JP2008167711A - Agricultural covering sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural covering sheet that is lightweight and has windproof and waterproof properties, excellent workability due to its flexibility, and excellent heat retention for keeping the inside of a tunnel at a higher temperature especially at night in winter. thing.
An agricultural covering sheet comprising a laminated sheet of a hydroentangled nonwoven fabric and a film, having a basis weight of 45 to 145 g / m ² and a heat retention of 15% or more.
[Selection] Figure 1

Description

  The present invention relates to an agricultural covering sheet useful as a covering sheet for house cultivation or tunnel cultivation, and more particularly, it is lightweight and windproof and waterproof, and has excellent workability due to its flexibility, particularly in winter. The present invention relates to an agricultural covering sheet excellent in heat retaining properties that keeps the temperature of a tunnel at a higher temperature at night.

Conventionally, house cultivation and tunnel cultivation have been actively performed as cultivation methods for efficiently cultivating agricultural crops such as vegetables. It is used for the purpose of supplementing the temperature drop from autumn to spring by keeping warm, and it is cultivated higher by keeping the heat absorbed by the ground and plants in the daytime as much as possible inside the house and tunnel to prevent the fall of the ground temperature. The goal is to gain efficiency.
For this purpose, polyvinyl chloride films, polyolefin films, etc. are widely used as covering sheets for houses and tunnels. However, the film alone is not sufficient in heat retention, particularly in severe cold periods, and a separate sheet for heat insulation is further coated (stacked). It will be necessary to remove it. In this case, there is a problem that the expansion work becomes difficult by handling two or more sheets.

  Moreover, the tunnel cultivation method which coat | covers a sheet | seat on a tunnel is especially performed actively by cultivation of leafy vegetables in the severe cold season. In this cultivation method, a support is set up around the flat rice cake and a vegetable seedling is planted, and then covered with a polyvinyl chloride film or a polyolefin film to produce a tunnel. The film is used to cover the tunnel before sunset in order to mitigate significant temperature drop in the morning tunnel, and to peel off the tunnel during the day to give light and heat to the vegetables. Thus, in the cultivation method using a general-purpose film, there is a problem that a large amount of labor is required because the covering and closing operations must be repeated regularly.

In order to solve these problems, a covering sheet made of a laminate of a translucent nonwoven sheet having a thickness of 0.05 to 2 mm and a synthetic resin film having a thickness of 0.03 to 0.2 mm has been proposed ( Patent Document 1).
However, some ideas have been added to enhance the heat retaining property, but the heat retaining property is not clear, and the technique for ensuring the heat retaining property is extremely unclear.

Moreover, the agricultural heat insulating material which consists of a laminated body of the nonwoven fabric containing a heat-fusible fiber and porous films, such as polyethylene, is proposed (refer patent document 2).
However, since the nonwoven fabric has a high content of heat-fusible fibers, it has low flexibility, and there is a problem in workability such that lighting and ventilation for tunnel lighting and house cultivation cannot be easily performed. is there.

Also proposed is a green house sheet comprising a laminate in which non-permeable and translucent synthetic resin films such as polyethylene terephthalate are provided with non-woven fabrics in which long fiber filaments are joined at a high density. (See Patent Document 3).
However, since the nonwoven fabric is a nonwoven fabric composed of long fibers, it is difficult to form an air layer in the nonwoven fabric, and satisfactory heat retention is not obtained.

Particularly in recent farmers, an increase in the weight of the seat with the aging of the farmer is not preferable because the workload increases. In addition, if the seat is not flexible, there is a problem that outside air can easily enter from the gap between the assembled house and the aggregate of the tunnel, and the desired heat retention cannot be obtained sufficiently.
Japanese Utility Model Publication No. 57-19037 JP 09-300511 A JP-A-10-248406

  An object of the present invention is to solve the above-mentioned conventional problems, and to provide an agricultural covering sheet that is lightweight and excellent in flexibility, heat retention and workability.

  As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. That is, the agricultural covering sheet excellent in heat retention and workability of the present invention has the following configuration.

(1) An agricultural covering sheet comprising a laminated sheet of a hydroentangled nonwoven fabric and a film, having a basis weight of 45 to 145 g / m ² and a heat retention of 15% or more.

