WO2013129666A1

WO2013129666A1 - Drip sheet

Info

Publication number: WO2013129666A1
Application number: PCT/JP2013/055739
Authority: WO
Inventors: 直人竹内
Original assignee: ユニ・チャーム株式会社
Priority date: 2012-03-02
Filing date: 2013-03-01
Publication date: 2013-09-06
Also published as: JPWO2013129666A1; JP6214522B2

Abstract

Provided is a drip sheet that offers an improvement over the prior art by having a required liquid absorption amount, by being relatively thin, and by the core side and the outer side of the wound drip sheet not suffering large differences in liquid absorption amount when the drip sheet is wound up into a roll. The drip sheet (10) has an upper layer (13) and a lower layer (14). The upper layer (13) includes at least heat-fusible fibers and is formed from fibrous non-woven fabric, the heat-fusible fibers of said fibrous non-woven fabric being heat sealed. The lower layer (14) is formed from fibrous non-woven fabric that includes at least hydrophilic fibers. The mass of the lower layer is approximately 30-100 g/m², and the liquid absorption amount difference between the core side (31) and the outer side (32) of a wound roll (30) of the drip sheet (10) is 400 g/m² or less.

Description

Drip sheet

The present invention relates to a drip sheet suitable for absorbing a drip that exudes from meat or the like.

Conventionally, drip sheets for absorbing drip oozing out from small pieces of fresh food such as fish fillets and beef placed in a tray made of polystyrene foam are generally known. For example, Patent Document 1 discloses a drip sheet having a two-layer structure in which a non-liquid-absorbing plastic sheet having an upper layer having a plurality of openings and a lower layer comprising a liquid-absorbing fiber nonwoven fabric sheet.

JP 2003-267455 A

According to the drip sheet disclosed in Patent Document 1, the drip oozed from fish meat or the like can be quickly moved downward through a plurality of openings formed in the upper plastic film, and the lower layer fiber nonwoven fabric. The drip can be absorbed and held by the sheet.

However, the upper layer is formed from a non-liquid-absorbing plastic film, and it is necessary to absorb the drip only with the lower layer nonwoven fabric sheet. Therefore, in order to absorb a certain amount of drip, the lower layer has a required thickness. It is necessary to use the fiber nonwoven fabric sheet which has. In such a case, in the state where the drip sheet is rolled up, the diameter of the roll becomes large, and the core side portion of the original fabric is considerably compressed compared to the outside of the roll, and the required liquid absorption performance can be exhibited. However, there is a risk that the product performance may vary between the outer winding side and the winding core side. On the other hand, in order to avoid such a situation, when the roll length and the diameter of the roll are reduced, the roll is manufactured and transported by being divided into a plurality of rolls, so that the production cost and the transport cost are increased.

An object of the present invention is an improvement of the conventional technique, which has a required liquid absorption amount, is relatively thin, and has a liquid absorption amount between the core side and the outer winding side in a state of being rolled up. It is to provide a drip sheet that does not cause a large difference.

In order to solve the above problems, the present invention has an upper surface and a lower surface and a thickness direction therebetween, and a liquid-permeable and liquid-absorbing upper layer and a liquid-absorbing property bonded to the upper layer. A drip sheet including a lower layer of the sheet.

A feature of the present invention is that the upper layer includes at least a heat-fusible fiber, the heat-fusible fiber is formed from a fiber nonwoven fabric that is heat-sealed to each other, and the lower layer is formed from a fiber nonwoven fabric that includes at least a hydrophilic fiber. The lower layer has a mass of about 30 to 100 g / m ² , and the maximum liquid absorption difference is 400 g / m ² between the core side and the outer side of the roll formed by winding the drip sheet. It is.

The drip sheet according to the present invention can absorb a required amount of drip without relatively increasing the thickness of the lower layer because the upper and lower layers are formed of a liquid nonwoven fabric having liquid absorbency. Therefore, in the state where the drip sheet is wound in a roll shape, the core side is not excessively compressed as compared with the outer side, and there is a relatively large difference in liquid absorption between the core side and the outer side. And there is no risk of variations in the product.

The perspective view of the drip sheet concerning the embodiment of the present invention. FIG. 2 is a schematic sectional view taken along line II-II in FIG. 1. The elements on larger scale enclosed with the III line of FIG. The perspective view of the roll of the state which wound the drip sheet. The figure which shows an example of the usage example of a drip sheet. The graph which shows the correlation with the difference of the amount of liquid absorption of the mass of a lower layer, and the roll outer side and core side of a drip sheet in each Example and each comparative example.

