JP4418221B2 - Non-woven sheet manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a non-woven sheet laid as a mat or the like on a sofa in an entrance, kitchen, or living room.

For example, mats are laid in an entrance, a sofa in the living room, a kitchen, a bathroom, and the like to prevent dust and dirt from entering from outside and the floor surface getting wet with water. The mat is used when a person walks or sits on the mat. For this reason, many mats made of synthetic fibers that are excellent in compression recovery and cushioning properties are used. Moreover, as shown in Patent Document 1, for example, disposable diapers, sanitary products, water-absorbing sheets and the like made of a dry nonwoven fabric made of natural fibers such as pulp are known. In recent years, disposable mats that can be easily disposed of after use have been proposed in consideration of user convenience.
JP-A-9-143850

  However, a dry nonwoven fabric made of natural fibers has a problem that it is inferior in compression recovery and cushioning properties compared to a dry nonwoven fabric made of conventional synthetic fibers due to the characteristics of the material. Therefore, when a dry nonwoven fabric made of natural fibers is used as a disposable mat, there is a problem that sufficient compression recovery and cushioning properties cannot be obtained.

The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a method for producing a non-woven fabric sheet for mats which can be easily disposed of after use and can exhibit excellent compression recovery and cushioning properties.

To achieve the above object, the invention according to claim 1, containing the cellulosic fibers and thermal bonding fibers, together with the cellulosic fibers are blended 50% by weight or more, the fiber density is 0. It is comprised with the dry nonwoven fabric set in the range of 02-0.10 g / cm < ³ >, The 1st layer which consists of a 1st dry nonwoven fabric, the 2nd layer which consists of a 2nd dry nonwoven fabric, and 3rd A third layer composed of a dry nonwoven fabric is laminated in layers, the first dry nonwoven fabric is blended with the first fibers, and the second dry nonwoven fabric has a fineness smaller than that of the first fibers. The third dry nonwoven fabric is blended with a third fiber having a fineness smaller than that of the second fiber, so that the first layer has a fiber density lower than that of the second layer, The third layer is a non-woven fabric for mats in which the fiber density is set higher than that of the second layer. A method for producing a sheet, comprising a step of pressing the first dry nonwoven fabric, the second dry nonwoven fabric, and the third dry nonwoven fabric in a laminated state, and in the pressing step, the first dry type The gist is that the surface of the nonwoven fabric is brought into contact with the first press surface made of a soft material, and the surface of the third dry nonwoven fabric is brought into contact with the second press surface made of a hard material .

With this configuration, by setting the fiber density to 0.02 to 0.10 g / cm ³ , the nonwoven fabric sheet containing cellulosic fibers and heat-fusible fibers has high compression recovery and cushioning properties. Can be made. Moreover, since the nonwoven fabric sheet contains 50% by weight or more of cellulosic fibers, the amount of combustion gas generated can be reduced, and the amount of combustion heat can also be reduced.
Moreover, the nonwoven fabric sheet is comprised so that the fiber density of the dry-type nonwoven fabric which forms each layer may become high gradually from a 1st layer to a 3rd layer. In this case, if the third layer is a surface layer, the surface strength of the dry nonwoven fabric can be increased extremely effectively, the wear resistance on the surface can be improved, and high durability can be realized.
Furthermore, the nonwoven fabric sheet is formed so that the fineness of the dry nonwoven fabric forming each layer gradually decreases from the first layer to the third layer. In this case, in the nonwoven fabric sheet, it is easy to increase the fiber density from the first layer to the third layer.

The invention according to claim 2 is the invention according to claim 1, wherein the total thickness of the first dry nonwoven fabric, the second dry nonwoven fabric, and the third dry nonwoven fabric is in the range of 1 to 8 mm. The gist is that it is set.
If it is set as this structure, since thickness is set to the range of 1-8 mm, sufficient compression recovery property and cushioning properties can be given to a nonwoven fabric sheet.

The invention according to claim 3 is the invention according to claim 1 or 2 , wherein the heat-bonding fiber is blended in each of the first dry nonwoven fabric, the second dry nonwoven fabric, and the third dry nonwoven fabric. The gist is that the amount is 15% by weight or more and less than 50% by weight.
If it is set as this structure, since the compounding quantity of a heat-fusion fiber is set to 15 to 50 weight%, the fibers which comprise a nonwoven fabric sheet can be adhere | attached firmly.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the second press surface is made of metal, and the second press surface is heated in the pressing process. The gist is to do.

