JP2003111525A - Sugar content-increasing sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sugar content-increasing sheet which has good sugar content-increasing functions such as good water resistance, moisture permeability, light transmittance, and the like, and simultaneously has excellent spreading workability. SOLUTION: This sugar content-increasing sheet is formed by laminating at least two or more nonwoven fabrics which comprise a nonwoven fabric A comprising biodegradable synthetic fibers having a fiber diameter of <=10 μm and a nonwoven fabric B comprising biodegradable synthetic fibers having a fiber diameter of 15 to 50 μm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sugar content increasing sheet for use in orchards, and more specifically, it has sugar content increasing functions such as water resistance (water repellency), moisture permeability (breathability) and translucency. However, the present invention relates to a sugar content up sheet having excellent laying workability.

[0002]

2. Description of the Related Art A sugar content increasing sheet is used as a means for increasing the sugar content by limiting the amount of rainwater absorbed by the root by laying it around the root of a fruit tree and making the fruit water-deficient. There is. The sugar content up sheet is
With such a sugar content increasing function, water resistance (water repellency) that limits rainwater from reaching the roots of fruit trees, moisture permeability (breathability) and permeability that keep bacteria (microorganisms) in the soil healthy It is designed to have lightness.

As a conventional sugar content increasing sheet, a hemp sheet has been used exclusively. However, hemp has a low water resistance due to its high water absorption, and has a problem that it easily emits harmful microorganisms to fruit trees because it has air permeability but has no translucency. Therefore, recently, synthetic fiber sheets such as polypropylene fiber and polyethylene fiber are often used. However, although the synthetic fiber sheet has excellent sugar content increasing functions such as water resistance, moisture permeability, and translucency, when it is replaced with a new sheet when it has reached the end of its life due to weather resistance, it deteriorates due to weather resistance. Therefore, there is a problem that the recovery work is very troublesome. Moreover, the recovered sheet does not rot and causes environmental pollution, which causes a problem as industrial waste.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems of the prior art and to provide excellent sugar content increasing functions such as water resistance, moisture permeability and translucency while having excellent laying workability. It is to provide a sugar content up sheet having the following.

[0005]

Means for Solving the Problems A sugar content upsheet of the present invention which achieves the above object is a nonwoven fabric A made of biodegradable synthetic fiber having a fiber diameter of 10 μm or less and a fiber diameter of 15 to 50 μm.
At least 2 with a non-woven fabric B made of biodegradable synthetic fiber of
It is characterized in that it is constituted by laminating different kinds of non-woven fabrics.

Since all the non-woven fabrics constituting the sugar content increasing sheet are made of biodegradable synthetic fibers, the deteriorated sheet is recovered when the new sheet is laid due to weather deterioration of the sheet in use. Even if it is left as it is, it can be naturally decomposed and eliminated by bacteria in the soil. Therefore, it is not necessary to collect the deteriorated sheet, and the pollution problem does not occur, so that the laying workability can be greatly improved.

Since the non-woven fabric A is made of ultrafine synthetic fibers having a fiber diameter of 10 μm or less, the water resistance and moisture permeability are increased by the densification of the fibers, and the biodegradable synthetic fibers have higher light transmission properties than natural fibers. Therefore, it can have a sugar content increasing function. In addition, since the non-woven fabric A made of ultrafine fibers has a large flexibility, it becomes difficult to perform the turning work that is sometimes performed at the time of laying work or intermediate management, but the fiber diameter is 15 to
Workability can be improved by laminating the non-woven fabric B made of highly rigid fiber of 50 μm.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The sugar content-up sheet of the present invention comprises at least a nonwoven fabric A formed from ultrafine biodegradable synthetic fibers and a nonwoven fabric B formed from biodegradable synthetic fibers having a relatively large fiber diameter. It is configured as a laminate of two types of non-woven fabric. Of these, the non-woven fabric A is made of ultrafine fibers, which facilitates densification between the fibers and has a sugar content increasing function of improving water resistance (water repellency), moisture permeability (air permeability), and the like.

