Convergent ceiling spreading material

Abstract

[Problem] To provide a curtain a sliding lining curtain for an agricultural greenhouse, the curtain having a simple configuration, being easy to fold, and having a small area in plan view when folded. [Solution] A sliding lining curtain for an agricultural greenhouse, the curtain being obtained by weaving warp yarns and weft yarns made of a synthetic resin, wherein the curtain is characterized in that: the warp yarns are configured from tape that has a certain width, one or more first monofilaments that are made of a polyolefin-based resin having a certain rigidity, and one or more second monofilaments that are made of a polyolefin-based resin having higher rigidity than the resin of the first monofilaments; the aforementioned components are arranged in a repeating pattern in which the tape and the first monofilaments or the second monofilaments are arranged alternately, and in which, after the tape and the first monofilaments are arranged consecutively a certain number of times, the tape and the second monofilaments are then arranged once; and the weft yarns are tape.

Description

Converging ceiling extension material

[0001] The present invention mainly relates to an interior curtain (converging ceiling extension material) used in agricultural greenhouses.

[0002] In agricultural greenhouses for cultivating crops, interior curtains are often installed to create an environment suitable for the crops. The main functions required for interior curtains are adjustment of irradiation amount, temperature adjustment, air permeability, and moisture permeability.

[0003] Adjustment of the irradiation amount aims to suppress excessive sunlight irradiation by closing the curtain and ensure an appropriate irradiation amount for the crops. Depending on the type of crops, a certain amount of irradiation is still required even when the curtain is closed, so translucent materials are often adopted for the entire curtain.

[0004] Temperature adjustment aims at heat preservation and heat insulation. By closing the curtain, it prevents the rise of warm air in winter and conducts heat insulation of sunlight in summer. For temperature adjustment, a curtain with high heat insulation and no gaps is preferred.

[0005] Air permeability aims to prevent heat retention, and moisture permeability aims to prevent humidity retention. In both cases, when the curtain is closed, it ensures the passage of air and moisture. To ensure air permeability and moisture permeability, a curtain with certain gaps is preferred.

[0006] The interior curtain must balance and satisfy some mutually contradictory purposes. Also, a lightweight material that can be easily opened and closed and a structure that is easy to open and close are required. It is also required to be a wide-width material that can handle a large agricultural greenhouse, a material that can be compactly folded for transportation from the factory and carried horizontally.

[0007] Indoor curtains for agricultural greenhouses come in several types: sliding type, which opens and closes by folding and extending the curtain using the movement of a drive wire; winding type, which opens and closes by winding and unwinding the curtain; and rack type, which opens and closes by moving the curtain using a drive unit such as a rack and then pressing and storing it in a truss, or moving it in the opposite direction. However, sliding type curtains are the most common because they can be used in a wide variety of greenhouses. This invention is an indoor curtain for sliding type curtains.

[0008] For sliding interior curtains, minimizing the area the curtain obstructs when folded will maximize the effectiveness of opening and closing the curtain. Therefore, the challenge lies in figuring out how to fold the curtain so that it fits within a smaller planar area.

[0009] There is a technology for a light-blocking screen that uses aluminum foil and synthetic resin strips as warp and weft threads, with gaps spaced at regular intervals between the warp strips. (Patent Document 1) This technology states that the gaps are flexible parts that can be bent freely and fold in an accordion shape. With a configuration in which such gaps are used as folds, the curtain will fold gently, so it is thought that the curtain area will not be able to be contained within a sufficiently small area.

[0010] Furthermore, there is a technique in which reinforcing stretching strips are placed at regular intervals over ribbons arranged in parallel, and as the support moves, the parts covered by the stretching strips become peaks, and the central part of the uncovered sections becomes the other side, causing the curtain to fold. (Patent Document 2) By making the parts with increased rigidity into folds, the area of ​​the curtain when folded is reduced, but the structure and manufacturing process becomes complex and cumbersome, and no particular technique has been shown for the folds in the valleys.