(2) The agricultural covering sheet according to (1), which is a hydroentangled nonwoven fabric containing 30% by weight or less of heat-fusible fibers.

(3) The agricultural covering sheet according to (1) or (2), wherein the hydroentangled nonwoven fabric is a nonwoven fabric obtained by hydroentangling a parallel web or a semi-random web.

(4) The agricultural covering sheet according to any one of (1) to (3), wherein the hydroentangled nonwoven fabric and the polyester film are bonded together via a polyethylene adhesive layer.

(5) The agricultural covering sheet according to any one of the above (1) to (4), wherein the sheet has a bending resistance in the width direction of 90 mm or less when measured based on JIS L1096 A method.

(6) The agricultural covering sheet according to any one of (1) to (5), which is used for house cultivation or tunnel cultivation.

(7) A method for cultivating vegetables and fruit trees using the agricultural coating sheet according to (1).

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the agricultural coating sheet excellent in workability | operativity by being excellent in heat retention, being lightweight and having flexibility. Moreover, it becomes possible to cultivate high-quality crops by using the agricultural covering sheet for house cultivation and tunnel cultivation.

  The agricultural covering sheet of the present invention is composed of a laminate of a specific hydroentangled nonwoven fabric and a polyester film.

  The kind of fiber which comprises the hydroentangled nonwoven fabric in this invention is not restrict | limited in particular, A natural fiber, a regenerated fiber, a semisynthetic fiber, a synthetic fiber, etc. can be utilized. Typical fibers include natural fibers (eg, cotton, hemp, wool, pulp, silk, etc.), recycled fibers (eg, rayon fiber, polynosic fiber, cupra fiber) and semi-synthetic fibers (eg, acetate fiber), Synthetic fiber (for example, polyolefin resin fiber such as polyethylene and polypropylene, acrylic fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, polyvinyl alcohol fiber or vinylon fiber, polyalkylene terephthalate, polyalkylene naphthalate, wholly aromatic Polyester fiber such as aliphatic polyester, polyamide fiber such as aliphatic, alicyclic or aromatic polyamide, polyurethane fiber, etc.). Two or more of these fibers may be used in combination. In addition, a composite fiber composed of a plurality of resins is not limited to a two-layer structure (for example, a two-layer structure such as a sheath core structure or a parallel structure), but a multilayer structure (for example, a parallel structure, a wood grain structure, a radiation structure, or a hollow structure). A multi-layer structure such as a radiation structure, a multi-core structure, a multi-core structure, a mosaic structure, an archipelago structure, or a nebula structure).

  Moreover, it does not restrict | limit especially about the cross-sectional shape of the fiber which comprises a hydroentangled nonwoven fabric, For example, a circular cross section, a deformed cross section, a polygonal cross section, a multilobal cross section, a hollow cross section etc. may be sufficient. Further, the single fiber fineness of the fiber is not particularly limited, but is preferably 0.5 to 10 dtex, more preferably 1 to 8 dtex, and still more preferably 1.5 to 6 dtex, from the viewpoint of heat retention and strength ensuring of the nonwoven fabric. . Furthermore, it is preferable that the average fiber length of a fiber exists in the range of 20-80 mm from points, such as manufacturing workability | operativity and the mechanical characteristic of a nonwoven fabric. More preferably, it is 30-70 mm, More preferably, it is 35-60 mm. By using such short fibers, it is possible to improve mechanical properties such as strength and elongation of the nonwoven fabric while increasing the mobility and entanglement degree of the fibers by hydroentanglement treatment.

  A particularly preferable non-woven fabric is obtained by hydroentangled a web composed mainly of polyester fibers such as polyethylene terephthalate having a general circular cross section and mixed with heat-fusible fibers as necessary. The ratio of the polyester fiber and the heat-fusible fiber is preferably 70/30 to 100/0, more preferably 80/20 to 95/5, by weight. If the ratio of the polyester fiber is less than 70% by weight, it becomes difficult to obtain the flexibility required for this application, which is not preferable.