The nonwoven fabric A having excellent water resistance limits the permeation of rainwater, and when it is placed at the root of a fruit tree as a sugar content up sheet, it restricts the supply of water to the root of the fruit tree to increase the sugar content of the fruit. The non-woven fabric A, which is also excellent in moisture permeability, does not allow water to permeate, but allows air to permeate. Therefore, the air on the surface side of the sugar content increasing sheet is passed through the soil surface inside so as not to kill microorganisms in the soil. Further, it is necessary to give light in order for the microorganisms to survive, but since the synthetic fiber itself is transparent, it can fulfill its function.

The non-woven fabric A has the above-mentioned sugar content increasing function,
The fiber diameter of the biodegradable synthetic fiber, which is a constituent fiber, is 10 μm or less. If the fiber diameter is larger than 10 μm, it becomes disadvantageous in the densification between the fibers, and the water resistance deteriorates. Non-woven fabric A
The smaller the fiber diameter of the biodegradable synthetic fiber constituting the above is, the more preferable it is, more preferably 3 μm or less, and further preferably 2
It is preferable that the thickness is μm or less. In order to stably and easily obtain such an ultrafine fiber diameter, the nonwoven fabric A is preferably manufactured by a melt blow method. That is, it is preferably a melt blown nonwoven fabric.

On the other hand, the non-woven fabric B has high strength and rigidity because it is composed of biodegradable synthetic fibers having a relatively large fiber diameter. By having this characteristic, the nonwoven fabric A having low strength and rigidity is reinforced. Since the non-woven fabric A is composed of ultrafine fibers, it is too soft by itself to make the laying work of the sheet unstable, but the non-woven fabric B solves this problem and improves the laying workability. The nonwoven fabric B having such an action is preferably manufactured by the spunbond method. That is, it is preferably a spunbond nonwoven fabric.

The biodegradable synthetic fiber constituting the nonwoven fabric B has a fiber diameter of 15 to 50 μm, preferably 1
The thickness is 5 to 40 μm, more preferably 15 to 30 μm. If the fiber diameter is smaller than 15 μm, yarn breakage occurs frequently in the spunbonding process, resulting in uneven quality and difficulty in increasing strength. Also, 50
If it is thicker than μm, the number of reinforcing fibers for the non-woven fabric A becomes small, and a sufficient reinforcing action cannot be performed. Therefore, when laying the sugar content up sheet, a problem such as a large number of fluffs occurring on the surface occurs.

The method of laminating the above-mentioned two kinds of non-woven fabrics A and B is not particularly limited. For example, as shown in FIG.
The non-woven fabric A is laminated on the non-woven fabric B to increase the sugar content S
May be formed so that the rainwater is first received by the nonwoven fabric A, or conversely, the nonwoven fabric B may be laminated on the nonwoven fabric A. Further, as shown in FIG. 2, the nonwoven fabric B may be laminated on both the front and back surfaces of the nonwoven fabric A. In addition, the number of the non-woven fabrics B to be laminated may be plural per one side of the non-woven fabric A, and particularly the non-woven fabrics B composed of fibers having different fiber diameters may be stacked.

As a method for producing a sugar content upsheet constituted by laminating two kinds of non-woven fabrics A and B, non-woven fabric A and non-woven fabric B are produced in separate steps, and they are laminated and adhered. Or, the non-woven fabric manufacturing process of the spunbond method and the non-woven fabric manufacturing process of the melt blow method are arranged in order, and the non-woven fabric manufactured continuously is sequentially laminated while being transferred to the downstream side, and temporarily bonded, and finally the adhesive treatment. You can do it. An embossing roller may be used to bond a plurality of laminated nonwoven fabrics so that a large number of partially fused portions are dispersed between the laminated layers. By interspersing a large number of partial fusion-bonded portions between the laminated layers in this way, relative movement in the plane direction between layers is partially allowed and flexibility is imparted, facilitating the laying work of the sugar content upsheet. Become.

FIG. 3 illustrates the steps for continuously producing the sugar content upsheet of the present invention.

