JP5755696B2 - Press felt for papermaking and method for producing the same - Google Patents

Description

  The present invention relates to a papermaking press felt (including an endless needle felt for papermaking, a needle felt with a seam for papermaking, etc. The same shall apply hereinafter, hereinafter also referred to as “felt”) and a method for producing the same. About. More specifically, the present invention relates to a papermaking press felt having durability and excellent exchanging workability, having a resin distribution precisely controlled, and having an optimized layered region, and a method for producing the same.

Conventionally, a papermaking press felt has been resin-processed for various reasons such as preventing hair loss, preventing soiling, and improving water squeezing.
Resin processing performed on these press felts for papermaking includes thermosetting resins and thermoplastic resins, and each resin has advantages and disadvantages. Thermosetting resins generally have the advantage that the durability of the resin itself is superior to that of thermoplastic resins. On the other hand, the disadvantage is that it contains a solvent or has a relatively long time due to the resin-forming reaction. In many cases, heating is required, and in the type of resin that is cured by ultraviolet rays, an ultraviolet irradiation device is required.
Thermoplastic resins generally have the advantages of good production workability (workability) such as a shorter heating time than thermosetting resins and many of them not containing a solvent.
Generally, a thermoplastic resin such as polyamide (nylon 6, nylon 66, etc.) is used as a main raw material for papermaking felt. Therefore, the melting point or flow starting temperature of the thermoplastic resin used for resin processing (when the melting point is not clear, such as thermoplastic polyurethane elastomer, the flow starting temperature is used instead of the melting point as measured by the test method described in JIS 7210. In many cases, it is necessary that the melting point of the main raw material of these felts is lower than that, and considering that the adhesion temperature of nylon 6 is about 193 ° C., it is preferably 180 ° C. or lower.
In resin processing using a thermoplastic resin, the lower the melting point or flow start temperature of the resin, the better the workability of manufacturing the resin processing felt. However, as the melting point or flow start temperature decreases, the mechanical properties of the resin tend to decrease, and the durability of resin processing often decreases.
In general, a papermaking press felt is subjected to several million presses during the period of use in order to remove moisture in the wet paper. Also, in order to remove felt stains, washing with a (high pressure) shower and dehydration with a suction box are often performed. When resin processing is performed on a felt used in such an environment, durability of the resin processing is an important factor in order to maintain the performance of the felt.

There is known a wet paper web transfer belt in which one of a polymer elastic member and a surface layer forming body (a bat, a woven fabric, a non-woven fabric) partly exposed on the paper making side surface is made of a hydrophobic material (for example, a patent) Reference 1). According to this wet paper web transfer belt, the effect of improving the sheet peelability and preventing the surface base material from falling off can be obtained.
Also, a conveyor belt comprising a base fabric, a bat layer, and a resin impregnated in at least the paper-making side bat layer, the bat extending on the surface of the resin, and the surface bat fiber formed of two types of fibers, hydrophilic and hydrophobic (For example, refer to Patent Document 2). According to this conveyance belt, it is excellent in sheet peelability improvement.
Further, a felt in which resin is impregnated from the bat fiber layer to the base fabric in a dispersed state to attach the bat fiber layer to the base fabric, and the surface is polished with a permeability of 2 m ³ / m ² min or more and a manufacturing method Is known (for example, see Patent Document 3). According to this felt, effects such as prevention of rewetting, improvement of water squeezing, surface smoothness, compression resistance, durability and familiarity, prevention of vibration, seam marks and base fabric marks, and maintenance of permeability (breathability) can be obtained. .
In addition, a wet paper web transfer belt is known in which a porous structure (porous filler, porous fiber) is exposed or protruded from the surface of the papermaking side layer (see, for example, Patent Document 4). According to this wet paper web transfer belt, the effects of improved durability, improved sheet peelability, and improved sheet conveying function can be obtained.
Furthermore, a wet paper web transfer belt is known in which the papermaking surface side layer is composed of a polymer elastic part and a fiber body, and the fiber body is hydrophilic and at least part of the fiber body is exposed on the surface (for example, Patent Document 5). reference.). According to the wet paper web transfer belt, the effect of improving the sheet sticking property and the sheet peeling property can be obtained.
In addition, a wet paper web transfer belt is known in which fiber bodies are exposed in an island shape on the surface of the base paper-making side layer and filler particles are exposed in other portions (see, for example, Patent Document 6). According to this wet paper web transfer belt, effects of improving sheet sticking property, improving sheet peelability, and preventing rewetting can be obtained.

However, all of the manufacturing methods of Patent Documents 1 to 6 have a structure in which resin processing is performed from the surface, and the bat fibers are exposed to the surface by polishing.
On the other hand, the importance of controlling the resin distribution has been recognized for various reasons regarding resin processing. In felt resin processing, it is important to suppress as much as possible the deterioration of air permeability due to resin coating, and it is necessary to determine the position of the resin (control of distribution) so that the function of resin processing is optimized and executed (For example, refer to Patent Document 7)
According to Patent Document 7, it is described that it is necessary to determine the position of the resin in the felt (control of distribution). This Patent Document 1 is an invention for resin processing on a base fabric. However, when resin processing is performed on a bat layer having a higher fiber density and lower air permeability as a target, the influence on air permeability is large, and the resin distribution It can be said that the importance of control is further increased. If the resin distribution range becomes wider than the setting, the resin distribution density will be lowered unless the resin amount is changed, and the resin processing effect will not be sufficiently obtained, and the resin distribution will be widened. If the amount of the resin is increased in consideration in advance, there is a risk that the air permeability of the felt is lowered and the bending rigidity of the felt is increased.

Furthermore, when the resin distribution penetrates not only to the bat fiber layer on the surface but also to the base fabric layer, there is a knowledge that it becomes harder than the allowable limit for use on a paper machine (for example, , See Patent Document 8).
Also, in recent years, in order to increase the operational efficiency of paper machines, felt with a hardness that reduces workability even if the hardness of the replacement work is acceptable (bending rigidity) can be avoided, and resin processing felt The demand for flexibility is increasing. The hardness of the resin processed felt depends on the basic (base fabric layer) structure of the felt, the hardness of the resin itself, and the thickness of the resin layer in the felt. Among them, the felt base fabric structure is changed only to secure the insertability at the expense of these other felt characteristics because the felt requires important characteristics such as water squeezing in addition to the insertability. It ’s difficult. In addition, the resin hardness affects the hardness of the resin processed felt, but the influence of the resin layer thickness on the felt hardness is greater than the resin hardness. This is because the felt exhibits flexibility by moving some of the internal fibers, but in the resin layer, the fibers and the resin are integrated, which restricts the movement of the fibers. Therefore, no matter how much the resin hardness is low and the resin processing is performed with a soft resin, if the resin processing range is wide, the flexibility of the resin processing felt is greatly reduced. Therefore, controlling the resin distribution is important in securing the flexibility of the resin processing felt and improving the felt exchanging workability. Therefore, in resin processing, it is important to optimize the layered region (minimizing the amount of resin and minimizing the thickness of the layered region within a range where the effect of resin processing can be obtained).

  There is a felt with seam for the purpose of improving the work of replacing the felt. In felts with seams, the hardness of the felt does not significantly affect the felt exchange workability. However, the felt with seam has a risk of marking the seam portion on the paper, so it is not often used for paper that emphasizes surface properties. In addition to the improvement of the exchange workability, it is important to control the resin distribution for the purpose as described above, which is also an important problem in the felt with seam.

In a felt that is used in a place where the moisture content of the wet paper is relatively small, there is a problem that there is a resin on the felt surface in a felt that is used in a place where a low air permeability is required, such as when the felt air permeability is zero. And a solution thereof are disclosed (for example, see Patent Document 9).
In general, the press felt for papermaking is set to an air permeability according to the place where it is used. In the first half of the press part, the wet paper has a lot of moisture and the amount of water to be treated is high, so the felt air permeability is set to be relatively high. The felt air permeability is set to be relatively small.
Among them, wet paper transportability is an important factor required for felts used everywhere throughout the press part, and is not a problem only when felts with low air permeability are used. For example, in the first half of the press part, wet paper moisture is high and wet paper strength is relatively weak. If there is a lot of resin on the felt surface that is used in such a place, the wet paper may not be removed cleanly when it is peeled off from the felt, which may cause the problem of the wet paper web sticking to the felt surface. is there. This is a phenomenon caused mainly by the poor wet paper peelability of the felt. In addition, if the felt has poor wet paper releasability, a phenomenon called “paper removal” will occur in which the wet paper is not separated from the felt.
As described above, when a large amount of resin is present on the surface of the felt, there is a high risk of causing a problem in wet paper transportability regardless of the felt air permeability. In addition, when resin processing is performed using the inside of the felt front bat as a target, if the resin is applied from the back side, the resin will exist up to the back bat layer and the base fabric layer. However, it becomes thicker than the case where only the inside of the felt is processed with resin, and the felt insertion property and air permeability are reduced.