  The heat-fusible fiber used here is formed of a high melting point component and a low melting point component, and the high and low melting point component has a melting point higher by 30 ° C. than the melting point of the low melting point component. preferable. Examples of the form of the fiber include a composite fiber in which a high melting point component and a low melting point component are bonded in a side-by-side type, and a composite fiber in which a high melting point component and a low melting point component are bonded in a core-sheath type. Form may be sufficient. Among these, a core-sheath type composite fiber having a high melting point component as a core component and a low melting point component as a sheath component is preferable. The cross-sectional shape of the composite fiber is not particularly limited, and may be any shape such as a round core sheath, an eccentric core sheath, and a modified cross-section core sheath. It is preferable that the low melting point component serving as the sheath covers at least 40%, particularly 60% or more around the core component. Moreover, 80 / 20-20 / 80 is preferable by weight ratio, and, as for the ratio of a core component and a sheath component, it is more preferable that it is 70 / 30-30 / 70.

  As a specific example of the cross-section of the core-sheath type composite fiber, for example, a combination in which the core component / sheath component is polypropylene / polyethylene, polyamide / polyethylene, polyester / polyethylene, polyester / polypropylene, polyester / polyamide is suitable. Among these, a combination of polyethylene terephthalate / polyethylene which is inexpensive and generally used for nonwoven fabrics is preferable.

  As a method for producing the hydroentangled nonwoven fabric in the present invention, a known method can be used. For example, the above-mentioned short fibers / heat-fusible fibers = 70/30 to 100/0 (weight ratio) are blended and opened by carding with a card machine, for example, to create a nonwoven web. Such non-woven webs are parallel webs arranged in the direction of travel of the card machine according to the blending ratio of the constituent fibers, cross webs where the parallel webs are cross-laid, random webs arranged randomly, or semi-random webs arranged in the middle of both. However, random webs and cross webs may be entangled in fibers in the horizontal direction, and may be poorly aligned when stretched into a tunnel. Therefore, in the present invention, parallel webs and semi-random webs may be used. It is preferable to use a web.

  Next, hydroentanglement treatment is performed on the obtained nonwoven web. The water entanglement treatment is, for example, a porous water flow that is jetted in a column shape at high pressure from a nozzle plate in which nozzle holes having a diameter of 0.05 to 0.20 mm and intervals of 0.30 to 1.50 mm are arranged in one or two rows. The non-woven web placed on the support member is made to collide, and the constituent fibers of the non-woven web are densely three-dimensionally entangled and integrated.

When three-dimensional entanglement is performed on the nonwoven fabric web, the nonwoven fabric web is placed on the moving porous support member, and the water pressure is 10 to 150 kg / cm ² , particularly 20 to 120 kg / cm ² , one or more times. The method of processing is mentioned suitably. The injection holes are arranged in a row in a direction perpendicular to the traveling direction of the nonwoven web, and the nozzle plate in which the injection holes are arranged is perpendicular to the traveling direction of the nonwoven web placed on the porous support member. It is preferable to cause the water flow to uniformly collide with the nonwoven fabric web by causing the water flow to swing at the same interval as the spray hole interval. The porous support member on which the nonwoven fabric web is placed is not particularly limited as long as the water flow can penetrate the nonwoven fabric web, such as a mesh screen such as a wire mesh or a perforated plate. The distance between the spray hole and the nonwoven fabric web is preferably 1 to 10 cm. If it is outside this range, the texture of the nonwoven fabric tends to be disturbed or the three-dimensional entanglement is insufficient.

  After the water entanglement process, the drying process is performed. First, it is preferable to remove excess moisture from the treated nonwoven web, and any known method can be used to remove excess moisture. For example, excessive moisture is removed to some extent using a squeezing device such as mangrol, and then the remaining moisture is removed using a drying device such as a suction band type hot air circulation dryer.

The basis weight of the nonwoven fabric thus obtained is preferably in the range of 15 to 100 g / m ² . More preferably, it is the range of 30-90 g / m < ² >. When the basis weight is less than 15 g / m ² , it becomes difficult to produce the hydroentangled nonwoven fabric itself, and it is difficult to form an air layer necessary for heat retention as an agricultural covering sheet. On the other hand, if the basis weight exceeds 100 g / m ² , it is difficult to produce the hydroentangled nonwoven fabric itself, and the weight of the covering sheet becomes heavy, which makes it difficult to carry. Further, the covering sheet becomes bulky, and handling becomes difficult in the folding work when opened.

