JP7562487B2 - Agricultural waterproof sheet - Google Patents

Description

The present invention relates to an agricultural waterproof sheet for use in agricultural greenhouses.

Agricultural greenhouses are known as agricultural crop growing facilities, constructed by covering an internal space surrounded by aggregates with glass panels or soft sheets. These agricultural greenhouses may be provided with agricultural water-stopping sheets on the undersides of the sides and gables, as disclosed in Patent Document 1, in order to keep the crops warm and to prevent water from entering the internal space from near the ground surface.

When installing an agricultural waterproof sheet in an agricultural greenhouse, for example, a long frame member with a groove is attached to the aggregate, and with part of the agricultural waterproof sheet placed in the groove of the frame member, the agricultural waterproof sheet is pressed against the inner wall of the groove in the groove width direction by a spring. This fixes the agricultural waterproof sheet to the frame member.

Patent No. 3114858

To ensure that agricultural water stop sheets are durable enough to withstand long-term use, they are manufactured to have a certain thickness to increase their strength. This increases the stiffness of the agricultural water stop sheet, which may reduce the ease of fixing the agricultural water stop sheet to the frame member within the groove of the frame member.

The present invention aims to effectively prevent a decrease in workability when fixing agricultural waterproof sheets to frame members.

In order to solve the above problems, the agricultural water-stop sheet of the present invention has a first fold, a second fold, and a third fold that extend linearly in one direction along the surface and are processed so that part of the surface can be easily folded in the thickness direction, and the first fold, the second fold, and the third fold are arranged in parallel in order from one end side.

According to the above configuration, the agricultural water stop sheet is easily folded in the thickness direction at the first to third folds, so that it can be easily folded at each fold even with a small force. Therefore, for example, when placing a part of the agricultural water stop sheet in a groove of a frame member, the part of the agricultural water stop sheet where the first to third folds are formed can be placed at an inner corner of the groove, and folded at the first to third folds, so that a part of the agricultural water stop sheet can be easily placed in the groove. This makes it possible to prevent the agricultural water stop sheet from jumping out of the groove due to the rebound force caused by folding. This makes it easier to fix the agricultural water stop sheet to the frame member within the groove of the frame member.

This invention effectively prevents a decrease in workability when fixing agricultural waterproof sheets to frame members.

1A is a front view showing a schematic diagram of an agricultural water stop sheet according to the present invention, and FIG. 1B is a cross-sectional view taken along line AA of the agricultural water stop sheet according to the present invention shown in FIG. 2 is a cross-sectional view showing a schematic state in which the agricultural water stop sheet of FIG. 1 is fixed to a groove portion of a frame member. FIG. 2 is a perspective view showing a schematic state of the agricultural water stop sheet and a frame member when a part of the agricultural water stop sheet shown in FIG. 1 is inserted into a groove of the frame member. FIG. FIG. 2 is a schematic diagram showing how a folded portion is formed in the agricultural water stop sheet according to the present invention. FIG. 11 is a cross-sectional view of an agricultural water stop sheet and a frame member when a part of a conventional agricultural water stop sheet is inserted into a groove of the frame member.

The following describes an embodiment of the present invention with reference to the figures.

Figure 1 (A) is a front view of an agricultural water stop (water impermeable) sheet 1 according to the present invention, (B) is a cross-sectional view of the agricultural water stop sheet 1 shown in (A) taken along line A-A, and Figure 2 is a cross-sectional view of the agricultural water stop sheet 1 and frame member 2 when the agricultural water stop sheet 1 in Figure 1 is fixed to the groove portion 2a of the frame member 2. Figure 3 is a perspective view showing a schematic view of the state of the agricultural water stop sheet 1 and frame member 2 when a part of the agricultural water stop sheet 1 shown in Figure 2 is inserted into the groove portion 2a of the frame member 2.

The agricultural water stop sheet 1 shown in Figure 1 is used as a covering material for an agricultural greenhouse. The agricultural water stop sheet 1 may be placed, for example, on the underside of the sides and gables of the agricultural greenhouse, with the lower part buried in the ground. In this case, the lower part of the agricultural water stop sheet 1 extends vertically in the ground, dividing the soil into the outside and inside of the agricultural greenhouse from a certain depth below the ground surface. In this way, the agricultural water stop sheet 1 prevents liquids such as water and small animals from entering the interior space of the agricultural greenhouse from the ground surface and its vicinity.

