JP2006083504A - Method for joining pressing felt for papermaking - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for joining a pressing felt for papermaking, capable of joining substrates with a high joining strength without damaging the surface smoothness of the substrate. <P>SOLUTION: This method for joining the pressing felt is provided by arranging a hot melt adhesive sheet 50 so as to stride on the side ends brought face to face for joining the substrates 20 each other, arranging further an assistant sheet 60 on it, putting a heating body 70 on the assistant sheet 60, heating the hot melt adhesive sheet 50 through the assistant sheet 60, bonding the hot melt sheet 50 together with the assistant sheet 60 with the substrate 20, and then interlacing to make pad fibers in one unit with the substrate 20 by needle punching. By using the method, the bonding with the heating body observed in the case of without using the assistant sheet is eliminated and it is possible to improve workability and join the substrates with a uniform and high bonding strength caused by the surface bonding without damaging the surface smoothness of the substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for connecting a papermaking press felt, and in particular, a base of a papermaking press felt (hereinafter sometimes simply referred to as “felt”) and / or a terminal-shaped press felt that forms a papermaking press felt. The present invention relates to a method for connecting endless strips.

  Conventionally, felt is used in the press part of the papermaking process, and the wet paper is transferred by passing the felt and wet paper through a press-pressing section provided in the press part and transferring the moisture of the wet paper to the felt. The water is squeezed from. In addition, the press pressurizing unit is generally configured by a pair of press rolls, or configured by a press roll and a shoe having a shape corresponding to the peripheral surface of the press roll.

  The construction of the papermaking press felt will be described with reference to FIG. The felt 10 includes an endless or endless belt 20 that forms a papermaking press felt together with the base and / or the base, and an endless or endless belt 20 that forms a papermaking press felt together with the base and / or the base. And the bat layer 30 intertwined with each other. The endless or endless belt-like body 20 constituting the papermaking press felt together with the base body and / or the base body is indispensable in order to develop the strength of the entire felt 10. And as a base | substrate, the endless base fabric comprised by weaving a warp and a weft is normally used.

In manufacturing the felt 10, first, the base body 20 which is an endless woven fabric having the desired width and substantially the same width as the completed felt 10 is manufactured. In the production of the base body 20, an endless base fabric is manufactured by weaving warps and wefts with a loom, or an endless woven fabric is woven, and then both ends are sewn to form an endless shape. It is common to do. After the base 20 is manufactured, the bat fiber is placed on the base 20 and the bat fiber and the base 20 are entangled and integrated by needle punching to complete the felt 10.
In addition, the endless or endless belt-shaped body constituting the papermaking press felt together with the substrate is preferably a three-dimensional knitted fabric as described in Patent Document 1 as a means for reinforcing the compression / recoverability of the substrate. it can. Hereinafter, the endless or endless belt-like body 20 constituting the papermaking press felt together with the base and / or the base is referred to collectively as the base 20 for ease of explanation.

  The conventional felt having the above configuration has various sizes and mechanical configurations in the press part of the paper machine to be used. Therefore, it has to be manufactured separately for each press part. However, since felt manufacturers usually have to deal with base fabrics of various sizes with a single loom, it takes a lot of time and man-hours to manufacture the base fabric, simplifying the process. In addition, it has been very difficult to reduce costs.

  In order to solve this problem, Patent Document 2 discloses a method of forming a base body by manufacturing a strip having a narrower width than a completed felt in advance and winding the strip in a spiral shape. Yes.

This method will be described with reference to FIG.
First, the belt-like body 23 is formed from a thread material or the like selected corresponding to the performance of the completed felt. Next, the interval between the pair of guide rolls GR is adjusted according to the length of the completed felt.
And by driving a pair of guide roll GR, the strip | belt-shaped body 23 is let out on both guide roll GR. At this time, the belt-like body 23 is spirally wound, and the feeding angle with respect to the guide roll GR is adjusted so that the side surfaces of the belt-like body 23 are arranged adjacent to each other.
This winding operation is continued until the width dimension constituted by the adjacent belt-like bodies 23 is substantially the same as the desired felt.
Then, the side surfaces of the spiral belt-like body 23 are connected and integrated with each other to produce a base, and then a bat layer is formed on the base to complete a papermaking press felt.

Furthermore, there is also a method as shown in FIG. 4 (see, for example, Patent Document 3).
In this method, an endless partial base 22 is formed by joining the start and end of a strip 21 having a width smaller than the width of the press felt 10 so that the side faces 41 of the plurality of partial bases 22 are adjacent to each other. The base 20 is constructed by connecting and integrating at the side surface 41, and the butt layer 30 (wet paper side layer 31 and machine side layer 32) is formed on the outer peripheral surface and inner peripheral surface of the base 20; Complete papermaking press felt.
According to this method, the paper felt press felt 10 having a desired size can be manufactured in a relatively short time and man-hour. Further, since the partial substrates may be arranged side by side without providing an angle, it is possible to prevent separation of the partial substrates, a decrease in connection strength associated with the separation, transfer of the separated partial substrates to the wet paper, and the like.