1-3, the drip sheet 10 has a thickness direction Z and includes an upper surface 11, a lower surface 12, an upper layer 13, and a lower layer 14. The upper layer 13 and the lower layer 14 are joined to each other via a hydrophobic or hydrophilic adhesive portion 15 which is a known adhesive means such as a hot melt adhesive.

The upper layer 13 can be formed from a known hydrophobic fiber nonwoven fabric such as an air-through fiber nonwoven fabric, a spunlace fiber nonwoven fabric, or a spunbond fiber nonwoven fabric. The air-through fiber nonwoven fabric, which is one of the materials of the upper layer 13, is manufactured by a known air-through method. In the air-through method, a fiber web such as a card web is placed on a net and hot air is blown from above. It is a method of forming into a sheet form partially by spraying, that is, by thermally fusing the intersections of the constituent fibers 18. The air-through fiber nonwoven fabric formed by such a method has a spray surface on which fibers gather relatively sparsely and a net surface that is a fiber support surface on which fibers gather relatively densely. In the drip sheet 10 according to the present invention, the upper layer 13 is disposed such that the upper surface 11 side is a net surface and the lower surface 12 side is a spray surface.

As the constituent fibers 18 of the air through fiber nonwoven fabric of the upper layer 13, staple fibers made of a hydrophobic thermoplastic synthetic resin can be preferably used. For example, polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE) Further, a core-sheath type composite fiber made of these can be used. The composite fiber has a fineness of 1 to 6 dtex and a fiber length of 30 to 70 mm, and the thermoplastic synthetic resin forming the sheath part has a lower melting temperature than the thermoplastic synthetic resin forming the core part. The Further, the rigidity of the entire upper layer 13 may be increased by using a thermoplastic synthetic resin that forms the core portion that has a higher elastic modulus than the thermoplastic synthetic resin that forms the sheath portion. Examples of the core-sheath type composite fiber include polyethylene and polypropylene, polyethylene and polyester, polypropylene and polyester, and a combination of polyethylene terephthalate and polyethylene. As long as the effects described later of the present invention are exhibited, the upper layer 13 may be formed of an air-through fiber nonwoven fabric having a structure of two or more layers, or may have different fiber diameters of fibers constituting each layer. Further, the upper layer 13 may partially include hydrophilic (hygroscopic, water-absorbing) fibers such as rayon in order to improve the liquid absorption.

The lower layer 14 is an airlaid pulp fiber non-woven fabric made of hydrophilic fibers. As a raw material, the constituent fiber 19 which is a pulp fiber having an average fiber length of about 1.0 to 10.0 mm can be preferably used. In addition to wood pulp fibers of softwood (preferably softwood), plant fibers other than wood can be mixed with wood pulp fibers as hydrophilic fibers. In order to improve the absorption performance of the lower layer 14, a hydrophilic enhancement treatment may be performed. For the lower layer 14, for example, an adhesive-type airlaid pulp fiber nonwoven fabric obtained by bonding separated constituent fibers 19 using a hydrophilic adhesive, for example, an acrylic ester (PVA) resin as a binder can be used. The adhesive-type airlaid pulp fiber nonwoven fabric is deposited, for example, by applying a negative pressure to the lower surface of the transport net belt and dispersing hydrophilic short fibers such as pulverized pulp on the net belt while being dispersed by an air flow. (PVA-based) It can be produced by spraying an adhesive. In such a case, as the constituent fibers 19 of the lower layer 14, for example, 5 to 30% by mass of a hydrophobic fiber (synthetic fiber) having a fiber length of 1 to 15 mm is mixed with the hydrophilic fiber as long as the required absorption performance is obtained. It may be. In order to bond the constituent fibers 19 to each other, instead of the adhesive, the fibers can be entangled with each other by a fluid, preferably a jet of water.