  The film in the present invention mainly plays a role of blocking outside air, rain and the like. For this reason, a thinner film is advantageous in terms of workability and economy. It is sufficient if lamination is possible, and a range of 5 to 50 μm, particularly a range of 10 to 20 μm is preferable. If the thickness is less than 5 μm, it is difficult to obtain a sufficient water-blocking property or cold-blocking property. On the other hand, if it exceeds 50 μm, it is uneconomical, and along the tunnel, workability is deteriorated.

  The material of the film includes polyolefins such as polyethylene and polypropylene, and polyesters such as polyethylene terephthalate. Polyester films such as polyethylene terephthalate are preferable from the viewpoint of ensuring heat retention and workability during tunnel cultivation and house cultivation. By laminating the polyester film on the hydroentangled nonwoven fabric, the heat retention property of the nonwoven fabric can be further improved. Further, when the polyester film is used to form a covering sheet, the alongness to the tunnel is good and the workability is also good.

  The film can be produced by a conventionally known T-die method, inflation method or the like, and an unstretched film or a uniaxially or biaxially stretched film can be used, but a biaxially stretched film can be used. preferable.

  The laminating method of the hydroentangled nonwoven fabric and the film can be arranged as it is and thermocompression bonded with a heating roll, but the laminating method can be used as a method that can be processed stably at high speed and provides a strong adhesive force. Can be mentioned. Lamination is, for example, a method of laminating a laminate component on one side of a hydroentangled nonwoven fabric and laminating it with a film, and then bonding by various fusion methods such as a hot oven type, a hot roll type, and a hot plate type. From the viewpoint of cost and productivity, polyethylene is preferably used as a laminate component.

The laminated sheet of the present invention thus obtained has a basis weight in the range of 45 to 145 g / m ² , preferably in the range of 60 to 125 g / m ² . Further, since the heat retention of the laminated sheet is 15% or more, preferably 20% or more, it is optimal as a covering sheet used for house cultivation or tunnel cultivation.

  Also, if the thickness of the laminated sheet of the present invention is from 0.10 to 1.00 mm, which is too thick, there may be cases where it is not possible to lightly perform the opening work for daytime daylighting and the heat insulation at night. Not very good. Although it varies depending on the hydroentangled nonwoven fabric and the material of the film, it is preferably in the range of 0.10 to 1.00 mm, particularly preferably in the range of 0.20 to 0.70 mm.

  Further, the laminated sheet of the present invention has a bending resistance of 90 mm or less, preferably 70 mm or less, when measured in accordance with the JIS L1096 A method in the width direction of the sheet (the direction perpendicular to the sheet length direction). If the bending resistance exceeds 90 mm, it will be difficult to follow the shape of the tunnel or house, and cold air from the outside will easily enter between the covering sheet and the tunnel or house film, making it difficult to obtain high heat retention performance. Further, the covering sheet is hard, and it becomes difficult to move the sheet for daylighting and heat collection in tunnel cultivation and house cultivation.

  The laminated sheet of the present invention is not particularly limited as long as it is a sheet used for agricultural products. For example, as a covering material used for house cultivation, tunnel cultivation, seedling frame cultivation, forcing frame cultivation, etc., it can be used as a stretched tent-like shape on a crop via a pillar, etc. Suitable as a cover sheet for cultivation.

  When the laminated sheet of the present invention is used for tunnel cultivation and house cultivation, the film layer of the laminated sheet is used as the outer surface to ensure windproof and waterproof properties, and the water flow nonwoven fabric layer can ensure excellent heat retention. . Moreover, the laminated sheet of the present invention is excellent in flexibility, and can well conform to the shapes of complex tunnels and houses. The gap between the coating sheet of the present invention and the tunnel film can be minimized, and high heat retention can be realized without intruding cool air from the outside. This makes it possible to minimize the temperature drop around the leaves, especially during the winter, and realize an efficient cultivation environment.