Here, a fiber web is overlaid on a mesh-like auxiliary sheet made of a low-melting-point heat-adhesive synthetic resin (hereinafter referred to as “resin”), and a needle felt sheet is formed by needling, and then this needle felt. A method for producing a papermaking felt is disclosed in which a sheet is polymerized on one or both sides of a base fabric, the two are bonded together, and then heated to melt the auxiliary sheet (for example, Patent Documents). 10).
In the manufacturing method of Patent Document 10, a resin is used as a mesh-like auxiliary sheet. The mesh shape has the advantage that air permeability and needle penetration are improved.
However, there are the following problems compared to resin processing using a normal film sheet. First, in order to create a mesh-like sheet, a hole is made in a resin film or a woven fabric is manufactured with a resin slit yarn, which leads to an increase in manufacturing cost. Next, the felt using this mesh sheet has a large unevenness in resin distribution and can be used for dry parts that are not subjected to press pressure, but the press pressure is high and uniform during squeezing. It is not suitable for press parts that require sex.
That is, if a resin film having a low flow start temperature and a low viscosity at the time of fluidization is used and the air permeability can be ensured by dispersing the resin, it is necessary to perform a process for ensuring air permeability such as making a hole in the film. There is no.

Moreover, in patent document 10, arrangement | positioning of resin is not between a bat layer but between a base fabric layer and a bat layer. In Patent Document 10, in order to ensure air permeability and prevent damage to the base fabric, resin processing is performed mainly for the purpose of improving the adhesion between the base fabric and the bat layer when the number of needlings (density) is reduced. A resin is disposed between the butt layer and the bat layer.
On the other hand, if the resin is processed for the purpose of improving water squeezing, it is necessary to dispose the resin inside the bat layer in order to optimize the void (water passage) of the bat layer at a position close to the wet paper. In the papermaking press felt, if resin processing is performed at a position in contact with the base fabric layer as in Patent Document 10, the effect of improving water squeezing is reduced. Also, in the press felt for papermaking, the portion where the base fabric layer and the bat layer are in contact with each other has a large amount of accumulated dirt. If the type of resin used for the resin processing is not selected (for example, fluorinated polymer), the accumulated dirt (clogging) There is a risk of speeding up.

Furthermore, a technique regarding a pressed cloth structure having contamination resistance and a method for manufacturing the structure is disclosed (for example, see Patent Document 11). The resin used in the press cloth structure disclosed in Patent Document 11 is limited to a fluorinated polymer. Further, the melting point of the resin listed in the subclaims as the fluorinated polymer is higher than or equal to the melting point of the polyamide resin. Therefore, after placing these resins inside the surface bat layer, if the temperature of these resins is raised to the melting point, the felt surface on the heat source side is expected to reach a higher temperature, and the nylon of that part melts. There is a high possibility that
Further, the arrangement position of the resin in the press cloth structure of Patent Document 11 is described in the specification as “on the base cloth layer or in the vicinity thereof”. This is because this press cloth structure is intended to improve the antifouling property, and it is considered that the portion of the felt where dirt is most likely to accumulate is the object of resin processing. When resin processing is performed on or near the base fabric layer, the pores of the portion become dense, and this promotes a decrease in water permeability due to dirt, so this portion other than antifouling resin such as fluororesin is used. It is not preferable to process the resin. Even when resin processing is performed with a fluororesin or the like, it is necessary to pay close attention.
Furthermore, it is described that the resin arrangement method of the press cloth structure of Patent Document 11 uses a spray or a kiss roll applicator. Therefore, processing is performed using a dispersant generally used for fluororesin processing. Therefore, a resin arrangement method that does not use a dispersant is not disclosed.

Furthermore, the technique about the industrial fabric which has a fluoropolymer layer, and its manufacturing method is disclosed (for example, refer patent document 12). In the manufacturing method of Patent Document 12, the inner bat is attached to the base fabric layer, the bat on the surface of the base fabric layer is then melted, then the fluororesin is attached onto the melted bat, and then the fluororesin is melted. And then attaching an outer bat on the molten fluororesin and needling.
That is, before attaching the outer bat, immediately after attaching the resin, the resin is melted and the resin is fixed. There are the following reasons for this.
In other words, since the melting point of the fluororesin is high, if the outboard bat is attached, the temperature rises to a temperature necessary for melting the fluororesin, and the outboard bat may be melted.
In addition, in the case of non-woven fabrics made of meltblown fibers, in particular, when attaching by spraying a resin that is powder or aqueous or liquid solvent, the resin is not melted and fixed to the base fabric layer, and additional batt fibers are attached with a needle. There is a problem that the resin is easily dispersed at the time of the needle, and the distribution of the resin is difficult to control.

Japanese Patent No. 3488403 Special table 2003-511582 gazette Japanese Patent No. 4064930 Japanese Patent No. 4036765 JP 2004-277971 A Japanese Patent No. 4041056 JP 2007-514879 A JP-A-56-134289 U.S. Pat. No. 4,500,588 Japanese Patent Publication No. 60-59360 Special table 2007-502378 JP-T-2007-514879

  The present invention solves the above-mentioned conventional problems, is durable, has excellent exchanging workability, has a precisely controlled resin distribution, and has an optimized layered region. And it aims at providing the manufacturing method.

The present invention is as follows.
(1) having a papermaking surface and a running surface that is opposite to the papermaking surface;
It comprises a base fabric layer and a front bat layer arranged on the papermaking surface side,
The surface bat layer contains a thermoplastic resin disposed inside the surface bat layer and melt-dispersed and solidified.
The thermoplastic resin has a resin viscosity of 100 to 7,000 Pa · s when the resin is fluidized at a temperature in the range from the melting point to less than 180 ° C.,
The surface vat layer includes an upper surface vat layer and a lower surface vat layer that do not contain the thermoplastic resin inside the surface vat layer, and a layered region that is a composite layer in which the thermoplastic resin is dispersed therebetween. , equipped with a,
The composite the thermoplastic resin in the layer press felt for papermaking to penetrate between the batt fibers, characterized that you have bundling the batt fibers.
(2) The press felt for papermaking according to (1), wherein the layered region of the surface bat layer has a distribution density of the thermoplastic resin of 0.05 to 0.40 g / cm ³ .
(3) The said thermoplastic resin is a press felt for papermaking as described in (1) or (2) whose melting | fusing point is 80-160 degreeC.
(4) The papermaking press felt according to any one of (1) to (3), wherein the thermoplastic resin is more unevenly distributed on the papermaking surface side than on the running surface side.
(5) The papermaking press felt according to any one of (1) to (4), wherein the thermoplastic resin does not exist in the base fabric layer.
(6) The press felt for papermaking according to any one of (1) to (5), wherein the capillary space formed in the direction in which the fibers extend is closer to the papermaking surface side by the fibers of the front bat layer. .
(7) The press felt for papermaking according to (6), wherein the fineness of the bat fibers constituting the surface bat layer becomes smaller as it approaches the papermaking surface side.
(8) The press felt for papermaking according to any one of (1) to (7), wherein a back bat layer is provided on the running surface side of the base fabric layer.
(9) The papermaking press felt according to (8), wherein the back bat layer does not contain the thermoplastic resin.
(10) A method for producing a papermaking press felt according to any one of claims 1 to 9,
A base fabric layer material, at least a bat layer material located on the base fabric layer side forming a part of the front bat layer, a resin layer made of the thermoplastic resin, and a paper surface side forming the other part of the front bat layer Laminating step of supplying the bat layer material located in this order in order to obtain a entangled laminate,
Melted by heating the thermoplastic resin contained in the laminate, and solidified dispersed in at least both the batt layer material, Ru bundling the batt fibers the thermoplastic resin to penetrate between the batt fiber A method for producing a papermaking press felt.
(11) The method for producing a press felt for papermaking according to (10), wherein the resin layer has a basis weight per layer in a range of 20 to 60 g / m ² .
(12) The laminated body includes three or more layers of the butt layer material and two or more layers of the resin layer disposed between the bat layer materials. Production method.
(13) Each of the bat layer materials has a weight per layer of 50 to 150 g / m ² , and each of the resin layers has a weight per layer of 20 to 60 g / m ² . The manufacturing method of the press felt for paper manufacture as described in a certain (12).

