JP6844151B2 - Plant cultivation equipment and reflective sheet - Google Patents

Description

The present disclosure relates to plant cultivation equipment and reflective sheets.

As a method for cultivating plants such as vegetables, for example, artificial light type cultivation using artificial light such as LED is known. As a plant cultivation device used for artificial light type cultivation, for example, in Patent Document 1, a cultivation rack having a plurality of columns and a mounting portion for mounting a cultivation tank provided by using the columns and in which plants are planted is provided. A lighting device is provided above the mounting portion and is arranged in the cultivation rack at intervals, and the lighting device is attached to the cultivation rack so that the height position of the lighting device with respect to the mounting portion can be changed. However, in a plant cultivation device including a frame-shaped frame and a plurality of straight tubular LED lamps detachably attached to the frame, a pair of frame members facing each other in the frame of the lighting device can be specified. A plant cultivation device having a lighting fixture receiving portion of the above is disclosed. An object of this technique is to provide a plant cultivation device capable of reducing the number of parts while making the work of attaching and detaching the LED lamp to and from the frame of the lighting device relatively easy.

Further, Patent Document 2 describes a plant cultivation apparatus including a cultivation rack having a mounting shelf on which a cultivation tank in which plants are planted is placed, and an LED lighting device arranged above the mounting shelf at intervals. Disclosed is a plant cultivation device provided with a support portion for supporting the LED lighting device so that the height position of the LED lighting device with respect to a mounting shelf can be changed in the cultivation rack. An object of this technique is to provide a plant cultivation apparatus capable of adjusting the light intensity of irradiating a plant.

Japanese Unexamined Patent Publication No. 2015-8126 Japanese Unexamined Patent Publication No. 2013-17397

For example, by arranging a reflective sheet on the side surface of the cultivation rack, it is possible to efficiently irradiate the plant with artificial light such as an LED. However, if the reflective sheet is placed on the side surface of the cultivation rack, heat and air tend to stay in the cultivation rack.

The present disclosure has been made in view of the above circumstances, and the main object of the present invention is to provide a plant cultivation apparatus capable of suppressing heat and air retention in a cultivation rack while efficiently irradiating plants with artificial light. And.

In the present disclosure, the first member on which the cultivation tank can be placed, the second member arranged with a space for the first member, and the second member arranged with a space for the first member are arranged. A cultivation rack having a structure having a lighting member arranged closer to the first member than the second member, and a plurality of pillar members for fixing the positions of the first member and the second member. Provided is a plant cultivation apparatus which is arranged on the side surface of the cultivation rack, has visible light reflectivity, and includes a reflective sheet having a plurality of penetrating portions.

Further, in the present disclosure, a first member on which a cultivation tank can be placed, a second member arranged with a space provided for the first member, and a space provided for the first member are arranged. A cultivation rack having a unit structure having a lighting member arranged on the first member side of the second member and a plurality of pillar members for fixing the positions of the first member and the second member. Provided is a reflective sheet arranged on the side surface of the above, which has visible light reflectivity and has a plurality of penetrating portions.

The plant cultivation apparatus of the present disclosure has an effect that heat and air can be suppressed from staying in the cultivation rack while efficiently irradiating the plant with artificial light.

It is a schematic front view which shows an example of the cultivation rack in this disclosure. It is a schematic side view of FIG. It is a schematic perspective view which shows an example of the plant cultivation apparatus of this disclosure. It is an enlarged view which enlarged a part of FIG. It is a schematic plan view which illustrates the reflective sheet in this disclosure. It is a schematic plan view which illustrates the reflective sheet in this disclosure. It is a schematic plan view which illustrates the reflective sheet in this disclosure. It is a schematic plan view which illustrates the penetration part in this disclosure.

Hereinafter, the plant cultivation apparatus and the reflective sheet of the present disclosure will be described in detail.

A. Plant Cultivation Equipment The plant cultivation equipment of the present disclosure will be described with reference to FIGS. 1 to 4. FIG. 1 is a schematic front view showing an example of a cultivation rack, and FIG. 2 is a schematic side view of FIG. Further, FIG. 3 is a schematic perspective view showing an example of a plant cultivation apparatus, and FIG. 4 is an enlarged view of a part of FIG.

As shown in FIGS. 1 and 2, the cultivation rack 10 includes a first member 12 on which the cultivation tank 11 can be placed, a second member 13 arranged with a space for the first member 12, and a first member 13. A plurality of lighting members 14 arranged with a space provided for one member 12 and arranged on the first member side 12 of the second member 13 and fixing the positions of the first member 12 and the second member 13. It has a structure 16 having the pillar member 15 of the above. The cultivation rack 10 in FIGS. 1 and 2 has a structure in which the structures 16 are stacked in four stages. Although not particularly shown, the cultivation rack 10 may be provided with a culture solution supply device for supplying the culture solution to the cultivation tank 11. Further, as shown in FIGS. 3 and 4, the plant cultivation apparatus 100 is arranged on the cultivation rack 10 and the side surface of the cultivation rack 10, has visible light reflectivity, and has a plurality of penetrating portions 21. And.

According to the present disclosure, since the reflective sheet arranged on the side surface of the cultivation rack has a penetrating portion, the plant can suppress heat and air from staying in the cultivation rack while efficiently irradiating the plant with artificial light. It can be a cultivation device. As described above, for example, by arranging the reflective sheet on the side surface of the cultivation rack, it is possible to efficiently irradiate the plant with artificial light such as an LED. In particular, by using a reflective sheet having good diffuse reflection, it is possible to efficiently irradiate plants with artificial light. As a result, the number of light sources of the lighting device can be reduced, and as a result, the equipment cost and the running cost can be reduced.

