JP4140336B2 - Papermaking felt - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The felt of the present invention relates to a papermaking felt used in a press part that squeezes moisture from wet paper in a process of producing paper with a papermaking machine.
[0002]
[Prior art]
The press part in the paper making process receives the wet paper dehydrated by the wire part, squeezes water from it, and at the same time smoothes the paper surface and sends it to the dry part.
In recent years, the papermaking speed has been increased, and the time that the wet paper stays between the press rolls has been greatly reduced. Therefore, the load applied between the rolls to squeeze out the water in the wet paper is higher than in the past, and the fiber of the paper is easily displaced by the pressure of the squeezed water, while the felt is water permeable and breathable. It is also easily accompanied by performance deterioration such as poor elasticity and shape deterioration such as cutting and flattening. Therefore, the felt for papermaking has been increasingly required to improve the mechanical performance such as strength, wear resistance, and shape stability and to suppress the vibration as well as the dewatering performance. On the other hand, with the increase in the load of the press roll, it becomes easy to leave a mark on the felt base fabric on the paper to be made, and countermeasures therefor are urgently required.
[0003]
For the purpose of improving the performance of papermaking felt, the base fabric is made by superposing two endless fabrics, such as single and double weaves, which are relatively easy to manufacture and low cost, as upper and lower fabrics. A method of using a cloth has been proposed [see Patent Document 1]. This method is easy to weave, stable in quality, can use a relatively thin cloth as a base fabric, and is flexible and easy to process, such as needling, compared to a multi-layer single layer base fabric of the same thickness. There is a void capacity, and there is little sag even after repeated pressing. However, after the endless upper and lower base fabrics designed and weaved to match the dimensions are combined on the needle machine, the bat is needled to produce the papermaking felt. In addition to requiring a technique, if the height dimension of the upper base fabric and the lower base fabric are slightly different, manufacturing becomes more difficult. In particular, when the two base fabrics are displaced in the manufacturing stage where the bat is needling, there is a problem that the bat must be peeled off from the machine.
[0004]
Also, a method in which a woven base fabric is continuously wound and laminated in an annular shape to form an endless base fabric structure, and a fiber web is needling and integrated on both sides or one side [see Patent Document 2] ] Was proposed. The advantage of this patent is that a base fabric made of multiple weaves can be manufactured in a shorter time and at a lower cost than weaving using a heavy loom, and the thickness of the base fabric structure can be reduced. Further, since the felt dimensions can be arbitrarily determined at the time of winding, the dimensional accuracy is improved. However, since the bat is needling after laminating only the base fabric, the respective base fabrics that are laminated are displaced due to the impact generated during the needling. In particular, the deviation was remarkable when three or more layers were laminated. Further, since only the base fabrics are laminated, the bonding force between the base fabrics is weak, and there is a problem in strength required when used in a high-speed paper machine. In addition, marks at the beginning and end of the base fabric may remain on the paper, which is inappropriate for the process of producing strict paper for the marks.
[0005]
In addition, a method of increasing the dewatering efficiency by placing a film-like material having fine holes in the lower layer of the surface bat layer to prevent re-wetting (see Patent Documents 3 and 4), a mesh of fiber cloth and thermoplastic resin In combination with a shaped product, it is used as a basic fabric, and a non-constricted reinforced yarn and a fiber layer (butt layer) are stacked on top of it to increase the strength and to increase the resistance to felt compression. Proposals such as a method for eliminating the defects (see Patent Document 5), a method for removing the yarn in one direction of the overlapping portion of the base fabric so as not to leave a step mark on the surface of the paper (see Patent Document 2), etc. There is.
[0006]
[Patent Document 1]
Japanese Patent Publication No. 2-2997 [Patent Document 2]
Japanese Patent No. 3045895 [Patent Document 3]
Japanese Patent No. 2718611,
[Patent Document 4]
Japanese Patent Laid-Open No. 3-8888 [Patent Document 5]
JP 2001-504167A [0007]
[Problems to be solved by the invention]
Although the purpose has been achieved to some extent by the proposed method above, as the papermaking speed increases, the demand becomes more and more advanced, and all marks such as dewatering performance, mechanical performance, and the mark of the fabric remaining on the paper surface are all It has become difficult to satisfy.