The adhesive portion 15 is formed by applying a hydrophobic or hydrophilic hot melt adhesive having a mass of about 1.5 to 2.5 g / m ² to the lower surface of the upper layer 13 and / or the upper surface of the lower layer 14 in the form of dots. . The hot melt adhesive forming the bonding portion 15 may be applied in various known patterns such as a straight shape, a wavy shape, a spiral shape, and a lattice shape in addition to the dotted shape. However, when the adhesive 15 is hydrophobic, it is preferably not applied to the entire facing surface of the upper layer 13 or the lower layer 14 in order not to inhibit the movement of the drip from the upper layer 13 to the lower layer 14. Examples of the hydrophobic hot melt adhesive include those based on ethylene-vinyl acetate copolymer, polyethylene or polypropylene, and examples of the hydrophilic hot melt adhesive include PVA resin or acetic acid having a hydrophilic group. What uses vinyl-type resin as a base polymer can be used.

Referring to FIG. 2, the thickness dimension D1 of the drip sheet 10 is about 1.0 to 4.0 mm, the thickness dimension D2 of the upper layer 13 is about 0.4 to 2.0 mm, and the thickness dimension D3 of the lower layer 14 is about 0.8 to 3.6 mm. The mass of the upper layer 13 is about 20 to 40 g / m ² , the apparent density is about 0.01 to 0.1 g / cm ³ , the mass of the lower layer 14 is about 30 to 100 g / m ² , and the apparent density is about 0.00. 01 to 0.07 g / cm ³ . However, the thickness dimension D1 of the drip sheet 10 is preferably 2.5 mm at the maximum. A thickness measuring device (manufactured by PEACOCK, measuring surface φ44 mm, measuring pressure 3 g / cm ³ ) was used for measuring the thickness dimension of each layer. For convenience of explanation, the drip sheet 10 is divided into a first layer 20 that is an upper portion of the upper layer 13, a second layer 21 that is a lower portion of the upper layer 13, and a third layer 22 that is a lower layer 14.

The original fabric of the drip sheet 10 having such a configuration is usually stored in a state of being rolled up in a roll having a predetermined winding length in a manufacturing process and a food processing process of a retail store. Referring to FIG. 4, the drip sheet 10 is wound in a roll shape, and the roll 30 has a winding core side 31 and a winding outer side 32. In the present embodiment, the roll 30 is coreless, but may be wound around a core member made of paper or plastic. The roll 30 has a winding length of about 200 to 800 m, a width dimension of about 100 cm, and a diameter of about 80 to 120 cm.

A commercially available drip sheet is composed of a perforated plastic film and a liquid absorbing sheet located below the perforated plastic film. Since the perforated plastic film itself does not have a liquid absorbing property, only the lower liquid absorbing sheet is used. Plays the role of absorbing and holding the drip. Therefore, in order to realize the required amount of liquid absorption, it is necessary to increase the thickness of the lower liquid absorption sheet according to the amount of liquid absorption, which means that the roll of the liquid absorption sheet becomes bulky during production and use. There's a problem. In such a case, the core side portion of the roll on which the drip sheet is wound is pressed and the lower liquid-absorbing sheet is crushed, and the required liquid-absorbing performance may not be exhibited. As a result, the liquid absorption amount varies between the roll core side and the roll outer side, and the product performance cannot be made uniform.

In the case of this embodiment, since not only the lower layer 14 but also the upper layer 13 has a predetermined amount of liquid absorption, the entire drip sheet 10 and the lower layer 14 can be made relatively thin, and a required amount of drip sheet can be obtained. The diameter of the roll 30 formed by winding 10 can be made relatively small. Therefore, the portion on the core side 31 of the roll 30 is considerably compressed as compared with the outer side 32 and the volume is reduced and the amount of liquid absorption is not significantly reduced. There is no big difference in the liquid volume.

In order to achieve such an effect, it is preferable that the upper layer 13 has a liquid absorption amount of at least 500 g / m ² and an apparent density of at least 0.02 g / cm ³ . When the liquid absorption amount of the upper layer 13 is at least 500 g / m ² , the upper layer 13 absorbs the required amount of drip, so that the thickness dimension D3 of the lower layer 14 can be about 0.8 to 3.6 mm. . However, the thickness D1 of the entire sheet is preferably about 2.5 mm or less. When manufacturing the roll 30 having the same winding length as the roll 30 when the thickness dimension D3 of the lower layer 14 is increased, the diameter can be suppressed when the thickness dimension D3 of the lower layer 14 is within the above range, There is no possibility that the portion on the winding core side 31 is compressed more strongly than the winding outer side 32 and the liquid absorption performance is not lowered. The liquid absorption amount of the upper layer 13 depends on the apparent density value. When the apparent density is 0.02 g / cm ³ , the liquid absorption amount of the upper layer 13 is at least 500 g / m ² . In addition to being able to absorb and hold a required amount of drip, the density as an excessively high density is not impaired.

