JP7094433B1 - Papermaking felt base cloth and papermaking felt made by joining them together. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a felt base cloth for papermaking capable of uniformly dehydrating from wet paper and suppressing the generation of seam marks on the dehydrated paper. SOLUTION: A wet paper side layer forming a wet paper side surface, a roll side layer forming a roll side surface, and a seam connecting a wet paper side layer and a roll side layer, through which a core wire is passed in the CD direction. It is a base cloth for felt for papermaking having loop portions at both ends, and the wet paper side layer and the roll side layer are made of MD thread material in the felt running direction (MD direction) and CD thread material in the felt transverse direction (CD direction). The seam loop portion is formed of MD thread material, and the papermaking felt base fabric is near the outside of one seam loop portion and inside the other seam loop portion or inside the other seam loop portion. The felt base fabric for papermaking, further comprising one or more filling yarns to be passed on the outside, wherein the filling yarn is a hydrophilic yarn. [Selection diagram] Fig. 3

Description

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

Conventionally, in the press part of a papermaking machine, wet paper is squeezed by a press felt and a pair of press rolls or a press roll and a shoe press. As this press felt, an end-shaped one having a seam loop shown in FIG. 1 is known. That is, the felt F is configured in an endped shape, and a plurality of seam loops L are formed at each end. As shown in FIG. 2, for example, the felt F is composed of a base cloth B made of a woven cloth and a two-layer butt layer W. In the butt layer W, short web fibers laminated on the base cloth B are entangled and integrated together with the base cloth B by needle punching. The base cloth B is composed of a yarn material in the felt traveling direction (MD direction) and a woven fabric in which the yarn material in the felt crossing direction (CD direction) is woven. Then, the seam loop L is formed by the thread 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, a press felt having a seam loop portion in which a filling thread is inserted is known in order to prevent hair loss of the butt fiber and reduce the core wire insertion resistance (Patent Documents 1 to 1). 4).
On the other hand, in the press felt having a seam loop portion, it has been reported that marks may be generated on the sheet of the dehydrated paper (Patent Document 2).

Japanese Unexamined Patent Publication No. 2004-232142 Japanese Patent Application Laid-Open No. 2003-239194 Japanese Unexamined Patent Publication No. 2004-285554 Special Table 6-504591A Gazette

An object of the present invention is to provide a felt base fabric for papermaking, which has a seam loop portion capable of suppressing the generation of seam marks on paper after dehydration.

In earnest research to solve the above problems, the present inventors have found that in a felt base fabric for papermaking having a seam loop portion, the vicinity of the outside of one seam loop portion and the inside of the other seam loop portion. We have found that the occurrence of seam marks can be suppressed by inserting one or more hydrophilic filled yarns inside and outside the seam loop portion on or on the other side, and as a result of further research, the present invention was completed. I came to do it.

That is, the present invention relates to the following.
<1> A seam loop that connects the wet paper side layer forming the wet paper side surface, the roll side layer forming the roll side surface, and the wet paper side layer and the roll side layer, and the core wire is passed through the inside in the CD direction. A base cloth for felt for papermaking that has parts at both ends.
The wet paper side layer and the roll side layer are composed of an MD thread material in the felt traveling direction (MD direction) and a CD thread material in the felt crossing direction (CD direction), and the seam loop portion is formed of the MD thread material.
The papermaking felt base fabric is one or more filled yarns that are passed near the outside of one seam loop and inside the other seam loop, or inside and outside the other seam loop. Including
The filling thread is a hydrophilic thread,
The base cloth for felt for papermaking.
<2> The felt base cloth for papermaking according to <1>, wherein the hydrophilic yarn is a fiber having a moisture content of 6% or more at a relative humidity of 65% and a moisture content of 20 ° C. (standard temperature).
<3> The felt base cloth for papermaking according to <1> or <2>, wherein the hydrophilic thread is rayon or hydrophilically treated nylon.
<4> A papermaking felt to which the base cloth for papermaking felt according to any one of <1> to <3> is joined.

