric elastic fiber provides a high degree of compression recovery to the toughness of the fiber, ensures that the density under pressure does not become excessive or insufficient, and reliably erases the base fabric mark on the surface side of the needle felt that directly touches the paper quality and friction. It was designed to reduce wear.

Further, in the invention according to a third aspect, the polyelastomer elastic fiber is made of one or more of a polyamide elastomer elastic fiber, a polyester elastomer elastic fiber, and a polyurethane elastomer elastic fiber. It is configured so that an effective recovery function against repeated compression fatigue can be effectively and fully exerted.

Further, according to the present invention, a bat made of only low-elasticity fiber is laminated on the outer layer of the blended bat layer of the polyelastomeric elastic fiber and low-elasticity fiber and entangled and integrated by needling. In the bat, the layer close to the base fabric is provided with a high degree of compression recovery, the surface layer is provided with toughness of low elastic fiber, wet paper web moisture, press roll vibration and It was configured so that excellent functions could be exhibited on any surface of the base fabric mark.

Further, the invention according to claim 5 is characterized in that the base cloth has a structure that is soft and has a high compression recovery property, and the base cloth has an effective recovery function against repeated compression fatigue. It was configured so that it could be taken by itself.

[0014]

Next, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a cross-sectional view of a single-sided needle felt of the present invention, FIG. 2 is a cross-sectional view of a type in which an outer layer is added to the needle felt of the present invention, FIG. 3 is a cross-sectional view of a double-sided needle felt of the present invention, and FIG. FIG. 2 is a schematic explanatory view showing a side surface of the wet paper web press machine.

In FIG. 1, reference numeral 1 denotes a needle felt formed by laminating a bat 3 in which a polyelastomer elastic fiber and a low elastic fiber are blended on a base cloth 2 and entangled and integrated by needling. In FIGS. 1 and 2, the bat 3 is laminated on one surface (the upper surface in the drawing) of the base fabric 2, but it is needless to say that the bat 3 may be laminated on both surfaces of the base fabric as shown in FIG. 3. .

Wet pressurization of the needle felt 1 30k
The actual felt density under g / cm ² is 0.6.
In the range of 00~0.850g / cm ^3, more preferably controlled in the range of 0.650~0.750g / cm ^3. This is for the purpose of preventing vibration of the press roll and forming good paper quality. The direction in which the density under pressure is adjusted in the range of 0.600 to 0.850 g / cm ³ is determined in consideration of paper machine conditions, base fabric structure, and the like.

In order to control the felt pressure density of the needle felt 1 within the range of 0.600 to 0.850 g / cm ³ , the structure of the base fabric and the bat, or the low elasticity of the polyelastomer elastic fiber It is important to stack the bats blended so as to be within the target range of the density under felt pressure while taking into account the ratio with the elastic fiber, and entangle and integrate them by needling. That is, depending on the configuration, the density under felt pressure under the wet pressure of 30 kg / cm ² may exceed the substantial felt pressure density of 0.850 g / cm ³ in some cases.

The polyelastomer elastic fibers include polyamide-based elastic fibers, polyester-based elastic fibers, and polyurethane-based elastic fibers. May be used.

Here, the selection of the polyelastomeric elastic fiber may be determined empirically, but the specific gravity of each elastic fiber (using the apparent arithmetic calculation specific gravity), the bulk per unit basis weight,
Base fabric and bat during needling, entanglement between bat and bat, finished density after needling, and wet pressurization 3
It is necessary to determine in consideration of the density under felt pressure under 0 kg / cm ² .

When the specific gravity is low in the mixed spinning of the polyelastomeric elastic fiber and the low elastic fiber constituting the bat 3, the bulk of the bat 3 is empirically increased and the density under pressure is reduced, so that the specific gravity is large. It is necessary to adjust the blending ratio of the polyelastomer elastic fiber or to increase the needle punching density.

Even when the blending ratio of the polyelastomeric elastic fiber is increased as described above, the blending ratio of the polyelastomeric elastic fiber and the low-elasticity fiber is preferably not more than 40% by weight of the polyelastomeric elastic fiber. It is preferable to securely erase the fabric mark on the surface side of the needle felt that directly touches the paper quality and to reduce frictional abrasion.

Among the above-mentioned polyelastomer elastic fibers, polyurethane-based elastomer elastic fibers are, for example, aliphatic polyether or aliphatic polyester and C2-C2.
6 is a fiber obtained by dry spinning, wet spinning, or melt spinning of a polyurethane elastomer resin obtained by polyaddition reaction of the aliphatic diol with a diisocyanate compound. The specific gravity of a typical elastic fiber is approximately 1.10 to
1.24 g / cm ³ .