  In addition, since the laminated sheet of the present invention is integrated with the film layer of the surface responsible for wind protection and waterproofing and the hydroentanglement layer mainly responsible for heat retention, in cultivation of vegetables and fruit trees by tunnel cultivation, house cultivation, etc. The laminated sheet itself is lightweight and has a low burden of extending to tunnels and houses. Furthermore, because of the excellent flexibility and slipperiness of the laminated sheet of the present invention, it is possible to lightly and speedily perform the opening work for daylighting and heat collection, and the covering work for tunnels and houses for keeping warm at night. . Also, during daytime daylighting, it can be folded compactly on the side of a tunnel or house so that daylighting can be performed efficiently. Thus, extremely excellent workability is exhibited.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In addition, each physical property value in this example was evaluated by the following method.

(1) Weight per unit area (g / m ² )
A sample is left for 24 hours in a standard state at a temperature of 20 ° C. and a humidity of 65%, then a sample of 1 m in the width direction and 1 m in the length direction is taken, and the weight (g) is measured using a balance. The weight (g) obtained was rounded to the nearest decimal place.

(2) Thickness (mm)
Five samples per 1 m in the width direction were taken from the sample and measured at a disk diameter of 10 mm and a load of 7.85 kpa based on JIS L1906.

(3) Tensile strength and elongation (%)
It measured according to JIS L1913.

(4) Transmittance (%)
As a light source used for light transmittance measurement, “Photo Reflector Blood” 100 V / 300 W manufactured by Toshiba Corporation was used. As the illuminance meter, “Lux-meter ANA-315” manufactured by Tokyo Koden Co., Ltd. was used. The light transmittance was measured by measuring the illuminance using the illuminometer and calculating the transmittance according to the following equation.
Transmittance (%) = (illuminance when sandwiching laminated sheets) / (blank illuminance) × 100

(5) Thermal insulation rate (%)
It measured according to JIS L1906 B method (cooling method).

(6) Flexibility (mm)
Measured according to JIS L1906 A method (cantilever method),

(7) Roll weight (Kg)
The roll weight was calculated based on the standard size of the product roll with a width of 2 m and a length of 100 m, which is the most common standard for coating materials used for tunnel cultivation.
Roll weight (Kg) = covering sheet basis weight (g / m ² ) × width 2 m × length 100 m

(8) Cultivation test As shown in FIG. 1, the soil of the soil a such as a field is raised to form a flat surface with a flat upper surface, the flat surface is covered with the multi-film b, and the end portion is in the soil. To fix the multi-film. The multi-film may be opened in advance using a planting hole or may be opened later using a film having no planting hole. In addition, a large number of frames are arranged above the flat plate c at substantially uniform intervals, covered with agricultural PVC film or agricultural PO film d, etc., and house bands are arranged at substantially uniform intervals to suppress film fluttering. Fixed and used as a tunnel for lettuce cultivation. Lettuce seedlings were planted in a multi-film planting hole, and lettuce was actually cultivated. The tunnel was covered with agricultural covering sheets listed in the examples and comparative examples for the purpose of keeping warm at night, and these were also fixed at substantially uniform intervals with a house band. The number of non-defective products and the grade were evaluated by the following formulas from the number of lettuce obtained by cultivation in this way.
The yield rate was calculated from the following formula from lettuce harvested from the tunnels tested in the examples and comparative examples.
Non-defective product rate (%) = Number of lettuce harvests that have been commercialized (pieces) / Number of planted lettuce seedlings (pieces) x 100

The lettuce grade is S with a weight per piece of 230-300 g and a diameter of about 12.4 cm, and M with a weight of 300-360 g per piece and a diameter of about 13.3 cm. The weight per piece is 360 to 430 g and the diameter is about 15.0 cm, L, and the weight per piece is 430 to 510 g and the diameter is about 15.6 cm is 2 L, and the weight per piece is 510. ˜680 g and a diameter of about 16.6 cm were determined to be 3 L. The L ratio was calculated from the number of harvested lettuce corresponding to L, 2L, 3L by the following formula.
L rate (%) = Number of harvested lettuce of L-3L grade (number) / Number of planted lettuce seedlings (number) x 100
Moreover, only the positive sphere which the shape of lettuce is not waist height, a petiole deformation, and a single roll was judged as excellent as a fruit standard, and the excellent L ratio was calculated from the following equation.
Hide L rate (%) = L-3L grade and excellent number of lettuce harvest (pieces) / number of lettuce seedlings planted (pieces) x 100