ADVANTAGE OF THE INVENTION According to this invention, while performing the disposal process after use, the nonwoven fabric sheet for mat | mattes which exhibits the outstanding compression recovery property and cushioning property can be manufactured .

Hereinafter, an embodiment embodying the present invention will be described in detail. In the following description, “%” represents “% by weight”.
The nonwoven fabric sheet of embodiment is comprised with the dry-type nonwoven fabric formed by containing the cellulosic fiber as a main fiber, and the heat-fusion fiber as a binder fiber. Since this dry nonwoven fabric contains 50% or more of the above-mentioned cellulosic fibers, it can be handled as paper (paper display) and can be disposed of as a combustible material. Is easy to dispose of. Furthermore, since this dry nonwoven fabric has a fiber density set within the range of 0.02 to 0.10 g / cm ³ , it can exhibit excellent compression recovery and cushioning properties. . Furthermore, in the dry nonwoven fabric, fine surface properties can be obtained by setting the fiber density within a range of 0.02 to 0.10 g / cm ³ . From this, it becomes possible to print clearly on the surface of a dry-type nonwoven fabric, the design property and design property can be improved, and the commercial value of a nonwoven fabric sheet can be improved.

  The compression recoverability means the ease of recovery when the dry nonwoven fabric recovers to its original thickness after the dry nonwoven fabric is compressed by applying a load and the load is removed. The cushioning property means the ease of repulsion when a dry nonwoven fabric is compressed by applying a load. Here, the compression elastic modulus is used as an index representing cushioning properties.

  As the cellulosic fibers, cellulose fibers such as pulp, kenaf and bagasse or regenerated cellulose fibers such as rayon are preferably used. These cellulosic fibers are fibers obtained from plants as raw materials, and when burned, the amount of combustion gas generated is small and the amount of combustion heat is small, so that it can be disposed of as a combustible material. Cellulosic fibers are natural materials made from plants, and therefore have characteristics that are gentle to the skin. Cellulosic fibers are materials that are highly hygroscopic and generate little static electricity.

  The blending amount of the cellulosic fibers in the dry nonwoven fabric is preferably 50 to 85%, more preferably 60 to 85%, still more preferably 70 to 80%. When the blending amount of the cellulosic fibers is less than 50%, the amount of generated combustion gas and the amount of combustion heat are increased during the incineration process, so that the dry nonwoven fabric cannot be easily disposed of. On the contrary, when the blending amount of the cellulosic fibers exceeds 85%, the fiber web cannot be firmly heat-sealed due to a decrease in the blending amount of the heat-sealing fibers.

  As the heat-fusible fiber, a chemical fiber made of a thermoplastic resin is used, which is excellent in chemical resistance and thermal processability, and does not generate contaminants even when incinerated, so that it is a polyester fiber such as polyethylene terephthalate (PET) fiber, or Polyolefin fibers such as polyethylene fibers and polypropylene fibers are preferably used. As the heat-sealable fiber, a core-sheath type composite fiber is particularly preferably used because it maintains the fiber shape even after fusion and contributes to compression recovery. Examples of the core-sheath type composite fiber include a core portion made of polypropylene or polyester and a sheath portion made of a material (polyethylene or the like) having a melting point lower than that of the core portion, or a core portion made of polyethylene terephthalate. And what was comprised by the sheath part which consists of a polyethylene terephthalate whose melting | fusing point is lower than a core part etc. are mentioned. Moreover, you may use the composite fiber comprised by two types of chemical fiber which has a semicircular cross section and a different melting | fusing point as said heat-fusion fiber. These heat-sealing fibers are preferably crimped into a spiral shape in order to improve the cushioning property of the dry nonwoven fabric.

  The blending amount of the heat-sealing fiber in the dry nonwoven fabric is preferably 15% or more and less than 50%, more preferably 15 to 40%, and still more preferably 15 to 30%. When the blending amount of the heat-sealing fibers is less than 15%, the fiber web cannot be firmly bonded by the heat-sealing fibers. Conversely, if the amount of heat-bonded fibers is 50% or more, the amount of combustion gas generated and the amount of combustion heat will increase during incineration, so that the disposal of dry nonwoven fabric can be performed easily. Disappear.

