JPS62250293A - Papermaking press felt with seam - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The felt of the present invention relates to a press felt used in a press part for squeezing water out of wet paper in the paper manufacturing process using a paper making machine. [Prior art] Felt used in the press parts of papermaking machines is produced by layering wet paper and felt and squeezing water out of the wet paper when pressurized with a press roll, and then transferring the wet paper to the next process. It must also have the ability of a conveyor to transfer at high speed. The pressure when pressing felt and wet paper with a press roll reaches 150 to 200 h/cti in recent large high-speed paper making machines, so if there are areas with uneven thickness or uneven density of the felt, it is necessary to deal with it. As a result, moisture spots and thickness unevenness occur on the paper, and marks called felt marks are generated on the paper, reducing the functionality of the paper and reducing its commercial value. It also causes vibration troubles in the press rolls of paper manufacturing machines. The performance required for press felt is durability, surface smoothness, and thickness so that the felt can withstand continuous operation at high speeds and under high pressure in the press parts of paper manufacturing machines. Uniformity of density etc. is required with high accuracy. For this purpose, press felt for papermaking is made by stacking several thin fiber pad layers on top of a base fabric that is woven endlessly using the bag weaving method using a large annular weaving method, and then integrating the base fabric and m miscellaneous pad layers using a needling method. Manufactured so that there is no non-uniformity in thickness, density, etc. throughout the felt. Recent large high-speed paper making machines have speeds of 500 to 1,000 m/nin and pressures of 150 to 20 m/nin.
0Kg/cm. The felt width is 500-900G, and the press felt weight is 100-400h. Loading such heavy felt into the press section of a papermaking machine equipped with a large number of rolls was not easy, requiring the papermaking machine to be shut down for several hours and requiring a lot of labor. In recent years, attempts have been made to create loops at both ends of a non-circular felt rather than an endless one, and process it endlessly on the paper-making machine, in order to reduce the downtime of the paper-making machine and reduce the labor involved in co-operation. What has been done is also shown in Japanese Patent Application Laid-open No. 112091/1983. However, these seamed press felts, in which the core wire is passed through a loop to create an endless loop on papermaking machines, have the effect of shortening the time it takes to insert the felt into the papermaking machine, but the thickness and density of the seam part is insufficient. However, when wet paper is pressed together with felt, there is a problem that marks may appear on the paper.
It can only be used to manufacture some special low-grade papers, and has not yet been put into practical use. In seamed press felt, when trying to make the seam loop smaller and the thickness of the core wire thinner in order to solve problems with the seam, it was difficult to pass the core wire through the paper making machine, and it took a long time to run the core wire. In addition, the thin core wire lacks the strength of the seam portion, resulting in poor felt durability, which increases the frequency of felt replacement, which increases the downtime of the papermaking machine.

Problem 1 to be Solved by the Invention By improving the poor writing performance of conventional endless press felt on paper making machines and the non-uniformity of seam parts of seamed press felt, The object of the present invention is to provide a seamed press felt that can be widely used. [Means for solving the problem] In a needle felt that integrates a base fabric and a fiber pad layer, both ends of the base fabric are made from warp yarns (weft yarns during weaving) of the needle felt base fabric. The loops of the two are butted against each other, and the core wire is inserted into the loops at both of the butted ends to make the base fabric endless, and the filler thread is inserted into the warp loop void on the side of the core wire portion throughout the felt. However, the pad layer on the surface of the base fabric is cut diagonally forward from the back of the seam to the contact surface with the base fabric when viewed in the felt traveling direction, so that one loop at the edge of the base fabric is exposed and the other loop is cut into the fibers. It was covered with a flap of pad layer. (Function) In the felt of the present invention, loops are formed in the warp yarns of the base fabric at both ends of the felt, and the felt is passed through the felt so that a predetermined roll of the am machine is inside the felt. The felt is made endless by aligning the loops and passing the core wire through the loops.Inside the loops,
By inserting filler yarns into the voids formed on both sides of the core wire, the yarn density in the weft direction of the seam portion is increased, and the difference in fabric density between the seam portion and the area other than the seam portion is eliminated. Then, the pad layer is cut diagonally forward from the back of the seam when viewed from the direction of felt travel, and the angle between the base fabric and the cut surface is 35 to 75 degrees.
By doing so, the bonding surface of the pad layer becomes flat, and the pad layer has durability even if it is repeatedly pressed under a press roll in continuous operation.