According to the press felt for papermaking of the present invention, it is durable and excellent in wet paper transportability and wet paper peelability, and further, the resin distribution is precisely controlled and optimized (out of the surface bat layers). A portion where the thermoplastic resin is dispersed).
Further, when the thermoplastic resin is more unevenly distributed on the papermaking surface side than on the running surface side, it becomes easy to optimize the water squeezing of the papermaking press felt.
Furthermore, when the thermoplastic resin is not present in the base fabric layer, an increase in felt bending rigidity can be suppressed and exchanging workability can be improved.
Moreover, when the surface vat layer has a layered region having a thermoplastic resin distribution density of 0.05 to 0.40 g / cm ³ , excellent exchange workability, water permeability, water squeezing, and antifouling properties are obtained. Can be achieved at the same time.
Furthermore, when the capillary space formed in the direction in which the fibers extend by the fibers of the front bat layer is so narrow that it approaches the papermaking surface side, the resin can easily penetrate and diffuse, and an appropriate resin distribution can be obtained. Can be obtained.
Moreover, when the fineness of the bat fiber constituting the front bat layer is smaller as it approaches the papermaking surface side, the capillary space formed in the fiber extending direction can be made thinner as it approaches the papermaking surface side.
Furthermore, when the surface bat layer is composed of two or more bat fiber layers having different finenesses, the fineness of the bat fiber layer closer to the base fabric layer is larger than the fineness of the bat fiber layer closer to the papermaking surface. In addition, the capillary space formed in the direction in which the fibers extend can be made narrower as it approaches the papermaking surface side.
Further, when the area where the thermoplastic resin on the papermaking surface side of the front bat layer is exposed is 40% or less (including 0%) with respect to the entire plane area of the surface of the front bat layer on the papermaking surface side The wet paper web transportability and the wet paper peelability can be excellent.
Furthermore, if the back bat layer is provided on the running surface side of the base fabric layer, the base fabric layer can be protected from abrasion.
Further, when the back bat layer does not contain a thermoplastic resin, it can be further excellent in work exchangeability, water permeability and antifouling property.

According to the paper felt press felt manufacturing method of the present invention, it has durability, excellent wet paper transportability and wet paper peelability, and has an optimized layered region in which the resin distribution is precisely controlled. Papermaking press felt can be easily manufactured compared to conventional resin processing.
Further, by supplying the thermoplastic resin as a film during the laminating process, the resin distribution can be precisely controlled. Moreover, it becomes easy to supply a thermoplastic resin at a lamination process by supplying a thermoplastic resin at a lamination process as a prebat with resin which integrated the thermoplastic resin film and the prebat beforehand. Moreover, since it is a film form, while being easy to handle and improving workability, the physical influence on an operator is also improved and the working environment is improved.
When the front bat layer comprises three or more bat layer materials and two or more resin layers arranged between the bat layer materials, the same basis weight resin is supplied and arranged in one layer In comparison, the resin layer can be thickened and the water permeability can be increased.
In addition, when the bat layer material has a basis weight per layer of 50 to 150 g / m ² and the resin layer has a basis weight per layer of 20 to 60 g / m ² Can produce a press felt for papermaking that is particularly durable and excellent in exchanging workability, has a resin distribution precisely controlled, and has an optimized layered region.

(A) Schematic sectional view of a press felt material, (b) Schematic sectional view of a papermaking press felt, (c) Schematic sectional view of another papermaking press felt material. (A) Explanatory drawing which shows penetration | invasion of resin to bat layer raw material from which density differs, (b) It is explanatory drawing which shows the penetration | invasion of resin to the bat layer raw material by the position of a heat source. It is explanatory drawing explaining the other example of a lamination process. It is explanatory drawing explaining the process following the process shown in FIG. It is explanatory drawing explaining the process following the process shown in FIG. It is explanatory drawing explaining the process following the process shown in FIG. It is a cross-sectional electron micrograph of the press felt for paper manufacture. It is explanatory drawing which shows supply of a resin film. It is a graph which shows the recovery rate of the water in a press. It is a schematic diagram of a paper peelability test apparatus.

Hereinafter, the present invention will be described in detail with reference to FIGS.
In addition, this invention is not restricted to what is shown in the specific example described in this drawing, It can be set as various changes according to the objective and the use.

[1] Paper-made press felt The paper-made press felt of the present invention has a paper-making surface and a running surface which is a facing surface thereof,
The front vat layer is provided with a base fabric layer and a front vat layer disposed on the paper-making surface side, and the front vat layer is disposed inside the front vat layer and is melted and dispersed to solidify and is solidified (hereinafter also referred to as “resin”). The thermoplastic resin has a resin viscosity of 100 to 7,000 Pa · s when the resin is fluidized at a temperature in the range from the melting point to less than 180 ° C. in comprising an upper table batt layer and the lower table batt layer containing no thermoplastic resin, and a layered region is a composite layer thermoplastic resin is dispersed in the meantime, the thermoplastic resin in the composite layer, batt fiber It permeated and said that you have bundled the bat fibers in between.

  FIG. 1 (a) schematically shows a cross section after the lamination process of the paper felt of the present invention, and FIG. 1 (b) shows that after the lamination process, the resin is melt-dispersed inside the front vat layer. It is a schematic representation of the felt cross section that has been solidified (after finishing). Here, reference numeral 15 in FIG. 1 (a) represents a thermoplastic resin, and reference numeral 28 in FIG. 1 (b) represents a resin layer in which the thermoplastic resin is dispersed by heating and melting and is integrated with the bat material. .

For example, the papermaking press felt 20 according to the embodiment of the present invention includes a base fabric layer 21 and a front bat layer 22 disposed on the papermaking surface side of the base fabric layer 21 as shown in FIG. .
The “base fabric layer” is a fiber layer made of a woven fabric or a non-woven fabric, and forms the main body of a papermaking press felt. It is generally known among felt manufacturers that materials other than fibers such as sheets may be used instead of the base fabric layer.
Hereinafter, in the present invention, the “papermaking surface side” means the same side as the papermaking surface side of the base fabric layer, and means the upper side in FIG. 1B and the wet paper surface side (papermaking surface side). It shall be.

The “front vat layer” is a layer formed on the papermaking surface side of the base fabric layer. This layer is also a fiber layer made of woven or non-woven fabric. This layer may consist of only one layer or a plurality of layers, but in the present invention, it consists of a plurality of layers . The material of the front bat layer is not particularly limited, and examples thereof include one or more of polyamide (nylon), polyester, polyethylene, polypropylene, polyvinyl chloride and the like.

  There is no particular limitation on the capillary space formed by the fibers of the front bat layer in the direction in which the fibers extend, but it is preferable that the capillaries become narrower as they approach the papermaking surface. By doing so, it is possible to facilitate the penetration and diffusion of the resin in the bat fiber in the papermaking surface side direction. For that purpose, it is preferable that the fineness of the bat fiber constituting the front bat layer becomes smaller as it approaches the papermaking surface side. The front bat layer is composed of two layers, a paper surface side batt fiber layer and a base fabric layer side batt fiber layer, and the fineness of the base fabric layer side batt fiber layer is larger than the fineness of the paper surface batt fiber layer. Can also be achieved.

  Further, the front vat layer contains a thermoplastic resin that is disposed therein and melted and dispersed and solidified. The distribution of the thermoplastic resin is not particularly limited as long as the thermoplastic resin is disposed inside the front bat layer and melted and dispersed and solidified, but the thermoplastic resin in the thickness direction of the front bat layer is compared to the running surface side. It is preferable that it is unevenly distributed on the papermaking surface side. In particular, the side of the papermaking surface above the portion where the thermoplastic resin inside the front bat layer is disposed (the portion disposed at the time of manufacture) is traveling downward. It is preferable that there are more than the surface side portions.

The type of the “thermoplastic resin” is not particularly limited, and examples thereof include one or more of polyurethane resins, polyamide resins, polyester resins, polyolefin resins, EVA resins, and the like. Of these, polyamide resins and some polyurethane resins are preferred from the viewpoints of compression resistance, flex resistance, and hydrolysis resistance.
Moreover, although melting | fusing point of a thermoplastic resin is not specifically limited, It is preferable that it is 80-160 degreeC, and it is still more preferable that it is 110-130 degreeC.
The “melting point” refers to a temperature at which a solid melts and liquefies, but for an elastomer whose melting point is not clear, it means a flow start temperature. Here, the “flow start temperature” is generally used as an alternative to the melting point of a thermoplastic polyurethane elastomer whose melting point is not clear, and is measured by a test method described in JIS 7210.

Further, the thermoplastic resin has a resin viscosity of 100 to 7,000 Pa · s when the resin is fluidized at a temperature in the range from the melting point to less than 180 ° C. And it is preferable that the viscosity in the resin temperature (80-170 degreeC) at the time of felt heat processing is 500-7,000 Pa.s, Furthermore, melting | fusing point or flow start temperature is 100-150 degreeC, The viscosity at the resin temperature (140 to 170 ° C.) is preferably 500 to 5,000 Pa · s, and particularly preferably 500 to 1,000 Pa · s.
In the present invention, the thermoplastic resin can contain a filler that can flow integrally with the thermoplastic resin. Also in the thermoplastic resin composition containing this filler, it is preferable that the said flow start temperature and the said viscosity are achieved.