  The thickness of the dry nonwoven fabric is preferably 1 to 8 mm, more preferably 2 to 5 mm, in order to improve the compression recovery property and cushioning property. When the thickness is less than 1 mm, the dry nonwoven fabric cannot have sufficient compression recovery and cushioning properties. On the other hand, when the thickness exceeds 8 mm, the thickness of the dry nonwoven fabric becomes too large, so that the compression recovery property and cushioning property may be impaired.

  As shown in FIG. 1, the nonwoven fabric sheet 11 of the embodiment is formed into a sheet shape by laminating the above dry nonwoven fabric, floor surface of entrance, kitchen, toilet, washroom, stairs, etc., living room sofa and car Used by laying on the laying surface of sheets, carpets, etc. The nonwoven fabric sheet 11 is formed by integrally laminating a first layer 12, a second layer 13, and a third layer 14, and does not peel at the boundary between adjacent layers.

  When the nonwoven fabric sheet 11 is laid on the laying surface, the first layer 12 is arranged on the back surface side in contact with the laying surface, and the third layer 14 is arranged on the surface side. Anti-slip means such as anti-slip members and anti-slip sheets are provided on the back surface of the first layer 12 as necessary. Examples of the anti-slip means include adhesive tape, rubber, soft resin, and the like.

  The 1st layer 12 is comprised by the 1st dry nonwoven fabric comprised similarly to the said dry nonwoven fabric. That is, the first dry nonwoven fabric is blended with the first fiber composed of the heat-sealing fiber and 50% or more of the first cellulosic fiber.

  The 2nd layer 13 is comprised by the 2nd dry nonwoven fabric comprised similarly to the said dry nonwoven fabric. That is, the second dry nonwoven fabric is blended with the second fiber composed of the heat-sealing fiber and 50% or more of the second cellulosic fiber. The fiber density of the second dry nonwoven fabric is preferably set higher than that of the first dry nonwoven fabric. In addition, the fineness of the second fiber blended in the second dry nonwoven fabric is the first fiber blended in the first dry nonwoven fabric so that the fiber density in the second layer 13 is higher than that in the first layer 12. It is preferable that the fineness of the fiber is smaller.

  The 3rd layer 14 is comprised by the 3rd dry-type nonwoven fabric comprised similarly to the said dry-type nonwoven fabric. That is, the third dry nonwoven fabric is blended with a third fiber composed of a heat-sealing fiber and 50% or more of a third cellulosic fiber. The fiber density of the third dry nonwoven fabric is preferably set higher than that of the second dry nonwoven fabric. Further, the fineness of the third fiber blended in the third dry nonwoven fabric is the second fineness blended in the second dry nonwoven fabric so that the fiber density in the third layer 14 is higher than that in the second layer 13. It is preferable that the fineness of the fiber is smaller.

  Thus, the nonwoven fabric sheet 11 is comprised so that the fiber density of the 1st, 2nd, 3rd dry nonwoven fabric which comprises each layer 12-14 may become high as it goes to the surface side from the back surface side. That is, the nonwoven fabric sheet 11 is configured so that a gradient of fiber density occurs in a stepwise manner in the thickness direction. In this case, on the surface side of the nonwoven fabric sheet 11, the third layer 14 made of the third dry nonwoven fabric having the highest fiber density is laminated, thereby effectively increasing the surface strength of the nonwoven fabric sheet 11.

  Moreover, the nonwoven fabric sheet 11 is comprised so that the fineness of the fiber mix | blended with the 1st, 2nd, 3rd dry nonwoven fabric which comprises each said layers 12-14 may become thin as it goes to the surface side from the back surface side. It is preferable. At this time, the nonwoven fabric sheet 11 is comprised so that the gradient of the fineness may arise in the thickness direction. In this case, the 3rd layer 14 laminated | stacked on the surface side of the nonwoven fabric sheet 11 is comprised by the 3rd dry-type nonwoven fabric with which the 3rd fiber with the finest fineness was mix | blended, Thereby, the fiber density of this nonwoven fabric sheet 11 is comprised. Increased even more effectively.

  Furthermore, it is preferable that an antibacterial agent is added to at least one dry nonwoven fabric selected from the first, second and third dry nonwoven fabrics constituting the layers 12 to 14. In this case, the non-woven fabric sheet 11 is suppressed by the antibacterial agent from propagation of germs and the generation of off-flavors. Examples of the antibacterial agent include silver-based, copper-based, calcium-based, sulfur-based, and chlorine-based inorganic antibacterial agents.