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. The press felt 10 of the present invention is a needle felt in which a base fabric 1 and a 41i fiber pad layer 2 are integrated.An example of the base fabric 1 is made as follows. That is, as shown schematically in Fig. 4, the length direction on the paper making machine is am
By driving the base fabric 1 in an appropriate structure in the order of abcd with the warp yarns 26 and the weft yarns 27 in the upper width direction, it is made into a flattened bag shape and endless on a paper making machine. Weave the part that will be the butting position when forming into a shape into one edge part 22 on the R machine. This ear part 22
By pulling out the selvage yarn 23, which is the warp on the most end 41 machine, after weaving, the bag-shaped base fabric upper layer 11W24 and the base fabric lower layer 25 are formed.
are separated to complete a non-circular base fabric 1. The felt traveling direction AJIr will be described below as the warp direction of the base fabric 1 when the press felt 10 is hung on a paper making machine. The warp yarns 3 of the base fabric 1 are inserted as weft yarns 27 when the base fabric 1 is weaved. The loops 4 and 4' at both ends of the base fabric 1 made of the warp yarns 3 (weft yarns 27 on the loom, Figure 4) of the base fabric 1 are butted against each other as shown in Figure 2, and the core wires are Insert the base fabric 1 into the loops 4 and 4' at both ends where the
By inserting the filling yarns 7, 7' over the entire width of the core wire 1, the base fabric 1 is made endless, and the filler yarns 7, 7' are inserted into the voids 6, 6' created in the warp loops 4, 4' on both sides of the core wire 5. Insert it across the entire width of the base fabric 1 in the same way as above, and press the seam part 9.
uniformize the thickness and density of the base layer. The above filling yarn 7, 7
When inserting ', the felt 10 is made into an endless shape and the length is 0.5 to 2. By stretching with the tension of ON9/cIR, the loop 4゜4' and the core s5 can be brought into close contact with each other, and the gap 6゜6' on both sides of the core can be enlarged. Insert 7, 7'. If the above tension is not applied, the gap 6.6
' becomes small and it becomes virtually impossible to insert the filling threads 7, 7'. The filling yarn 7.7' is made of monofilament or multifilament of synthetic polymer such as polyamide.
There are single yarns and twisted yarns. The thickness angle (thickness angle) and number of filling threads 7, 7' to be inserted into the voids 6, 6' are as follows:
The state of color development when the pressure-sensitive paper is stacked on the seam portion 9 and pressed is checked to select an appropriate fineness and number of sheets. That is, when the seam part 9 and the pressure-sensitive paper are stacked and pressurized in accordance with the water squeezing conditions of the papermaking machine, the filling yarn 7 inserted into the void part 6.6'
If ゜7' is insufficient, the color development at the location corresponding to the seam portion 9 of the pressure-sensitive paper will become lighter or no color will develop. or,
If the amount of filling thread 7°7' inserted into the voids 6, 6' is too large, the coloring of the pressure-sensitive paper corresponding to the seam 9 will be darker. Even if the filler yarns 7, 7' are properly inserted into the voids 6°6', if the seam part 9 of the fiber pad layer is not suitable,
This causes thickness unevenness and density unevenness throughout the felt.
The seam 9 of the fiber pad layer 2 also poses a significant problem. The filling threads 7, 7' are inserted into the entire base fabric 1 using a lead wire or a sewing needle. The press fel I.10 must pass continuously in an endless manner between the press rolls of the paper machine, overlapping the wet paper. During this time, the flap 8 of the fiber pad layer 2
There must be no gap between the fiber pad layer 2 and the fiber pad layer 2. For this purpose, the shape of the fiber pad layer 2 of the seam portion 9 is important. Loose fibers on the surface of the base fabric 1] - Layer 2 is cut diagonally forward from the rear R of the seam to the contact surface F with the base fabric 1 when viewed in the direction of travel of the felt 10 (arrow A), and the edge of the base fabric One loop 4 of is exposed and the other end loop 4
' cuts the fiber pad 112 so that it is covered with the flap 8 of the a-fiber pad layer 2. In this case, the fiber pad layer 2 must not be cut diagonally backward from the front of the seam portion 9 from its upper surface to the surface of the base fabric 1 when viewed from the arrow A) in the traveling direction of the felt 10. If it is cut in this way, the flap 8 will be damaged when it passes through the press rolls,
A defect occurs in the seam 9 of the padded layer 2, giving the paper a significant upper pull. The angle θ formed by the cut surface 8 of the base fabric 1 and the fiber pad layer 2 is 35
It is important for the seam portion 9 of the 41i11ft pad layer 2 to be stable that the angle is ˜75°. Angle θ is 35°
If it is less, the strength of the tip of the flap 8 of the fiber pad layer 2 will be low, and the tip will fall off during pressing with a breath roll, and the space between it and the 4IH pad layer 2 will not be flat.