[0011] Japanese Utility Model Publication No. Hei 2-82789, Special Publication No. Hei 10-502817

[0012] The present invention aims to provide a sliding inner curtain for agricultural greenhouses that has a simple structure, is easy to fold, and has a small planar area when folded.

[0013] To solve the aforementioned problems, a sliding lining curtain for agricultural greenhouses is provided, woven from warp and weft threads made of synthetic resin, wherein the warp threads consist of a tape having a certain width, one or more first monofilaments made of polyolefin resin having a certain rigidity, and one or more second monofilaments made of polyolefin resin having higher rigidity than the first monofilaments, and the arrangement is such that the tape and the first monofilaments or the second monofilaments are arranged alternately, and the pattern is repeated such that the tape and the first monofilaments are arranged a certain number of times consecutively, followed by the tape and the second monofilaments being arranged once, and the weft threads are tape or twisted yarn.

[0014] The warp threads consist of synthetic resin tape and polyolefin resin monofilaments. The tape is a flat yarn, also called flat yarn. The monofilament is a yarn made of a single fiber, also called a single fiber. The weft threads are synthetic resin tape or twisted yarn. Twisted yarn refers to a yarn made by twisting two or more single yarns together.

[0015] Furthermore, the warp tape has a certain width, and the monofilament consists of one or more first monofilaments having a certain rigidity and one or more second monofilaments having higher rigidity than the first monofilaments. The tape and the first monofilaments, or the tape and the second filaments, are arranged alternately. The arrangement between the one or more first monofilaments having a certain rigidity and the one or more second monofilaments having higher rigidity than the first monofilaments is not alternating, but rather the first monofilaments are arranged consecutively a certain number of times before the second monofilaments are arranged once.

[0016] Since the width of the warp tape is constant and the number of first monofilaments is also constant, the total width (distance) of the tape and first monofilaments arranged a certain number of times is constant. Therefore, the distance between the second monofilaments is approximately constant. In other words, the highly rigid second monofilaments are arranged at approximately equal distances. Rigidity refers to the ability of an object to withstand breakage from bending, twisting, etc., and represents its resistance to deformation. Increasing the fineness of the monofilament increases rigidity, but rigidity can also be increased by other methods.

[0017] Preferably, both the warp and weft tapes are made by slitting and stretching a synthetic resin film. By cutting (slitting) the film into strips and stretching it, a tape with increased strength can be produced. The width of the weft tape is preferably constant from a manufacturing standpoint, but it is not limited. Also, if the weft is a twisted yarn, the method of twisting is not particularly limited. In order to ensure the opening and closing performance of the inner curtain for agricultural greenhouses, flexibility of the material is required. Therefore, monofilament yarn is not suitable as the weft.

[0018] Furthermore, the present invention provides an interior curtain characterized in that the first monofilament is a monofilament having a certain fineness, and the second monofilament is a monofilament having a certain fineness greater than that of the first monofilament.

[0019] The rigidity can be easily adjusted by changing the fineness of the thread. Fineness refers to the thickness of the thread, and here it is indicated by the constant length formula (decitex), which represents the weight of a certain length of thread.

[0020] Furthermore, an interior curtain is provided characterized in that the second monofilament has a fineness three times or more than that of the first monofilament.

[0021] Furthermore, an interior curtain is provided characterized in that the second monofilaments are arranged at regular intervals of 5 to 10 centimeters.

[0022] Furthermore, an interior curtain is provided characterized in that the weft thread is made of acrylic fiber. Acrylic fiber has a bulky and soft texture similar to wool, and possesses high elasticity and heat retention. In addition, it has higher water absorption than polyethylene and polypropylene, which are synthetic fibers widely used as industrial materials. It also has excellent weather resistance.

[0023] Furthermore, an inner lining curtain is provided, characterized in that the acrylic fiber is acrylic twisted yarn. Inner lining curtains for agricultural greenhouses require light blocking, heat shielding, moisture absorption, and heat retention, while breathability is not a major requirement. For this reason, tapes with excellent shielding properties are often used, but twisted yarn was used to further enhance moisture absorption.