On the other hand, if the reflective sheet is arranged on the side surface of the cultivation rack, heat and air tend to stay in the cultivation rack. For example, the light source of a lighting device also generates heat when emitting light. When the reflective sheet is arranged on the side surface of the cultivation rack, heat stays in the cultivation rack and the temperature in the cultivation rack tends to rise. Further, depending on the plant to be cultivated, it may be preferable that an air flow exists in the cultivation rack, but if a reflective sheet is arranged on the side surface of the cultivation rack, air stays in the cultivation rack and the ventilation property is lowered. It will be easier to do.

On the other hand, according to the present disclosure, since the reflective sheet arranged on the side surface of the cultivation rack has a penetrating portion, heat and air stay in the cultivation rack while efficiently irradiating the plant with artificial light. It can be a plant cultivation device that can suppress this. In particular, the reflection efficiency can be maintained high by providing the minimum through portion that can suppress the retention of heat and air.
The plant cultivation apparatus of the present disclosure will be described for each configuration.

1. 1. Reflective sheet The reflective sheet in the present disclosure is arranged on the side surface of the cultivation rack. The "side surface of the cultivation rack" refers to the surface specified by the first member, the second member and the pillar member. For example, when the shape of the cultivation rack is a cube, four of the six surfaces, excluding the top surface and the bottom surface, correspond to the side surfaces of the cultivation rack. The reflective sheet may be arranged on at least one side surface of the cultivation rack, may be arranged on two sides, may be arranged on three sides, or may be arranged on four sides. Above all, it is preferable that the reflective sheets are arranged on two opposite surfaces of the cultivation rack. This is because the air flow becomes smooth. In particular, as illustrated in FIGS. 3 and 4, it is preferable that the reflective sheet is arranged on the side surface of the first member 12 and the second member 13 parallel to the longitudinal direction. On the other hand, it is possible to further improve the reflection efficiency by arranging it on all four sides of the cultivation rack. The shape of the reflective sheet is not particularly limited, and examples thereof include a square and a rectangle. In particular, the reflective sheet is preferably a long rectangular sheet.

The reflective sheet is a sheet having visible light reflectivity. The visible light reflectance (average reflectance at a wavelength of 380 nm or more and 780 nm or less) of the reflective sheet is, for example, 70% or more, preferably 80% or more, and more preferably 90% or more.

Further, the reflective sheet has a plurality of penetrating portions. Examples of the shape of the penetrating portion include a circular shape, an elliptical shape, a square shape, an indefinite shape, and the like. The size of the penetrating portion is preferably, for example, 0.5 mm or more and 20 mm or less. The size of the penetrating portion means the longest length in the penetrating portion, and corresponds to, for example, the diameter when the penetrating portion is circular.

Further, the region in which a plurality of penetrating portions are formed is referred to as a first region. The aperture ratio of the first region is, for example, 0.5% or more, may be 1% or more, or may be 2% or more. On the other hand, the aperture ratio of the first region is, for example, 10% or less, 6% or less, or 4% or less. Further, the ratio of the penetrating portions in the first region is, for example, 100 pieces / m ² or more and 1000 pieces / m ² or less.

Further, the plurality of penetrating portions may be formed in a pattern. The pattern shape of the penetrating portion is not particularly limited, and examples thereof include a linear shape and a strip shape. The reflective sheet preferably has a first region having a plurality of penetrating portions and a second region having no penetrating portions.

Here, the reflective sheet 20 shown in FIG. 5A has a first region X on one end side and a second region Y on the other end side in the lateral direction. Further, the first region X and the second region Y are each formed in a strip shape along the longitudinal direction of the reflective sheet 20. As shown in FIG. 5A, the length of the first region X in the lateral direction of the _{reflective sheet 20 is L 1,} and the length of the reflective sheet 20 in the lateral direction is L ₂ . The value of L ₁ / L ₂ is, for example, 0.3 or more, 0.5 or more, or 0.6 or more. If _{the value of L 1} / L ₂ is too small, the effect of ventilation may be reduced. L ₁ is, for example, 10 cm or more and 100 cm or less. L ₂ is, for example, 20 cm or more and 200 cm or less.

Further, as shown in FIG. 5B, the reflective sheet 20 arranged on the side surface of the cultivation rack has a first region X on the first member 12 side and the second member 13 side along the vertical direction. It is preferable to have a second region Y in the area. In this case, by arranging the second region Y on the second member 13 side, the reflection efficiency can be maintained high, and the first region X is arranged on the first member 12 side where the reflection efficiency tends to be low due to the influence of plants and the like. As a result, heat and air can be effectively suppressed from staying. Although not shown, contrary to FIG. 5B, the reflective sheet arranged on the side surface of the cultivation rack has a second region on the first member side along the vertical direction and is on the second member side. May have a first region.

Further, the reflective sheet 20 shown in FIG. 6A alternately has a plurality of first regions X and second regions Y in the longitudinal direction. Further, the first region X and the second region Y are each formed in a strip shape along the lateral direction of the reflective sheet 20. As shown in FIG. 6A, the widths of the first region X and the second region Y in the longitudinal direction of the reflective sheet 20 are W ₁ and W ₂ , respectively. The values of W ₁ and W ₂ can be set as appropriate.

Further, as shown in FIG. 6B, the reflective sheet 20 arranged on the side surface of the cultivation rack preferably has a plurality of first regions X and second regions Y alternately along the horizontal direction. In this case, by arranging the second region Y in the vicinity of the plants according to the distance between the cultivated plants, the reflection efficiency can be maintained high, and by arranging the first region X between the adjacent plants, the first region X can be arranged. Heat and air can effectively suppress retention.

