JP2023097187A - Base fabric for papermaking felt and papermaking felt obtained by combining the same - Google Patents

Abstract

To provide a base fabric for a papermaking felt which can perform uniform dewatering from wet paper and can suppress formation of seam marks in paper after dewatering.SOLUTION: A base fabric for a papermaking felt includes: a wet paper side layer forming a wet paper side face; a roll side layer forming a roll side face; and seam loop parts on both ends for connecting the wet paper side layer and the roll side layer and through which a core wire passes in its inner part in a CD direction, wherein the base fabric for the papermaking felt is characterized by that the wet paper side layer and the roll side layer are composed of an MD yarn material in a felt travel direction (MD direction) and a CD yarn material in a felt cross direction (CD direction), the seam loop part is formed of the MD yarn material, the base fabric for the papermaking felt further includes one or two or more filling yarns which are passed in an outside vicinity of one seam loop part and in the inside of the other seam loop part or the inside and the outside of the other seam loop part, and the filling yarn comprises a hydrophilic yarn.SELECTED DRAWING: Figure 3

Description

The present invention relates to a base cloth for papermaking felt and a papermaking felt formed by joining the same.

Conventionally, in the press part of a papermaking machine, a press felt and a pair of press rolls or a press roll and a shoe press are used to extract water from wet paper webs. As this press felt, one with ends having seam loops as shown in FIG. 1 is known. That is, the felt F is configured to have ends, and a plurality of seam loops L are formed at each end. The felt F is composed of a base fabric B made of woven fabric and two batt layers W, for example, as shown in FIG. The batt layer W is formed by entangling and integrating short web fibers laminated on the base fabric B together with the base fabric B by needle punching. The base fabric B is composed of a woven fabric obtained by weaving thread material in the running direction of the felt (MD direction) and thread material in the transverse direction (CD direction) of the felt. A seam loop L is formed by the yarn material in the MD direction. A core wire S is passed through the seam loop L in the CD direction.

As such a press felt, there is known a press felt having a seam loop portion in which a filler yarn is inserted in the periphery in order to prevent hair loss of batt fibers and reduce resistance to insertion of the core wire (Patent Documents 1 to 10). 4).
On the other hand, it has been reported that in a press felt having a seam loop portion, marks may occur on the sheet after dehydration (Patent Document 2).

Japanese Patent Application Laid-Open No. 2004-232142 Japanese Patent Application Laid-Open No. 2003-239194 JP 2004-285554 A Japanese Patent Publication No. 6-504591

SUMMARY OF THE INVENTION An object of the present invention is to provide a papermaking felt base fabric having a seam loop portion capable of suppressing the occurrence of seam marks in dewatered paper.

In the course of intensive research to solve the above problems, the present inventors have found that, in a papermaking felt base fabric having seam loops, a It was found that the occurrence of seam marks can be suppressed by inserting one or more hydrophilic filler yarns into the inner and outer sides of the other seam loop portion, and as a result of further research, the present invention was completed. came to.

That is, the present invention relates to the following.
<1> A wet paper web side layer forming the wet paper web side surface, a roll side layer forming the roll side surface, and a seam loop that connects the wet paper web side layer and the roll side layer and has a core wire passed through inside in the CD direction. A base fabric for papermaking felt having parts at both ends,
The wet paper web side layer and the roll side layer are made of MD thread material in the running direction of the felt (MD direction) and CD thread material in the transverse direction (CD direction) of the felt, and the seam loop portion is formed by the MD thread material,
The papermaking felt base fabric includes one or more filler yarns passed near the outside of one seam loop portion and inside the other seam loop portion, or inside and outside the other seam loop portion. further comprising
The filling thread is a hydrophilic thread,
The base fabric for the papermaking felt.
<2> The base fabric for papermaking felt according to <1>, wherein the hydrophilic yarn is a fiber having a moisture content of 6% or more at 65% relative humidity and 20°C (standard conditions).
<3> The base fabric for papermaking felt according to <1> or <2>, wherein the hydrophilic yarn is rayon or hydrophilically treated nylon.
<4> A papermaking felt obtained by joining the base fabrics for a papermaking felt according to any one of <1> to <3>.