The surface bat layer containing the dispersed thermoplastic resin is a composite layer in which the thermoplastic resin is dispersed in the material of the surface bat layer.
Specifically, as shown in FIG. 1B, the papermaking press felt 20 includes an upper surface bat layer 22a and a lower surface bat layer 22b that do not contain a thermoplastic resin inside the surface bat layer 22, and a space therebetween. A layered region 28 which is a composite layer in which a thermoplastic resin is dispersed is provided.
The bat layer material is generally used for felt. Although the fiber type which comprises this felt is not specifically limited, For example, single fibers (25-200 mm), such as nylon (polyamide), polyester, and wool, can be used.
When the “resin distribution density (g / cm ³ )” in the layered region 28 is defined as “resin amount per unit area / thickness of the layered region 28”, the resin distribution density is 0.05 to 0. is preferably .50g / cm ^3, further preferably 0.10 to 0.40 g / cm ^3.

Further, considering the balance between the effect of the layered region, the workability of the felt (particularly the insertion property) and the felt air permeability, the mass per unit area of the resin is 1.5 to 5 of the mass per felt unit area. It is more preferable that the resin viscosity is 500 to 5000 Pa · s and the resin distribution density is 0.10 to 0.40 g / cm ³ within mass%, at the resin temperature during heat treatment. Further, the mass per unit area of the resin is within 1.5 to 5 mass% of the mass per felt unit area, the resin viscosity at the resin temperature during heat treatment is 500 to 1000 Pa · s, and the resin distribution density is 0.15 to 0. It is particularly preferable to set it to 20 g / cm ³ . Here, the mass per unit area of the resin is the mass per unit area supplied in the laminating step, and when the resin film is used, the mass per unit area (mass per unit area) is used.
The resin distribution density can be determined from an electron micrograph of a felt cross section (see FIG. 8). Specifically, an electron micrograph was taken using JEOL Co., Ltd. JSM-6390LV, and the thickness of the resin layer was measured by using the length measurement function of the same device. The average value is taken as the thickness of the resin layer.

  In addition to fillers (particles), a mixture of other additives can be used as the resin. By mixing a filler etc. as mentioned above, the flow start temperature of the thermoplastic resin film mentioned later and the viscosity at the time of flow can be adjusted. Furthermore, it can also be used for modifying resins such as improving durability and imparting hydrophilicity.

Examples of the filler include inorganic materials, polymer materials (preferably those having a melting point or flow start temperature of 200 ° C. or higher), metal materials, and the like that are generally known to be used for adding a function to a resin. For example, when kaolin clay is mixed with a resin, hydrophilicity can be imparted to the resin. These fillers may use only 1 type and may use 2 or more types together.
Moreover, when containing a filler, content of a filler is not specifically limited, For example, when the whole quantity of a thermoplastic resin is 100 mass parts, 5-50 mass parts can be contained. Furthermore, 10-30 mass parts is more preferable. It should be noted here that the resin viscosity increases when a filler is mixed into the resin. And when mixing a filler with resin, the viscosity of the said thermoplastic resin containing the filler after mixing needs to be in the said viscosity range.

  Furthermore, as the resin, two or more kinds of thermoplastic resins having a flow start temperature in the range of 80 to 160 ° C. are mixed, and the resin viscosity after mixing is 500 to 500 at 80 to 170 ° C., which is the resin temperature during heat treatment. Those at 5000 Pa · s can be used. Moreover, two or more types of thermoplastic resins having a flow start temperature in the range of 100 to 150 ° C. are mixed, and the resin viscosity after mixing is 500 to 1000 Pa · s at 160 to 170 ° C., which is the resin temperature during heat treatment. If something is used, it is particularly preferable.

The above “inside the front bat layer” means that a layered region 28 exists between the upper surface bat layer 22a and the lower surface bat layer 22b as shown in FIG.
Thus, when a layered region exists only inside the surface bat layer, the resin does not protrude from the surface of the surface bat layer, so there is no need for surface polishing, and wet paper releasability when using felt. It will be excellent. Further, since the base fabric layer does not contain a resin, the flexibility of the felt can be ensured and the workability (placing property) is excellent.

In addition, those including the resin up to the base fabric layer beyond the lower surface bat layer 22b have high bending rigidity and may deteriorate the insertion property. Therefore, it is preferable not to impregnate the resin up to the base fabric layer. good. Regarding the bending rigidity, the level of bending rigidity required varies depending on the location of use. This bending rigidity is increased by restricting the movement of the fibers that make up the felt due to resin processing. Therefore, in order to suppress the increase in bending rigidity, the bending rigidity must be kept to the minimum necessary to exert the effect of resin processing. It is important to process the resin. Therefore, if the resin processing is performed with the felt surface bat layer as a target, it is important that only the necessary portion inside the surface bat layer is performed, not to mention that no resin exists up to the base fabric layer. In other words, processing near the felt surface, which adversely affects wet paper transportability and wet paper peelability, and near the boundary with the base fabric layer where dirt tends to accumulate, will not only cause adverse effects due to resin processing such as accumulation of dirt. However, it causes an increase in bending rigidity more than necessary, leading to a decrease in hookability.
In the bending stiffness measurement method, the “bending stiffness” is an external force (kg) / displacement (cm), which is a value measured by a measurement method in Examples described later.

  As the papermaking press felt, one in which the base fabric layer and the front bat layer are intertwined and integrated by needling (needle felt) is often used. This is because the entire layer constituting the papermaking press felt is firmly integrated by needling, and is excellent in compressibility and durability.

A back bat layer 23 is preferably formed on the other side of the base fabric layer 21 as in the papermaking press felt 20 shown in FIG. This is because the back bat layer 23 protects the base fabric layer 21 and the entire felt 20 is further excellent in durability. The material of the back bat layer is not particularly limited, and may be one or more of polyamide (nylon), polyester, wool, polyethylene, polypropylene, polyvinyl chloride and the like, similar to the front bat layer.
Moreover, it is preferable that the back bat layer 23 is entangled and integrated with the base fabric layer 21 or both the base fabric layer 21 and the back bat layer 23 by needling. This is because the entire layer constituting the press felt for papermaking is firmly integrated by needling and is excellent in durability.
In addition, in FIG.1 (b), the code | symbol 211 represents the thread | yarn (cross section) which comprises a base fabric layer. Similarly, in FIG. 1A to be described later, reference numeral 111 represents a thread (cross section) constituting the base fabric layer.

[2] Method for Producing Paper-Pressed Felt The method for producing a paper-made press felt according to the present invention is a method for producing a paper-made press felt, which is a base fabric layer material and at least a part of a surface bat layer. Lamination which obtains the entangled laminate by supplying the bat layer material located on the fabric layer side, the resin layer made of thermoplastic resin, and the bat layer material located on the papermaking surface side forming the other part of the front bat layer in this order. Process,
Heating the thermoplastic resin contained in the laminate was melted, it solidified and dispersed in at least both the batt layer material, a dispersion step of Ru bundling batt fibers thermoplastic resin to penetrate between the batt fibers, It is characterized by providing.
More specifically, for example, at least one bat layer material is laminated and needling is performed in order to form a bat layer located on the base fabric layer side forming a part of the surface bat layer on the base fabric layer material. Entangled,

Further, in order to form a resin layer made of the thermoplastic resin, only the thermoplastic resin, or the thermoplastic resin and the butt layer material are laminated at the same time, and they are entangled and integrated, and then the front bat layer Laminate the bat material located on the papermaking side forming the other part, perform needling and confound and integrate,
Further, a lamination process for obtaining an entangled laminated body that performs needling without laminating the bat layer material,
A dispersion step of heating and melting the thermoplastic resin contained in the laminate and dispersing and solidifying at least both the batt layer materials.
Here, in order to form the back butt layer in the above-described lamination step, the bat material may be supplied and laminated on the back side of the base fabric layer, and needling may be performed.
The bat layer material in the present invention is a material that constitutes the front bat layer together with a thermoplastic resin. The base fabric layer material is a material constituting the base fabric layer. Moreover, a thermoplastic resin film can be used as the thermoplastic resin contained in the front vat layer, and in this case, the papermaking felt of the present invention can be more easily produced. Furthermore, the thermoplastic resin film may be laminated as a single film, or pre-butted with resin by pre-integrating with pre-batted by heat welding, needling, or other methods before the laminating process, and laminating pre-batted with resin You may supply in a process. Furthermore, the bat material that is integrated with the thermoplastic resin film in advance before lamination may be arranged on one side of the film, or may be arranged on both sides of the film and integrated. Here, the pre-bat is a sheet-like non-woven fabric made of bat material monofilaments that is manufactured by needling only the bat material in advance before the lamination process of laminating the bat material on the base fabric and confounding and integrating. Say.
As an example in the case of using a thermoplastic resin other than a film, for example, the bat material 12b of FIG. 1A is laminated on a base fabric layer and integrated by needling, and then the molten resin is roll coater method. Alternatively, it can be disposed on 12b by a melt blow method. In addition, by using a roll coater method or a melt blow method for a molten thermoplastic resin, a prebat with a resin is manufactured by integrating the thermoplastic resin with the prebat, and this prebat with a resin is supplied in the lamination process. The papermaking press felt of the invention can be manufactured.