In the upper layer 13, as described above, in the manufacturing process of the air-through method, the net surface side made of fibers deposited on the net is the upper surface 11 side on which food is placed, and the hot air of the second layer 21 is blown to the fibers. As compared with the first layer 20, the number of the fusion-bonded portions 17 that are thermally fused is increased. Further, since the fibers are pressed against the net and restrained from each other on the net surface, the first layer 20 has a denser arrangement of fibers than the second layer 21, and a suction box or the like positioned below the net Therefore, the surface forming the upper surface 11 of the upper layer 13 is flatter than the surface facing the lower layer 14 of the upper layer 13. In the drip sheet 10 having such an aspect, when it is placed in a styrofoam tray and fresh food such as meat and vegetables is placed on the surface, the drip (blood juice) that exudes from the food is temporarily stored in the upper layer 13. In addition, the drip can be absorbed and held in the lower layer 14 by moving to the lower layer 14 through the interfiber gap. The liquid absorption amount of the upper layer 13 is about 500 to 1000 g / m ² , the liquid absorption amount of the lower layer 14 is about 1000 to 2000 g / m ² , and the lower layer 14 absorbs drip in an amount more than twice that of the upper layer 13. Can do.

In the drip sheet 10 of the present embodiment, not only the lower layer 14 but also the upper layer 13 has liquid absorbency, so that the thickness dimension of the entire drip sheet 10 can be suppressed even when the required amount of liquid absorption is required. The whole can be formed relatively thin. Thereby, the roll 30 does not become bulky when the drip sheet 10 and the lower layer 14 are manufactured and used. In particular, when the lower layer 14 has a thickness dimension greater than or equal to a predetermined thickness, the portion located on the core side 31 of the roll 30 is compressed to reduce the volume, and absorbs liquid compared to the portion located on the outer side 32. There is a risk that the amount will be reduced and the amount of liquid absorption will be uneven in each product. Further, the upper layer 13 is mainly made of hydrophobic fibers, the lower layer 14 is mainly made of hydrophilic fibers, and the former has a higher fiber density than the latter, so that liquid return to the upper layer 13 due to rewetting is suppressed. And prevent the food from coming into contact with the drip again.

When the drip sheet 10 is formed only from an airlaid pulp fiber nonwoven fabric, the surface has a undulating form in which large and small irregularities are repeated, and there is a possibility that the surface of the food is damaged and drip is likely to occur. In order to prevent such disadvantages, it is necessary to cut the surface of the airlaid pulp fiber nonwoven fabric in contact with food with a cutter or the like. In the case of the drip sheet 10 of this embodiment, the upper surface 11 side of the upper layer 13 is the air-through fiber nonwoven fabric. Since the outer surface is flat, the outer surface is flat and it is not necessary to perform such smoothing. In the first layer 20, the fibers are constrained and arranged relatively densely, whereas in the second layer 21, the fibers are not constrained and are arranged relatively sparsely. Specifically, the apparent density of the fibers of the first layer 20 is about 0.07 to 0.09 g / cm ³ , and the apparent density of the fibers of the second layer 21 is about 0.03 to 0.06 g / cm ³ . . As described above, since the apparent density of the first layer 20 is higher than that of the second layer 21, it can be said that the interfiber spacing of the constituent fibers 18 of the first layer 20 is smaller than that of the third layer 22. When the surface of the drip sheet 10 is formed from the sprayed surface of the upper layer 13, the fibers are arranged relatively sparsely compared to the net surface, so that the inter-fiber gap is large and the drip is more quickly applied to the lower layer 14. Can be moved. However, when the drip is absorbed in a relatively short time, the water retention component of the food placement surface is drastically reduced, and the placement surface is partially dried, which tends to cause discoloration, cracks, and the like. In this embodiment, by positioning the net surface side of the upper layer 13 on the upper surface 11 side of the drip sheet 10, all the drip is not absorbed in a relatively short time. Therefore, at least at a retail store such as a supermarket, even when food is displayed in a state of being packed in a tray for a predetermined time (about 2 to 10 hours), The absorption speed of the drip sheet 10 is adjusted so that moisture is not excessively absorbed.

The fineness of the composite fiber of the upper layer 13 is preferably 1 to 6 dtex. This is because the strength is insufficient when it is 1 dtex or less, and the capillarity is weakened when it is 6 dtex or more, and the barrier function against rewetting may be lowered. Further, the second layer 21 is preferably subjected to a hydrophilic treatment in order to quickly move the drip to the third layer 22.