[0024] As described above, sliding interior curtains fold (open) and extend (close) the curtain by repeatedly creating and releasing numerous folds perpendicular to the opening and closing direction in the curtain. The most important point is how to minimize the planar viewing area of ​​the curtain when folded, i.e., when the curtain is opened (convergence).

[0025] To minimize the planar area of ​​a curtain, it is necessary that the folded section be sharp and that there is no sagging in the middle section when folded. Since sliding lining curtains are generally folded or stretched in the width direction of the fabric, the differences in the properties of each thread that make up the warp greatly influence the formation of sharp folded sections and sagging-free middle sections.

[0026] In the lining curtain according to the present invention, a highly rigid second monofilament is folded into sharp mountain and valley folds. The mountain folds and valley folds can overlap perfectly without any gaps. The number of second monofilaments is not limited, but two to four are preferable from the viewpoint of ensuring rigidity and preventing the width of the folds from widening due to a large number of monofilaments.

[0027] Furthermore, in the intermediate sections between the peaks and valleys, monofilaments with a certain degree of rigidity are arranged alternately with the tape. If only tape were used, it would be lightweight and have low rigidity, making it prone to bulging in the width direction. However, the presence of monofilaments with a certain weight and rigidity between the tapes pulls on the adjacent tapes above and even higher tapes, ensuring flatness in the intermediate sections. This maintains flatness and suppresses bulging in the intermediate sections of the curtain when folded. The number of monofilaments with a certain degree of rigidity is not limited, but two to four are preferable from the perspective of ensuring rigidity to guarantee flatness and ensuring as large an area of ​​tape as possible. For agricultural greenhouse curtains, the amount of light irradiation is adjusted based on the light reflectivity and transmittance of the curtain material, and tape is a suitable material for this adjustment, so it is necessary to ensure a wide area of ​​tape to achieve its functionality.

[0028] The rigidity can be easily adjusted by changing the fineness of the monofilament.

[0029] If the difference in rigidity between the second monofilament and the first monofilament is small, repeated folding and unfolding will result in folding at different positions each time. By making the fineness of the second monofilament three times or more that of the first monofilament, it is possible to prevent the formation of bends at positions other than those of the second monofilament.

[0030] If a curtain is folded too many times, the cumulative thickness of the folded sections becomes too large, while if it is folded too few times, the flatness of the intermediate sections between the peaks and valleys cannot be maintained, resulting in a lack of stiffness and a tendency to sag. Furthermore, if the number of folds is too few, the peaks become too high, which increases the load on the opening and closing operation due to contact with the shelf wire. In the configuration according to the present invention, a length of 5 to 10 centimeters in the intermediate section is considered to be an appropriate range for maintaining flatness, and therefore the arrangement of the second monofilament, which is the folded section, is also done at intervals of 5 to 10 centimeters.

[0031] The lining curtain for agricultural greenhouses according to the present invention is used with frequent folding and stretching. Due to the high elasticity and recovery power based on the high elasticity of the acrylic fiber, it can withstand long-term use. Furthermore, compared to polyethylene fiber, which has been commonly used as a material in this field, it has higher water absorption and, moreover, high water retention capacity due to its bulky and soft texture. It can also withstand prolonged exposure to sunlight.

[0032] As mentioned earlier, the weft threads of lining curtains for agricultural greenhouses are often made of tape, but by using twisted acrylic fibers, moisture absorption and heat retention can be further enhanced. This prevents water droplets from falling from the curtain, which can wet plant leaves and cause mold and disease, while also improving humidity control and heat retention.