On the other hand, there are various means for connecting the bases. For example, when stitching with water-soluble fibers, the felt is exposed to a large amount of water after the completion of the felt, so that the water-soluble fibers can be dissolved. Thus, by eliminating the fibers used for suturing, it becomes possible to reduce the difference in physical properties between the connecting portion and other locations.
In this case, even if the water-soluble fiber is dissolved, the connection portion is connected through the bat fiber by the needling operation of the bat fiber, so that the connection state of the connection portion is maintained. Therefore, even after the water-soluble fiber is dissolved, the end of the belt-like body does not peel off, and the strength as a base can be expressed.
In addition, as such a water-soluble fiber, the fiber melt | dissolved at normal temperature and the fiber melt | dissolved with warm water like PVA (polyvinyl alcohol) etc. can be used.

Other than this, there are stitching with insoluble fibers, adhesion with adhesives, welding of non-woven materials of molten fibers (by ultrasonic welding), and the like. Patent Document 4 discloses a method of connecting adjacent turns of a woven fabric band to each other using ultrasonic energy.
JP 2004-232098 A JP-T 6-503385 JP 2004-36046 A JP-A-10-226978

However, when connecting by stitching, there are the following problems.
(1) In a plurality of bases to be connected, the penetrating part of the suture thread to the base is pulled by the tension of the thread, but the pulling force is different between the vicinity of the base penetrating part and the other part. That is, in the connection of the suture thread, since the thread is connected at the point (penetrating part to the base) and the line (presser), the thread tension acts between the point by the thread and is pulled, but the point is removed. The substrate in the section is placed in a relaxed state. When placed in such a slack state, the stitching of the substrate with the partial spots inherently causes partial dimensional change spots in the subsequent process, and when the dimensional change is large, the connection part is partially opened. Sometimes.
(2) Since stress is concentrated on the thread-penetrating portion of the base when handling the base after connecting the base to the needle process or when placing the base in a needle machine, Damage, suture breakage or elongation may occur.
(3) When stitch skipping at the time of sewing of the sewing machine or suture breakage at the time of handling occurs, partial opening of the mouth may occur. In addition, handling means mechanical or human handling, such as producing a base | substrate and conveying to a needle process.
(4) In the case of a highly compressible sheet, the two substrates are strongly drawn so that there is no gap between the substrates when stitched, so that the yarn tension is increased, but if the yarn tension is increased, The vicinity of the suture thread penetrating portion of the sheet is dented, and the connecting portion is uneven.

Moreover, when connecting using an ultrasonic wave, there exists a problem that the compressibility of a connection part is lost.
Further, in welding with a nonwoven material of molten fiber, thermocompression bonding (thermal pressing) has been performed by a heating body without using ultrasonic waves, but the nonwoven material adheres to the heating body during thermocompression bonding. In many cases, the surface smoothness of the substrate is impaired, and the connection strength is lowered.

  In view of the above-described problems, an object of the present invention is to provide a paper felt press felt connection method capable of connecting a substrate with high connection strength without impairing the surface smoothness of the substrate.

  In the present invention, a thermal adhesive sheet is disposed so as to straddle a portion to be connected to the base of the papermaking press felt, an auxiliary sheet is further disposed thereon, a heating body is applied to the auxiliary sheet, and the auxiliary sheet is The paper is made by heating the heat-bonding sheet, bonding the heat-bonding sheet to a portion to be connected to the base together with the auxiliary sheet, and tangling the bat fiber to the base by a needle punch. The above-mentioned problems have been solved by the press felt connecting method. In this invention, it is preferable to arrange | position a thermal-bonding sheet and also an auxiliary sheet | seat further on it so that it may straddle at least one of the front and back of a base | substrate in the part which should connect a base | substrate, or arrange | positions both front and back.

  According to the present invention, the auxiliary sheet is disposed on the thermal adhesive sheet, the thermal adhesive sheet is heated via the auxiliary sheet, and the thermal adhesive sheet is bonded to the portion to be connected together with the auxiliary sheet, thereby the auxiliary sheet. Adhesion to the heating body, which is seen when not using, is eliminated, and the substrates can be connected with uniform and high connection strength by improving workability and surface adhesion without impairing the surface smoothness of the substrate. In particular, since the substrate is fixed by surface bonding, there is no problem as in conventional stitching, and there are no partial spots, so that a substrate with uniform and high connection strength can be configured.

The present invention will be described with reference to FIG.
In the connection method of the present invention, the thermal bonding sheet 50 is disposed so as to straddle the side ends of the base bodies 20 that are abutted to be connected to each other, and the auxiliary sheet 60 is further disposed thereon, thereby assisting the heating body 70. The thermal adhesive sheet 50 is heated through the auxiliary sheet 60 and applied to the sheet 60, and the thermal adhesive sheet 50 is adhered to the base body 20 together with the auxiliary sheet 60. Thereafter, the bat fibers are entangled and integrated with the base body 20 by needle punching. Made up of.
The heat bonding sheet 50 is made of a non-woven fabric, a woven fabric, or a film composed of heat-bonding fibers, and is heated by a heating body 70 such as an iron or a heat roller via the auxiliary sheet 60, whereby the heat bonding sheet 50 Are bonded across the side edges of the base 20 to be connected. The heat-sealing fiber is preferably one having adhesiveness in the range of 60 to 160 ° C., and for example, copolyamide fiber or the like can be used.