Usually used for disposable diapers and sanitary napkins, it is composed of a top sheet made of non-woven fabric located on the skin facing surface side of the wearer and an absorbent core made of a mixture containing fluff pulp located below the top sheet. In the case of the absorbent member, in order to separate the excreted bodily fluid from the skin of the wearer, the bodily fluid is quickly transferred from the top sheet (within a few minutes after excretion) to the lower absorbent core, The surface needs to be dry. Therefore, the surface of the top sheet is subjected to a hydrophilic treatment, or the fiber density of the top sheet and / or the absorbent core is gradually increased downward. However, in the drip sheet 10, if the drip is absorbed rapidly from the upper surface 11, the moisture of the food is excessively absorbed and part of the food may be dried. Therefore, in the drip sheet 10, it is preferable that the upper surface 11 is not subjected to a hydrophilization treatment, and the fiber density of the upper layer 13 is configured such that the first layer 20 is higher than the second layer 21. .

FIG. 5 shows an example of a usage example of the drip sheet 10. In this usage example, the food 44 from which a drip such as meat or fish exudes is interposed between the composite layers 40 composed of a plurality of layers. Arranged. The composite layer 40 has a three-layer structure including a first outer surface layer 41, a second outer surface layer 42, and an intermediate layer 43 located between the first and second outer surface layers 41, 42. The first and second outer surface layers 41 and 42 are formed from an air-through fiber nonwoven fabric as in the upper layer 13, and the intermediate layer 43 is formed from an airlaid pulp fiber nonwoven fabric as in the lower layer 14. The surfaces of the first and second outer surface layers 41, 42 that are in contact with the food 44 are net surfaces, the fibers are densely arranged compared to the smooth and opposite surface, and the food is not damaged. Do not absorb too much moisture in food. Examples of such use include, for example, when delivering to a retail store such as a supermarket by a truck or the like, or storing the product before displaying it on a display shelf in the retail store.

Also in this use example, since the composite layer 40 as a whole has liquid absorption performance, the required liquid absorption amount can be ensured even when the composite layer 40 is formed relatively thin. Therefore, the diameter of the roll 30 does not become relatively large, and there is no possibility that the core side 31 is pressed and a large difference in the amount of liquid absorption between the core side 31 and the winding outside 32 is caused. In addition, in the field of fresh food processing at retail stores, etc., a combination of drip sheets and food is often stored in a stacked state. There is a risk that the drip sheet positioned will absorb excessive moisture from the food and reduce the freshness of the food. According to the composite layer 40 in the present use example, even in such a case, the first and second outer surface layers 41 and 42 made of air-through fiber nonwoven fabric are positioned above and below the food 44, and the contact surfaces thereof are air-through fibers. Since it is a nonwoven fabric net surface, it has excellent cushioning properties, does not damage the surface of the food 44, and does not cause excessive absorption of moisture in the food 44.

Table 1 shows the difference in liquid absorption between the core side 31 and the outer winding side 32 of each roll 30 obtained by manufacturing a plurality of drip sheets under various conditions and winding the drip sheets in a roll shape. It has been evaluated. Each roll 30 has a diameter of 100 cm, and the winding length (m) of the manufactured roll 30 differs depending on the thickness dimension D1 of the drip sheet 10.

[Measuring method]
<Sheet thickness>
Based on the standard of JISL1096.6.5, it measured using the desk | table-top thickness meter (The product made from PEACOCK, measurement surface (phi) 44mm, measurement pressure 3g / cm < ² >). First, a sample of 100 mm × 100 mm was cut from the roll core side 31 and the roll outer side 32 of each roll 30 and the center of the sample was gently sandwiched between the upper and lower disks, and the value of the measuring instrument at that time was obtained ( N = 10).