[0033] **Slope view of an agricultural greenhouse** **Cross-sectional view of an agricultural greenhouse** **Conceptual view of the installation and operation of the curtain according to the present invention** **Slope view of the installation and operation of the curtain according to the present invention** **Side view of the curtain according to the present invention** **Configuration of another configuration of the curtain according to the present invention** **Conceptual view of the shape of a conventional curtain when folded** **Conceptual view of the shape of a curtain according to the present invention when folded** **Conceptual view of the bulge of the curtain when folded** **Measurement photograph of the fixing part of the curtain when folded** **Measurement photograph of the bulge of the curtain when folded** **Comparison photograph of a conventional product and a curtain according to the present invention when opening (curtain extension)** **Comparison photograph of a conventional product and a curtain according to the present invention when closing (curtain folding)** **Comparison photograph of a conventional product and a curtain according to the present invention when closing (curtain folding)** **Enlarged comparison photograph of a conventional product and a curtain according to the present invention when closing (curtain folding)** **Conceptual measurement diagram of a conventional product and a curtain according to the present invention when closing (curtain folding)** **Conceptual diagram of a cantilever test** **Sample for cantilever test** **Conceptual diagram of cantilever test method** **Photograph of an existing product with part of the weft (polyethylene monofilament) replaced with acrylic twisted yarn** **Photograph of humidification test equipment** **Comparison photograph of an existing product and a product with acrylic twisted yarn weft after immersion test**

[0034] The sliding interior curtain according to the present invention will be described in more detail below, in comparison with the prior art.

[0035] Sliding curtains come in two types: the pipe-tip type, where the curtain's drive mechanism is a pipe, and the rope-tip type, where the drive mechanism is a rope. Furthermore, in a single building, there are two types of curtains: two-panel and four-panel. Four-panel curtains are created by dividing one of the two panels into two. While slightly more expensive than two-panel curtains, four-panel curtains are more common these days due to their lower load on the equipment resulting from a shorter driving distance and ease of installation. Sliding curtains can be installed either inclined or horizontally, but inclined installation is more common because it reduces the motor load and slows curtain deterioration. This invention is applicable to all of these various types of sliding curtains.

[0036] The opening and closing of a sliding curtain according to the present invention will be described. Figure 1A is a perspective view of an agricultural greenhouse 1 in which an inner lining curtain according to the present invention is installed below a transparent roof supported by a frame. The curtain in Figure 1A is a single-axis, single-layer sliding curtain, but the present invention is not limited to this type. Figure 1B is a cross-sectional view of the above agricultural greenhouse, showing that the drive wire 31 is inclined downwards with the central part as the boundary.

[0037] Dozens of shelf wires 34 are fixedly installed along the curtain opening and closing direction, supporting the entire curtain. The curtain according to the present invention is installed on the shelf wires with the direction along the weft threads as the opening and closing direction, and the direction along the warp threads as perpendicular to the opening and closing direction (the length direction of the agricultural greenhouse). Several drive wires 31 that operate the opening and closing of the curtain are installed along the curtain opening and closing direction.

[0038] The opening and closing operation of the curtain according to the present invention will be explained with reference to Figures 2A and 2B. The curtain drive mechanism 3 includes a prime mover 35 (not shown), a drive wire 31, and a drive pipe 32. There are four curtains; the two left and right curtains have one end face fixed to the greenhouse wall, and the two central curtains have one end face fixed to the center pipe 11 in the center of the greenhouse. The other end face of each curtain is connected to a drive pipe 32. The four drive pipes 32 are each fixed to a drive wire and move in conjunction with the drive wire 31.

[0039] When the lower drive wire in Figure 2A moves to the left, the right and center-left curtains move to the left (in the direction of the lower arrow). Simultaneously, the upper drive wire moves to the right, and the left and center-right curtains move to the right (in the direction of the upper arrow). As a result, the curtains close. On the other hand, when the drive wire moves in the opposite direction, the opposite movement occurs, and the curtains are pushed back in the direction of the weft threads, folding and opening up, forming numerous sharp folds. Figure 2B is a side view showing the movement of the curtains. The left and right curtains are installed below the drive wires, and the center curtain is installed above the drive wires, but the present invention is not limited to this embodiment. A curtain retaining cover is provided at the portion where the drive wires intersect with the drive pipe to which the curtain end faces are attached.