As another pattern shape of the penetrating portion, for example, as shown in FIG. 7A, there is a pattern in which a plurality of penetrating portions 21 are formed in a check shape. Further, for example, as shown in FIG. 7A, the plurality of penetrating portions 21 may be uniformly formed on the reflective sheet 20. Further, for example, as shown in FIG. 7 (c), the plurality of penetrating portions 21 may be formed in a notch shape.

Further, the plurality of penetrating portions may be arranged in a grid pattern. In addition, the fact that a plurality of penetrating portions are arranged in a grid means that a plurality of penetrating portions exist at the grid points of the grid. The distance between the grid points is preferably 1 mm or more and 10 cm or less, for example. Examples of the type of lattice arrangement include a four-sided arrangement such as a cubic arrangement, a rectangular arrangement, and an orthorhombic arrangement. FIG. 8A shows an example of a four-sided arrangement, and the four-sided arrangement is suitable when it is desired to improve the tensile strength of the reflective sheet. Further, as a type of lattice arrangement, a three-way arrangement can also be mentioned. FIG. 8B shows an example of the three-way arrangement, and the three-way arrangement is suitable when it is desired to improve the aperture ratio of the reflective sheet.

The reflective sheet is preferably arranged on the side surface of the cultivation rack so as to cover both ends of the first member and the second member. This is because the reflection efficiency can be maintained high. The method of fixing the reflective sheet is not particularly limited. The reflective sheet may be fixed by a magnet, may be fixed by a tape, or may be fixed by a known fastening jig such as a bolt and a nut.

Examples of the reflective sheet include a metal plate, a sheet in which a resin film is bonded to a metal plate, a resin sheet, a non-woven fabric, and the like. Among them, the reflective sheet is preferably a sheet including at least a resin sheet, and more preferably a sheet including at least a porous resin sheet. This is because the resin sheet has good diffused reflectivity. Further, the reflective sheet may be composed of only the porous resin sheet, and may further have another sheet in addition to the porous resin sheet. As another sheet, for example, a reinforcing sheet can be mentioned. Further, the porous resin sheet and the reinforcing sheet may be laminated via an adhesive layer, or may be directly laminated without an adhesive layer. Further, another multilayer film or the like to which titanium oxide is added can also be used as the reflective sheet.

(1) Porous resin sheet The porous resin sheet is a sheet having voids inside and contains a resin. The porous resin sheet may contain an additive such as a filler, if necessary. The porous resin sheet exhibits light reflectivity more than the porous structure.

(I) Resin The porous resin sheet contains a resin. The resin may be a thermoplastic resin or a thermosetting resin, but the former is preferable. Examples of the thermoplastic resin include polyolefin-based resins, acrylic-based resins, styrene-based resins, vinyl fluoride-based resins, amide-based resins, saturated ester-based resins, and the like. Among them, polyolefin-based resins are preferable. This is because it is excellent in heat resistance, water resistance, chemical resistance, and cost.

Examples of the polyolefin-based resin include homopolymers of olefins, copolymers of two or more types of olefins, copolymers of one or more types of olefins, and one or more polymerizable monomers that can be polymerized with olefins. Can be mentioned. Examples of the olefin (monomer unit) include ethylene, propylene, butene, and hexene. Further, the copolymer may be a binary system, a ternary system, or a quaternary system. Further, the copolymer may be a random copolymer or a block copolymer.

Specific examples of the polyolefin-based resin include polyethylene-based resin, polypropylene-based resin, and the like. Among them, polypropylene-based resin and the like are preferable. An example of a polypropylene-based resin is a propylene homopolymer. The propylene homopolymer preferably has isotactic or syndiotactic stereoregularity. Other examples of polypropylene-based resins include copolymers of propylene and other α-olefins. Examples of other α-olefins include at least one of ethylene, butene-1, hexene-1, heptene-1,4-methylpentene-1 and the like. The polypropylene-based resin preferably contains propylene as the main component of the monomer unit.

On the other hand, examples of the polyethylene-based resin include low-density polyethylene and high-density polyethylene. The polyethylene-based resin may be linear polyethylene. The polyethylene-based resin preferably contains ethylene as the main component of the monomer unit. Further, as the polyolefin-based resin, poly (4-methylpentene-1), poly (butene-1), ethylene-vinyl acetate copolymer and the like may be used.

Further, as described above, as the thermoplastic resin, an acrylic resin, a styrene resin, a vinyl fluoride resin, an amide resin, an ester resin and the like can be used. Examples of the acrylic resin include polymethyl acrylate, polymethyl methacrylate, ethylene-ethyl acrylate copolymer and the like. Examples of the styrene resin include a butadiene-styrene copolymer, an acrylonitrile-styrene copolymer, polystyrene, a styrene-butadiene-styrene copolymer, a styrene-isoprene-styrene copolymer, a styrene-acrylic acid copolymer, and the like. Can be mentioned. Examples of the vinyl fluoride resin include vinyl chloride resin, polyvinyl fluoride, polyvinylidene fluoride and the like. Examples of the amide resin include 6-nylon, 6,6-nylon, 12-nylon and the like. Examples of the ester resin include polyethylene terephthalate and polyplybutylene terephthalate. Further, as the thermoplastic resin, polycarbonate, polyphenylene oxide, polyacetal, polyphenylene sulfide, silicone resin, thermoplastic urethane resin, polyetheretherketone, polyetherimide, thermoplastic elastomer and the like may be used.