(1) Laminating step The “laminating step” includes a base fabric layer material, at least a bat layer material positioned on the base fabric layer side forming a part of the front bat layer, a resin layer made of the thermoplastic resin, and This is a step of arranging the bat layer material located on the papermaking surface side forming the other part of the front bat layer in this order and obtaining a laminated body integrated by entanglement by needling.
That is, as shown in FIG. 1A, a bat layer material 12b positioned on the base fabric layer side forming the front bat layer 12, a resin layer 15 made of a thermoplastic resin, and paper making the other part of the front bat layer. This is a step of obtaining the entangled laminate 10 by repeatedly laminating and needling the bat layer material 12a located on the surface side in this order.
The above “lamination” may be performed in any manner and is not particularly limited, and the base fabric layer material, the batt layer material, and the thermoplastic resin may be laminated so as to achieve the target lamination order.

For example, as shown in FIG. 1A, the “front bat layer material 12” includes a first bat layer material 12b disposed on the base fabric layer side of the base fabric layer material 11, and a first bat layer material. And a second batt layer material 12a disposed on the papermaking surface side of 12b. The first front bat layer material 12b and the second front bat layer material 12a are provided with a thermoplastic resin (film) 15 between these layers, and the first butt layer material 12b and the second butt layer material 12a. And the front bat layer 22 of the press felt 20 for papermaking is constituted by the thermoplastic resin (film) 15. The first bat layer material 12b can be composed of at least one layer, preferably 2 to 6 layers of bat material. The second bat layer material 12a can be composed of at least one bat material, preferably 1 to 3 layers.
In the laminating step, the papermaking felt of the present invention can be easily manufactured by using, for example, a thermoplastic resin film in order to dispose the thermoplastic resin 15 in the front batt layer material 12. Furthermore, the thermoplastic resin film may be laminated as a single film, or integrated with the pre-bat (by pre-needing the bat material into a sheet-like non-woven fabric) by heat welding or needling before the lamination process. The integrated product (prebat with resin) may be supplied in the laminating step. Furthermore, the bat material that is integrated with the thermoplastic resin film in advance before lamination may be arranged on one side of the film, or may be arranged on both sides of the film and integrated.
Furthermore, the thermoplastic resin may be divided into two or more layers in the laminating step, and may be arranged with a bat material sandwiched between the resin layers. For example, FIG. 1C shows an example in which a thermoplastic resin is divided into two layers. The two layers of the thermoplastic resins 15a and 15b are supplied and laminated, and the second butt layer material 12a is disposed between the thermoplastic resin layers. That is, even if the resin is arranged as a plurality of layers as shown in FIG. 1C in the laminating process, the resin is dispersed by heating and melting, and when finished, one resin layer as shown in FIG. 1B is formed. be able to.

FIG. 8 shows a schematic diagram of a needling method in a laminating process using the needling apparatus 50. Reference numeral 19 in the figure denotes a first laminate in which a bat material forming a lower surface butt layer is integrated with a base fabric layer material by needling. On the first laminated body 19, the bat material 12 a is supplied as a pre-bat and the thermoplastic resin 15 is supplied as a film and is entangled and integrated by a needling device 50.
Here, in FIG. 8, the thermoplastic resin 15 is supplied separately from the pre-bat made of the bat material 12a, but it is also possible to supply the thermoplastic resin and the bat material in an integrated state as the pre-bat with resin. .

  Moreover, in this lamination process, as shown in FIG.1 (c), a thermoplastic resin can be divided | segmented into two or more layers, and a bat raw material can be supplied in the form which pinches | interposes between each thermoplastic resin layer.

  This method has a high melt viscosity (for example, the viscosity of the thermoplastic resin at the resin temperature during the felt heat treatment is 4,000 to 7,000 Pa · s), and does not easily penetrate even when melted in the bat layer material. This is effective in the case of using, particularly when a thermoplastic resin having a high melt viscosity is contained at a lower resin distribution density. Thereby, the resin distribution range in the felt thickness direction can be widened, and even a thermoplastic resin having a high melt viscosity can be contained with a low resin distribution density.

  On the other hand, even when using a thermoplastic resin having a low melt viscosity (for example, the viscosity of the thermoplastic resin at the resin temperature during the felt heat treatment is 500 to 4,000 Pa · s), The thermoplastic resin film is divided into a plurality of layers in the bat layer material for the purpose of obtaining higher air permeability within the range that does not cause a decrease in effect and an extreme decrease in entrapment property due to an increase in the thickness of the resin layer. It is effective to arrange in.

  Further, regardless of the melt viscosity of the thermoplastic resin to be used, a plurality of different types of thermoplastic resins can be dispersed in the front bat layer by dividing the thermoplastic resin film into a plurality of layers. For example, it can arrange | position as two thermoplastic resin film layers which divided | segmented hydrophobic resin and hydrophilic resin, respectively.

Specifically, as shown in FIG. 1C, first, a first laminated body 19 is formed, and a hydrophobic resin film 15b and a surface of the first bat layer material 12b in the first laminated body 19 are formed. The second bat layer material 12a is sequentially laminated, and further, the hydrophilic resin film 15a and the third bat layer material 12c are sequentially laminated on the surface of the second bat layer material 12a, and then the whole is needling. It is possible to produce a laminate by integrating them.
Then, heating is performed in a temperature range in which the two types of resins are not mixed to melt and disperse the resins. Thereby, the surface bat layer which has simultaneously the hydrophilic layer-like area | region where only hydrophilic resin was disperse | distributed in the surface bat layer, and the hydrophobic layer-like area | region where only hydrophobic resin was disperse | distributed can be formed.
Moreover, even when the same resin is used, by using a film formed only by a resin on one side and using a resin film imparted with hydrophilicity by mixing a filler on the other side, the degree of hydrophilicity can be increased. A surface bat layer having different layered regions simultaneously can be formed.

  The surface vat layer in which both the hydrophilic layered region and the hydrophobic layered region are separately arranged in a mutually independent form is impregnated with felt in a liquid resin in which a thermoplastic resin is dispersed and contained in a medium, It is a form that cannot be applied by the method of applying from the felt surface, and does not lower the felt insertion performance and air permeability more than necessary.

Furthermore, as the thermoplastic resin film, a thermoplastic resin film containing both a water-insoluble thermoplastic resin and a water-soluble thermoplastic resin can also be used. When such a thermoplastic resin film is used, the front vat layer (or the whole felt) may be washed with water (water, hot water, hot water, etc.) before and after the heating step for dispersing the thermoplastic resin in the front vat layer. Including the water-washing step of (including) water-soluble thermoplastic resin can be dissolved and removed. As the basis weight of the thermoplastic resin decreases (for example, 30 g / m ² or less), it is difficult to arrange the resin uniformly, but a water-insoluble resin mixed with a water-insoluble resin is placed and removed by washing with water. By doing so, it becomes easy to arrange resin uniformly.
Here, the “weight per unit area” is a mass (g) per unit area (m ² ).
Furthermore, since the felt for papermaking remains wet during use without removing the water-soluble resin, the water-soluble thermoplastic resin is removed during use, so it is necessary to perform water washing to remove the water-soluble resin. Is not necessarily.

The thermoplastic resin film is not particularly limited in its shape and function as long as it is thin and made of a soft material. For example, it can be a strip-shaped soft material. Because of the film shape, a uniform resin layer can be formed, and it becomes easy to control the resin distribution of the papermaking press felt.
On the other hand, if small pieces of resin are dispersed and sandwiched between bat layer materials, a non-uniform resin layer may be formed, so small pieces of resin may be used. It is preferable to use it as a film that is integrated by heat treatment or the like so that it is difficult to disperse.

  However, it is preferable that the thermoplastic resin does not disperse to the paper making surface side of the bat layer material during needling. Therefore, it is preferable that the thermoplastic resin film is difficult to be fragmented by needling and can maintain the film shape even after needling. In particular, the dispersion in the batt layer material after needling is preferably suppressed to 20% by mass or less of the entire thermoplastic resin film. Specifically, the resin used is selected from resins having an elongation of 500% or more in a 50 μm-thick film, thereby suppressing the dispersion of the resin during the needling to 20% by mass or less of the entire film. That can be easily achieved.