Next, the manufacturing method of the said nonwoven fabric sheet 11 is demonstrated.
As schematically shown in FIG. 2, the manufacturing apparatus 20 a includes a mesh-like first conveyor 21 and a second conveyor 22 that carry the fiber web constituting the nonwoven fabric sheet 11 while placing them, and the first and second conveyors. And a first press working portion 23 as press working means disposed between the conveyors 21 and 22. Further, in the manufacturing apparatus 20a, a hot air dryer 24 is disposed in front of the second conveyor 22 (traveling direction), and a second press as a press working means is provided in front of the hot air dryer 24. A processing unit 25 is provided.

  Above the first conveyor 21, a plurality of duct openings 31a, 31b, 31c for discharging the fibers 30a, 30b, 30c constituting the nonwoven fabric sheet 11 onto the first conveyor 21 are provided. . Here, in the fibers 30a, 30b, and 30c, a cellulose-based fiber as a main fiber and a heat-sealing fiber as a binder fiber are blended in a predetermined blending ratio. Directly below each duct opening 31a, 31b, 31c, fibers 30a, 30b, 30c discharged from the duct openings 31a, 31b, 31c by air suction are gathered in layers on the first conveyor 21, and a fiber web 32a. , 32b, 32c are provided with suction machines 33a, 33b, 33c, respectively. In this case, the fiber webs 32a, 32b, and 32c are formed by an airlaid method that is a method of dispersing the fibers 30a, 30b, and 30c in the air. In front of the duct opening 31c, a nozzle 37 for spraying a binder for bonding the fibers 30a, 30b, and 30c is disposed downward.

  The first press working part 23 includes a pair of upper press rolls 23a and lower press rolls 23b each formed in a horizontal cylindrical shape, and is layered between the upper and lower press rolls 23a and 23b. The fiber webs 32a, 32b, and 32c thus formed are sandwiched and pressed in the vertical direction. Further, in the first press working portion 23, the outer peripheral surface (first press surface) of the upper press roll 23a is made of a soft material such as rubber, silicone, thermoplastic elastomer, and the outer peripheral surface (second press surface) of the lower press roll 23b. The press surface is made of a hard material such as a synthetic resin or metal excluding the thermoplastic elastomer. The soft material has plasticity, and the hard material does not have plasticity. The second press surface of the lower press roll 23b is preferably configured to be heated to a predetermined temperature. In this case, the press surface is mainly composed of a metal material. In front of the first press working portion 23, a nozzle 38 for spraying the binder is disposed upward. Examples of the binder sprayed from the nozzles 37 and 38 include acrylic, polyvinyl alcohol, vinyl acetate, and synthetic rubber.

  The second press working part 25 is configured in the same manner as the first press working part 23. That is, the second press working section 25 includes an upper press roll 25a made of a soft material and a lower press roll 25b made of a hard material, and a fiber web 32a between the upper and lower press rolls 25a and 25b. , 32b, 32c are sandwiched and pressed up and down. Moreover, it is preferable that the outer peripheral surface (second press surface) of the lower press roll 25b is configured to be heated to a predetermined temperature.

  When manufacturing the nonwoven fabric sheet 11 having a layered structure using the manufacturing apparatus 20a, first, fibers 30a constituting the third, second, and first dry nonwoven fabrics from the duct openings 31a, 31b, and 31c, respectively. 30b and 30c are discharged. And the 3rd fiber web 32a, the 2nd fiber web 32b, and the 1st fiber web 32c are formed in a sheet form on the 1st conveyor 21, laminating sequentially.

  Subsequently, after the fiber webs 32a, 32b, and 32c are transported in a stacked state on the first conveyor 21, the fiber webs 32a, 32b, and the like between the upper press roll 23a and the lower press roll 23b of the first press working unit 23 are transferred. The whole 32c is sent out to the second conveyor 22 while being crushed in the vertical direction.

  Next, when the fiber webs 32a, 32b, and 32c are fed into the hot air dryer 24 by the second conveyor 22, the heat-bonding fibers contained in the fiber webs 32a, 32b, and 32c are heated in the hot air dryer 24. Melt. When the heat-sealable fiber is the core-sheath type composite fiber, the sheath part is thermally melted so that the heat-sealable fiber and the cellulose fiber are bonded to each other, and the fibers 30a, 30b, 30c are bonded to each other to form a nonwoven fabric. A sheet 11 is formed. Finally, the nonwoven fabric sheet 11 is crushed again in the vertical direction between the upper and lower press rolls 25a, 25b of the second press working part 25, and the first layer 12, the second layer 13, and the third layer 14 The difference in fiber density between them is further emphasized.