Reference numeral 1 is a spunbond spinning machine, 2 is a melt blow spinning machine, and 3 is a net conveyor. The continuous filament Y discharged from the spunbond spinning machine 1 is spread on the net conveyor 3 together with the jet flow to form the nonwoven fabric B. When this non-woven fabric B is conveyed by the net conveyor 3 and comes under the melt blow spinning machine 2, ultrafine short fibers y jetted together with hot air from the melt blow spinning machine 2 spread on the upper surface thereof to form the non-woven fabric A. .

Nonwoven fabric B thus laminated vertically
When the non-woven fabric A and the non-woven fabric A pass through the heated embossing roller 4, the layers are fused by a number of partial fusion-bonding portions to form a sugar content upsheet S having a laminated structure as shown in FIG. (S) is rolled up.

In FIG. 3, two units, the spunbond spinning machine 1 and the melt blow spinning machine 2, are arranged in series. However, when another spunbond spinning machine 1 is arranged in series on the downstream side, the spunbond spinning machine 1 and the meltblowing spinning machine 2 are arranged in series. The sugar content up sheet S with a laminated structure as shown in
Can be manufactured. Further, if necessary, another spunbond spinning machine or meltblown spinning machine that discharges fibers having different fiber diameters can be arranged.

It is more preferable that the above-mentioned nonwoven fabrics A and B each have a basis weight in the range of 15 to 30 g / m ² . In the case of non-woven fabric A, the basis weight is 15 g /
When it is smaller than m ^2, it becomes difficult to maintain the water resistance and moisture permeability required for the sugar content upsheet, and particularly when the fiber diameter of the synthetic fiber constituting the nonwoven fabric A is 2 μm or less. Further, in the case of the non-woven fabric B, if the basis weight is less than 15 g / m ² , the reinforcing effect on the non-woven fabric A becomes insufficient. Therefore, during the laying work of the sugar content up sheet, breakage occurs and the workability is deteriorated.

If the basis weight is larger than 30 g / m ² , the total basis weight of the nonwoven fabrics A and B exceeds 60 g / m ² ,
It becomes difficult to handle when laying a sugar content up sheet. In particular, as shown in FIG. 2, in the case of the sugar content upsheet in which the nonwoven fabric B is laminated on both sides of the nonwoven fabric A, the total basis weight is 9
Since it exceeds 0 g / m ² , it becomes more difficult to handle and the cost becomes higher.

The apparent densities of the nonwoven fabrics A and B are preferably 0.2 to 0.5 g / cm ³ , and more preferably 0.3 to 0.45 g / cm ³ . When the apparent density of the nonwoven fabric A is less than 0.2 g / cm ^3, it becomes difficult to maintain water resistance as the sugar content up sheet. The apparent density of the non-woven fabric B is 0.2 g
When it is less than / cm ^{3, the} reinforcing effect on the non-woven fabric A is reduced, and fluff is easily generated on the sheet surface of the non-woven fabric A. If the apparent density is larger than 0.5 g / cm ³ ,
Since both the non-woven fabrics A and B are film-like, the sugar content up sheet is difficult to handle and the laying workability is deteriorated.

The means for adhering the layers of the non-woven fabrics A and B at a number of partially fused portions can be easily performed by using an embossing roll. The total area of the partially fused portions between such layers is preferably 7 to 20% of the interlayer area. More preferably, 10 to 1
7% is recommended. If the total area of the partially fused portions is less than 7%, the sugar content upsheet is soft and easily fluffed. On the other hand, if it is more than 20%, the bending strength of the sugar content up sheet becomes hard and the handleability deteriorates.

When a large number of partially fused portions are formed between the non-woven fabrics by the embossing roll as described above, when the apparent density of each non-woven fabric is high, the non-woven fabrics are individually adjusted with a calender roll to the required density. After that, if these nonwoven fabrics are laminated and treated with an embossing roll, fusion can be improved. Further, as shown in FIG. 3, in the case of a continuous process in which spunbond fabric making processes and melt blow fabric making processes are connected in series, a calender roll is formed at the last stage where a plurality of nonwoven fabrics are laminated and before being passed through an embossing roll. If the density is adjusted to the required value with, the fusion can be improved.