[0040] Next, the structure of the curtain 2 according to the present invention will be described. When the curtain is closed, it is required that the planar area of ​​the curtain be compressed in the weft direction, so the weft is made of tape with flexible properties. The warp is made of monofilaments with high fineness (high rigidity) arranged at regular intervals so that it can be folded into an accordion shape by forming mountain folds and valley folds 23 at regular intervals. In addition, tape and monofilaments are arranged alternately in the intermediate parts between the folds so as to prevent slack and maintain a flat shape. The fineness (rigidity) of the monofilaments in these intermediate parts is adjusted so as not to compete with the monofilaments that form the folds. If all the warp threads were monofilaments, problems such as increased bulkiness when folded, increased weight of the curtain, and difficulty in adjusting the light transmittance would occur, so the warp as a whole is mainly made of tape, and the compactness of the planar area when folded is ensured by combining monofilaments with two levels of fineness (rigidity).

[0041] Figure 3A shows the configuration of the curtain according to the present invention. The curtain 2 according to the present invention is a fabric woven from warp threads made of synthetic resin or polyolefin resin and weft threads made of synthetic resin. The warp threads are arranged such that a tape and two monofilaments are alternately disposed. Further, these two monofilaments are arranged such that those having a certain fineness are continuously arranged a certain number of times, and then those having a thicker fineness are arranged once. For example, a pattern is repeated in which monofilaments (a set of two) of 310 dtex are alternately arranged with the tape 20 times, then the tape and monofilaments (a set of two) of 1100 dtex are arranged once, and then again the tape and monofilaments (a set of two) of 310 dtex are arranged 20 times. Note that all the weft threads are tapes.

[0042] The shape change when the closing operation (curtain folding) is performed will be described. FIG. 4A is a conceptual diagram of the shape of a conventional curtain. No clear fold lines are formed and it undulates, and its position is not constant and varies depending on the balance of forces during the closing operation. Also, the intermediate portions between the fold lines are slack and loose. FIG. 4B is a conceptual diagram of the shape of the curtain according to the present invention. Clear fold lines are formed and the intermediate portions are flat.

[0043] FIG. 5 shows the swelling of the curtain during the closing operation (curtain folding). The curtain 2 has the minimum area in plan view when the driven pipe 32 to which it is fastened reaches a predetermined stop position close to the center pipe 11 or the like. At this time, the protruding portion of the curtain that appears beyond the range between the center pipe or the like and the driven pipe is the curtain swelling 243. The distance obtained by subtracting the distance 242 between the center pipe 11 and the driven pipe from the distance 241 between the maximum protruding portion of the curtain and the center pipe 11 is the swelling portion 243 of the curtain.

[0044] FIG. 6A is a photograph measuring the distance 242 between the center pipe 11 and the driven pipe, and FIG. 6B is a photograph measuring the distance between the maximum protruding portion of the curtain and the center pipe 11.

[0045] Hereinafter, examples and comparative examples will be shown, but the present invention is not limited to these examples.

[0046] The curtain according to Embodiment 1, shown in Figure 3B, was woven in a plain weave using monofilaments and tape for the warp threads and tape for the weft threads. The warp monofilaments were made of high-density polyethylene, with monofilament 212 having a fineness of 310 dt and monofilament 211 having a fineness of 1100 dt. The warp tape consisted of a 50 μm ribbon-shaped tape 213A made by bonding aluminum foil on both sides with high-density polyethylene film, and a slit tape 213p made of 23 μm high-density polyethylene film. The weft thread was made of stretched tape 221 made of high-density polyethylene.