The porous resin sheet may contain one kind of resin or may contain two or more kinds of resins. When two or more kinds of resins are used, it is preferable to use a polyolefin-based resin as a main component, and more preferably a polypropylene-based resin as a main component. The resin content in the porous resin sheet is, for example, 45% by mass or more, and may be 55% by mass or more. On the other hand, the content of the resin in the porous resin sheet is, for example, 99% by mass or less, and may be 98% by mass or less.

(Ii) Filler The porous resin sheet may contain a filler. By adding a filler and producing a porous resin sheet by, for example, stretching, voids are generated inside the porous resin sheet. Examples of the filler include an inorganic filler and an organic filler.

Examples of the inorganic filler include calcium carbonate such as heavy calcium carbonate and light calcium carbonate, calcined clay, talc, silicon oxide, diatomaceous soil, titanium oxide, magnesium oxide, zinc oxide, barium sulfate and the like. Further, the inorganic filler may be surface-treated with a fatty acid. Among them, the inorganic filler is preferably heavy calcium carbonate, light calcium carbonate, calcined clay or talc. This is because it is inexpensive and has good moldability.

The average particle size of the inorganic filler is, for example, 0.01 μm or more and 15 μm or less, and may be 0.01 μm or more and 8 μm or less. The average particle size is defined as a statistical average value of the particle size distribution measured on a volume basis, and means, for example, a value measured by LA-920 manufactured by Horiba Seisakusho Co., Ltd.

Examples of the organic filler include polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyamide, polyethylene naphthalate, polystyrene, melamine, polyethylene sulfite, polyimide, polyethyl ether ketone, polyether ether ketone, polyphenylene sulfide, and poly-4. -Methyl-1-pentene, polymethylmethacrylate and the like can be mentioned. Further, as the organic filler, it is a homopolymer of cyclic olefin or a copolymer of cyclic olefin and ethylene, and has a melting point of 120 ° C. or higher and 300 ° C. or lower or a glass transition temperature of 120 ° C. or higher and 280 ° C. or lower. Materials can also be used.

The content of the filler in the porous resin sheet is, for example, 1% by mass or more and 65% by mass or less, and preferably 2% by mass or more and 55% by mass or less.

(Iii) Other Additives The porous resin sheet may contain various additives such as a surfactant, a lubricant, and an antistatic material, if necessary. By adding a surfactant, for example, dew condensation can be prevented. Examples of the surfactant include nonionic surfactants, anionic surfactants, amphoteric surfactants and the like. Examples of the nonionic surfactant include glycerin fatty acid ester, pentaerythritol fatty acid ester, polyoxypropylene / polyoxyethylene block polymer and the like. Examples of the anionic surfactant include salts of sulfonates, alkylbenzene sulfonates and the like. Examples of the salt include sodium salt, potassium salt, ammonium salt and the like.

Examples of the lubricant include aliphatic hydrocarbons such as liquid paraffin, synthetic paraffin, and microcrystalline wax, stearic acid ester of linear alcohol, and higher fatty acid amide. Examples of the antistatic material include alkyldiethanolamine, hydroxyalkylmonoethanolamine, glycerin fatty acid ester, polyglycerin fatty acid ester, sodium alkylsulfonic acid, sodium alkylbenzenesulfonic acid, tetraalkylammonium perchlorate and the like. The content of the additive is not particularly limited, and is appropriately selected according to the type of the additive.

(Iv) Porous resin sheet The porous resin sheet preferably has at least one of moisture permeability, breathability and water impermeability. On the other hand, when the porous base material sheet has a penetrating portion, it is preferable that the penetrating portion has water permeability and the portion other than the penetrating portion has moisture permeability, air permeability and water shielding. In addition, the porous resin sheet usually has voids inside. The porosity of the porous resin sheet is not particularly limited, but is preferably 35% or more and 60% or less, and preferably 40% or more and 58% or less. If the porosity is too low, the light reflectivity may be low. If the porosity is too high, the sheet strength may be weakened.

The porosity refers to the ratio of voids to the porous resin sheet, and can be calculated by the following formula 1.
Porosity (%) = {(ρo−ρ) / ρo} × 100… (Equation 1)
In formula 1, ρ is the density of the porous resin sheet, which conforms to JIS P 8118. ρo is the true density of the porous resin sheet. The true density can be determined by analyzing the types of the main material components constituting the porous resin sheet and their composition ratios, and using the general values of the types of the material components. For example, the density of polypropylene is 0.9 g / cm ³ , and the density of calcium carbonate is 2.7 g / cm ³ . When the porous resin sheet is stretch-treated, the true density is substantially equal to the density of the material before stretching unless the material before stretching contains a large amount of air. Therefore, the true density may be obtained from the material before stretching, and can be obtained by the dry density measuring method by the constant volume expansion method. As a measuring device, for example, the dry automatic density meter Accupic manufactured by Shimadzu Corporation. 1330 can be mentioned.

The average diameter of the voids is, for example, 1 μm or more and 50 μm or less, preferably 2 μm or more and 40 μm or less, and more preferably 5 μm or more and 30 μm or less. The maximum diameter (L) of the void and the maximum diameter (M) in the direction perpendicular to the maximum diameter (L) are measured and averaged [(L + M) / 2] as the diameter of the void. The diameters of at least n (n is an integer of 1 or more, preferably an integer of 100 or more) are measured, and the average value thereof is taken as the average diameter of the voids. For observing the cross section of the sample, for example, a scanning electron microscope S-2400 manufactured by Hitachi, Ltd. can be used.