In the present invention, the sugar content upsheet obtained by laminating the two types of non-woven fabrics A and B as described above has a moisture permeability of 3500 to 8000 g / g as a sugar content upsheet.
m ² · 24 hr, more preferably 5000 to 8000 g / m
^It should be set to 2/24 hours. By setting the moisture vapor transmission rate within such a range, it is possible to keep the microorganisms in the soil healthy and prevent the generation of harmful microorganisms to fruit trees. More preferably, the air permeability as a sugar content up sheet is 0.01 to 10 cc / cm ² · se.
c, more preferably 0.01 to 8 cc / cm ² ·
It is better to set it in the range of sec.

The water resistance as a sugar content up sheet is in the range of 800 to 2000 mm, more preferably 1000.
It is good to set it to about 1700 mm. By setting such water resistance (water repellency), permeation of rainwater can be appropriately suppressed, and the sugar content of fruits can be improved. However, if the water resistance is large enough to exceed 2000 mm, the rainwater hardly penetrates the sugar content upsheet, so that the fruit becomes water-deficient.

The biodegradable synthetic fibers constituting the nonwoven fabrics A and B are not particularly limited as long as they have a property of being decomposed by microorganisms in the soil. For example, as the polymer of the biodegradable synthetic fiber, polylactic acid, polyhydroxybutyrate, polyglycolic acid, polycaprolactone and polybutylene succinate can be mentioned as the aliphatic polyester type. Examples of polyamide-based materials include polyether amide, and examples of vinyl-based materials include polyvinyl alcohol. From these, polymers may be used alone or in combination of two or more. Among these, polylactic acid is most suitable.

The polylactic acid is preferably polyester containing L-lactic acid as a main component. Having L-lactic acid as a main component means that 60% by weight or more of the constituent components are composed of L-lactic acid, and the rest is a polyester containing D-lactic acid in an amount not exceeding 40% by weight. It is not.

The method for producing polylactic acid includes a two-step lactide method in which lactide which is a cyclic dimer is once produced from lactic acid as a raw material and then ring-opening polymerization is carried out, and lactic acid as a raw material in a solvent. A one-step direct polymerization method in which direct dehydration condensation is performed is known. The polylactic acid used in the present invention is
It may be obtained by any manufacturing method. In the case of a polymer obtained by the lactide method, the cyclic dimer contained in the polymer vaporizes during melt spinning and causes yarn unevenness, so the cyclic dimer contained in the polymer prior to melt spinning is It is desirable that the body content is 0.1% by weight or less. Further, in the case of the direct polymerization method, since there is substantially no problem caused by the cyclic dimer, it is more preferable from the standpoint of spinnability.

The polylactic acid used in the spunbond method preferably has a weight average molecular weight of 100,000 to 300,000, more preferably 100,000 to 200,000. If the weight average molecular weight is less than 100,000, the strength of the fiber will be low and the strength of the nonwoven fabric will not be sufficient. Further, if the weight average molecular weight is more than 300,000, even if the filament spun from the spinneret is sucked and pulled by air sucker, it cannot be spun at high speed due to lack of spinnability and becomes undrawn yarn-like. It is not possible to obtain good fiber strength.

The polylactic acid used in the meltblown nonwoven fabric has a weight average molecular weight of 150,000 or less, preferably 30,000 to 100,000, and more preferably 30,000 to 70,000. . Weight average molecular weight is 15
If it is more than 10,000, the melting temperature cannot be set to 240 ° C. or higher when the polylactic acid is melted due to its thermal decomposability, so that the melting viscosity cannot be lowered by increasing the melting temperature. Therefore, the fiber diameter required for nonwoven fabric A is 10 μm
The following ultrafine fibers cannot be obtained. Further, if the weight average molecular weight is less than 30,000, polymer lumps are likely to be mixed in when melted and spun from the spinneret, so that the quality may be deteriorated.