Cause trouble on paper. In addition, if the angle θ is less than 35°, the strength of the tip of the flap 8 of the fiber pad l1W2 will be low, and the tip will fall off during pressing with a press roll, resulting in loose fibers, layer 1, and layer 2.
The space between the paper and paper becomes uneven, causing problems with the paper. Further, if the angle θ is 75° or more, the corners of the surface of the m-fiber pad layer 2 are likely to be damaged and marks will be formed on the paper when it is pressed with a press roller. The cut surface 11 of the fiber pad layer 2 constituting the flap 8 is formed when the press felt 10 is made endless on a paper making machine and stretched with a required tension.
It is cut into a shape that exactly matches the cut surface 12 of. Example 1 Base fabric used for No. 2 press felt of core manufacturing machine Warp direction yarn (thread of IIavF) φ0.52 Dark TEX 2445 (6 nylon monofilament) Gentle direction yarn (warp during weaving) φ0. 2 mrrTEX 2445 (6 nylon seven filament) four twisted yarns 1/3 collapse Warp double weave surface pad layer Mixture of nylon 11dTEX and 16dTEX 700 g/rIt Dimensions of felt 18. QOmx 420(1)x /
L/t” I fM 1068g filled yarn φ0.
2.5 nylon seven filament yarns twisted together, 4 each for a total of 8 filler yarns The angle of the cut plane of the base fabric and pad layer is 58°. Felt combination time: Conventional endless: 120 minutes Felt of the present invention: 30 minutes Example 2 Base fabric used for felt for No. 3 press of liner manufacturing machine Warp yarn (weft during weaving) φ0.47 rm1266~4
,000 decitex (6 nylon monofilament) Willow direction yarn (warp during weaving) φ0.47 rm1266~
4,000 decitex (6 nylon monofilament) 1/3 collapse Warp double weave Table f) Hyl/WI Nylon 11"EXx16"Ex mixture 7509/butt Felt dimensions 28.00 mX 520cm felt iliIJ1228Kg Core wire (lead) (with wire) φ0.5M nylon monofilament filled yarn φ0゜2 fins 3 threads made by twisting 3 nylon monofilaments and 3 630d multifilaments together
Felt installation time: 150 minutes for conventional endless felt 40 minutes for felt of the present invention [Effects of the Invention] Since the press felt of the present invention is not endless, even large paper-making machines can use many rolls. 30 to 50 sheets can be easily assembled with a small number of people on the press part of a papermaking machine equipped with
It can be installed in parallel in a short time of minutes, making it possible to shorten the downtime of the papermaking machine, improving productivity and reducing costs. Since non-uniformity in the seam portion of seamed felt can be eliminated, it has become possible to produce paper that is as good as paper produced from endless felt, although it is made from seamed felt.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view of a seamed felt in a non-annular state, Figure 2 is a cross-sectional view of a seamed felt with a core wire passed through it into an endless shape, and Figure 3 is a seamed felt with a filling yarn inserted]・A sectional view of FIG. 4 is a schematic sectional view showing an example of a weaving state. 1... Base fabric, 2... Fiber pad layer. -3...Warp thread, 4.4'...Loop. 5...Core wire, 6.6'...Gap portion. 7... Filling yarn, 8... Flap. 9... seam part, 10... press felt 11, 1
2...Cut surface

Claims (1)

[Scope of Claims] 1. In a papermaking needle felt composed of a base fabric and a fiber pad layer, warp yarns of the base fabric form loops at both ends of the base fabric, and The loops are fitted together, and a core wire is inserted into the loops to make the base fabric endless.Furthermore, filler threads are inserted into the gaps in the loops on the circumferential side of the core wires, and the fiber pad layer teeth,
The cut is made from the back of the seam to the diagonally forward direction of the seam, from the surface of the padding layer to the contact surface with the base fabric, when viewed in the felt traveling direction, so that only the loops at one end of the base fabric are exposed from the fiber padding layer, and the loops at the other end are cut. Pressed felt with a seam for papermaking, which is covered with a flap of a layer of fiber padding. 2. The seamed press felt for papermaking according to claim 1, wherein the core wire is made of a synthetic polymer such as polyamide. 3. The seamed press felt for papermaking according to claim 1, wherein the filling yarn is a monofilament, a multifilament, a single yarn of a spun yarn, or a twisted yarn made of a synthetic polymer such as polyamide. 4. The seamed press felt for papermaking according to claim 1, wherein the warp is a filament of 1,000 to 4,000 decitex. 5 The angle of inclination between the base fabric surface and the cut surface of the fiber pad layer is 3
The press felt with a seam for papermaking according to claim 1, wherein the seam angle is within the range of 5 to 75 degrees.