The thickness of the porous resin sheet is not particularly limited, but is preferably, for example, 30 μm or more and 90 μm or less, and 40 μm or more and 80 μm or less. Further, the porous resin sheet may have a single-layer structure or a multi-layer structure. When the porous resin sheet has a multi-layer structure, the resin components contained in each layer may be the same or different. As an example of the porous resin sheet having a multi-layer structure, it has an inner layer and two outer layers arranged on both sides of the inner layer, and the resin components contained in the two outer layers are the same, and the resin contained in the outer layer. Examples thereof include a porous resin sheet in which the components and the resin components contained in the inner layer are different.

The porous resin sheet preferably has a high visible light reflectance. The visible light reflectance (average reflectance at a wavelength of 380 nm or more and 780 nm or less) of the porous resin sheet is, for example, 70% or more, preferably 80% or more, and more preferably 90% or more.

The smoothness of the porous resin sheet is preferably high. Specifically, the arithmetic mean height Sa of the surface of the porous resin sheet is, for example, 1 μm or less, preferably 0.7 μm or less, and more preferably 0.5 μm or less. Further, it is preferable that the porous resin sheet has high antifouling property. Specifically, the contamination grade (JIS-L-1919) of the surface of the porous resin sheet is preferably 3 or more, and more preferably 3.5 or more.

The porous resin sheet preferably has at least one of moisture permeability, breathability and water impermeability. Moisture permeability means the property of passing water as a gas, that is, water vapor, air permeability means the property of passing gas such as carbon dioxide, and water impermeability means the property of passing water as a liquid. It refers to the property of not allowing it to occur. The moisture permeability of the porous resin sheet is, for example, 600 g / m ² · day or more, ^{preferably 700 g / m 2} · day or more, and more preferably 800 g / m ² · day or more. The water pressure resistance of the porous resin sheet is, for example, 10 kPa or more, and preferably 20 kPa or more. The opacity of the porous resin sheet is preferably 70% or more and 100% or less, for example. The opacity of the porous resin sheet shall comply with JIS Z 8722. The density of the porous resin sheet is, for example, 0.50 g / cm ³ or more and 0.90 g / cm ³ or less, and ^{preferably 0.50 g / cm 3} or more and 0.70 g / cm ³ or less.

The method for producing the porous resin sheet is not particularly limited as long as it is a method for obtaining a desired porous resin sheet, and a known production method can be adopted. Further, the porous resin sheet is preferably stretched.

(2) Reinforcing Sheet The reinforcing sheet is a sheet that is arranged on one surface side of the porous resin sheet and reinforces the porous resin sheet.

The reinforcing sheet preferably contains a resin. The resin may be a thermoplastic resin or a thermosetting resin, but the former is preferable. The resin is the same as that described in "(i) Resin" above. In particular, the resin contained in the reinforcing sheet is preferably a polyolefin-based resin. This is because it is excellent in heat resistance, water resistance, chemical resistance, and cost. Further, the polyolefin-based resin may be, for example, a polyethylene-based resin or a polypropylene-based resin.

Further, it is preferable that both the reinforcing sheet and the porous resin sheet are polyolefin resin sheets containing a polyolefin resin as the resin. For example, when the adhesive layer described later is provided, the polyolefin-based resin has the same adhesiveness to the adhesive, so that a strongly bonded reflective sheet can be obtained. Further, since the degree of expansion and contraction due to heat and moisture is close, warpage is unlikely to occur and the adhesive is hard to peel off. The result is a highly durable reflective sheet. Further, since a polyolefin resin is used, the reflective sheet has high water resistance.

Further, it is preferable that the reinforcing sheet contains a polyethylene resin as a main component and the porous resin sheet contains a polypropylene resin as a main component. This is because the workability of the reflective sheet is improved. Specifically, since polypropylene-based resin is a relatively hard resin, it is difficult to process. On the other hand, since the polyethylene-based resin is a relatively soft resin, the processability of the reflective sheet is improved by combining the polypropylene-based resin and the polyethylene-based resin.

The reinforcing sheet may have a single-layer structure or a multi-layer structure. The thickness of the reinforcing sheet is not particularly limited, but is preferably, for example, 10 μm or more and 150 μm or less, and 20 μm or more and 100 μm or less. When the reinforcing sheet has a multi-layer structure, the thickness of each layer constituting the reinforcing sheet is preferably within the above-mentioned range. Further, the reinforcing sheet may be arranged on the outermost surface of the reflective sheet, or may be arranged inside.

The reinforcing sheet may have higher moisture permeability than the porous resin sheet. The moisture permeability of the reinforcing sheet is preferably 8 times or more the moisture permeability of the porous resin sheet, for example. Moisture permeability of the reinforcing sheet is, for example, 5000g ^/ m 2 · day or more, preferably 6000g ^/ m 2 · day or more.

(3) Adhesive Layer The reflective sheet may be a porous resin sheet and a reinforcing sheet laminated via an adhesive layer, or may be directly laminated without an adhesive layer. The adhesive layer is composed of an adhesive material. The adhesive is not particularly limited, but is preferably a dry-laminated adhesive.

The type of adhesive is not particularly limited, but for example, a polyether adhesive, a polyester adhesive, a polyurethane adhesive, a vinyl adhesive, a (meth) acrylic adhesive, a polyamide adhesive, and an epoxy adhesive. Examples include materials and rubber-based adhesives. The adhesive may be a one-component curing type or a two-component curing type.