By using the felt base cloth for papermaking of the present invention, it is possible to suppress the generation of seam marks on the paper after dehydration.
The mechanism that can suppress the generation of seam marks on paper after dehydration is not always clear, but there is a difference in water absorption between the base cloth and the seam loop part, and the water transferred from the wet paper is not uniformly dehydrated. One or more hydrophilics near the outside of one seam loop and inside the other seam loop, or inside and outside the other seam loop, where it is thought to be the cause of the seam mark. By inserting a sex-filled yarn, the difference in water absorption between the base cloth and the seam loop part can be compensated, and the water transferred from the wet paper can be uniformly dehydrated, and the generation of seam marks on the dehydrated paper can be generated. It is thought that this is due to the fact that it can be suppressed.

FIG. 1 is a schematic view of a papermaking seam felt. FIG. 2 is a diagram showing a meshing operation of a papermaking seam felt. FIG. 3 is a schematic view of the felt base cloth for papermaking of the present invention.

The felt base cloth for papermaking of the present invention has a wet paper side layer forming a wet paper side surface, a roll side layer forming a roll side surface, and an internal CD direction connecting the wet paper side layer and the roll side layer. The wet paper side layer and the roll side layer are composed of an MD thread material in the felt running direction (MD direction) and a CD thread material in the felt crossing direction (CD direction). , The seam loop portion is formed of MD thread material, and the felt base cloth for papermaking is near the outside of one seam loop portion and inside the other seam loop portion, or inside and outside the other seam loop portion. Is a felt base fabric for papermaking, further comprising one or more filled yarns to be passed through, wherein the filled yarn is a hydrophilic yarn (FIG. 3).

The felt base cloth for papermaking of the present invention has a wet paper side layer forming a wet paper side surface, a roll side layer forming a roll side surface, and an internal CD direction connecting the wet paper side layer and the roll side layer. It has seam loops at both ends through which the core wire is passed. The wet paper side layer and the roll side layer are composed of an MD thread material in the felt traveling direction (MD direction) and a CD thread material in the felt crossing direction (CD direction), and the seam loop portion is formed of the MD thread material.

The felt base cloth for papermaking of the present invention is one or two or more that are 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 includes the filling yarn of.
The filled yarn of the present invention is a hydrophilic yarn. In the present invention, the "hydrophilic thread" refers to a thread capable of effectively absorbing water transferred from the wet paper to the felt base cloth for papermaking. When the filling yarn is a hydrophilic yarn, the generation of seam marks on the paper after dehydration can be suppressed. The hydrophilic yarn is preferably a fiber having a moisture content of 6% or more, more preferably 8% or more, still more preferably 10% or more at a relative humidity of 65% and 20 ° C. (standard temperature). be.
On the other hand, if the filled yarn is not a hydrophilic yarn, seam marks are likely to occur on the dehydrated paper.

The hydrophilic yarn is not limited to this, but rayon (moisture content: about 11%), hydrophilic treated nylon (moisture content: about 20%), 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, the "hydrophilic treated nylon" refers to nylon whose moisture content is adjusted to about 20% by adhering a water-absorbent resin to nylon which is not a hydrophilic thread. The water-absorbent 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, and acrylic-based resins. As the hydrophilic yarn, rayon and hydrophilically treated nylon are preferable from the viewpoint of suppressing the generation of seam marks and having cleaning resistance (chemical resistance) and durability.

The number of filling threads may be 1 or 2 or more, and is not particularly limited as long as the generation of seam marks can be suppressed. As the filling thread, one may be inserted alone, or a plurality of twisted threads may be inserted. Further, a plurality of pieces may be inserted into a plurality of places, for example, one piece may be inserted in one place, and then a twisted three pieces may be inserted in another place.
The filling yarn is inserted in the CD direction in the vicinity of 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 the filling yarn is inserted in the wet paper side layer. Examples include a mode of weaving into the MD yarn material, a mode of inserting straight between the wet paper side layer and the roll side layer, a mode of weaving into the MD yarn material of the roll side layer, etc., but it is particularly limited as long as the occurrence of seam marks can be suppressed. Not done. Further, the structure when the filled yarn is woven into the MD yarn material of the wet paper side layer or the roll side layer is 1/1 flat, 2/1 collapse, 3/1 collapse, 4/1 collapse, 5/1 collapse, 6 Examples thereof include 1/1 collapse and 7/1 collapse, but the present invention is not particularly limited as long as the occurrence of seam marks can be suppressed.