[0047] The arrangement of the warp threads in the width direction is described below. Within a 5.35 stitch / 2.54 cm (approximately 4.7 mm / stitch) pattern, two monofilaments 212 with a fineness of 310 dt and tape were arranged alternately. The tape consisted of alternating aluminum foil tape 213A and high-density polyethylene tape. Both the aluminum foil tape and the high-density polyethylene tape were 4 mm wide. Furthermore, 1100 dt high-fiber monofilaments were arranged in the width direction at 10 cm intervals, replacing the 310 dt monofilaments 212. The manufacturing method for this curtain used a projectile loom, with a beam wound with 310 dt monofilaments attached. For the film, both types were slit to a width of 4 mm using a dedicated slitting device before being arranged as described above. For the high-fiber 1100 dt monofilaments, an additional step was added: a dedicated creel was installed, and each monofilament was inserted into the aforementioned position via a tensioning device. The weft threads were woven as 550 dt tape at a density of 11.2 threads / 2.54 cm to complete a curtain fabric 3 m wide. The woven curtain fabric was sewn to a 1.7 m wide x 19 m long and stretched in a glasshouse for convergence evaluation. [Comparative Example 1]

[0048] The curtain was woven in a plain weave with the warp being a monofilament and a tape, and the weft being a tape, as in the examples. The monofilament of the warp is a high-density polyethylene monofilament as in Example 1, but it is only the monofilament 212 with a fineness of 310 dtex. Also, for the tape of the warp, as in Example 1, an aluminum foil was adhered to both sides with a high-density polyethylene film to form a 50-μm ribbon-like tape, and a slit film of 23-μm high-density polyethylene film was used. For the weft as well, a stretched tape 221 made of high-density polyethylene was used as in Example 1.

[0049] The arrangement of Comparative Example 1 is the same as that according to Example 1 except that there is only one type of monofilament. Two monofilaments with a fineness of 310 dtex and tapes were alternately arranged within 5.35 ends / 2.54 cm (about 4.7 mm / end), and the tapes were alternately arranged with an aluminum foil tape 213A and a tape made of high-density polyethylene. All the tapes are 4 mm wide. As the manufacturing method, a projectile loom was used, a beam wound with a 310-dtex monofilament was installed, and for the film, both types were slit to a width of 4 mm through a dedicated slitting device, and then woven in the above-described arrangement. The weft was woven as a 550-dtex tape at a density of 11.2 ends / 2.54 cm to complete a curtain fabric with a width of 3 m. The woven curtain fabric was sewn into a width of 1.7 m and a length of 19 m and extended in a greenhouse to conduct a comparative evaluation of the convergence property. [Comparative Example 2]

[0050] Both the warp and the weft are the same as those of Comparative Example 1, and the arrangement is also the same as that of Comparative Example 1, but instead of weaving, an aluminum foil ribbon-like tape was knitted to create a curtain of a raschel fabric. Also, it was extended in the same house as in Example 1 and Comparative Example 1 to conduct a comparative evaluation of the convergence property.

[0051] Figures 7A and 7B show a comparative test of the convergence property between the example and the comparative example inside an agricultural greenhouse. Figure 7A shows the situation during extension, and Figure 7B shows the situation during convergence. The left side is the curtain according to the example, and the right side is the curtain according to the comparative example. Figure 7C is a figure showing only the curtain part during convergence in Figure 7B. The upper side is the curtain according to the example, and the lower side is the curtain according to the comparative example. In both cases, the curtain according to the example has less spread and is more compact than the curtain according to the comparative example.

[0052] The improvement in convergence shown by the comparative tests of the above-described embodiment and Comparative Examples 1 and 2 will be explained in detail. Figure 8 is a conceptual diagram showing the above-described test results, and shows the bulge of the curtain when it converges in Embodiment 1 (upper part of the figure) and Comparative Example 2 (lower part of the figure). Measurements were taken at five locations, at the position where the curtain was most bulging (the same position for both Embodiment and Comparative Examples).

[0053] Let me explain the bulging of the curtain again. When the curtain is folded, it is pushed back towards the center pipe 11 in conjunction with the drive wire. However, when the drive pipe 32 reaches the stopping position, a portion of the curtain does not fit within the range of the center pipe and the drive pipe 11, and extends beyond the drive pipe to the opposite side of the center pipe. In many cases, a cover (a semicircular cover shown in Figure 2B) is provided at the part of the drive pipe that is fixed to the drive wire where it intersects to suppress the curtain from bulging out. However, it is difficult to install a cover over the entire drive pipe due to the heavy load on the cover and other reasons. Therefore, when a cover is provided, the shape of the curtain when folded (folded) is such that the covered part is constricted and the middle part bulges out. The drive wires are installed at approximately 3m intervals, but in conventional curtains, there is no effective restriction in the middle part where there are no drive wires, and as a result the curtain has a large bulge.