Examples of the polyether adhesive include polyether polyurethane. The polyether polyurethane is obtained by reacting a polyether polyol with a polyisocyanate. Examples of the polyether polyol include compounds obtained by polymerizing an oxylan compound such as ethylene oxide or propylene oxide with a polyhydric alcohol such as ethylene glycol, 1,2-propanediol or glycerin as a polymerization initiator.

Examples of the polyisocyanate include 1,6-hexamethylene diisocyanate, methylene diisocyanate, trimethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, tetramethylene diisocyanate, 1, Alibo diisocyanates such as 2-propylene diisocyanate, isopropylene diisocyanate, 1,3-butylene diisocyanate; 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanate methyl) cyclohexane, methyl Alicyclic isocyanates such as -2,6-cyclohexane diisocyanate; m-phenylenedi isocyanate, p-phenylenedi isocyanate, 4,4-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthylene diisocyanate And the like, such as aromatic isocyanate.

Examples of the polyester-based adhesive include polyester polyurethane. Polyester polyurethane is obtained by reacting polyester polyol with polyisocyanate. Examples of the polyester polyol include a polyester polyol obtained by reacting a polyvalent carboxylic acid and a polyhydric alcohol, a polyester polyol obtained by ring-opening polymerization of a lactone ring, and the like. Examples of the polyvalent carboxylic acid include saturated aliphatic polycarboxylic acids such as adipic acid, azelaic acid, succinic acid and sebacic acid; unsaturated aliphatic polycarboxylic acids such as fumaric acid and maleic acid; 1,4- Alicyclic polyvalent carboxylic acids such as cyclohexanedicarboxylic acid; aromatic polyvalent carboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid can be mentioned.

Examples of the polyhydric alcohol include polyhydric alcohols such as aliphatic and alicyclic groups, and aromatic polyhydric alcohols. Specifically, ethylene glycol, diethylene glycol, 1,3-propylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, xylylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, Examples thereof include 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol. The polyisocyanate is as described above.

Moreover, you may use a polyether polyester polyurethane as an adhesive material. The polyether polyester polyurethane is also a polyether adhesive and a polyester adhesive. Polyester polyester polyurethane is obtained by reacting a polyether ester polyol with a polyisocyanate. Examples of the polyether ester polyol include a polyether ester polyol obtained by reacting the above-mentioned polyether polyol with the above-mentioned polyvalent carboxylic acid.

The thickness of the adhesive layer is not particularly limited, but is preferably thinner from the viewpoint of ensuring moisture permeability. The thickness of the adhesive layer is, for example, 10 μm or less.

(4) Reflective sheet The reflective sheet may or may not have a light reflecting layer. When the light reflecting layer is provided, the visible light reflectance can be made higher. The light reflecting layer contains, for example, a white powder and a resin component. Examples of the white powder include anatase-type or rutile-type titanium oxide, titanium oxide whose surface is treated with a metal oxide such as Al or Si, calcium carbonate, barium sulfate and the like. Examples of the resin component include polyurethane-based resin and polyester-based resin. Examples of the polyurethane-based resin include polyester polyurethane, polyether polyurethane, polyether polyester polyurethane, polycarbonate polyurethane, and polycaprolactam polyurethane. The location of the light reflecting layer is not particularly limited, and may be the outermost surface of the reflective sheet or the inside. Further, it is preferable that the light reflecting layer is provided on the side opposite to the reinforcing sheet with the porous substrate sheet as a reference. The thickness of the light reflecting layer is, for example, 0.5 μm or more and 4 μm or less.

The thickness of the reflective sheet is not particularly limited, but is preferably, for example, 50 μm or more and 200 μm or less, and 80 μm or more and 150 μm or less. The moisture permeability of the reflective sheet may be, for example, 10 g / m ² · day or more, or 20 g / m ² · day or more.

2. Cultivation rack The cultivation rack in the present disclosure includes a first member on which a cultivation tank can be placed, a second member arranged with a space for the first member, and a space for the first member. It has a structure having a lighting member arranged on the side of the first member with respect to the second member, and a plurality of pillar members for fixing the positions of the first member and the second member. .. In addition, "the cultivation tank can be placed" means that it can be placed directly or via another member on the first member. Further, the first member does not necessarily have to be able to place a cultivation tank independently. For example, the cultivation tank can be connected to a pillar member or the like, and by dispersing the weight of the cultivation tank by the above connection, the first member may be in a state where the cultivation tank can be placed.

(1) First member, second member and pillar member The skeleton of the cultivation rack is formed by the first member, the second member and the plurality of pillar members. The material of the first member, the second member, and the plurality of pillar members is not particularly limited, and examples thereof include metals such as stainless steel, iron, and aluminum. The first member and the second member may be, for example, plate-shaped or mesh-shaped. The plan-view shape of the first member and the second member is not particularly limited, and examples thereof include a square and a rectangle. Examples of the cross-sectional shape of the pillar member include a circle, a square, and a rectangle. The number of pillar members is preferably such that the first member and the second member can be stably fixed, for example, 3 or more, 4 or more, or 8 or more. It is preferable that the first member and the second member and the pillar member are connected by using a known connecting tool.

The shape of the cultivation tank placed on the first member is not particularly limited, and examples thereof include a pot shape, a bag shape, and a bed shape. Further, hydroponics (deep flow type hydroponics, NFT type hydroponics) may be carried out using a cultivation tank, or soil cultivation may be carried out. Further, a rock wool mat may be laid on the first member, and a rock wool pot may be placed on the rock wool mat to cultivate rock wool. Further, instead of rock wool, coco bag cultivation using coco peat, which is easily discarded after use, as a medium may be used.