The method for producing the base fabric for seam felt for papermaking of the present invention is not particularly limited. Typically, the MD yarn of the weft on the loom and the CD yarn of the warp on the loom are woven by the loom, and the MD yarn is entangled with the core wire at the end of the base fabric to form a loop. An endless base cloth can be obtained.

The present invention further relates to a papermaking felt formed by joining the above-mentioned papermaking felt base fabrics. The preferred embodiment of the papermaking felt is the same as that described for the papermaking felt base fabric.

Hereinafter, the felt for papermaking, which is formed by joining the base fabrics for the felt for papermaking of the present invention, will be described in detail with reference to examples, but these are not limited to the present invention.

[Examples 1 to 7, Comparative Examples 1 to 2]
(1) Manufacture of base cloth for felt for paper making (a) Manufacture of base cloth for felt for paper making according to Example 1 1590d made by twisting three 530d threads to the MD yarn material of the wet paper side layer of the base cloth. Rayon spun yarn was woven with a 1/1 hill structure, and 1500d nylon spun yarn was woven with a 1/1 hill 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 felt, and the protective core wire for the needle is pulled out, and the fiber layer at the upper part of the loop is cut and separated for papermaking according to Example 1. Obtained a base cloth for felt.

(B) Production of base cloth for felt for papermaking of Examples 2 to 3 and Comparative Example 1 In Example 2, 1500 d nylon spun yarn was used as the MD thread material of the wet paper side layer of the base cloth in 1/1 flat. Weaving with a structure, 1590d nylon spun yarn made by twisting three 530d yarns into the MD yarn material of the roll side layer of the base fabric is woven with a 1/1 hill structure, and in Example 3, the wetness of the base fabric. A 1500d nylon spun yarn coated with a water-absorbent resin and subjected to a hydrophilic treatment, specifically a urethane-based water-absorbent resin, is woven into the MD thread material of the paper side layer with a 1/1 hill structure for comparison. Regarding Example 1, in the production of the felt base cloth for papermaking of Example 1, except that 1500 d nylon spun yarn was woven into the MD thread material of the wet paper side layer of the base cloth with a structure of 1/1 flat. The base cloth for the felt for papermaking of Examples 2 to 3 and Comparative Example 1 was obtained by the same method as described above.

(C) Production of base cloth for felt for paper making according to Example 4 1500d nylon spun yarn is woven into the MD yarn material of the wet paper side layer of the base cloth with a 1/1 flat structure, and the MD of the roll side layer of the base cloth is woven. A 1500d nylon spun yarn is woven into the yarn material with a 1/1 flat structure, and a 1770d rayon spun yarn made by twisting 10 177d yarns between the wet paper 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 felt, and the protective core wire for the needle is pulled out, and the fiber layer at the upper part of the loop is cut and separated for papermaking according to Example 4. Obtained a base cloth for felt.

(D) Production of base cloth for felt for papermaking in Examples 5 to 7 and Comparative Example 2 In Example 5, 585d yarns of 177d are twisted between the wet paper side layer and the roll side layer. In Example 6, the rayon spun yarn of No. 1 was inserted straight, and in Example 6, a water-absorbent resin was adhered between the wet paper side layer and the roll side layer to perform a hydrophilic treatment, specifically, a urethane-based water-absorbent material. A 1500d nylon spun yarn coated with a resin is inserted straight, and in Example 7, 800d wool is inserted straight between the wet paper side layer and the roll side layer, and in Comparative Example 2, the wet paper is inserted. Examples 5 to 7 are carried out in the same manner as described in the production of the base cloth for felt for papermaking in Example 4, except that 800d untwisted yarn is inserted straight between the side layer and the roll side layer. And a base cloth for felt for papermaking of Comparative Example 2 was obtained.

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

(2) Manufacture of felt for papermaking Insert a core wire of five monofilaments having a diameter of 0.35 mm into the seam portion of the felt base cloth for papermaking of Examples 1 to 7 and Comparative Examples 1 to 2. Papermaking felts of Examples 1 to 7 and Comparative Examples 1 and 2, respectively, were obtained.