An example of a manufacturing process in the case of arranging a thermoplastic resin film in two layers will be described with reference to FIGS.
As shown in FIG. 3, a backing bat layer material 13 is laminated on the base fabric layer material 11, and needling is performed. Here, an example of supplying one back bat layer material 13 is shown. Usually, one or two back bat layer materials are often supplied, but in rare cases there are no back bat layer materials or three or more layers.
The step of integrating the back butt layer material may be before the first butt layer material is laminated, or after the first bat layer material is laminated, as in this example. Further, it may be after the second laminate is laminated.

Next, as shown in FIG. 4, the batt layer material is laminated on the surface (papermaking surface) side of the base fabric layer material, and is subjected to needling. Here, an example is shown in which a bat layer material 12b composed of two layers of bat materials 121b and 122b is supplied. The total supply amount of the bat material constituting the bat layer material is at least one layer, preferably 2 to 6 layers, but 6 or more layers of bat material may be supplied.
Here, regarding the bat fineness of the bat layer material, the same fineness as that of the back bat layer material 13 may be used, or a different fineness may be used.
It is also possible to use a plurality of bat materials having different finenesses in the same bat layer. At that time, it is preferable to use a bat fiber 122b having a large fineness for the bat layer material 122b on the base fabric layer material 11 side, and using a bat fiber having a small fineness for the bat material 121b on the papermaking surface side. .

After that, as shown in FIG. 5, the resin film 152 and the pre-bat 122a made of a bat material are supplied and entangled and integrated by needling, and the resin film 151 and the pre-bat 121a are supplied and entangled and integrated by needling.
Here, when the resin film and the bat material are supplied at the same time, as shown in FIG. 5, it is desirable in terms of workability in the laminating process that the bat material is disposed on the upper (outer) side and needsling. Further, it is desirable to use a bat material having the same or smaller fineness as that of 12b.

Next, as shown in FIG. 6, the third bat layer material 16 is laminated on the second laminated body 14 and needsling. The bat material constituting the third bat layer is preferably arranged in one to three layers, and more preferably in one or two layers. (If the number of the third surface bat layers is small, the resin is likely to be exposed on the surface when the resin is melt-dispersed, and if the number of the third surface bat layers is large, the heat insulating layer becomes difficult to increase the temperature of the resin. )
The bat fineness of the third butt layer material is preferably the same as or smaller than the bat fineness of the second bat layer material.

(2) Heating step The “heating step” is a step in which the thermoplastic resin film is melted, and a thermoplastic resin (a thermoplastic resin constituting the thermoplastic resin film) is infiltrated and dispersed inside the bat layer material. is there.
The kind of heat source for heating is not particularly limited. Moreover, not good if caused to penetrate and disperse the thermoplastic resin within at least batt layer material.

  The heating temperature in the heat processing is not particularly limited, but when a resin having a melting point of 80 to 160 ° C. and a viscosity at a resin temperature (80 to 170 ° C.) during felt heat treatment of 500 to 7,000 Pa · s is used, The temperature is preferably 110 to 170 ° C, more preferably 140 to 170 ° C, and particularly preferably 160 to 170 ° C.

  The heating is preferably performed from the papermaking surface side of the bat layer material. As shown in FIG. 2B, by arranging the heat source 30 on the papermaking surface side (front side) of the second butt layer material 12a, the temperature of the second butt layer material 12a is higher than that of the first butt layer material 12b. The resin becomes higher and more resin can penetrate into the upper bat layer material 12a. Further, as shown in FIG. 2 (a), the second butt layer material 12a has a higher density of thermoplastic resin than the first butt layer material 12b, thereby causing a first butt layer. A large amount of resin can penetrate into the material 12a.

Hereinafter, the present invention will be described specifically by way of examples.
[1] Effect of heating temperature (Examples 1 to 4 and Comparative Example 1)
The paper felt press felt samples of Examples 1 to 4 and Comparative Example 1 (hereinafter referred to as “test products”) include a front bat layer material 12 and a thermoplastic resin film 15 disposed in the front bat layer material 12. The base fabric layer material 11 and the back bat layer material 13 are configured. Details of each of these are as follows.

Base fabric layer material 11; composed of nylon monofilament 211 having a diameter of 0.4 mm
This is a woven fabric having a total basis weight of 560 g / m ² .
The front bat layer material 12 includes a first bat layer material 12b and a second bat layer material 12b.
The total basis weight not including the thermoplastic resin film is 600 g / m ² .
First batt layer material 12b; having a basis weight of 100 g / m ² having a single fiber made of nylon as a constituent fiber
Five layers of non-woven fabric (pre-bat) are supplied and configured.
Second batt layer material 12a; with a basis weight of 100 g / m ² comprising a single fiber made of nylon
One layer of non-woven fabric (pre-bat) is supplied.
Thermoplastic resin film; 50 μm thick film with thermoplastic resin content
It is 54 g / m ² and the flow start temperature is 140 to 145 ° C. (Filler is not included.)
Back bat layer material 13; with a basis weight of 100 g / m ² comprising a single fiber made of nylon
Two layers of pre-bats which are non-woven fabrics are supplied and configured.

(Production of test product)
First, 5 layers of prebats are integrated with the base fabric layer material by repeating the supply and needling of the prebat to be the first vat layer material 12b on the papermaking surface side of the base fabric layer material 11 repeatedly, and thereafter The first laminated body 19 was formed by entanglement and integration of two layers of prebats with the base fabric layer material by repeatedly supplying the prebat serving as the back bat layer material 13 twice on the running surface side of the base fabric layer material 11.
Next, as shown in FIG. 8, one layer of the thermoplastic resin film 15 and one layer of the second butt layer material 12 a are formed on the paper making surface side of the first butt layer material 12 b in the first laminate 19. The bat material was supplied and the whole was integrated by needling to form the laminate 10 (lamination step).

Thereafter, heat treatment was carried out by heating from the papermaking surface side of the second batt layer material 12a at any of 100 ° C., 140 ° C., 160 ° C., and 170 ° C. shown in Table 2 for 90 seconds (heating step).
Table 1 shows the viscosity at each temperature of the thermoplastic resin constituting the thermoplastic resin film at each temperature. This melt viscosity is a numerical value measured under the measurement conditions of Shimadzu flow tester constant temperature method die: 1 × 1, weight 294N.
Furthermore, in Examples 1 to 4, the second batt layer material 12a closest to the heat source has a thin thickness of 100 g / m ^{2 and} a sufficiently long heating time, so the temperature of the thermoplastic resin is substantially the same as the heating temperature. It is thought that it is at temperature. Comparative Example 1 is an example in which the same laminate as in Examples 1 to 4 was formed and no heat treatment was performed.

(Evaluation and evaluation method)
For Examples 1 to 4 and Comparative Example 1, the resin distribution density, the air permeability ratio when the air permeability of the test product not containing the resin was 100%, and the bending rigidity were measured and are shown in Table 2. Each evaluation is a value measured by the following method.
That is, the resin distribution density (g / cm ³ ) was calculated by dividing the basis weight of the thermoplastic resin arranged in the front vat layer by the thickness of the resin layer measured with an electron microscope.
The air permeability ratio (%) is the ratio of the air permeability of each sample, assuming that the air permeability of the felt manufactured by the same manufacturing method as in Examples 1 to 4 and Comparative Example 1 is 100, with no thermoplastic resin disposed. The numerical value calculated.
Flexural rigidity (g / cm) is a numerical value measured by measuring the force required to fold the felt to a certain thickness using a force gauge (manufactured by Nidec Simpo) and dividing it by the folded width of the sample.

(Test results)
The air permeability ratio of the test product of Comparative Example 1 without heat treatment was 76.9%. Therefore, it can be seen that in the felt of Comparative Example 1, the air permeability is reduced by about 23% in the state where the resin is disposed inside and the resin is not melted as compared with the case where the resin is not disposed. Here, the air permeability ratio of 76.9% is achieved without melting the resin because air permeability is obtained by needling.
Since the resin used at this time does not melt at 100 ° C., even in Example 1 in which heat treatment at 100 ° C. was performed, the air permeability ratio was the same level as that of the test product without heat treatment. The air permeability ratio of Example 2 that was heat-treated at 140 ° C. was 89.7%, which is an improvement over Comparative Example 1 and Example 1. This is presumably because the resin was melted and dispersed and the resin distribution density was lowered.

However, since the air permeability ratio is less than 90%, there is a concern that the air permeability may be lowered at an early stage when used as a papermaking press felt. Further, in Example 4 in which the heating temperature was 170 ° C., the air permeability ratio was improved to 95% or more, and the risk of a decrease in air permeability at an early stage during use was low. In Table 2, “permeability ratio” means the ratio of the air permeability when the air permeability of a test product not containing a resin (produced under the same conditions as in Examples 1 to 4 except for the resin) is 100% ( %).
On the other hand, the bending rigidity was 705 g / cm in the treatment at 140 ° C. in Example 2, but was 823 g / cm in the treatment at 160 ° C. in Example 3, and 911 g / cm at 170 ° C. in Example 4. As the heat treatment temperature rises, the bending rigidity value also increases, but it can be said that neither of the rigidity values is a value that makes it difficult for the felt to work.
From the above physical property test results, the heating temperature performed on this felt varies depending on the place of use, but considering the air permeability ratio and securing of penetration, it is preferably 130 ° C. to 180 ° C., 150 to 180 ° C. More preferably, it is 155 degreeC, and it is especially preferable that it is 155-165 degreeC. However, when the air permeability ratio is more important than the throwing property, the temperature is particularly preferably 165 to 175 ° C.