By using the base fabric for papermaking felt of the present invention, the occurrence of seam marks on dewatered paper can be suppressed.
The mechanism by which the occurrence of seam marks on dewatered paper can be suppressed is not necessarily clear, but it is possible that there is a difference in water absorption between the base fabric and the seam loops, and the water that moves from the wet paper is not dewatered uniformly. Where it is considered to be the cause of the occurrence of seam marks, one or two or more hydrophilic By inserting elastic filler yarn, it is possible to compensate for the difference in water absorption between the base fabric and the seam loop part, and it is possible to uniformly dehydrate the water that has moved from the wet paper, preventing the occurrence of seam marks on the paper after dehydration. This is thought to be due to the fact that it can be suppressed.

FIG. 1 is a schematic diagram of a papermaking seam felt. FIG. 2 is a diagram showing an engagement operation of seam felts for papermaking. FIG. 3 is a schematic diagram of the base fabric for papermaking felt of the present invention.

The papermaking felt base fabric of the present invention comprises a wet paper web side layer forming the wet paper web side surface, a roll side layer forming the roll side surface, and a CD direction inside connecting the wet paper web side layer and the roll side layer. The wet paper web side layer and the roll side layer are made of MD thread material in the running direction of the felt (MD direction) and CD thread material in the transverse direction of the felt (CD direction). , the seam loop portion is formed of MD yarn material, and the papermaking felt base fabric is located near the outside of one seam loop portion and inside the other seam loop portion, or between the inside and outside of the other seam loop portion. 2, a base fabric for papermaking felt, further comprising one or more filler yarns passed through, wherein the filler yarns are hydrophilic yarns (Fig. 3).

The papermaking felt base fabric of the present invention comprises a wet paper web side layer forming the wet paper web side surface, a roll side layer forming the roll side surface, and a CD direction inside connecting the wet paper web side layer and the roll side layer. It has seam loops on both ends through which the core wire is passed. The wet paper web side layer and the roll side layer are made of MD thread material in the running direction (MD direction) of the felt and CD thread material in the transverse direction (CD direction) of the felt, and the seam loop portion is formed by the MD thread material.

The papermaking felt base fabric of the present invention is one or more that is passed near the outside of one seam loop portion and inside the other seam loop portion, or between the inside and outside of the other seam loop portion. further includes a fill thread of
The filler thread of the present invention is a hydrophilic thread. In the present invention, "hydrophilic yarn" refers to yarn that can effectively absorb water transferred from the wet paper to the base fabric for papermaking felt. When the filler yarn is a hydrophilic yarn, it is possible to suppress the occurrence of seam marks on the paper after dehydration. The hydrophilic yarn preferably has a moisture content of 6% or more, more preferably 8% or more, and still more preferably 10% or more at a relative humidity of 65% and 20°C (standard conditions). be.
On the other hand, if the filler yarn is not a hydrophilic yarn, there is a high possibility that seam marks will occur on the dewatered paper.

Examples of hydrophilic yarn include, but are not limited to, rayon (moisture content: about 11%), hydrophilic treated nylon (moisture content: about 20%), and wool (moisture content: about 16%). , cupra (moisture content: about 12-14%), hemp (moisture content: about 7-10%), silk (moisture content: about 9%), cotton (moisture content: about 7%), and the like. Here, "hydrophilic treated nylon" refers to nylon which is not a hydrophilic yarn and has a moisture content adjusted to about 20% by attaching a water-absorbing resin to the nylon. The water-absorbing resin is a resin having a hydrophilic group having a hydroxyl group, a carboxyl group, an amino group, or the like, and examples thereof include urethane-based resins, cellulose-based resins, acrylic-based resins, and the like. As the hydrophilic thread, rayon and hydrophilic-treated nylon are preferable from the viewpoint of suppressing the occurrence of seam marks and durability with washing resistance (chemical resistance).

The number of filler yarns may be 1 or 2 or more, and is not particularly limited as long as the occurrence of seam marks can be suppressed. A single filling thread may be inserted, or a plurality of twisted threads may be inserted. Also, a plurality of wires may be inserted in a plurality of positions, for example, after inserting one wire in one position, three wires may be twisted together and inserted in another position.
The filler yarns are inserted in the CD direction near the outside of one seam loop portion and inside the other seam loop portion, or inside and outside the other seam loop portion, respectively, and are inserted into the wet paper web side layer. Examples include a mode in which it is woven into the MD thread material, a mode in which it is inserted straight between the wet paper web side layer and the roll side layer, and a mode in which it is woven into the MD thread material of the roll side layer. not. In addition, when the filling yarn is woven into the MD yarn material of the wet paper web side layer or the roll side layer, the texture is 1/1 flutter, 2/1 collapse, 3/1 collapse, 4/1 collapse, 5/1 collapse, 6 Examples include /1 collapse, 7/1 collapse, and the like, but are not particularly limited as long as the occurrence of seam marks can be suppressed.