[0054] The curtain's ability to converge (fold) was evaluated by subtracting the distance between the drive pipe and the fixed part (center pipe) 242 from the distance between the fixed part (center pipe) and the maximum bulge of the curtain (dimension) 241. The distance between the fixed part (center pipe) and the drive pipe (dimension) 242 was defined as the smaller distance between the left and right constricted sections. The curtain widths separated by the constricted sections were 2 meters for the second section from the right and 3 meters for the others.

[0055]

[0056] Table 1 is a table comparing the measured values ​​based on the above measurements. The dimensions of the curtain's fullness and the improvement rate of Example 1 compared to the comparative examples will be explained based on Figure 8 and Table 1. The dimensions of the curtain's fullness in Example 1 are 7, 5, 6, 1, and 8 (all in centimeters) from left to right in Figure 8. On the other hand, for Comparative Example 2, the dimensions are 14, 9, 17, 8, and 9 (same), and for Comparative Example 1, they are 16, 10, 15, 10, and 10 (same). The improvement rates (percentage reduction in fullness) for Example 1 compared to Comparative Examples 1 and 2 were 56, 50, 60, 90, and 20 (all in %), while the improvement rates for Example 2 were 50, 44, 64, 87, and 11 (same). An average improvement rate of 50% or more was achieved for both Comparative Example 1 and Comparative Example 2.

[0057] A stiffness test was performed using a sample of a curtain with the configuration according to the present invention. The cantilever method stiffness test shown in Figure 9B is one of the tests for the stiffness of fabric. A test piece is placed on a horizontal table with a 45-degree incline, slid in the direction of the incline, and the position when the center point of one end of the test piece touches the incline is read from the scale on the horizontal table. The stiffness is evaluated by the length the test piece moves. In addition, three cut samples of the curtain, each 3 cm wide and 30 cm long, were prepared: one with the configuration according to the present invention (same as Example 1; monofilaments of 310 dt and 1100 dt), and another where all warp monofilaments were 310 dt without using any high-denier monofilaments. Measurements were taken on both sides of each sample.

[0058]

[0059] As shown in Table 2, when a monofilament with a finer diameter approximately 3.5 times greater was used, the straight length at the point of contact with the inclined surface of the sample increased by approximately 32%, indicating increased rigidity.

[0060] In a curtain constructed according to the present invention, a comparative hygroscopic test was conducted using acrylic twisted yarn as the weft. The hygroscopic test was performed by immersion testing and humidification testing.

[0061] Figure 10 is a comparative photograph of an existing product and a product according to the present invention in which the weft is replaced with acrylic twisted yarn. The upper part of the photograph shows the applicant's existing product, Baron Screen B&S 85 210. The materials used are polyethylene monofilament yarn and polyethylene tape (aluminum vapor deposition) for the warp and polyethylene monofilament yarn for the weft. The fineness of the monofilament yarn is 310 dt for both the warp and weft, and it is a plain weave. There is no difference in fineness between the monofilaments of the warp. The weaving density is 10.7 threads / 2.54 cm for the warp and 14.4 threads / 2.54 cm for the weft. On the other hand, the lower part of the photograph shows the same product as above, but with the weft replaced (from polyethylene monofilament yarn) with acrylic twisted yarn. The fineness of the acrylic twisted yarn is 137 d (152 dt), and the weaving density is 14.4 threads / 2.54 cm. While not limited to these specifications, a fineness of 135–215d for the acrylic yarn and a weave density of 11.2–14.4 threads / 2.54cm are preferred. All other materials are identical except for the weft. Immersion and humidification tests were performed by cutting this single continuous piece.