[2] Effect of resin film layer (Examples 5 and 6)
The test products of Examples 5 and 6 are composed of a front bat layer material 12, a thermoplastic resin film 15 disposed in the front bat layer material 12, a base fabric layer material 11, and a back bat layer material 13. Is done. Details of each of these are as follows.

Base fabric layer material 11: Four nylon monofilaments having a diameter of 0.2 mm were combined.
The woven fabric is composed of twisted yarn 211 and has an overall basis weight of 610 g / m ² .
A front bat layer material 12; a first bat layer material 12b and a second bat layer material 12b;
It does not include a thermoplastic resin film, and has an overall basis weight of 700 g / m ² .
First batt layer material 12b; having a basis weight of 100 g / m ² having a single fiber made of nylon as a constituent fiber
Six layers of non-woven fabric (pre-bat) are supplied.
Second batt layer material 12a; with a basis weight of 100 g / m ² comprising a single fiber made of nylon
One layer of non-woven fabric (pre-bat) is supplied.
Thermoplastic resin film; 30 μm thick film with a thermoplastic resin amount of 33.5 g /
m ² and a flow start temperature of 105 to 108 ° C. (Filler
Does not contain. )
Back bat layer material 13; a non-woven fabric with a basis weight of 100 g / m ² comprising a single fiber made of nylon
One prebat is supplied and configured.

(Production of test product)
Example 5: Six layers of butt base layers serving as the first butt layer material 12b are supplied to the paper making surface side of the base fabric layer material 11, and one layer serving as the back bat layer material 13 is provided on the running surface side of the base fabric layer material 11. The first laminated body 19 was formed by supplying the bat material and integrating them by needling.
Next, as shown in FIG. 9, two layers of the thermoplastic resin film 15 and one layer of the second butt layer material 12a are formed on the paper making surface side of the first butt layer material 12b in the first laminate 19. The bat base layer was supplied, and the whole was integrated by needling to form the laminate 10 (lamination step).

Example 6: A five-layer bat material serving as the first butt layer material 12 b is supplied to the paper making surface side of the base fabric layer material 11, and one layer serving as the back bat layer material 13 is provided on the running surface side of the base fabric layer material 11. The first laminated body 19 was formed by supplying the bat material and integrating them by needling.
Next, as shown in FIG. 9, one layer of the thermoplastic resin film 15 and one layer of the bat material are supplied to the paper making surface side of the first bat layer material 12b of the first laminated body 19, All of these were integrated by needling to form a second laminate. Further, similarly, one layer of the thermoplastic resin film 15 and one layer of the bat material are supplied to the paper making surface side of the second butt layer material 12a of the second laminate, and these are all needed. The laminate 10 was formed by integration with a ring.
The only difference between the laminate of Example 6 and the laminate of Example 5 is that one bat material (100 g / m ² ) is disposed between two layers of the thermoplastic resin film 15.

  Thereafter, heat treatment was performed by heating at 140 ° C. for 60 seconds from the papermaking surface side of the second bat layer material 12a (heating step).

(Evaluation and evaluation method)
In the same manner as in Examples 1 to 4, the resin distribution density and the air permeability ratio when the air permeability of the test product not containing the resin was 100% were measured and are shown in Table 3.

(Test results)
As shown in Table 3, in Example 6, the second bat layer material was disposed between the resins, so that the resin layer was about 24% thicker than Example 5 and the air permeability ratio was increased by 3.7%. From this, it is easy to secure the breathability of the felt by thickening the layered region and lowering the resin distribution density by sandwiching the second butt layer material between the resin and the resin when placing the resin. I understand that In Table 3, “permeability ratio” means the ratio of the air permeability when the air permeability of a test product that does not contain a resin (produced under the same conditions as in Examples 5 and 6 except for the resin) is 100% ( %).

[3] Influence of the form of the thermoplastic resin (Example 7, Comparative Examples 2 and 3)
The test product of Example 7 is composed of a front bat layer material 12, a thermoplastic resin film 15 disposed in the front bat layer material 12, a base fabric layer material 11, and a back bat layer material 13. . Details of each of these are as follows.

Base fabric layer material 11: Four nylon monofilaments having a diameter of 0.2 mm were combined.
The woven fabric is composed of twisted yarn 211 and has an overall basis weight of 630 g / m ² .
A front bat layer material 12; a first bat layer material 12b and a second bat layer material 12b;
It does not contain a thermoplastic resin film and has an overall basis weight of 630 g / m ² .
First batt layer material 12b; with a basis weight of 110 g / m ² comprising a single fiber made of nylon as a constituent fiber
Three layers of non-woven fabric (pre-bat) are supplied and configured.
Second batt layer material 12a; with a basis weight of 100 g / m ² comprising a single fiber made of nylon
Three layers of non-woven fabric (pre-bat) are supplied and configured.
Thermoplastic resin film; 30 μm thick film with a thermoplastic resin amount of 33.5 g /
m ² and a flow start temperature of 105 to 108 ° C. (Filler
Does not contain. )
Back bat layer material 13; a non-woven fabric with a basis weight of 110 g / m ² comprising a single fiber made of nylon
A certain layer of prebat is supplied and configured.

(Production of test product)
Example 7: Three layers of bat materials serving as the first butt layer material 12b are supplied to the paper making surface side of the base fabric layer material 11, and two layers serving as the back bat layer material 13 are provided on the running surface side of the base fabric layer material 11. The first laminated body 19 was formed by supplying the bat material and integrating them by needling.
Next, as shown in FIG. 8, one layer of the thermoplastic resin film 15 and one layer of the second butt layer material 12 a are formed on the paper making surface side of the first butt layer material 12 b in the first laminate 19. We supply bat material and needling. Since the supply of the thermoplastic film and the second butt layer material and the needling were repeated three times, a total of three layers of the thermoplastic film and the second butt layer material were supplied. Then, these were integrated by needling, and the laminated body 10 was formed (lamination process).

Thereafter, heat treatment was performed by repeating heating at 140 ° C. for 60 seconds three times from the paper making surface side of the second bat layer material 12a (heating step).
Further, as Comparative Example 2, a laminate having the same structure and material as that of Example 7 was formed except that the thermoplastic resin film was not used. Furthermore, as Comparative Example 3, a laminated body was formed by coating with a water-dispersed thermosetting resin so as to be 80 g / m ² .

(Evaluation and evaluation method)
In the same manner as in Examples 1 to 4, the resin distribution density and the air permeability ratio when the air permeability of the test product not containing the resin was 100% were measured and are shown in Table 4. Furthermore, about Example 7, the comparative example 2, and the comparative example 3, thickness was measured with the following method, respectively, and it described together in Table 4.

(Test results)
In Example 7, the bending rigidity is only increased by about 40% compared to Comparative Example 2 without resin, and the flexibility is not lost so much, and it can be said that the deterioration of the insertion property is small. On the other hand, the flexural rigidity of Comparative Example 3 using a water-dispersed resin is increased by 150% or more from Comparative Example 2 and exceeds 1100 g / cm. Depending on the place of use, the bending property may be greatly affected. High nature.
The reason why the bending rigidity is greatly different is that the thickness of the resin layer is greatly different. That is, in Comparative Example 3, the thickness of the resin distribution is thicker than that in Example 7, and the resin is distributed to the base fabric layer, so that the bending rigidity is greatly increased.
In Comparative Example 3, the air permeability ratio exceeds 100% because the thickness of the felt was recovered by coating the water-dispersed thermosetting resin.

  Furthermore, a comparative test of initial water squeezing was performed using Example 7, Comparative Example 2 and Comparative Example 3. This test was conducted by the following method. That is, a felt sample is run at a speed of 1000 m / min and a pressure of 20 kN / m using a press simulator device (manufactured by our company), and the flow rate of water supplied by the shower and the change in the amount of dehydration in the suction box or press are measured. is there. The results are shown in FIG. According to this test, the correlation between the water recovery rate and the number of presses can be observed. From the operation results of the simulator test machine so far, it is clear that there is a correlation between the result of this test method and the water squeezing performance in an actual paper machine.