There is no particular limitation on the method for producing the base fabric for papermaking seam felt of the present invention. Typically, it is obtained by weaving MD yarns of the weft on the loom and CD yarns of the warp on the loom, and the MD yarns are entwined with the core wire at the end of the base fabric to form a loop, An endless base fabric is obtained.

The present invention further relates to a papermaking felt formed by joining the above-described papermaking felt base fabrics. Preferred aspects of the papermaking felt are the same as those described for the papermaking felt base fabric.

The papermaking felt formed by joining the papermaking felt base fabrics of the present invention will be described in detail below using examples, but these are not intended to limit the present invention in any way.

[Examples 1 to 7, Comparative Examples 1 to 2]
(1) Production of base fabric for papermaking felt (a) Production of base fabric for papermaking felt of Example 1 A 1590d yarn made by twisting three 530d yarns to the MD yarn material of the wet paper web side layer of the base fabric. A rayon spun yarn was woven with a 1/1 girder structure, and a 1500 d nylon spun yarn was woven with a 1/1 girder structure into the MD yarn material of the roll side layer of the base fabric.
After weaving the base fabric, the fiber layers are laminated and integrated by needling to form a felt, and the protective core wire for the needle is pulled out, and the fiber layer above the loop is cut and separated to obtain the papermaking material of Example 1. A base fabric for felt was obtained.

(b) Production of papermaking felt base fabrics of Examples 2 and 3 and Comparative Example 1 For Example 2, 1500 d nylon spun yarn was used as the MD thread material of the wet paper side layer of the base fabric at 1/1 flutter. A 1590 d rayon spun yarn obtained by twisting three 530 d yarns into the MD yarn material of the roll side layer of the base fabric is woven with a 1/1 flutter structure. A 1500 d nylon spun yarn coated with a urethane-based water-absorbing resin was applied to the MD yarn material of the paper side layer by attaching a water-absorbing resin to it, and was woven with a 1/1 flutter structure for comparison. For Example 1, the manufacturing of the papermaking felt base fabric of Example 1 was repeated, except that the MD thread material of the wet paper web side layer of the base fabric was woven with 1500 d of nylon spun yarn in a 1/1 flutter structure. The papermaking felt base fabrics of Examples 2 and 3 and Comparative Example 1 were obtained in the same manner as described above.

(c) Manufacture of base fabric for papermaking felt of Example 4 Nylon spun yarn of 1500 d was woven into the MD thread material of the wet paper side layer of the base fabric in a 1/1 flutter structure, and the MD of the roll side layer of the base fabric A 1500 d nylon spun yarn is woven into the yarn material with a 1/1 flutter structure, and a 1770 d rayon spun yarn made by twisting 10 177 d yarns between the wet paper web side layer and the roll side layer is used as a CD yarn material. It was inserted straight without being entangled with the MD thread material.
After weaving the base fabric, the fiber layers are laminated and integrated by needling to form a felt, the protective core wire for the needle is pulled out, and the fiber layer above the loop is cut and separated to obtain the papermaking material of Example 4. A base fabric for felt was obtained.

(d) Manufacture of papermaking felt base fabrics of Examples 5 to 7 and Comparative Example 2 For Example 5, 885d made by twisting five 177d yarns between the wet paper web side layer and the roll side layer In Example 6, a water-absorbent resin was attached between the wet paper web side layer and the roll side layer to give a hydrophilic treatment. Specifically, the urethane-based water-absorbent A 1500 d nylon spun yarn coated with a resin was inserted straight. Examples 5 to 7 were prepared in the same manner as described in the production of the papermaking felt base fabric of Example 4, except that the non-twisted yarn of 800 d was inserted straight between the side layer and the roll side layer. And the base fabric for papermaking felt of Comparative Example 2 was obtained.

The rayon spun yarn used in Examples 1 to 7 and Comparative Examples 1 and 2 (relative humidity 65%, moisture content at 20 ° C. (standard condition) is about 11%), hydrophilically treated nylon spun yarn (same 20%) and wool (about 16%) are hydrophilic yarns. On the other hand, nylon spun yarns (approximately 5%) and nylon untwisted yarns (approximately 5%) are not hydrophilic yarns.