In addition, the thermal bonding sheet 50 is preferably made of a non-woven fabric. This is because when the bat fiber is entangled and integrated with the base body 20 by needle punching, it tends to be entangled with the bat fiber like a non-woven fabric made of long fibers. This is because it contributes to the efficiency of the connecting work. Further, when a film is used for the thermal bonding sheet 50, the inner bat fiber and the outer bat fiber are not easily entangled with the film interposed therebetween, and the movement of the bat fiber is impaired.
The auxiliary sheet 60 is made of a nonwoven fabric, a woven fabric, or a film. The auxiliary sheet 60 prevents the heating body 70 such as an iron or a heat roller from coming into direct contact with the thermal bonding sheet 50, so that the base body 20 can be connected with high connection strength without impairing the surface smoothness of the base body 20. Can do.
FIG. 1 illustrates a method of connecting the side ends of the bases that are to be connected to each other. However, the present invention is not limited to this, and the ends to be connected are overlapped and connected. Also good.

Depending on the thickness and basis weight of the heat-bonding sheet and auxiliary sheet, a partial level difference, weight variation, etc. may occur, causing problems such as vibration or transfer of the level difference to the paper when using felt in the press part. There is.
In order to prevent this, it is preferable to make the thermal bonding sheet as light as possible and to make the auxiliary sheet water-soluble. In this way, if the auxiliary sheet is made water-soluble, it will be exposed to a large amount of moisture after the end of the needle process, when the felt is scoured (washing water, etc.), or when the felt is used in the papermaking process. Accordingly, the auxiliary sheet can be lost. When the auxiliary sheet is composed of water-soluble fibers, as water-soluble fibers, fibers that dissolve at room temperature or fibers that dissolve in warm water such as PVA (polyvinyl alcohol) can be used. Further, even if the auxiliary sheet is made of a material that is not water-soluble and is soluble in a certain solvent, the same effect can be obtained.

Furthermore, the thermal bonding sheet itself may be made of a water-soluble material or a material that is soluble in a certain solvent. In this case, even if the thermal adhesive sheet is melted, the connecting portion of the base body is connected through the bat fiber by the needling operation of the bat fiber, so that the connection strength of the base body is maintained. Therefore, even after the thermal bonding sheet is melted, the connecting portion of the base does not peel off, and the strength as the base can be expressed.
However, in the connection part which requires higher strength, the combined use of the connection method of the present invention and stitching is more desirable. In particular, since the substrate is fixed by surface bonding, there is no problem as in the conventional stitching by using it together with stitching, and there are no partial spots, so that a substrate with uniform and high connection strength can be configured.

The connecting method of the present invention can be suitably used for connecting the side ends of the strips 23 as shown in FIG. 3 and connecting the side ends 41 of the partial base 22 as shown in FIG. However, the present invention is not limited to this. For example, after connecting the start and end of the belt-like body 21 as shown in FIG. 4 or weaving a conventional endless woven fabric, both ends are connected to endless shape. It can be suitably used also in the case of.
Moreover, a connection part is not restricted to a linear form (plane), A slope, a convex shape, or a step shape may be sufficient.

  As described above, according to the present invention, the auxiliary sheet is disposed on the thermal adhesive sheet, the thermal adhesive sheet is heated via the auxiliary sheet, and the thermal adhesive sheet is bonded to the portion to be connected together with the auxiliary sheet. By doing so, there is an effect that the substrates can be connected with high connection strength without impairing the surface smoothness of the substrate.

Explanatory drawing which shows the connection method of the press felt for papermaking of this invention. Sectional drawing of the press felt for papermaking. Explanatory drawing which shows the conventional press felt manufacturing method for papermaking. Explanatory drawing which shows the other conventional press felt manufacturing method for papermaking.

Explanation of symbols

10: Press felt for papermaking 20: Substrate 30: Butt layer 50: Thermal adhesive sheet 60: Auxiliary sheet 70: Heating body

Claims (2)

A base sheet of a papermaking press felt and / or a thermal adhesive sheet so as to straddle a portion to be joined of an endless or endless belt-like body constituting the papermaking press felt together with the base, and an auxiliary sheet thereon. Place and
An endless or endless strip that forms a press felt for papermaking by applying a heating body to the auxiliary sheet, heating the thermal adhesive sheet through the auxiliary sheet, and the thermal adhesive sheet together with the base and / or the base Adhering to the part to be connected together with the auxiliary sheet,
The bat fiber is entangled and integrated with the endless or endless belt-shaped body constituting the papermaking press felt together with the base body and / or the base body by a needle punch,
How to connect press felt for papermaking. The thermal adhesive sheet and / or the auxiliary sheet is soluble in water or a certain solvent, and after the needle punching, the thermal adhesive sheet and / or the auxiliary sheet is lost by the water or the certain solvent. The method for connecting paper felts according to claim 1, further comprising a step.

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