The polylactic acid used in the present invention is L-lactic acid, D
-Copolymerized polylactic acid obtained by copolymerizing other components having ester forming ability in addition to lactic acid may be used. As the copolymerizable component, glycolic acid, 3-hydroxybutyric acid, 4-
In addition to hydroxycarboxylic acids such as hydroxyvaleric acid and 6-hydroxycaproic acid, ecatylene glycol,
Compounds having a plurality of hydroxyl groups in the molecule such as propylene glycol, butanediol, neopentyglycol, polyethylene glycol, glycerin, pentaerythritol or their derivatives, adipic acid, sebacic acid, fumaric acid, terephthalic acid, isophthalic acid, 2 , 6-
Examples thereof include compounds having a plurality of carboxylic acid groups in the molecule such as naphthalenecarboxylic acid, 5-sodium sulfoisophthalic acid, and 5-tetrabutylphosphonium isophthalic acid, or derivatives thereof.

To reduce the melt viscosity, aliphatic polyester polymers such as polycaprolactone, polybutylene succinate, and polyethylene succinate can be used as an internal plasticizer or an external plasticizer. Furthermore, inorganic fine particles and organic compounds can be added as necessary as matting agents, deodorants, flame retardants, thread friction reducing agents, antioxidants, color pigments and the like.

[0033]

EXAMPLES The present invention will be described below with reference to examples. Each characteristic value used in the examples is obtained by the following measuring method.

A. Fiber diameter (μm) By randomly collecting 5 samples from each non-woven fabric and using a scanning electron microscope on the sheet surface of each non-woven fabric, the non-woven fabric A is 1000 to 3000 times,
Nonwoven fabric B was each expanded 200 to 300 times, and the fiber diameter of each of 20 fibers (total 100 fibers = 20 fibers x n (= 5)) was measured with a caliper and the average value thereof was calculated.

B. Unit weight (g / m ² ) Three 20 cm × 20 cm samples were taken from the non-woven fabric, and the average value of the weight measured for each was converted to the mass per 1 m ² .

C. Apparent density (g / cm ³ ) Five samples were randomly sampled from the non-woven fabric, and the thickness (mm) of each sample was measured by a dial gauge method according to JIS L-1096 under a load of 7 g / cm ² , and the thickness was measured. The sheet basis weight (g / m ² ) was divided by (mm) to obtain the value by the following formula, and the average value of the values for 5 samples was calculated.

Apparent density = basis weight / (thickness x 1000) D. Water vapor transmission rate (g / m ² · 24 hr) Measured by the modified method of JIS Z-0208 (30 ° C, 90%).

E. Water resistance (mm) It was measured by the low water pressure method of JIS L-1902.

F. Evaluation of sugar content Fruits using the sugar content upsheet and fruits not used were tasted and compared by 10 panelists.
It was determined to be effective when 7 or more panelists out of 10 judged that the fruit using the sugar content upsheet had a higher sugar content.

G. Evaluation of Biodegradation Performance A sample obtained by cutting the sugar content upsheet into 5 cm × 5 cm was embedded in soil at a temperature of 35 ° C. and a water content of 30%, and left for 1 year to visually determine the degree of degradation.

Example 1 Production of Nonwoven Fabric A: Polylactic acid chips having a weight average molecular weight of 100,000 were dried for 24 hours in a vacuum dryer at a temperature of 120 ° C. to prepare a raw material. This polylactic acid chip has 1000 holes
Melt blow non-woven fabric equipment with pores / m is used, melt blow spinning is performed at an extruder melting temperature of 230 ° C. and a spinning temperature of 235 ° C., and a fiber diameter of 1.5 μm on a net conveyor.
A nonwoven fabric A composed of m fibers was produced. This non-woven fabric A has a basis weight of 28 g / m ² and an apparent density of 0.14 g / cm ^3.
Met.

Production of Nonwoven Fabric B: Polylactic acid chips having a weight average molecular weight of 130,000 were dried for 24 hours in a vacuum dryer at a temperature of 120 ° C. to prepare a raw material. This polylactic acid chip was manufactured by using a spunbonded non-woven fabric manufacturing facility having a spinneret hole count of 2500 holes / m, and the melting temperature of the extruder was 235 ° C. and the spinning temperature was 23.
Spunbond spinning was performed at 0 ° C. to produce a nonwoven fabric B made of fibers having a fiber diameter of 27 μm on a net conveyor. The basis weight of this non-woven fabric B is 30 g / m ² , and the apparent density is 0.24 g.
/ Cm ³ .