  When the laminated fiber webs 32a, 32b, 32c are crushed between the upper and lower press rolls 23a, 23b of the first press working part 23, the third fiber web 32a side of the lower press roll 23b made of a hard material is used. It is crushed by the outer peripheral surface, and the first fiber web 32c side is crushed by the outer peripheral surface of the upper press roll 23a made of a soft material. For this reason, in the fiber webs 32a, 32b, and 32c in the laminated state, the crushing force to the first fiber web 32c applied from the upper press roll 23a is greatly reduced by the plasticity of the soft material, The crushing force toward the third fiber web 32a is not reduced. Therefore, in the fiber webs 32a, 32b and 32c after being crushed, the amount of compression in the vertical direction relative to the first fiber web 32c (first dry nonwoven fabric) is small, and the third fiber web 32a (third The amount of compression in the vertical direction with respect to the dry nonwoven fabric) is increased, and the fiber density of each of the fiber webs 32a, 32b, 32c is formed to be different depending on the amount of compression. Note that the second press working section 25 is similarly pressed. In these 1st and 2nd press work parts 23 and 25, when pressing while heating the 2nd press surface of lower press rolls 23b and 25b at about 100-200 ° C, plastic deformation of fiber 30a by heating is carried out. Since it is easily promoted, the fiber density of the third dry nonwoven fabric that is crushed while coming into contact with the second press surface is further increased.

The effects exhibited by the above embodiment will be described below.
-Since the nonwoven fabric sheet 11 is set in the range whose fiber density is 0.02-0.10 g / cm < ³ >, it can exhibit the outstanding compression recovery property and cushioning properties. That is, the nonwoven fabric sheet 11 can exhibit an appropriate cushioning property when a person walks or sits on the nonwoven fabric sheet 11, and can quickly recover the thickness once compressed. Moreover, since the dry-type nonwoven fabric which comprises the nonwoven fabric sheet 11 contains 50% or more of cellulosic fibers, it can be handled as paper (paper indication). Furthermore, since the fine surface properties can be obtained by setting the fiber density within the range of 0.02 to 0.10 g / cm ³ , it becomes possible to print clearly on the surface of the nonwoven fabric sheet 11. Therefore, the design property and design property of the nonwoven fabric sheet 11 can be improved, and a commercial value can be improved. Moreover, the nonwoven fabric sheet 11 is easy to handle because it is mainly composed of cellulose fibers that are rich in hygroscopicity and generate little static electricity.

  -The dry-type nonwoven fabric which comprises the nonwoven fabric sheet 11 contains 15% or more and less than 50% of heat-sealing fibers. For this reason, the nonwoven fabric sheet 11 can raise the whole intensity | strength by a fiber web being adhere | attached firmly.

  -Since the nonwoven fabric sheet 11 is comprised so that the fiber density of the dry nonwoven fabric which comprises each layer 12-14 may become high as it goes to the surface side from a back surface side, the surface strength can be raised. For this reason, the nonwoven fabric sheet 11 can improve the durability on the surface where wear occurs between clothes, pants, and the like when a person walks or sits on the nonwoven fabric sheet 11.

  -The nonwoven fabric sheet 11 is comprised so that the fineness of the fiber mix | blended with the 1st, 2nd, 3rd dry nonwoven fabric which comprises each said layers 12-14 may become thin as it goes to the surface side from the back surface side. Yes. In this case, since the surface strength of the nonwoven fabric sheet 11 is further effectively increased, the durability on the surface can be further improved. Furthermore, at this time, since the first layer 12 is easily recessed and the third layer 14 is not easily recessed, the appearance quality of the nonwoven fabric sheet 11 is not easily impaired.

  -Since the antibacterial agent is added to at least one dry nonwoven fabric selected from the first, second and third dry nonwoven fabrics constituting each layer 12 to 14, the propagation of various germs can be suppressed, and the off-flavor Occurrence can be suppressed. For this reason, the nonwoven fabric sheet 11 can also be used cleanly over a long period of time.