(9) Workability evaluation test Lettuce cultivation was carried out on five tunnel lettuce-cultivating farmers with the agricultural covering sheets listed in Examples and Comparative Examples over the tunnel. At that time, A transportability B covering / opening C covering / opening after rain D folding at opening E storage management after cultivation was evaluated by questionnaire. In the evaluation, 1 to 5 points were set. The points were very good: 5 points, good: 4 points, normal: 3 points, bad: 2 points, very bad: 1 point.

(10) Nighttime temperature measurement A T & D thermometer (TR-51A) was installed at a height of 20 cm from the upper surface of the flat wall at the center in the width direction and at the center in the longitudinal direction of the flat wall in the tunnel. (Temperature 1). In addition, a thermometer of the same type was installed at a position 20 cm above the ground at a position 50 cm away from the tunnel end, near the tunnel temperature measurement position (air temperature 2), and the temperature was measured.
The value of temperature 1 when temperature 2 is -7.3 degrees is shown.

The following were prepared as raw materials for agricultural covering sheets.
[Polyester fiber]: Polyethylene terephthalate fiber (manufactured by Teijin Ltd., “TT02T”) 1.7 dtex × 51 mm
[Heat-bondable fiber]: Core-sheath type composite fiber whose core component is polyethylene terephthalate and whose sheath component is polyethylene ("NBF (SH) 0174", 2.2 dtex x 51 mm, manufactured by Daiwabo Polytech Co., Ltd.)
[Polyester film]: Polyethylene terephthalate film (manufactured by Toray Industries, Inc., “Lumirror PX52”, basis weight 16.6 g / m ² , thickness 12 μm)
[Adhesive resin]: LD polyethylene (Petrocene) thickness 15μm

A 90% by weight polyester fiber and 10% by weight heat-fusible fiber were mixed to produce a semi-random web having a basis weight of 60 g / m ² . Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. In the water entanglement treatment, the nozzles in which the injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web were injected and entangled at a water pressure of 60 kg / cm ² .
After the entanglement treatment, drying was performed at 135 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 60 g / m ² .
The obtained water-entangled nonwoven fabric and the above-mentioned 12 μm-thick polyethylene terephthalate film were bonded by using a 15 μm-thick polyethylene resin film extruded from a T-die to obtain a laminated sheet. Table 1 shows various physical properties of the laminated sheet.
The laminated sheet was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show workability, crop cultivation results, and the like. As a result of using the laminated sheet as a covering sheet, lettuce was very good and workability was also good. On the morning of the day when it was most cold, the outside temperature was -7.3 ° C, while the temperature inside the tunnel was -2.5 ° C.

A 90% by weight polyester fiber and 10% by weight heat-fusible fiber were mixed to produce a semi-random web having a basis weight of 30 g / m ² . Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. In the water entanglement treatment, the nozzles in which injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web were injected and entangled at a water pressure of 30 kg / cm ² .
After the entanglement treatment, drying was performed at 135 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 30 g / m ² . A laminated sheet was obtained under the same other conditions as in Example 1. Table 1 shows various physical properties of the laminated sheet.
The laminated sheet was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show the workability and the result of crop multiplication. As a result of using the laminated sheet as a covering sheet, the lettuce was extremely good and the workability was also good. The heat retention effect was also sufficient.

A 90% by weight polyester fiber and 10% by weight heat-fusible fiber were mixed to produce a semi-random web having a basis weight of 15 g / m ² . Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. In the water entanglement treatment, the nozzles in which injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web were injected and entangled at a water pressure of 15 kg / cm ² .
After the entanglement treatment, drying was performed at 135 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 15 g / m ² . A laminated sheet was obtained under the same other conditions as in Example 1. Table 1 shows various physical properties of the laminated sheet.
The laminated sheet was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show workability, crop cultivation results, and the like. As a result of using the laminated sheet as a covering sheet, lettuce was very good and workability was also good. The heat retention effect was also sufficient.