From such a viewpoint, the object of the present invention is to provide a papermaking felt that has dewatering performance and mechanical performance that can withstand high papermaking speed, and that can suppress vibration without leaving a mark of the base fabric on the paper surface. There is to do.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is a papermaking felt. While supplying an end-like base cloth and a bat on a needle machine, a bat is overlapped on the end-like base cloth and is needling and entangled. while forming a base fabric / batt layer, subsequently the base fabric / batt layer laminated wound annularly while needling base fabric / batt layer of a plurality of layers laminated base fabric / batt stacking, further base fabric / A bat is disposed on the outer side of the butt stack as a bat layer on the outermost peripheral surface to form a multilayer structure, and the whole is needled and integrated.
[0009]
The invention according to claim 2 is the papermaking felt according to claim 1 , wherein a preform comprising a base fabric / bat layer in which a bat is overlapped on an end-shaped base fabric and entangled by needling is made in advance. said base fabric / batt layer laminated wound annularly while needling a plurality of layers laminated base fabric / batt stacking further distribution bat outside the base fabric / bat deposited as the outermost surface batt layer Thus, a multilayer structure is formed and integrated as a whole by needling.
[0012]
Invention of Claim 3 is the felt for papermaking of Claim 1 or 2 , The bat in the said base fabric / butt | stacking laminated | stacked thickness thinner than the other part in the at least one end part of the start end and the termination | terminus. .
[0013]
Invention of Claim 4 is the felt for paper manufacture of any one of Claim 1 thru | or 3 , Comprising: The said multilayered structure is the innermost peripheral bat | bath which further arranged the bat inside the base fabric / bat | vat laminated | stacked Has a layer.
[0014]
Invention of Claim 5 is the felt for paper manufacture of any one of Claim 1 thru | or 4 , The said multilayered structure is further substantially mutually mutually between a base fabric / butt lamination | stacking and an outermost peripheral bat layer. It has a nonwoven fabric layer in which yarns are arranged in parallel only in the circumferential direction.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a multilayer structure having a base fabric / bat laminate in which a bat is stacked on an end-like base fabric and wound in a ring shape, and an outermost peripheral bat layer having a bat disposed outside thereof, or further A multilayer structure having an innermost surface bat layer with bats arranged inside the base fabric / bat laminate, or in addition, substantially parallel between the base fabric / bat laminate and the outermost surface bat layer. A felt for papermaking in which a multilayer structure having a layer formed by arranging a nonwoven fabric layer in which yarns are arranged only in the circumferential direction is integrated by needling.
[0017]
That is, the felt for papermaking of the present invention has a base fabric / bat laminate 4 formed by laminating a bat 3 on a base fabric 2 and winding it in a ring shape, and an outermost peripheral bat layer 5 having a bat arranged on the outer side. The multilayer structure has a feature in that it is used by needling and integrated.
[0018]
The warp and weft of the woven fabric used for the base fabric 2 can be various as required. For example, monofilaments such as polyamide (nylon), polyester, polyethylene, polypropylene, polyvinyl chloride, or monofilaments Twisted yarn can be used. The diameter of the monofilament is arbitrarily selected, but is usually a 0.1 to 0.5 mm monofilament or a twisted yarn containing 2 to 10 monofilament yarns. The density of the warp and / or weft of the woven fabric is also arbitrarily selected, but is usually 12 to 40 yarns / inch. The weaving structure is not limited, and can be a simple weaving structure that has been used for conventional paper felt base fabrics such as plain weave and twill weave.
[0019]
The bat 3 is a fiber assembly, and the material thereof is selected from polyamide (nylon), polyester, polyethylene, polypropylene, polyvinyl chloride, and the like. The basis weight of the bat is not particularly limited, but is generally about 30 to 180 g / cm ² , preferably 50 to 160 g / cm ² .
[0020]
The base fabric / bat laminate 4 is obtained by arranging the bat 3 on the end-shaped base fabric 2 and winding and laminating the bat 3 and supplying the end-like base fabric 2 and the bat 3 on the needle machine to provide the need. It may be wound in a ring while being entangled in a ring, or a preform in which a bat 3 is previously entangled on a base fabric 2 having an end shape is made and wound in a ring while further needling. You may laminate.
[0021]
FIG. 1 is an explanatory diagram in which a bat 3 formed by carding a raw material fiber is directly placed on an end-like base fabric 2 and wound in a ring while being entangled by needling, and FIG. FIG. 3 is an explanatory diagram in which a pre-butt that has been wound by winding a carded bat in advance on the end-like base fabric 2 is placed and wound in a ring while being wound by needling, and FIG. It is explanatory drawing which made the preform which made the bat 3 needling and entangled with the end-like base fabric 2 beforehand, and was wound and laminated | stacked cyclically | annularly.