  -In the 1st and 2nd press work parts 23 and 25, the outer peripheral surface of upper press roll 23a, 25a is comprised with the soft material, and the outer peripheral surface of lower press roll 23b, 25b is comprised with the hard material. For this reason, the third fiber web 32a (third dry nonwoven fabric) has a large amount of compression in the vertical direction, and the fiber density of the third layer 14 is effectively increased. Further, by pressing while heating the second press surfaces of the lower press rolls 23b and 25b, plastic deformation of the fiber 30a by heating is promoted, so that the fiber density of the third layer 14 is effectively increased. Can do.

Hereinafter, test examples and comparative examples embodying the embodiment will be described.
The test samples of Test Examples 1 to 8 and Comparative Examples 1 to 3 shown in Table 1 were manufactured by the manufacturing method of the above embodiment using the nonwoven sheet manufacturing apparatus 20a shown in FIG. The chemical fiber mixing ratio (%) in Table 1 indicates the blending ratio of the heat-sealing fibers. Here, pulp was used as the cellulosic fiber, and a core-sheath type composite fiber composed of a core part made of polypropylene and a sheath part made of polyethylene was used as the heat-sealing fiber. In each test example and comparative example, a test sample having a three-layer structure is formed as shown in the above embodiment, and the fiber density and the fineness of the dry nonwoven fabric from the first layer to the third layer are the same. Formed.

  The basis weight shown in Table 1 was determined using a weight scale (Electronic Balance EK-120 manufactured by A & D Co., Ltd.). The thickness was measured by using a thickness meter (Peacock Direct Reading Digital Linear Gauge PDN-12 manufactured by Ozaki Mfg. Co., Ltd.). Various tests were performed using the test samples thus obtained. Table 1 shows the test results of various tests. Table 2 shows criteria for determining test results of various tests.

  For compression recovery, first, a test sample of 10 cm × 10 cm was prepared, and left for 18 hours with a 3 kg weight placed on the test sample (pressurization), then the weight was removed (open), 60 minutes The thickness of the test sample after the lapse was measured and obtained by dividing the thickness by the thickness before pressing. And based on the criterion shown by Table 2, the compression recoverability of each test sample was evaluated. After removing the weight, the thickness of the test sample after 1, 5, 10, 20, 30, 60 minutes was measured at the same time, and the measurement result is shown in FIG. Further, the thickness recovery rate (%) after 1, 5, 10, 20, 30, and 60 minutes has been calculated, and the result is shown in FIG. The thickness recovery rate (%) was calculated as a value obtained by dividing the thickness of the test sample after removing the weight by the thickness of the test sample before placing the weight.

  About the cushioning property, compression elastic modulus was calculated | required using KES-G5 of the handy compression tester made from Kato Tech, and this compression elastic modulus was made into the index which shows the cushioning property of each test sample. As for the surface strength, CAT-124 (universal type method) of a castor fabric abrasion tester manufactured by Daiei Chemical Seiki Co., Ltd. is used. L-1096. It measured by A-1 (plane method). As a measurement method, a test sample formed in a predetermined shape is placed on a rubber table, the surface of the test sample is rubbed in multiple directions with abrasive paper, and the number of frictions until a hole is opened in the test sample is measured. did. The number of frictions at this time was used as an index indicating the surface strength of each test sample.

図３（ａ）に示すように、試験サンプルの厚みは、重りにより加圧されることで小さくなり、重りを取り除き加圧から開放することで徐々に回復する。このとき、加圧開放直後、試験サンプルの厚みは速やかに回復するが、時間の経過に伴い厚みの回復が徐々に鈍くなる。

As shown in FIG. 3 (a), the thickness of the test sample is reduced by being pressurized by the weight, and gradually recovered by removing the weight and releasing from the pressure. At this time, immediately after releasing the pressure, the thickness of the test sample quickly recovers, but the recovery of the thickness gradually decreases with time.

As shown in FIG. 3B, the first group consisting of the test results of Test Example 1 and Comparative Example 1, the second group consisting of the test results of Test Example 2, Test Examples 3 to 8, and Comparative Examples 2 and 2 It is classified into a third group consisting of 3 test results. The first group test results yielded only a compression recovery rate of less than 70%, the second group test results yielded a compression recovery rate of 70-80%, and the third group test results yielded a compression rate of 80% or more. A recovery rate was obtained. In this case, from the density shown in Table 1 and the compression recovery rate shown in FIG. 3B, in order to obtain a high compression recovery property of the dry nonwoven fabric, the density is set to 0.023 g / cm ³ or more. Is preferable, and is more preferably set to 0.030 g / cm ³ or more.