The two types of non-woven fabric A and non-woven fabric B obtained as described above were laminated and passed through an embossing roll at a temperature of 135 ° C. to produce a sugar content-up sheet which was fused together.

The apparent density of the obtained sugar content-up sheet was 0.38 g / cm ³ , and its water resistance and water vapor transmission rate were measured. The water resistance was 1580 mm and the water vapor transmission rate was 680.
It was 0 g / m ² · 24 hr.

The above-mentioned sugar content upsheet was used in a grape orchard for one year, and the harvested grapes and the grapes obtained from the fruit trees in the same grape orchard which did not use the sugar content upsheet were 10 panelists. When asked to taste it, everyone admitted that the grapes that used the sugar content up sheet had a higher sugar content.

Further, when the biodegradability of the sugar content up sheet was examined, it was found that most of the sheets were decomposed to such an extent that the original shape could not be retained.

Example 2 Using the non-woven fabrics A and B obtained in Example 1, the non-woven fabrics B were laminated on both sides of the non-woven fabric A, and then thermocompression bonded to each other with an embossing roll at a temperature of 135 ° C. to obtain a sugar content up sheet. Manufactured. The apparent density of the resulting sugar content upsheet was 0.
43g / cm ³ , water resistance 1530mm, moisture vapor transmission rate 74
It was 00 g / m ² · 24 hr.

When the sugar content upsheet was used in a grape orchard, the sugar content of the grape was evaluated, and it was confirmed that the sugar content was higher than that of the fruit tree without the sugar content upsheet. Was given. In addition, there was no occurrence of tears during construction and the handleability was excellent, and workability was also satisfactory.

Example 3 Using the manufacturing apparatus and the raw materials used in Example 1, a nonwoven fabric A having a fiber diameter of 5 μm and a basis weight of 30 g / m ² and a fiber diameter of 18 μm and a basis weight of 30 g / m ² were used. Nonwoven fabric B was produced. Using the obtained non-woven fabrics A and B, the non-woven fabric B was laminated on both sides of the non-woven fabric A and passed through an embossing roll at a temperature of 135 ° C to produce a sugar content-up sheet which was fused to each other. The apparent density of the obtained sugar content upsheet is 0.33 g / cm.
³ , water resistance 910mm, moisture vapor transmission rate 7800g / m ² ·
It was 24hr.

When the sugar content upsheet was used in a grape orchard, the sugar content of the grapes was evaluated, and it was confirmed that the sugar content was higher than that of the fruit tree without the sugar content upsheet. Was given.

Comparative Example 1 Using the manufacturing apparatus and raw materials used in Example 1, a nonwoven fabric A having a fiber diameter of 15 μm and a basis weight of 30 g / m ² and a fiber diameter of 24 μm and a basis weight of 25 g / m ² were used. Nonwoven fabric B was produced. Using the obtained non-woven fabrics A and B, the non-woven fabric B was laminated on both sides of the non-woven fabric A and passed through an embossing roll at a temperature of 135 ° C to produce a sugar content-up sheet which was fused to each other. The apparent density of the obtained sugar content upsheet is 0.17 g / c.
m ³ , water resistance 320 mm, moisture vapor transmission rate 8500 g / m ²
・ It was 24 hours.

When the sugar content-up sheet was used in a grape orchard and the sugar content of the grapes was evaluated, there was no difference from the grapes of fruit trees that did not use this sugar content-up sheet, and no sugar content-increasing effect was observed. It was Moreover, when the sugar content up sheet was applied to an orchard, fluff was generated and the workability was poor.

Comparative Example 2 Using the production apparatus and raw materials used in Example 1, a nonwoven fabric A having a fiber diameter of ² μm and a basis weight of 10 g / m ² and a fiber diameter of 35 μm and a basis weight of 13 g / m ² were used. Nonwoven fabric B was produced. The obtained nonwoven fabrics A and B are laminated and the temperature is 135 ° C.
Was passed through an embossing roll to produce a sugar content-up sheet which was fused to each other. The apparent density of the obtained sugar content-up sheet was 0.30 g / cm ³ , the water resistance was 500 mm, and the water vapor transmission rate was 8300 g / m ² · 24 hr.