(3) Production of Evaluation Samples Examples 1 to 7 and Comparative Examples 1 to 2 were punched into a circular shape having a diameter of 70 mm so that the seam portion was at the center of the felt base cloth for papermaking. Evaluation samples 1 to 7 and Comparative Examples 1 to 2 were obtained.

(4) Sample production and evaluation The samples of Examples 1 to 7 and Comparative Examples 1 and 2 were produced and evaluated according to the following procedure.
(A) The felt base fabrics for papermaking of Examples 1 to 7 and Comparative Examples 1 and 2 are punched into a circular shape having a diameter of 70 mm so that the seam loop portion is at the center, and Examples 1 to 7 and Comparative Examples are used. One or two samples were obtained. The sample was immersed in water for at least 1 hour to allow it to fully immerse in water. Before the test, the water content of the felt of the sample was adjusted to about 30%.
(B) LBKP (Leaf bleached kraft pulp) with a degree of beating of 300 to 400 C.I. S. F. (Canadian standard freeness; an index of the fineness of the paper raw material) was beaten, and then a wet paper with a basis weight of 220 gsm was prepared with a sheet former. For the test, it was punched out in a circular shape of 60 mm, and the water content of the wet paper was adjusted to about 80% before the test.

(C) The drop height of the press machine in which the mechanism freely falls was adjusted so that the surface pressure of pressurization was 50 kg / cm ² .
(D) Felt and wet paper were placed on the press board in an overlapping manner, and the press board was freely dropped from a predetermined height to collect dehydration 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 mark was visually evaluated, and the thickness and clarity of the seam mark were evaluated as follows. The evaluations are summarized in Table 1.
◎ (Very good): The width of the seam mark is very narrow and hardly observed visually.
〇 (Good): The width of the seam mark is narrow and can withstand practical use.
× (defective): The width of the seam mark is wide, and there is a problem in practical use.

In Examples 1 and 3 in which rayon spun yarn which is a hydrophilic yarn or nylon spun yarn which has been treated with hydrophilicity is woven into the MD yarn material of the wet paper side layer, nylon spun yarn which is not a hydrophilic yarn is woven at the same position. However, the occurrence of seam marks was suppressed as compared with Comparative Example 1. Further, Example 2 in which the rayon spun yarn which is a hydrophilic yarn is woven into the MD yarn material of the roll side layer is a seam as compared with Comparative Example 1 in which a nylon spun yarn which is not a hydrophilic yarn is woven at the same position. The generation of marks was suppressed. Further, Examples 4 to 7 in which rayon spun yarn, which is a hydrophilic yarn, nylon spun yarn treated with hydrophilicity, or wool is inserted between the wet paper side layer and the roll side layer are also hydrophilic at the same position. The generation of seam marks was suppressed as compared with Comparative Example 2 in which a nylon spun yarn other than the yarn of No. 2 was inserted.

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

F: Papermaking felt L: Seam loop B: Base cloth W: Butt layer S: Core wire

Claims (3)

Both ends of the wet paper side layer that forms the wet paper side surface, the roll side layer that forms the roll side surface, and the seam loop portion that connects the wet paper side layer and the roll side layer, through which the core wire is passed in the CD direction. It is a base cloth for felt for papermaking, which is owned by
The wet paper side layer and the roll side layer are composed of an MD thread material in the felt traveling direction (MD direction) and a CD thread material in the felt crossing direction (CD direction), and the seam loop portion is formed of the MD thread material.
The papermaking felt base fabric is one or more filled yarns that are passed near the outside of one seam loop and inside the other seam loop, or inside and outside the other seam loop. Including
The filling thread is a hydrophilic thread ,
The hydrophilic yarn is a fiber having a moisture content of 6% or more at a relative humidity of 65% and 20 ° C. (standard temperature).
The base cloth for felt for papermaking. The felt base fabric for papermaking according to claim 1 , wherein the hydrophilic thread is rayon or hydrophilically treated nylon. A felt for papermaking, wherein the base cloth for the felt for papermaking according to claim 1 or 2 is joined together.

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