[0022]
Needleing is performed every time the layers are laminated, and the base fabric and the bat can be bonded together, as well as the bonding between the preforms can be strengthened, and the felt can have a high interlayer strength. The number of laminated layers is not particularly limited, but is practically 2 to 5 layers, particularly preferably 2 to 3 layers.
[0023]
When the base fabric 2 and the bat 3 are overlapped with each other and are wound and laminated in an annular shape, it is preferable that the starting end and the terminal end are located on the same line, but actually the winding lamination is finished in a state where the terminal end and the starting end are slightly overlapped. For this reason, the total thickness of the stack may be uneven, and this uneven thickness causes marks on the paper. Accordingly, in order to loosen the step, the base fabric 2 is pulled out of the yarn in the direction (width direction) perpendicular to the circumference at least at one end of the start and end, or at least one of the start and end of the bat 3. It is preferable to make it thinner than other parts. In particular, when the end portion is thinned, the effect of preventing the mark on the paper is great. Of course, this treatment may be applied to both the base fabric and the bat. The start and end points here are the portions where the stacked start and end portions overlap each other more than other portions, and usually overlap by 5 to 10 mm. It is preferable to overlap the start end and the end by 5 to 10 mm because a treatment for reducing the step can be performed.
[0024]
The outermost peripheral bat layer 5 is a bat disposed outside the base fabric / bat stack 4. This bat may be the same as or different from the bat 3 used together with the base fabric 2, and is arbitrarily selected from polyamide (nylon), polyester, polyethylene, polypropylene, polyvinyl chloride and the like. The basis weight of the bat of the outermost peripheral bat layer 5 is not particularly limited, but is generally about 400 to 1100 g / cm ² , preferably 500 to 900 g / cm ² .
[0025]
In another embodiment of the present invention, in addition to the base fabric / bat laminate 4 and the outermost peripheral butt layer 5, a multilayer structure having an innermost peripheral bat layer 6 inside the base fabric / butt laminate is provided. , Needle and integrate.
[0026]
The bat in the innermost circumferential surface bat layer 6 may be the same as or different from the bat in the base fabric / bat laminate 4 and the outermost circumferential bat layer 5. That is, it is arbitrarily selected from polyamide (nylon), polyester, polyethylene, polypropylene, polyvinyl chloride and the like. The basis weight of the innermost circumferential bat layer 6 is not particularly limited, but is generally about 50 to 220 g / cm ² , preferably 60 to 200 g / cm ² .
[0027]
In another embodiment of the present invention, a multilayer structure comprising the base fabric / butt laminate 4 and the outermost peripheral bat layer 5, or the innermost peripheral bat layer 6, the base fabric / butt laminated 4, the outermost peripheral surface. A multilayer structure layer having a nonwoven fabric layer 7 in which yarns are arranged only in the circumferential direction substantially parallel to each other between the base fabric / bat laminate and the outermost peripheral bat layer on the multilayer structure composed of the bat layer 5 Then, this is needling and integrated. Alternatively, a thermoplastic resin sheet layer having pores can be added to the multilayer structure layer.
[0028]
The nonwoven fabric layer 7 is a nonwoven fabric in which yarns are arranged substantially parallel to each other only in the circumferential direction, and does not have a knuckle portion where warps and wefts intersect like a woven fabric. This nonwoven fabric layer arranged substantially parallel to one direction is described in a patent document [Japanese Patent Publication No. 46-3315]. By having the nonwoven fabric layer 7, the influence of the overlapping portion of the start and end of the base fabric / bat laminate 4 can be mitigated so that it does not appear on the paper, and the nonwoven fabric layer 7 itself also has a knuckle portion as described above. Therefore, it is possible to improve the smoothness and surface properties of the paper by preventing the paper from being made from being marked. The yarn constituting the nonwoven fabric can be various as required. For example, monofilaments such as polyamide (nylon), polyester, polyethylene, polypropylene, polyurethane, polyvinyl chloride, or monofilament twisted yarn can be used. . Although the diameter of the monofilament is arbitrarily selected, it is usually a monofilament of 0.10 to 0.45 mm, or a twisted or non-twisted yarn containing 2 to 10 monofilament yarns.