When the above-mentioned sugar content increasing sheet was applied to a grape orchard, the strength was weak such as breakage and the sugar content increasing sheet was insufficient.

[0055]

As described above, according to the present invention, since the non-woven fabric constituting the sugar content increasing sheet is composed of biodegradable synthetic fibers, the sheet in use is deteriorated due to weathering and a new sheet is formed. Bacteria (microorganisms) in the soil even if left unattended without collecting the deteriorated sheet when laying
Can be decomposed and eliminated by. Therefore, it is not necessary to collect the deteriorated sheet, and the pollution problem does not occur, so that the laying workability can be greatly improved.

Since the nonwoven fabric A is made of ultrafine synthetic fibers having a fiber diameter of 10 μm or less, the water resistance and moisture permeability are increased by the densification of the fibers, and the biodegradable synthetic fibers have higher light transmission properties than natural fibers. Therefore, it can have a sugar content increasing function. In addition, since the non-woven fabric A made of ultrafine fibers has a large flexibility, it becomes difficult to perform the turning work that is sometimes performed at the time of laying work or intermediate management, but the fiber diameter is 15 to
Workability can be improved by laminating the non-woven fabric B made of highly rigid fiber of 50 μm.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a sugar content upsheet of the present invention.

FIG. 2 is a vertical cross-sectional view showing another embodiment of the sugar content upsheet of the present invention.

FIG. 3 is a schematic view illustrating an apparatus for producing a sugar content upsheet according to the present invention.

[Explanation of symbols]

A non-woven fabric A B Non-woven fabric B S sugar content up sheet 1 Spunbond spinning machine 2 Melt blow spinning machine 3 Net conveyor 4 Embossing roller

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2B024 DA07 DB03 DB07                 4F100 AK01A AK01B AK01C AK21A                       AK21B AK21C AK41A AK41B                       AK41C AK46A AK46B AK46C                       AK54A AK54B AK54C BA02                       BA03 BA04 BA05 BA10A                       BA10B BA10C BA32 DG15A                       DG15B DG15C EC03 GB01                       JA13A JA13B JA13C JC00A                       JC00B JC00C JD04 JD05                       YY00A YY00B YY00C                 4L032 AA07 AB04 AC01 BD01 BD05                       CA01 CA03 CA05 DA00 EA02                 4L047 AA16 AA21 AB07 AB10 CA05                       EA05

Claims (9)

[Claims] 1. A sugar content composed of a laminate of at least two types of nonwoven fabrics, a nonwoven fabric A made of biodegradable synthetic fibers having a fiber diameter of 10 μm or less and a nonwoven fabric B made of biodegradable synthetic fibers having a fiber diameter of 15 to 50 μm. Up sheet. 2. The non-woven fabric A is a melt blown non-woven fabric, and the non-woven fabric B is a spunbonded non-woven fabric.
The sugar content up sheet described in. 3. The sugar content-up sheet according to claim 1, wherein the non-woven fabrics A and B have a basis weight of 15 to 30 g / m ² , respectively. 4. The apparent density of the nonwoven fabrics A and B is
The amount is 0.2 to 0.5 g / cm ³ , respectively.
Alternatively, the sugar content increasing sheet according to item 3. 5. The sugar content-up sheet according to claim 1, wherein the nonwoven fabric B is laminated on both front and back surfaces of the nonwoven fabric A. 6. A plurality of partially fused portions are dispersed between the laminated layers of the non-woven fabrics A and B and adhered to each other.
5. The sugar content up sheet according to any one of 5 above. 7. The sugar content upsheet according to claim 6, wherein the total area of the partially fused portions occupies 7 to 20% of the laminated surface. 8. The moisture permeability of the sugar content improving sheet is 3500 to 8000 g / m ² · 24 hr, and the water resistance is 8.
The sugar content increasing sheet according to any one of claims 1 to 7, which has a size of 00 to 2000 mm. 9. The biodegradable synthetic fiber comprises at least one selected from the group consisting of polylactic acid, polyhydroxybutyrate, polyglycolic acid, polycaprolactone, polybutylene succinate, polyetheramide and polyvinyl alcohol. The sugar content up sheet according to any one of claims 1 to 8.