As shown in Table 1, when the compression recoverability of each test example and comparative example is determined based on the determination criteria shown in Table 2, good results are obtained in the test samples of Test Examples 2 to 8 and Comparative Examples 2 and 3. was gotten. Next, when the cushioning properties were determined, good results were obtained with the test samples of Test Examples 2 to 7. Subsequently, when the surface strength was determined, good results were obtained with the test samples of Test Examples 3 to 7 and Comparative Examples 1 and 2. As described above, according to the comprehensive evaluation obtained from the results of compression recovery property, cushioning property, and surface strength, it is preferable that the fiber density of the dry nonwoven fabric is set within a range of 0.02 to 0.10 g / cm ³ , It has been found that it is more preferable to set it within the range of 0.025 to 0.080 g / cm ³ .

  Using these results, the relationship between the density and the thickness recovery rate, the relationship between the density and the cushioning property, the relationship between the density and the surface strength, and the relationship between the thickness and the surface strength were examined. Good results were obtained with the test samples 1 to 9, and good results were not obtained with the test samples of Comparative Examples 1 to 3.

  Test samples of Test Example 9 and Comparative Examples 4 and 5 shown in Table 3 were manufactured by the manufacturing method of the above embodiment using the nonwoven fabric sheet manufacturing apparatus 20a shown in FIG. The chemical fiber mixing ratio (%) in Table 2 indicates the blending ratio of chemical fibers (including heat-bonded fibers). In the test samples of Test Example 9 and Comparative Example 4, the surface-side layer is formed of pulp and 6.6 to 20 dtex heat-sealing fibers, and the layers other than the surface side are formed of pulp and 1.7 to 2.2 dtex. Of the heat-sealing fiber. In the test sample of Comparative Example 5, the surface side layer is composed of pulp and 6.6 to 20 dtex polypropylene, and the layers other than the surface side are composed of pulp and 1.7 to 2.2 dtex polypropylene. These were formed by adhering with a binder. Here, the numerical values in parentheses shown in Table 2 indicate the blending ratio of the binder. In addition, a binder shall be discharged to a fiber web from the nozzles 37 and 38 of the manufacturing apparatus 20a shown by FIG. 2 in the manufacturing process of each test sample. Since the test samples of Test Example 9 and Comparative Examples 4 and 5 are the same as Example 1 with respect to the configuration other than the chemical fiber and the binder, description thereof will be omitted below.

表３に示すように、試験例９の試験サンプルでは、圧縮回復性、クッション性、表面強度のいずれにおいても良好な結果を得ることができた。特に、表面強度について、試験例９では、高い表面強度を得ることができた。このことから、表面側の層を繊度の太い化学繊維で構成することは、乾式不織布を不織布シート１１として使用する場合、表面強度を効果的に高めることができ、耐摩耗性を向上させるのに有利である。尚、比較例４、５では、紙表示することができない。

As shown in Table 3, in the test sample of Test Example 9, good results could be obtained in any of compression recovery property, cushioning property, and surface strength. In particular, with respect to the surface strength, in Test Example 9, high surface strength could be obtained. From this, it is possible to effectively increase the surface strength and improve the wear resistance when the dry nonwoven fabric is used as the nonwoven fabric sheet 11 by configuring the surface side layer with chemical fibers having a large fineness. It is advantageous. In Comparative Examples 4 and 5, paper cannot be displayed.

In addition, this embodiment can also be changed and embodied as follows .

· Nonwoven sheet 11, the gradient of the fiber density may be configured to occur continuously in the thickness direction. Moreover, the nonwoven fabric sheet 11 may be comprised with the dry-type nonwoven fabric which thickness is less than 1 mm or exceeds 8 mm according to the utilization form.

  -In the manufacturing process of the nonwoven fabric sheet 11, you may form the nonwoven fabric sheet 11 by spraying a binder on the fiber webs 32a, 32b, 32c from the nozzles 37,38. If it does in this way, when the quantity of the heat sealing | fusion fiber contained in a dry-type nonwoven fabric is decreased, cellulose fibers can be adhere | attached reliably. Moreover, when a heat-fusion fiber is abbreviate | omitted, you may form the nonwoven fabric sheet 11 by adhere | attaching cellulose fibers with a binder. Furthermore, you may form the nonwoven fabric sheet 11 by adhere | attaching a cellulose fiber and a chemical fiber with a binder.