[0029]
The thermoplastic resin sheet layer 8 is a sheet formed by melt-molding a thermoplastic resin so as to have a large number of pores. Here, the thermoplastic resin is arbitrarily selected from polyamide (nylon), polyester, polyethylene, polypropylene, polyurethane, polyvinyl chloride and the like. The thickness of the sheet is not particularly limited, but is typically about 0.5 to 1.5 mm. In the thermoplastic resin sheet layer 8, when pressure is applied, the bat on one surface and the bat on the other surface come into contact with each other through the gap to move moisture. Functions as a rewet resistance layer. Moreover, since the warp and weft do not overlap each other like a woven fabric, the surface is smooth, and there is an advantage that no mark is left on the paper.
[0030]
【Example】
1. Preparation of Felt 1) Example 1: A schematic cross-sectional view of the papermaking felt 1 of Example 1 is shown in FIG. The felt 1 for papermaking of Example 1 includes a base fabric / bat laminate 4 formed by laminating a bat 3 on one side of a base fabric 2 and winding it in an annular shape, and an outermost peripheral bat layer 5 arranged on the outer and inner sides thereof. And the innermost surface butt layer 6. In FIG. 4, the thickness of the felt and the stepped portion are exaggerated for easy understanding. Actually, the thickness of the felt is much thinner if the diameter of the cylindrical shape is taken into consideration, and the ratio of the thickness of each layer is also shown. It is different and the level difference is not felt.
The base fabric 2 has 20 warp yarns that are twisted by twisting two yarns that are polyamide monofilaments having a diameter of 0.15 mm, and twisting these three twisted yarns (twisted yarns including a total of six yarns). A woven fabric having a basis weight of 131 g / m ² woven into a plain structure using 15 wefts / inch, which is a polyamide monofilament having a diameter of 0.21 mm / inch. The bat 3 is a polyamide suf web of 17 dtex 100% and a basis weight of 80 g / m ^2. The bat 3 is placed on the upper surface (paper making surface) of the base fabric 2, and circulated three times in an annular shape while being entangled, and the basis weight is 633 g / m. ² base fabric / bat laminates 4 were obtained. The end portion was cut by overlapping 10 mm from the start end, and the weft at the end was pulled out to a position where the weft at the start end was located.
The outermost peripheral bat layer 5 disposed on the outer side of the base fabric / bat laminate 4 was a polyamide suf with a web weight of 600 g / m ² at 17 dtex 100%. The innermost circumferential bat layer 6 disposed on the inner side of the base fabric / bat laminate 4 is a polyamide suf with a web weight of 100 g / m ² at 17 dtex 100%. The outermost peripheral butt layer 5 and the innermost peripheral bat layer 6 were overlapped on the outer side and inner side of the base fabric / butt stack 4 and bonded by a known method such as needling.
[0031]
2) Example 2: A schematic cross-sectional view of the papermaking felt 1 of Example 2 is shown in FIG. FIG. 5 is also exaggerated for the sake of easy understanding. In addition to the construction of the papermaking felt 1 of the first embodiment, the papermaking felt 1 of the second embodiment is further provided between the base fabric / bat laminate 4 and the outermost peripheral bat layer 5 in a circumferential direction substantially parallel to each other. A non-woven fabric layer 7 in which only yarns were arranged was arranged.
That is, the nonwoven fabric layer 7 of the papermaking felt 1 of Example 2 is formed by twisting two twisted yarns obtained by twisting two yarns of polyamide monofilament having a diameter of 0.21 mm and one spun yarn having a count of 12 meters. A nonwoven fabric having a basis weight of 269 g / m ^{2 in which} the combined yarns were arranged substantially in parallel so as to be 27 pieces / inch in the papermaking felt length direction was used.
[0032]
3) Comparative Example: As a comparative example, a papermaking felt having the same conditions and configuration as those of Example 1 except for the bat 3 was manufactured.
[0033]
2. Evaluation Method Prescale pressure-sensitive paper was overlapped on the overlapping portion of the base and vat laminates 4 at the start and end, and color was developed by pressing with an experimental paper machine under a press roll pressure condition of 41.2 kN / m. This is based on the fact that the pressure applied to the felt changes when the thickness of the felt changes, and the degree of color development varies depending on the pressure difference. The higher the pressure, the darker the color.
[0034]
3. Results The results of comparing the degree of color development in the papermaking felt length direction for the papermaking felts of Examples 1 and 2 and Comparative Examples are shown in FIGS. There is a correlation between the color density and the pressure, and the pressure can be calculated by measuring the density.