Specific examples of the polyurethane elastomer elastic fiber include elastic fibers obtained by wet spinning a thermoplastic polyurethane elastomer resin, such as "Milactran" manufactured by Nippon Milactran Co., Ltd. and "Mobilon" manufactured by Nisshinbo. .

The polyester elastomer elastic fiber among the above-mentioned polyelastomer elastic fibers is, for example, a dry spinning of a block copolymerized polyester elastomer resin having a hard segment of polybutylene terephthalate and a soft segment of polytetramethylene glycol. And fibers obtained by wet spinning or melt spinning. The specific gravity of typical elastic fiber is approximately 1.12~1.26g / cm ^3.

Specific examples of the polyester elastomer elastic fiber include “Perprene” manufactured by Toyobo,
It is an elastic fiber obtained by melt spinning a thermoplastic polyester elastomer resin such as "Hytrel" manufactured by Toray DuPont.

Further, among the above-mentioned polyelastomer elastic fibers, polyamide-based elastomer elastic fibers include, for example, dry spinning of a block copolymer polyamide elastomer resin in which the hard segment is polyamide and the soft segment is polytetramethylene glycol. It is a fiber obtained by a wet spinning or melt spinning method. The specific gravity of a typical elastic fiber is approximately 1.01 to 1.12.
g / cm ³ .

Specific examples of the polyamide elastomer elastic fiber include elastic fibers obtained by melt spinning a thermoplastic polyamide elastomer resin such as “PAE” manufactured by Ube Industries and “Greak” manufactured by Dainippon Ink. It is.

The specific properties of the polyelastomeric elastic fiber are as follows: fineness = 6 to 30 denier, preferably 10
This is a variable cut centering on デ 20 denier, the number of crimps = 5-20 / inch, preferably 10-15 / inch, and the fiber length = 50-100 mm, preferably 76 mm.

The low elasticity fibers constituting the bat include nylon 6, nylon 66, nylon 46 and nylon 61.
0, nylon 612, nylon 11, nylon 12, nylon 1212, copolymerized nylon such as nylon 6 and 66, nylon 6 and 10, nylon 6 and 12, or semi-aromatic nylon, aromatic nylon, polyester, polyphenylene sulfide, Short fibers selected from one or more of polyetheretherketone can be suitably used. Of course, a composite fiber partially containing these components may be used.

The specific properties of the low elasticity fiber are as follows: fineness = 6 to 30 denier, preferably 10 to 20 denier, number of crimps = 5 to 20 / inch, preferably 10 to 15 / inch, fiber length = 50-100 mm, preferably 76 mm
It is a variable cut around the center.

In order to make the function of the papermaking needle felt of the present invention more effective, as shown in FIG. 2, a mixed spinning bat 3 of a polyelastomeric elastic fiber and a low elastic fiber is laminated, and the outer layer is further provided with a low elastic fiber. It is advisable to stack the bats 4 composed of only the bats 4 and entangle them together by needling. Low-elasticity fibers, for example, short fibers of nylon 6, have excellent abrasion resistance and are effective for eliminating paper quality, in particular, base fabric marks.

Here, the "outer layer" includes the paper side or both sides when the bat 3 is formed close to both sides (upper and lower surfaces) of the base fabric 2 (only two sides are shown in FIG. 3). .
The reason why the bat made of only the low elasticity fiber is laminated on the outer layer in order to be applicable to a high-speed paper machine having a speed of 1000 m / min or more and a paper machine having a press nip pressure of 100 kg / cm or more. is there.

It is preferable to use the base fabric 2 having a structure that is flexible and has a high compression recovery property. Here, "the base fabric structure having high compression recovery" is a single woven fabric that is not high in rigidity, for example, a nylon 6 twist yarn of a sweet twist is used for the warp and the weft. 1 /
A good example is a relatively light basis weight base fabric having a break weave of 3, 3/1, 1/5, 5/1, or the like. Of course, a polyelastomeric elastic yarn can be used instead of nylon 6.

When such a base fabric having a high compression recovery property is used, the base fabric itself has a function of recovering from compression fatigue which is repeatedly applied. The density under felt pressure can be controlled to the optimum range in combination with the bat having resiliency, but if the compression recovery of the base fabric itself is further improved, the low elastic fiber can be used without mixing the polyelastomer elastic fiber as the bat. It is also possible to configure only with.

The fabric structure of the base cloth 2 varies widely, and a structure having a structure corresponding to the required degree is selected and used. Naturally, in a paper machine with a high mechanical load, a multi-woven structure having a heavy basis weight is used. In this case, the needle felt 1 finished by needling has a lower pressed density due to the incompressibility of the base fabric 2, but it is important that the above-described felt press density is maintained. .