  From FIG. 9, the increase in the water recovery rate in the press of Comparative Example 3 using a water-dispersed resin is faster than that of Comparative Example 2 without resin, and Comparative Example 3 has better initial water squeezing than Comparative Example 2. Is shown. On the other hand, the increase in the water recovery rate of Example 7 is equivalent to that of Comparative Example 3, and it can be seen that the initial water squeezing has the same performance. Thus, Example 7 shows that the press felt for papermaking according to the present invention is excellent in initial water squeezing without impairing the insertability.

[4] Effect of resin exposure ratio on wet paper peelability ( Reference Example 1 , Reference Example 2 , Example 8 and Comparative Example 4)
The test samples of Reference Example 1 , Reference Example 2 , Example 8 and Comparative Example 4 were formed in the same manner as the above-described test products, and the base fabric layer material, the bat layer material 610 g / m ^2, and the back bat layer material 200 g / m ² and a thermoplastic urethane resin 54 g / m ² having a flow start temperature of 140 to 145 ° C. Batt layer material 610 g / ^{m 2} is supplied divided into Purebatto of Purebatto and 110g / ^{m 2} 1 layer of 100 g / ^{m 2} by 5 layers, it was supplied during needling behind batt layer material 100 g / ^{m 2} 2 layers. The resin was supplied in a single layer of 54 g / m ² film.

(Production of test product)
In the test product of Reference Example 1 , first, 100 g / m ² pre-batt was laminated on the paper-making side of the base fabric layer material, and the needling was performed. By repeating this five times, five layers of pre-batts were laminated. The first laminate was formed by integrating with a ring.
Next, a prebat with a resin in which a resin film is welded to a 110 g / m ² prebat is laminated on the surface of the first vat layer material so that the resin film is in contact with each other, and then the whole is integrated by needling. A laminate was formed.

In the test product of Reference Example 2 , first, 100 g / m ² of the pre-batt was laminated on the paper-making side of the base fabric layer material, and the needling was performed. By repeating this four times, four layers of the pre-batt were laminated. The first laminate was formed by integrating with a ring.
Next, a resin-prepared pre-butt having a resin film welded to a 100 g / m ² pre-vat is laminated and needling so that the resin film side is in contact, and then a 110-g / m ² pre-bat is laminated and needling is performed. Furthermore, these were integrated by needling to form a laminate.
In the test product of Example 8 , first, 100 g / m ² of a prebat was laminated on the paper-making surface side of the base fabric layer material, and then needling was performed. By repeating this three times, three layers of prebat were laminated. The first laminate was formed by integrating with a ring.
Then, a resin with Purebatto the resin film welded formed Purebatto of 100 g / m ^2, needled and ring are laminated so that the resin film side is in contact, then subjected to needling by laminating Purebatto of 100 g / m ^2, further 110 g / m ² of prebats were laminated and subjected to needling, and then the whole was integrated by needling to form a laminate.
The difference in the test products of Reference Example 1 , Reference Example 2 and Example 8 manufactured in this way is only the position where the resin film is arranged in the front bat layer.
The test product of Comparative Example 4 was prepared by laminating a bat layer material consisting of 6 layers of pre-bats on the paper-making side of the base fabric layer material and a back bat layer material consisting of 2 layers of pre-bats on the other side without using a resin. The laminated body was formed by integration by needling.
The laminates of Reference Example 1 , Reference Example 2 , Example 8 and Comparative Example 4 were heated from 140 ° C. for 60 seconds from the surface side of the bat layer material to perform heat treatment to obtain respective test products.

The test apparatus shown in FIG. 10 includes a top felt 91, a bottom felt 92, and press rolls 95 and 96.
In the test, wet paper having a basis weight of 60 g / m ² was used, and wet paper moisture was 80%. 80% wet paper moisture is moisture at the entrance of the first press (first press) in the press part of the paper machine where felt is used.
As the moisture content of the wet paper becomes higher, the strength becomes lower, and the wet paper peelability is likely to be different. The felt speed of the test apparatus was 300 m / min. The test products of the reference examples 1 , 2 , 8 and 4 were used as the top felt 91 of the test apparatus. The wet paper 70 is placed on the aluminum plate 80 and placed on the bottom felt 92 at the press entrance. Then, after pressing by the press rolls 95 and 96, the wet paper and the aluminum plate are accommodated in the cradle 97 if the paper is not taken into the felt. The test was performed 10 times for each test product under the same conditions. The wet paper peelability was evaluated by observing the wet paper felt on the felt with a video camera. The surface of the wet paper after the test was also observed. The results are shown in Table 5 as the felt surface resin exposure ratio of each test product and the wet paper peelability test results. In addition, the felt surface resin exposure ratio of each test product was measured as follows. First, the test product is dyed by the Bokenstein stain test. By this dyeing, nylon is dyed in a green color and urethane resin is dyed in a red color. Thereafter, the stained sample surface was photographed with a digital camera installed in an optical microscope, and the ratio of red color (urethane resin) was measured with image analysis software.

(Test results)
The peelability evaluations in the table are ◎ (very good), ◯ (may be unstable at the edge, etc., but not taken off at all), △ (once during 10 tests) However, paper was taken out). From this result, it is understood that if the resin exposure ratio on the felt surface is high, the wet paper peelability is likely to be affected. Therefore, it is important to control the resin exposure ratio on the felt surface in order to stably operate the paper machine, and in the present invention, it is possible to manufacture a felt with the felt surface resin exposure ratio controlled.

  10; laminate, 11; base fabric layer material, 12; bat layer material, 12a; second bat layer material, 12b; first bat layer material, 13; back bat layer material, 15; thermoplastic resin film, 19; 1st laminated body, 20; Press felt for papermaking, 21; Base fabric layer, 22; Front bat layer, 22a; Upper front bat layer, 22b; Lower front bat layer, 23; Back bat layer, 28; 30; Heat source, 50; Needling device, 70; Wet paper, 80; Aluminum plate, 91; Top felt, 92; Bottom felt, 95 and 96; Press roll, 97;

Claims (13)

While having a papermaking surface and a running surface that is opposite to it,
It comprises a base fabric layer and a front bat layer arranged on the papermaking surface side,
The surface bat layer contains a thermoplastic resin disposed inside the surface bat layer and melt-dispersed and solidified.
The thermoplastic resin has a resin viscosity of 100 to 7,000 Pa · s when the resin is fluidized at a temperature in the range from the melting point to less than 180 ° C.,
The surface vat layer includes an upper surface vat layer and a lower surface vat layer that do not contain the thermoplastic resin inside the surface vat layer, and a layered region that is a composite layer in which the thermoplastic resin is dispersed therebetween. , equipped with a,
The composite the thermoplastic resin in the layer press felt for papermaking to penetrate between the batt fibers, characterized that you have bundling the batt fibers. 2. The papermaking press felt according to claim 1, wherein a distribution density of the thermoplastic resin is 0.05 to 0.40 g / cm ³ in the layered region of the front vat layer.   The press felt for papermaking according to claim 1 or 2, wherein the thermoplastic resin has a melting point of 80 to 160 ° C.   The papermaking press felt according to any one of claims 1 to 3, wherein the thermoplastic resin is more unevenly distributed on the papermaking surface side than on the running surface side.   The papermaking press felt according to any one of claims 1 to 4, wherein the thermoplastic resin is not present in the base fabric layer.   The press felt for papermaking according to any one of claims 1 to 5, wherein a capillary space formed in the direction in which the fibers extend by the fibers of the front bat layer becomes narrower toward the papermaking surface side.   The paper felt press felt according to claim 6, wherein the fineness of the bat fibers constituting the front bat layer decreases as it approaches the paper surface side.   The press felt for papermaking according to any one of claims 1 to 7, further comprising a back bat layer on the running surface side of the base fabric layer.   The papermaking press felt according to claim 8, wherein the back bat layer does not contain the thermoplastic resin. A method for producing a papermaking press felt according to any one of claims 1 to 9,
A base fabric layer material, at least a bat layer material located on the base fabric layer side forming a part of the front bat layer, a resin layer made of the thermoplastic resin, and a paper surface side forming the other part of the front bat layer Laminating step of supplying the bat layer material located in this order in order to obtain a entangled laminate,
Melted by heating the thermoplastic resin contained in the laminate, and solidified dispersed in at least both the batt layer material, Ru bundling the batt fibers the thermoplastic resin to penetrate between the batt fiber A method for producing a papermaking press felt. The method for producing a press felt for papermaking according to claim 10, wherein the resin layer has a basis weight per layer in a range of 20 to 60 g / m ² .   The said laminated body is a manufacturing method of the press felt for paper manufacture of Claim 10 provided with the said batt layer raw material of 3 or more layers, and the said 2 or more layers of said resin layer arrange | positioned between the layers of this batt layer raw material. Each of the bat layer materials has a basis weight per layer of 50 to 150 g / m ² , and each of the resin layers has a basis weight per layer of 20 to 60 g / m ^2. 12. A method for producing a press felt for papermaking according to 12.