(2) Lighting member The lighting member is arranged so as to provide a space with respect to the first member, and is arranged closer to the first member than the second member. The lighting member may be arranged directly on the surface of the second member, or may be arranged with a space provided with respect to the second member via another member. Further, the lighting member may also have the function of the second member. In that case, the lighting member is arranged with a space provided with respect to the first member.

The lighting member has at least a light source. Examples of the light source include LEDs and fluorescent lamps, and among them, LEDs are preferable. This is because it consumes less power. The color of the light source is not particularly limited, and is appropriately selected according to the plant to be cultivated. Further, the light source is preferably arranged directly on the substrate or via another layer. A refrigerant pipe may be connected to the substrate. This is because the heat generated from the light source can be removed. Examples of the substrate material include aluminum and copper. Examples of the refrigerant include ammonia, water and the like.

Further, a reflector may be arranged between the light source and the substrate. This is because even when the light emitted from the light source is reflected on the medium surface of the cultivation tank and returned to the light source, the reflected light can be irradiated to the plant again by providing the reflector.

In addition, the number of light sources may be changed according to the growth of the plant. This is because plants require different amounts of light depending on the stage of growth. That is, it is preferable that a plant having overgrown leaves and near the harvest time has a large amount of light, and a plant having buds and small leaves has a small amount of light. By setting the amount of light appropriately in this way, the number of light sources can be reduced as a result, and the equipment cost and the running cost can be reduced.

(3) Cultivation rack The cultivation rack has a structure having a first member, a second member, a lighting member, and a plurality of pillar members. The cultivation rack may have one or a plurality of the above structures. For example, the cultivation rack 10 in FIGS. 1 and 2 has a structure in which the structures 16 are stacked in four stages. When the cultivation rack has a plurality of structures, the second member may also have the function of the first member. For example, in FIG. 2, in the second member 13 of the second structure 16 from the top, the lighting member 14 is arranged on one surface side, and the cultivation tank 11 is placed on the other surface side. That is, the second member 13 also has the function of the first member 12.

The cultivation rack may be a fixed type or a movable type. Further, the cultivation rack may be a hanging type.

3. 3. Plant Cultivation Equipment The plant cultivation equipment of the present disclosure includes at least the above-mentioned cultivation rack and reflective sheet. The plant cultivation device may have a culture solution supply device that supplies the culture solution to the cultivation tank. As the culture solution supply device, for example, a storage section for storing the culture solution, a piping section and a pump section for circulating the culture solution in the storage section, and a piping section connected to each cultivation tank to supply the culture solution in the piping section to the cultivation tank. A device having a supply unit and a supply unit can be mentioned. _{In addition, the plant cultivation device further has at least one of a CO 2} supply device, a blower, an air purifier, a dehumidifier, a humidifier, a heater, and a cooler that increase _{the CO 2} concentration in the cultivation rack, if necessary. You may.

The use of the plant cultivation device is not particularly limited, but it is preferably used for artificial light type cultivation that does not use sunlight. Moreover, you may use a plant cultivation apparatus as a seedling raising apparatus. The plant cultivated by the plant cultivation device may be a long-day plant (a plant that regulates flower bud formation in response to a long day) or a short-day plant (a plant that regulates flower bud formation in response to a short day). It may be a neutral plant (a plant that does not respond to the photoperiod). Specific examples include leafy vegetables, fruit vegetables, and flowers. Examples of leafy vegetables include lettuce, bok choy, arugula, coriander, basil, celery, kale, perilla, ice plant, saffron and the like. Examples of fruit vegetables include tomatoes, okra, squash, cucumber and the like.

B. Reflective sheet The reflective sheet of the present disclosure includes a first member on which a cultivation tank can be placed, a second member arranged with a space for the first member, and a space for the first member. It has a unit structure having a lighting member arranged on the side of the first member with respect to the second member, and a plurality of pillar members for fixing the positions of the first member and the second member. A reflective sheet arranged on the side surface of a cultivation rack, which has visible light reflectivity and has a plurality of penetrating portions.

According to the present disclosure, since the plant has a penetrating portion, it is possible to obtain a reflective sheet capable of suppressing the retention of heat and air in the cultivation rack while efficiently irradiating the plant with artificial light. Since the details of the reflective sheet are the same as those described in "A. Plant cultivation apparatus" above, the description here is omitted.

The present disclosure is not limited to the above embodiment. The above embodiment is an example, and in any case, the present invention has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits the same effect and effect. Included in the technical scope of the disclosure.

[Manufacturing Example 1]
(Preparation of porous resin sheet)
As a resin composition constituting the inner layer of the porous resin sheet, 65.5% by mass of a propylene homopolymer (manufactured by Japan Polychem Corporation, trade name "Novatec PP: MA-8", melting point 164 ° C.), high density Polypropylene (manufactured by Japan Polychem Corporation, trade name "Novatec HD: HJ580", melting point 134 ° C., density 0.960 g / cm ³ ) is 6.5% by mass, and calcium carbonate powder having an average particle size of 1.5 μm. A non-stretched sheet was obtained from a resin composition consisting of 28% by mass using an extruder. Next, this unstretched sheet was stretched four times in the longitudinal direction to obtain a uniaxially stretched sheet.

On the other hand, as the resin composition constituting the outer layer of the porous resin sheet, the same material as above was used, with 51.5% by mass of the propylene homopolymer, 3.5% by mass of the high-density polyethylene, and an average particle size of 1. A resin composition consisting of 42% by mass of calcium carbonate powder of .5 μm and 3% by mass of titanium oxide powder having an average particle size of 0.8 μm was melt-kneaded using another extruder to obtain the above uniaxially stretched sheet. Extruded from dies on both sides of the surface, a laminated sheet having a layer structure of an outer layer, an inner layer, and an outer layer was obtained.