The substantial felt pressure density under a wet pressure of 30 kg / cm ² of the needle felt described in the present invention is, for example, a JIS L1022 test method for a decrease in thickness of a fiber floor covering due to a load. The standard pressure of the static load tester is 30 kg / cm ^2, and a test piece (needle felt) with a known air-dry basis weight is immersed in water for 24 hours. / Cm ² load was applied and the thickness after 5 minutes was measured.
/ Cm ² is a substantial density under felt pressure.

(Formula) Density under Felt Pressing under Wet Pressing 30 kg / cm ² =
Air-dry basis weight (g / cm ² ) of test piece / thickness under pressure (cm)

[0038]

【Example】

Base fabric: Nylon 6 monofilament (diameter 0.2 mm)
Is an endless double-textile woven fabric in which the three twisted yarns are used as warps on a loom and the same twisted yarns are used as wefts. Base fabric weight 6
It was set to 00 g / m ² .

Polyelastomeric elastic fiber: Polyurethane elastomer (Milactran E300 manufactured by Nippon Milactran, specific gravity 1.16 g / cm ³ ) Polyester elastomer (Perprene P manufactured by Toyobo)
-280, specific gravity 1.26 g / cm ³ ) Polyamide elastomer (Greak A-350 manufactured by Dainippon Ink, specific gravity 1.01 g / cm ³ )

Bat: A polyelastomer elastic fiber (fineness = 15 denier, number of crimps = 10) obtained by a usual dry, wet or melt spinning method using each of the above resins
Inch, fiber length = 76 mm) and one or more kinds of polyelastomer elastic fibers and commercially available nylon 6 (fineness = 1
5 denier, number of crimps = 10 pieces / inch, fiber length = 76 mm)
Are blended at a predetermined mixing ratio.

[0041] Thus, planted the base fabric to the needle machine, put the bat, which is supplied from the carding machine to the top and bottom of the base cloth, until the weight per unit area is on the front side 400g / cm ^3, the back side 200g / cm ^3, Needling is performed, and furthermore, the needling is performed several times without placing a bat to enhance the entanglement, and the needle felt for papermaking (a to
e) was obtained. The distinction between a and e is based on the difference in the blending ratio between the polyelastomeric elastic fiber and the low elastic fiber of the bat.

Further, a bat made of only nylon 6 which is a low elastic fiber is used as an outer layer on the front side of the papermaking needle felt (the above c) in which the blending ratio of the polyelastomeric elastic fiber and the low elastic fiber is 15:85. 200g / m ²
And needled to obtain a papermaking needle felt (f).

The needle felts for papermaking (a to f) are shown in Table 1. (Table 1)---------------------------------------- Low elasticity fiber (g / m ² ) Remarks --------------------------------------------------------------------------- 0: 100 0.590 Outside the requirements of the invention b 5:95 0.610 Satisfies the requirements of the invention c 15:85 0.705 Satisfies the requirements of the invention d 35:65 0.830 Satisfaction e 45:55 0.860 Outside of constitutional requirements of the present invention f 15: 85: 33 * 0.655 Satisfaction of constitutional requirements of the present invention -------------------------------------------------------------------------- -------- The blend ratio of the bat close to the base cloth and the blend ratio of the outer bat, and the final blend ratio is 11:89.

The obtained needle felt was subjected to a density under wet pressurization, a vibration value of a press roll by a paper making simulation machine, and a wet paper squeezing test. The results shown in Table 2 below were obtained.

(Table 2)-------------------------------------------- Roll Wet paper squeezing test (after pressing) Rult (g / m ² ) Vibration value (G) Wet paper moisture Base fabric mark −−−−−−−−−−−−−−−−−−−−−−−− A 0: 100 0.590 0.30 55% None (Comparative Example) b 5:95 0.610 0.31 53% None (Example) c 15 : 85 0.705 0.32 52% No (Example) d 35:65 0.830 0.35 50% Slightly present (Example) e 45:55 0.860 0.40 50% Yes (Comparative example) f 11:89 0.655 0.31 52% None (Example) ---------------------------------------------------------------------------------- --- * Pre Rolling vibration value represents the vertical direction of the gravitational acceleration of the roll.

Here, the method of evaluating the functionality of the needle felt described in the results in Table 2 will be described. (I) Preparation of wet paper by hand-making method The pulp weight loss LBKP is measured by a TAPPI standard type Niagara beater using the pulp freeness. Is 400CS
F (freeness as specified by TAPPI Standard T227m-58), dilute the beaten pulp to a pulp concentration of 0.4%, and use a laboratory oriented paper machine (manufactured by Kumagaya Riki Kogyo Co., Ltd.) to contain water. Rate 60% (dry weight 20
0 g / m ² ) was prepared.

(Ii) Wet paper press water squeezing method The needle felts a to e are put into a wet paper press machine 400 shown in FIG. 4 and the wet paper P obtained in the above (i) is thrown from the inlet. The water of the wet paper web P is squeezed by the needle felt 402 by the pressure of the rolls 403 and 404. The water-squeezed paper P 'was collected at the outlet, and the water content was measured.