(2) Manufacture of papermaking felt A core wire made of five monofilaments with a diameter of 0.35 mm is inserted into the seam portion of the base fabric for papermaking felt of Examples 1 to 7 and Comparative Examples 1 and 2, Papermaking felts of Examples 1 to 7 and Comparative Examples 1 and 2 were obtained, respectively.

(3) Production of evaluation samples A circular sample with a diameter of 70 mm was punched out from the papermaking felt base fabrics of Examples 1 to 7 and Comparative Examples 1 and 2 so that the seam was in the center. Samples for evaluation of Examples 1 to 7 and Comparative Examples 1 and 2 were obtained.

(4) Sample Preparation and Evaluation Samples of Examples 1-7 and Comparative Examples 1-2 were prepared and evaluated according to the following procedures.
(a) The papermaking felt base fabrics of Examples 1 to 7 and Comparative Examples 1 and 2 were punched into a circular shape with a diameter of 70 mm so that the seam loop portion was centered, Examples 1 to 7 and Comparative Examples 1-2 samples were obtained. The sample was immersed in water for 1 hour or more to fully absorb the water. The moisture content of the sample felt was adjusted to about 30% prior to testing.
(b) LBKP (Leaf bleached kraft pulp) is beaten to a degree of beating of 300 to 400C. S. F. (canadian standard freeness; an index of fineness of paper stock), and then a wet paper web having a basis weight of 220 gsm was produced by a sheet former. 60 mm circles were punched out for testing, and the moisture content of the wet paper was adjusted to about 80% prior to testing.

(c) The height of the free-falling press platen was adjusted so that the pressurizing surface pressure was 50 kg/cm ² .
(d) The felt and the wet paper were placed on a press platen, and the press platen was allowed to fall freely from a predetermined height to extract water and seam marks from the wet paper.

(e) The wet paper after pressing was dried while being sandwiched between rings so as not to bend during drying.
(f) The seam marks were evaluated visually, and the thickness and clarity of the seam marks were evaluated as follows. Evaluations are summarized in Table 1.
⊚ (very good): The width of the seam mark is very narrow and hardly visible.
◯ (Good): The width of the seam mark is narrow and can withstand practical use.
x (defective): The width of the seam mark is wide, and there is a problem in terms of practical use.

In Examples 1 and 3, in which hydrophilic rayon spun yarn or hydrophilically treated nylon spun yarn is woven into the MD yarn material of the wet paper web side layer, non-hydrophilic nylon spun yarn is woven at the same position. However, as compared with Comparative Example 1, the occurrence of seam marks was suppressed. In addition, in Example 2, in which rayon spun yarn, which is a hydrophilic yarn, was woven into the MD yarn material of the roll side layer, the seam Suppressed the generation of marks. Further, in Examples 4 to 7, in which a hydrophilic rayon spun yarn, hydrophilic treated nylon spun yarn, or wool was inserted between the wet paper web side layer and the roll side layer, hydrophilicity was also found at the same position. The occurrence of seam marks was suppressed as compared with Comparative Example 2 in which a nylon spun yarn was inserted instead of a spun yarn.

By using the base fabric for papermaking felt of the present invention, it is possible to suppress the occurrence of seam marks on paper after dehydration.

F: Felt for papermaking L: Seam loop B: Base fabric W: Bat layer S: Core wire

Claims (4)

The wet paper web side layer forming the wet paper web side surface, the roll side layer forming the roll side surface, and the seam loop portion connecting the wet paper web side layer and the roll side layer and through which the core wire is passed in the CD direction are provided on both ends. A base fabric for papermaking felt having
The wet paper web side layer and the roll side layer are made of MD thread material in the running direction of the felt (MD direction) and CD thread material in the transverse direction (CD direction) of the felt, and the seam loop portion is formed by the MD thread material,
The papermaking felt base fabric includes one or more filler yarns passed near the outside of one seam loop portion and inside the other seam loop portion, or inside and outside the other seam loop portion. further comprising
The filling thread is a hydrophilic thread,
The base fabric for the papermaking felt. 2. The base fabric for papermaking felt according to claim 1, wherein the hydrophilic yarn is a fiber having a moisture content of 6% or more at 65% relative humidity and 20[deg.] C. (standard conditions). The base fabric for papermaking felt according to claim 1 or 2, wherein the hydrophilic yarn is rayon or hydrophilically treated nylon. A papermaking felt obtained by joining the base fabrics for a papermaking felt according to any one of claims 1 to 3.

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