<Liquid absorption>
The mass (Ag) of each sample used in the thickness measurement of the sheet was measured. After measuring the mass, each sample was placed on a 10-mesh wire net, and each sample was immersed in a test solution (tap water, physiological saline, edible oil) placed in a tray. After soaking in the test solution for 3 minutes, each sample was taken out of the tray together with the wire mesh, drained lightly, and allowed to stand for 5 minutes. Thereafter, the mass (Bg) of the wire mesh and each sample was measured, the sample was removed, and the mass (Cg) of only the wire mesh was measured. Then, each sample was placed on a sample table, a 420 g weight was placed on the sample, and the sample was allowed to stand for 3 minutes. Using the values (A to C) obtained by the above measurement method, the liquid absorption amount was obtained by the following calculation method. The measurement was performed three times, and the average value was defined as the liquid absorption amount of the core side 31 and the outer side 32 of each roll 30.
Liquid absorption (g / m ² ) = (B−C−A) /0.1/0.1

<Difference in liquid absorption>
The difference (g) in the liquid absorption amount was obtained by subtracting the liquid absorption amount on the winding core side 31 from the liquid absorption amount on the roll outer side 32 of the roll 30 in each example and comparative example.

<Example 1>
An air-through fiber nonwoven fabric having a thickness of 1.30 mm, a mass of about 30 g / m ² and a density of 0.022 g / cm ³ using a polyethylene / polypropylene core-sheath composite fiber (staple fiber) having a fineness of 2.2 dtex as the upper layer 13. used. As the lower layer 14, 85% by mass of NBKP (conifer kraft bleached pulp) is sprinkled on the net by a suction device placed at the bottom of the transfer net and deposited in a vat form, and 15% by mass of PVA resin as a binder The PVA resin was sprayed to dry the PVA resin to obtain an airlaid pulp fiber nonwoven fabric having a thickness of 0.8 mm, a mass of about 40 g / m ² and a density of 0.049 g / cm ³ . In each Example and each Comparative Example, the hot melt adhesive as the bonding part 15 had a mass of 2.2 g / m ² . The upper layer 13 had a net surface on the upper surface 11 side and a spray surface on the lower surface 12 side.

<Example 2>
Using the same upper layer 13 as in Example 1, an airlaid pulp fiber nonwoven fabric having a thickness of 1.2 mm, a mass of about 52 g / m ² , and a density of 0.043 g / cm ³ was obtained as the lower layer 14.

<Example 3>
Using the same upper layer 13 as in Example 1, an airlaid pulp fiber nonwoven fabric having a thickness of 2.2 mm, a mass of about 80 g / m ² and a density of 0.036 g / cm ³ was obtained as the lower layer 14.

<Example 4>
Using the same upper layer 13 as in Example 1, an airlaid pulp fiber nonwoven fabric having a thickness of 2.5 mm, a mass of about 100 g / m ² , and a density of 0.040 g / cm ³ was obtained as the lower layer 14.

<Comparative Example 1>
Using the same upper layer as in Example 1, an airlaid pulp fiber nonwoven fabric having a thickness of 2.8 mm, a mass of about 110 g / m ² , and a density of 0.039 g / cm ³ was obtained as the lower layer.

<Comparative example 2>
Using the same upper layer as in Example 1, an airlaid pulp fiber nonwoven fabric having a thickness of 3.0 mm, a mass of about 120 g / m ² and a density of 0.040 g / cm ³ was obtained as the lower layer.

<Comparative Example 3>
Using the same upper layer as in Example 1, an airlaid pulp fiber nonwoven fabric having a thickness of 3.5 mm, a mass of about 150 g / m ² and a density of 0.043 g / cm ³ was obtained as the lower layer.

<Measurement results>
Referring to the measurement results in Table 1, the difference in the liquid absorption amount in Examples 1 to 4 was about 70 to 310 g / m ² , whereas the difference in the liquid absorption amount in Comparative Examples 1 to 3 was about 700 to It was 970 g / m ² . Thus, when the mass and thickness dimension of the airlaid pulp fiber nonwoven fabric of the lower layer 14 are equal to or greater than a certain level, a relatively large difference in liquid absorption occurs between the core side 31 and the outer side 32 of the drip sheet 10. There is a risk that the product may vary.

Referring to FIG. 6, the difference in liquid absorption increased rapidly between Example 4 and Comparative Example 1, that is, when the mass of the airlaid pulp fiber nonwoven fabric of the lower layer 14 was about 100 to 110 g / m ² . It was found that there is a change point P located between the gradients of Example 4 and Comparative Example 1. After the change point P, the difference in the liquid absorption amount is 400 g / m ² or more.

Unless otherwise specified, each component constituting the drip sheet 10 is limited to various known materials that are commonly used in this type of field in addition to the materials described in this specification. Can be used. In addition, the terms “first”, “second”, and “third” used in the present specification and claims are merely used to distinguish similar elements, positions, and the like.