(Iii) Wet Paper Mark The surface of the wet paper P 'obtained in the above (ii), that is, the back surface of the dry paper, that is, the surface of the wet paper P' in contact with the needle felt 402 was visually determined.

As a result, in the cases of b to d satisfying the constitutional requirements of the present invention, since the proper density under pressure is maintained, the vibration of the press roll is small, and the moisture of the wet paper web is small. It has received a reputation saying that no marks can be seen. Of course, the base cloth mark is not seen at a outside the constituent requirements of the present invention, but the wet paper web is high, and at e, the vibration of the press roll is large and the base cloth mark is also strong, which is suitable as a needle felt for papermaking. is not. Conversely, f of the present invention was excellent in all aspects of wet paper web moisture, press roll vibration and base cloth mark.

[0050]

As described above, the present invention relates to a needle felt obtained by laminating a bat obtained by blending a polyelastomer elastic fiber and a low elastic fiber on a base cloth, and entangled and integrated by needling. Felt is wet pressurized 30
The actual felt pressure density under kg / cm ² is 0.
Since it is characterized by being within the range of 600 to 0.850 g / m ² , the operating conditions of any type of paper machine, ie, vibration of the press roll, water squeezing (wet paper) Excellent effects can be obtained in both aspects of water content and the base fabric mark.

The invention according to claim 2 is characterized in that the blending ratio of the polyelastic elastic fiber and the low elastic fiber is 40% or less by weight of the polyelastic elastic fiber. The polyelastomeric elastic fiber gives high compressive recovery to the toughness of the low elastic fiber, the density under pressure does not become excessive or insufficient, and the erasure of the base cloth mark on the surface side of the needle felt that directly touches the paper quality This has the effect of reducing friction wear.

Further, in the invention according to a third aspect, the polyelastomer elastic fiber is made of one or more of a polyamide elastomer elastic fiber, a polyester elastomer elastic fiber, and a polyurethane elastomer elastic fiber. Thus, an effect of effectively and maximally exhibiting an effective recovery function against repeatedly applied compression fatigue can be obtained.

Further, the invention according to claim 4 is characterized in that a bat made of only low-elasticity fiber is laminated on the outer layer of the mixed spinning bat layer of the polyelastic elastic fiber and low-elasticity fiber, and entangled and integrated by needling. The bat has a high compression recovery property on the layer close to the base cloth, a low elastic fiber toughness on the surface layer, wet paper moisture, press roll vibration In addition, excellent effects can be obtained on both surfaces of the base cloth mark.

Furthermore, the invention according to claim 5 is characterized in that the base cloth has a structure that is flexible and has high compressive recovery properties, so that it has an effective recovery function against repeated compression fatigue. This has the effect that the base fabric itself can carry.

[Brief description of the drawings]

FIG. 1 is a sectional view of a single-sided type of a needle felt according to the present invention.

FIG. 2 is a sectional view of a type in which an outer layer of the needle felt of the present invention is added.

FIG. 3 is a cross-sectional view of a double-sided needle felt according to the present invention.

FIG. 4 is a schematic explanatory view showing a side surface of the wet paper web press machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Needle felt 2 Base fabric 3 Blended bat of polyelastomeric elastic fiber and low elastic fiber 4 Bat of low elastic fiber only 400 Wet paper press machine 401 Felt roll 402 Needle felt 403 Upper press roll 404 Lower press roll P Wet paper P ' Wet paper after water removal

Claims (5)

[Claims] 1. A needle felt obtained by laminating a bat obtained by blending a polyelastomer elastic fiber and a low elastic fiber on a base cloth and entangled and integrated by needling, wherein the needle felt has a wet pressure of 30 kg / kg. a substantial felt pressure density under cm ² of 0.600 to 0.850 g
/ Cm ³ , which is in the range of / cm ³ . 2. The papermaking needle felt according to claim 1, wherein a blending ratio of the polyelastomeric elastic fiber and the low elastic fiber is 40% or less by weight of the polyelastomeric elastic fiber. 3. The polyelastomer elastic fiber is formed by blending one or more of a polyamide elastomer elastic fiber, a polyester elastomer elastic fiber, and a polyurethane elastomer elastic fiber. 3. The papermaking needle felt according to 1 or 2. 4. A bat comprising only a low elasticity fiber is laminated on an outer layer of the blended bat of the polyelastomeric elastic fiber and the low elasticity fiber, and is entangled and integrated by needling. 4. The papermaking needle felt according to any one of Items 1 to 3. 5. The papermaking needle felt according to claim 1, wherein the base fabric has a structure that is soft and has a high compression recovery property.