[0062] Two 15cm x 20cm test pieces were cut from each of the existing product and the acrylic yarn replacement product. The dry weight of one piece of each was measured, and then it was soaked in water for one hour. After removing each piece from the water, the weight was measured after draining it for one minute on a mesh draining tray.

[0063] Table 3 shows the weight measurements before and after the immersion test. It clearly demonstrates that the acrylic yarn substitute has a significantly higher water retention effect.

[0064] Figure 11 is a photograph of the equipment used in the humidification test. A beaker is at the top, with the test piece, funnel, and humidifier (T-fal) below it. Boiling steam was generated from the humidifier for two minutes, and this steam was directed onto the test piece through the hole in the funnel.

[0065] Table 4 shows a comparison of the weights of the test pieces immediately after 2 minutes of steam generation, after 1 hour, and after 2 hours. In all cases, the weight increase of the acrylic twisted yarn substitute was larger compared to the weight before the test, indicating a higher water retention effect. It is thought that, in addition to being acrylic fiber, the twisted yarn structure allows the yarn and the frayed fibers to absorb water, and that this water retention effect works between the fibers, further enhancing the water retention effect of the sheet surface.

[0066] Figure 12 shows comparative photographs of test pieces after the humidification test. (B) is the conventional product, and (A) is the acrylic yarn replacement product. The distortion of the white acrylic yarn in the acrylic yarn replacement product is thought to be due to the water retention effect of the internal space of the yarn.

[0067] In summary, both the immersion test and the humidification test clearly demonstrated that the hygroscopic properties of acrylic twisted yarn were higher than those of polyethylene monofilament yarn. It should be noted that conventional agricultural greenhouse curtains typically use polyethylene tape as the weft thread instead of the polyethylene monofilament yarn used in this test; however, the evaluation of hygroscopic properties is not different from that of polyethylene monofilament yarn.

[0068] This invention enhances the convergence properties of curtain fabric for greenhouses and can be widely used for general curtain installation.

[0069] 1. Agricultural greenhouse 10. Transparent roof 11. Center pipe 2. Curtain 21. Warp threads 211. Warp threads (high fiber monofilament) 212. Warp threads (medium fiber monofilament) 213. Warp threads (slit film) 213A. Warp threads (aluminum foil slit film) 213B. Warp threads (polyethylene transparent film) 22. Weft threads 221. Weft threads (slit film) 222. Weft threads (polyethylene monofilament) 223. Weft threads (acrylic twisted yarn) 23. Curtain fold lines 24. Curtain when folded 241. Dimension from curtain fixing point to maximum curtain bulge 242. Dimension from curtain fixing point to drive pipe 243. Curtain bulge 3. Drive mechanism 31. Drive wire 32. Drive pipe 33. Fixed end 34. Shelf wire 35. Prime mover

Claims

1. A sliding lining curtain for an agricultural greenhouse, woven from warp and weft threads made of synthetic resin, wherein the warp threads are composed of a tape of a certain width, one or more first monofilaments made of polyolefin resin having a certain rigidity, and one or more second monofilaments made of polyolefin resin having higher rigidity than the first monofilaments, and the arrangement is such that the tape and the first monofilaments or the second monofilaments are arranged alternately, and the pattern is repeated such that the tape and the first monofilaments are arranged a certain number of times consecutively, followed by the tape and the second monofilaments being arranged once, and the weft threads are tape or twisted yarn.

2. The lining curtain according to claim 1, characterized in that the first monofilament is a monofilament having a certain fineness, and the second monofilament is a monofilament having a certain fineness greater than that of the first monofilament.

3. The lining curtain according to claim 2, characterized in that the second monofilament has a fineness three times or more than the first monofilament.

4. The lining curtain according to claim 2 or 3, characterized in that the second monofilaments are arranged at regular intervals of 5 to 10 centimeters.

5. The interior lining curtain according to claim 1 to 3, characterized in that the weft thread is made of acrylic fiber.

6. The lining curtain according to claim 5, characterized in that the acrylic fiber is acrylic twisted yarn.

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