-After forming each layer 12-14 separately by the airlaid method, you may manufacture the nonwoven fabric sheet 11 by bonding each layer 12-14.
-In the manufacturing apparatus 20a, you may comprise the outer peripheral surface of the upper press rolls 23a and 25a with a hard material. Even in this case, since the fibers 30a, 30b, and 30c having different finenesses are discharged from the duct openings 31a, 31b, and 31c, the nonwoven fabric sheet 11 is formed so as to have a fiber density gradient in the thickness direction. It becomes possible.

Further, the technical idea that can be grasped from the embodiment will be described below.
-It is a manufacturing method of the nonwoven fabric sheet of any one of Claims 1-3, Comprising: It has the process of pressing the fiber web which comprises the said dry-type nonwoven fabric, At the time of this process, one side of the said fiber web A method for producing a non-woven fabric sheet, characterized in that is in contact with a first press surface made of a soft material and the other surface of the fiber web is in contact with a second press surface made of a hard material.

  -The manufacturing method of the nonwoven fabric sheet of Claim 4 or 5, Comprising: The 1st fiber web which comprises a 1st dry-type nonwoven fabric, the 2nd fiber web which comprises a 2nd dry-type nonwoven fabric, and 3rd A step of pressing in a state of being laminated with a third fiber web constituting the dry nonwoven fabric of the first, while the surface of the third fiber web is in contact with the first press surface made of a soft material, A method for producing a non-woven fabric sheet, characterized in that the surface of the fiber web is in contact with a second press surface made of a hard material.

The fiber density of each of the first, second and third dry nonwoven fabrics is set within a range of 0.02 to 0.10 g / cm ³ , according to claim 4 or 5 Nonwoven sheet.

Sectional drawing which shows the nonwoven fabric sheet of this embodiment typically. The schematic diagram which shows the manufacturing apparatus of the nonwoven fabric sheet of this embodiment. (A) is a graph which shows the change of the thickness of a nonwoven fabric sheet, (b) is a graph which shows the thickness recovery rate of a nonwoven fabric sheet. Sectional drawing which shows the nonwoven fabric sheet of a modification typically.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Nonwoven fabric sheet, 12 ... 1st layer, 13 ... 2nd layer, 14 ... 3rd layer, 30a, 30b, 30c ... Fiber.

Claims (4)

Containing cellulosic fibers and heat-sealing fibers ,
The cellulosic fiber is blended in an amount of 50% by weight or more, and is composed of a dry nonwoven fabric in which the fiber density is set in the range of 0.02 to 0.10 g / cm ³ ,
The first layer composed of the first dry nonwoven fabric, the second layer composed of the second dry nonwoven fabric, and the third layer composed of the third dry nonwoven fabric are laminated in layers,
The first dry nonwoven fabric is blended with the first fiber, the second dry nonwoven fabric is blended with the second fiber having a fineness smaller than the first fiber, and the third dry nonwoven fabric is When the third fiber having a fineness smaller than that of the second fiber is blended, the first layer has a fiber density lower than that of the second layer, and the third layer has a fiber density higher than that of the second layer. A method for producing a non-woven fabric sheet for mat,
The first dry nonwoven fabric, the second dry nonwoven fabric and the third dry nonwoven fabric are provided with a step of pressing in a laminated state, and in the pressing step, the surface of the first dry nonwoven fabric is made of a soft material. A method for producing a non-woven fabric sheet for mats , characterized in that the surface of the third dry nonwoven fabric is brought into contact with a second press surface made of a hard material while being brought into contact with the first press surface . 2. The nonwoven fabric sheet according to claim 1, wherein the total thickness of the first dry nonwoven fabric, the second dry nonwoven fabric, and the third dry nonwoven fabric is set in a range of 1 to 8 mm. Production method. The blending amount of the heat-sealing fibers in each of the first dry nonwoven fabric, the second dry nonwoven fabric, and the third dry nonwoven fabric is 15 wt% or more and less than 50 wt%. Item 3. A method for producing a nonwoven fabric sheet according to Item 2. The method for producing a nonwoven fabric sheet according to any one of claims 1 to 3, wherein the second press surface is made of metal, and the second press surface is heated in the step of pressing .

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