The disclosure relating to the present invention described above can be summarized in at least the following matters.
In a drip sheet having an upper surface and a lower surface, and a thickness direction therebetween, a liquid-permeable and liquid-absorbing upper layer, and a liquid-absorbing lower layer joined to the upper layer, the upper layer is At least including a heat-fusible fiber, the heat-fusible fiber is formed from a fiber non-woven fabric that is heat-bonded to each other, the lower layer is formed from a fiber non-woven fabric including at least a hydrophilic fiber, the mass of the lower layer The drip is about 30 to 100 g / m ² , and the difference in liquid absorption between the roll core side and the roll outside of the roll formed by winding the drip sheet is 400 g / m ² or less. Sheet.

The drip sheet according to the present invention disclosed in the paragraph 0043 can include at least the following embodiments.
(1) The drip sheet has a maximum mass of about 140 g / m ² and a thickness dimension of about 2.5 mm at the maximum.
(2) The said hydrophilic fiber of the said lower layer is a pulp fiber, The said lower layer is formed from the airlaid pulp fiber nonwoven fabric.
(3) The upper layer is formed of an air-through fiber nonwoven fabric and has a mass of about 20 to 40 g / m ² .
(4) The roll has a winding length of about 200 to 800 m and a diameter of about 80 to 120 cm.
(5) The upper layer has a first layer located on the upper surface side and a second layer located on the lower surface side of the first layer and opposed to the lower layer, and is located on the second layer. The number of fused portions of the heat-fusible fiber is larger than the number of fused portions of the heat-fusible fiber located in the first layer, and the upper surface side surface of the upper layer is on the lower surface side. Smoother than the surface.
(6) Of the first and second layers, only the second layer is hydrophilized.
(7) The apparent density of the constituent fibers of the first layer is about 0.07 to 0.09 g / cm ³ , and the apparent density of the constituent fibers of the second layer is about 0.03 to 0.06 g / cm ³ . .

DESCRIPTION OF SYMBOLS 10 Drip sheet 11 Upper surface 12 Lower surface 13 Upper layer 14 Lower layer 17 Fusion part 18 Upper layer constituent fiber 19 Lower layer constituent fiber 20 First layer 21 Second layer 22 Third layer 30 Roll 31 Roll core side 32 Roll outer side of roll Z Thickness direction

Claims

In a drip sheet having an upper surface and a lower surface, and a thickness direction between them, a liquid-permeable and liquid-absorbing upper layer, and a liquid-absorbing lower layer joined to the upper layer,
The upper layer includes at least a heat-fusible fiber, the heat-fusible fiber is formed from a fiber nonwoven fabric that is heat-sealed to each other, and the lower layer is formed from a fiber nonwoven fabric that includes at least a hydrophilic fiber,
The lower layer has a mass of about 30-100 g / m 2 ,
The drip sheet according to claim 1, wherein a difference in liquid absorption between the roll core side and the roll outside of the roll formed by winding the drip sheet is 400 g / m 2 or less.
The drip sheet of claim 1, wherein the drip sheet has a mass of at most about 140 g / m 2 and a thickness dimension of at most about 2.5 mm.
The drip sheet according to claim 1 or 2, wherein the hydrophilic fiber in the lower layer is a pulp fiber, and the lower layer is formed of an airlaid pulp fiber nonwoven fabric.
The drip sheet according to any one of claims 1 to 3, wherein the upper layer is formed of an air-through fiber nonwoven fabric and has a mass of about 20 to 40 g / m 2 .
The drip sheet according to any one of claims 1 to 4, wherein the roll has a winding length of about 200 to 800 m and a diameter of about 80 to 120 cm.
The upper layer has a first layer located on the upper surface side and a second layer located on the lower surface side of the first layer and opposed to the lower layer, and the heat fusion located on the second layer. The number of fused parts of the adhesive fiber is larger than the number of fused parts of the heat-fusible fiber located in the first layer, and the upper surface side surface of the upper layer is more than the lower surface side surface. The drip sheet according to any one of claims 1 to 5, which is smooth.
The drip sheet according to claim 6, wherein, of the first and second layers, only the second layer is subjected to a hydrophilic treatment.
The apparent density of the constituent fibers of the first layer is about 0.07 to 0.09 g / cm 3 , and the apparent density of the constituent fibers of the second layer is about 0.03 to 0.06 g / cm 3. Or the drip sheet of 7.