A 90% by weight polyester fiber and 10% by weight heat-fusible fiber were mixed to produce a semi-random web having a basis weight of 100 g / m ² . Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. The water entanglement treatment was carried out using a nozzle in which injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web and entangled at a water pressure of 80 kg / cm ² .
After the entanglement treatment, drying was performed at 135 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 100 g / m ² . A laminated sheet was obtained under the same other conditions as in Example 1. Table 1 shows various physical properties of the laminated sheet.
The laminated sheet was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show workability, crop cultivation results, and the like. As a result of using the laminated sheet as a covering sheet, lettuce was very good and workability was also good. The heat retention effect was also sufficient.

A semi-random web having a basis weight of 60 g / m ² was produced with 100% by weight of the above-described polyester fiber. Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. In the water entanglement treatment, the nozzles in which the injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web were injected and entangled at a water pressure of 60 kg / cm ² .
After the entanglement treatment, drying was performed at 135 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 60 g / m ² . A laminated sheet was obtained under the same other conditions as in Example 1. Table 1 shows various physical properties of the laminated sheet.
The laminated sheet was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show workability, crop cultivation results, and the like. As a result of using the laminated sheet as a covering sheet, lettuce was very good and workability was also good. The heat retention effect was also sufficient.

A 70% by weight polyester fiber and 30% by weight heat-fusible fiber were mixed to produce a semi-random web having a basis weight of 60 g / m ² . Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. In the water entanglement treatment, the nozzles in which the injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web were injected and entangled at a water pressure of 60 kg / cm ² .
After the entanglement treatment, drying was performed at 135 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 60 g / m ² . A laminated sheet was obtained under the same other conditions as in Example 1. Table 1 shows various physical properties of the laminated sheet.
The laminated sheet was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show workability, crop cultivation results, and the like. As a result of using the laminated sheet as a covering sheet, lettuce was very good and workability was also good. The heat retention effect was also sufficient.

90% by weight of the polyester fiber and 10% by weight of the heat-fusible fiber were mixed to produce a parallel web having a basis weight of 60 g / m ² . Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. In the water entanglement treatment, the nozzles in which the injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web were injected and entangled at a water pressure of 60 kg / cm ² .
After the entanglement treatment, drying was performed at 135 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 60 g / m ² . A laminated sheet was obtained under the same other conditions as in Example 1. Table 1 shows various physical properties of the laminated sheet.
The laminated sheet was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show workability, crop cultivation results, and the like. As a result of using the laminated sheet as a covering sheet, lettuce was very good and workability was also good. The heat retention effect was also sufficient.

Comparative Example 1
A 90% by weight polyester fiber and 10% by weight heat-fusible fiber were mixed to produce a semi-random web having a basis weight of 120 g / m ² . Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. In the water entanglement treatment, nozzles in which injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web were injected at a water pressure of 80 kg / cm ² and entangled.
After the entanglement treatment, drying was performed at 135 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 120 g / m ² . A laminated sheet was obtained under the same other conditions as in Example 1. Table 1 shows various physical properties of the laminated sheet.
The laminated sheet was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show workability, crop cultivation results, and the like. As a result of using the laminated sheet as a covering sheet, the lettuce was very good, but the covering sheet was heavy and difficult to carry. In addition, there were many opinions that the folding work at the time of opening was bulky and difficult to handle.

Comparative Example 2
A 90% by weight polyester fiber and 10% by weight heat-fusible fiber were mixed to produce a semi-random web having a basis weight of 60 g / m ² . Next, a water stream was sprayed on the obtained web to perform an entanglement treatment. In the water entanglement treatment, the nozzles in which the injection holes having a diameter of 0.10 mm were provided at intervals of 0.6 mm in the width direction of the web were injected and entangled at a water pressure of 60 kg / cm ² .
After the entanglement treatment, drying was performed at 130 ° C. with a cylinder dryer to obtain a hydroentangled nonwoven fabric having a basis weight of 60 g / m ² . Then, lamination with the film in Example 1 was not performed. Table 1 shows various physical properties of the hydroentangled nonwoven fabric.
Moreover, this nonwoven fabric was used as a tunnel cultivation covering sheet of lettuce. Table 2, Table 3 and Table 4 show workability, crop cultivation results, and the like. As a result of using the nonwoven fabric as a covering sheet, lettuce was poor. Also, after the rain, the covering sheet became wet and heavy, and the covering / opening operation was very difficult. The temperature inside the tunnel was -3.8 ° C, and the heat retention was insufficient.