Next, by stretching this laminated sheet 7 times in the lateral direction and slitting the selvage portion, the thickness is 70 μm, and the layer structure of the outer layer (15 μm), the inner layer (40 μm), and the outer layer (15 μm) is fine. A porous resin sheet containing voids was obtained. The porosity of the obtained porous resin sheet was 55%, and the opacity was 93%.

(Making a reflective sheet)
As a reinforcing sheet, an L-LDPE film (linear low-density polyethylene film, thickness 30 μm, TUX TC-S, manufactured by Mitsui Chemicals Tohcello Co., Ltd.) is prepared, and the reinforcing sheet and the porous resin sheet are joined by a dry laminating method. did. Specifically, Takelac A-969V (polyester component) and Takenate A-5 (isocyanate component) were used as the polyether adhesives. The polyether adhesive was applied and bonded under the conditions of a drying temperature of 70 ° C. and 2 g / m ^2. In this way, a reflective sheet was obtained.

The obtained reflective sheet was subjected to visible light reflectance measurement, smoothness evaluation, and antifouling property evaluation. In the visible light reflectance measurement, using an ultraviolet / visible / near-infrared spectrophotometer (Shimadzu Seisakusho UV-3600) and an integrating sphere attachment (ISR-3100), the visible region is 380 nm or more and 780 nm or less at an incident angle of 8 °. The reflectance (total reflectance) of the above was measured, and the average reflectance was obtained. As a standard plate, Spectralon (manufactured by Teflon (registered trademark)) manufactured by Lovesphere Inc. of the United States was used. The measurement surface was the surface of the reflective sheet on the porous resin sheet side. As a result, the visible light reflectance was 97%. Further, in the smoothness evaluation, the calculated average height Sa of the surface on the porous resin sheet side was obtained. As a result, Sa was 0.3 μm. In the antifouling property evaluation, the contamination grade was evaluated based on JIS-L-1919. As a result, the pollution grade was 3.5.

[Example 1]
In an artificial light type plant factory, 50 leaf lettuce strains were cultivated for 40 days in a cultivation rack for hydroponics having a height of 30 cm, a width of 1 m and a depth of 1.2 m. A 30 cm × 1 m reflective sheet was fixed to the two opposite sides of the cultivation rack on the side of the shelf using gum tape. As a result, the side surface of the cultivation rack was covered with a reflective sheet without any gaps. On the reflective sheet, 35 circular penetrating portions having a diameter of 10 mm were formed 15 cm below the side surface of the cultivation rack, and no penetrating portions were formed 15 cm above the side surface of the cultivation rack. The arrangement of the penetrating portions was the arrangement shown in FIG. 5 (a). When lettuce, which was in the harvest season 40 days after planting, was harvested and the yield was measured, it was 3.3 kg.

[Comparative Example 1]
Hydroponic cultivation of leaf lettuce was carried out in the same manner as in Example 1 except that the reflective sheet was not used. When lettuce, which was in the harvest season 40 days after planting, was harvested and weighed, it was 3 kg. Comparing Example 1 and Comparative Example 1, the yield of Example 1 was increased by about 10% as compared with Comparative Example 1.

10 ... Cultivation rack 11 ... Cultivation tank 12 ... First member 13 ... Second member 14 ... Lighting member 15 ... Pillar member 16 ... Structure 20 ... Reflective sheet 21 ... Penetration 100 ... Plant cultivation device

Claims (8)

The first member on which the cultivation tank can be placed, the second member arranged with a space provided with respect to the first member, and the second member arranged with a space provided with respect to the first member. A cultivation rack having a structure having a lighting member arranged closer to the first member than the member, and a plurality of pillar members for fixing the positions of the first member and the second member.
A reflective sheet arranged on the side surface of the cultivation rack, having visible light reflectivity, and having a plurality of penetrations,
Equipped with a,
A plant cultivation apparatus in which the size of the penetrating portion of the reflective sheet is 0.5 mm or more and 20 mm or less. The plant cultivation apparatus according to claim 1, wherein the reflective sheet has a first region having the plurality of penetrating portions and a second region having no penetrating portions. The plant cultivation apparatus according to claim 2, wherein the reflective sheet has the first region on the first member side and the second region on the second member side along the vertical direction. The plant cultivation apparatus according to claim 2, wherein the reflective sheet alternately has a plurality of the first region and the second region along the horizontal direction. The plant cultivation apparatus according to any one of claims 1 to 4, wherein the reflective sheet has a visible light reflectance of 90% or more. The plant cultivation apparatus according to any one of claims 1 to 5, wherein the reflective sheet includes a porous resin sheet containing a thermoplastic resin. The thermoplastic resin in the porous resin sheet is a polypropylene-based resin,
The plant cultivation apparatus according to claim 6, wherein the porous resin sheet has a porosity of 35% or more and 60% or less, and the thickness of the porous resin sheet is 30 μm or more and 90 μm or less. The first member on which the cultivation tank can be placed, the second member arranged with a space provided with respect to the first member, and the second member arranged with a space provided with respect to the first member. A reflection arranged on the side surface of a cultivation rack having a unit structure having a lighting member arranged on the first member side of the member and a plurality of pillar members for fixing the positions of the first member and the second member. a sheet has a visible light reflectivity, have a plurality of through portions, the size of the through portion is 0.5mm or more 20mm or less, the reflection sheet.

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