[0035]
6 to 8, the X axis indicates the distance in the length direction of the papermaking felt, and the Y axis indicates the pressure (Mpa). The right side from the center of the X-axis is the starting end of the base fabric / bat laminate 4, and the starting end overlaps the terminal end, so the right side that is the overlapping part is slightly thicker and the pressure is higher. Since the weft of the part is pulled out to the end of the starting end part, as shown in FIG. 6, the pressure spots near the center part of Example 1 are small. Moreover, since Example 2 has the nonwoven fabric layer 7 further on the base fabric / bat laminated | stacking 4, as shown in FIG. 7, there is almost no pressure spot near the center part. However, in the comparative example shown in FIG. 8, the pressure spot at the center is large and has a step. This shows that the base fabric laminated at the time of needling is displaced, and the weft part at the start and end is separated, so the thickness of that part is reduced and a step is generated. In the actual paper manufacturing process, marks are generated on the paper at this portion. On the other hand, in Examples 1 and 2, the uneven thickness of the overlapping portion between the start and end of the base fabric / butt laminate 4 is alleviated, and there is no deviation between the overlap between the start and end portions of the base fabric / butt stack 4. It can be seen that the pressure spots are small and marks on the paper can be suppressed.
[0036]
【The invention's effect】
The felt for papermaking of the present invention is a multilayer structure centered on a base fabric / butt laminate, thereby providing excellent dewatering performance, mechanical performance that can withstand high speed of papermaking, and the surface of the base fabric. Vibration can be suppressed without leaving a mark. It can be used in a high-speed papermaking process, and the quality of the paper is improved.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory view in which a bat formed by carding raw material fibers is directly placed on an end-like base fabric, and wound and laminated in an annular shape while being entangled by needling.
FIG. 2 is an explanatory view in which a pre-butt that has been wound by winding a bat that has been carded in advance on an end-like base fabric is placed and wound in a ring while being entangled by needling.
FIG. 3 is an explanatory diagram in which a preform in which a bat is needling is entangled in advance on an end-shaped base fabric, and the preform is wound and laminated in an annular shape.
4 is a schematic cross-sectional view of a papermaking felt 1 in Example 1. FIG.
5 is a schematic cross-sectional view of a papermaking felt 1 in Example 2. FIG.
FIG. 6 is a result of calculating the pressure applied to the felt from the degree of color development for the papermaking felt of Example 1, where the horizontal axis (X axis) represents the distance in the length direction of the papermaking felt, and the vertical axis (Y The axis represents the pressure (Mpa).
7 is a result of calculating the pressure applied to the felt from the degree of color development for the papermaking felt of Example 2. FIG. The horizontal axis (X axis) indicates the distance in the length direction of the papermaking felt, and the vertical axis (Y axis) indicates the pressure (Mpa).
FIG. 8 is a result of calculating the pressure applied to the felt from the degree of color development for the papermaking felt of the comparative example. The X axis indicates the distance in the length direction of the papermaking felt, and the Y axis indicates the pressure (Mpa).
[Explanation of symbols]
1: felt for papermaking 2: base fabric 3: bat 4: base fabric / bat laminate 5: outermost peripheral butt layer 6: innermost peripheral bat layer 7: non-woven fabric layer

Claims (5)

While supplying the end-like base cloth and the bat on the needle machine, the base cloth / bat layer is formed by overlapping the bat on the end-like base cloth and needling it to form the base cloth / bat layer. said base fabric / batt layer laminated wound annularly while needling a plurality of layers laminated base fabric / batt stacking further distribution bat outside the base fabric / bat deposited as the outermost surface batt layer A felt for papermaking, characterized in that a multilayer structure is formed and integrated as a whole by needling. A preform made of a base fabric / bat layer in which a bat is overlapped on an end-shaped base fabric in advance and is entangled to make a preform, and the preform is wound and laminated in an annular shape while needling the base fabric / bat A base fabric / bat laminate in which a plurality of layers are laminated, and a bat is arranged on the outer side of the base fabric / butt laminate as an outermost peripheral bat layer to form a multilayer structure, and the whole is needled and integrated. A felt for papermaking. Bat in the base fabric / batt stacking is felt for papermaking according to claim 1 or 2 wherein, characterized in that is obtained by reducing the thickness than other portions at least one end of the start and end. The multilayer structure, the inside of the base fabric / butt laminate, felt for papermaking according to any one of claims 1 to 3, characterized in that it has a further innermost surface batt layer which arranged bat. The multilayer structure, between the base fabric / Bat laminated and the outermost surface batt layer, to further claims 1 characterized in that it has a non-woven layer having an array of threads only in the circumferential direction substantially parallel to each other 4 The papermaking felt according to any one of the above.

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