Comparative Example 3
As a result of using Asahi Kasei Fiber's polyethylene terephthalate spunbonded nonwoven fabric “Mariace” as a cover for tunnel cultivation of lettuce, lettuce was poor. Further, the covering sheet made of the nonwoven fabric was harder than the covering sheets of Examples 1 to 4, and the covering / opening operation was difficult. Further, after the rain, the covering sheet became wet and heavy, and the covering / opening operation was more difficult. Furthermore, the folding property at the time of opening was poor, and the lettuce on the side where the folding was performed did not grow well due to lack of sunlight. Moreover, along the tunnel, the temperature inside the tunnel was -3.8 ° C, and the heat retaining property was insufficient.

Comparative Example 4
A polyethylene terephthalate spunbond nonwoven fabric “Mariace” manufactured by Asahi Kasei Fiber Co., Ltd. was used to cover the tunnel, and from above the tunnel was covered with an agricultural polyvinyl chloride film, which was used as an agricultural covering sheet.
As a result of using the coated sheet, lettuce was poor. The covering and opening work was very difficult because it was a double stack. Furthermore, the folding property at the time of opening was poor, and the lettuce on the side where the folding was performed did not grow well due to lack of sunlight. Moreover, along the tunnel, the temperature inside the tunnel was -3.8 ° C, and the heat retaining property was insufficient.

Comparative Example 5
The polyethylene terephthalate spunbond nonwoven fabric “Mariace” manufactured by Asahi Kasei Fibers Co., Ltd. was bonded to the polyethylene terephthalate film having a thickness of 12 μm as an adhesive layer to obtain a laminated sheet. Table 1 shows various physical properties of the laminated sheet.
Moreover, although this laminated sheet was used as a tunnel cultivation covering sheet of lettuce, the result of lettuce was bad. Further, the covering sheet was very hard and the covering / opening operation was difficult. Furthermore, the folding property at the time of opening was poor, and the lettuce on the side where the folding was performed did not grow well. Moreover, along the tunnel, the temperature inside the tunnel was -3.9 ° C, and the heat retaining property was insufficient.

Comparative Example 6
As a result of using DuPont polyethylene flashspun non-woven fabric "Tyvek" as a tunnel cultivation cover of lettuce, the lettuce was poor. Further, the covering sheet was very hard and the covering / opening operation was difficult. And the folding property at the time of opening was bad, and the lettuce of the side which performed folding was bad growth. Also, along the tunnel, the temperature inside the tunnel was -4.1 ° C, and the heat retention was insufficient.

Explanatory drawing of the cultivation test of the present invention Perspective view showing tunnel cultivation Explanatory drawing of cover sheet opening work in tunnel cultivation Explanatory drawing of covering work of covering sheet in tunnel cultivation

Explanation of symbols

a: soil b: multi-film c: flat ridge d: agricultural film e: agricultural covering sheet

Claims (7)

An agricultural covering sheet comprising a laminated sheet of a hydroentangled nonwoven fabric and a film, having a basis weight of 45 to 145 g / m ² and a heat retention of 15% or more. The agricultural covering sheet according to claim 1, which is a hydroentangled nonwoven fabric containing 30% by weight or less of heat-fusible fibers. The agricultural covering sheet according to claim 1 or 2, wherein the hydroentangled nonwoven fabric is a nonwoven fabric obtained by hydroentangling a parallel web or a semi-random web. The agricultural covering sheet according to any one of claims 1 to 3, wherein the hydroentangled nonwoven fabric and the polyester film are bonded together via a polyethylene adhesive layer. The agricultural covering sheet according to any one of claims 1 to 4, wherein the bending resistance in the width direction of the sheet is 90 mm or less as measured based on JIS L1096 A method. The agricultural covering sheet according to any one of claims 1 to 5, which is used for house cultivation or tunnel cultivation. A method for cultivating vegetables and fruit trees using the agricultural coating sheet according to claim 1.

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