The agricultural waterproof sheet 1 is fixed to one or more frame members (soft film stoppers) 2 attached to the aggregates of an agricultural greenhouse. The frame member 2 has a main body 2b, which is a long plate, and a pair of side portions 2c that protrude from both sides of the width of the main body 2b to one side in the thickness direction of the main body 2b. The frame member 2 has a groove portion 2a formed by the main body 2b and the pair of side portions 2c and extending in the longitudinal direction of the main body 2b. An example of such a frame member 2 is "Vinipet" manufactured by Tohto Kogyo Co., Ltd., but is not limited to this.

The agricultural water stop sheet 1 of this embodiment preferably has a light blocking property that prevents external light from entering the inside of the agricultural greenhouse. The color of such an agricultural water stop sheet 1 is, for example, silver, but it may also be black or white. The agricultural water stop sheet 1 is made of a material that is flexible and highly durable (for example, polyolefin such as MCPE (metallocene catalyzed polyethylene) or EVA (ethylene-vinyl acetate copolymer)).

The maximum thickness dimension of the agricultural water stop sheet 1 can be set as appropriate, but as an example, it is set to a value in the range of 1 mm or less (here, 700 μm or less). Various additives such as insect repellents may be added to the agricultural water stop sheet 1. In addition, the agricultural water stop sheet 1 may be a laminate formed by stacking two or more layers of film.

As shown in FIG. 1(A), the agricultural water-stop sheet 1 has a first folded portion 1a, a second folded portion 1b, and a third folded portion 1c that extend in one direction along the surface (the horizontal direction in FIG. 1(A)). Folded portions 1a, 1b, and 1c (hereinafter collectively referred to simply as "folded portions") are processed portions in which part of the surface of the agricultural water-stop sheet 1 is easily folded in the thickness direction.

The folding portion is preferably composed of a plurality of parallel convex portions protruding from one side of the agricultural water stop sheet 1. It can be easily folded without impairing the durability of the agricultural water stop sheet 1. The folding portion shown in Fig. 1(B) is composed of four convex portions arranged in parallel, but the number of the convex portions may be three or less, or five or more.
It is preferable that the bent portion having a convex portion is bent so that the protruding portion forms a peak.

The number of convex portions constituting the folding portions 1a, 1b, and 1c may be the same or different, but it is preferable that the number of convex portions constituting each folding portion is the same, since this will not result in any difference in the strength of the agricultural water-stop sheet 1 and will not result in any difference in the ease of folding during the folding process.
In addition, in order to obtain durability, etc., it is preferable for the above-mentioned folded portion to have a structure having a convex portion protruding from one side as shown in Figure 1 (B), but it is also acceptable for it to be formed, for example, by intermittently (in the form of perforations) penetrating the agricultural water-stop sheet 1 in one direction along its surface.

The height L1 of the convex portion of the bent portion can be set as appropriate, but is preferably set to a value in the range of 0.5 mm to 1.5 mm. If it is less than 0.5 mm, it may be difficult to perform the bending process at the bent portion, and if it exceeds 1.5 mm, a thin portion may be formed in the convex portion, resulting in poor strength.

As shown in Figure 2, the agricultural waterproof sheet 1 according to the present invention is folded at the bend 1a at the corner between the upper main body 2b and side 2c of the frame member 2, at the bend 1b at the corner between the lower main body 2b and side 2c of the frame member 2, and at the bend 1c at the corner of the opening of the lower side 2c of the frame member 2, so that it hangs down to the ground. The width of the bend is preferably 1.8 to 2.5 mm so that it can be folded in this state.

Furthermore, the distance (N1) from the edge of the agricultural water stop sheet 1 to the folded portion 1a is preferably 15 to 25 mm. If it is less than 15 mm, it may not be possible to fix it with the spring 3 when it is attached to the frame member 2, and if it exceeds 25 mm, it may protrude too much from the top of the frame member 2, which not only looks bad but may also result in a gap being formed between the ground and the agricultural water stop sheet 1.
The distance (N2) between the bent portions 1a and 1b and the distance (N3) between the bent portions 1b and 1c are appropriately determined according to the size of the frame member 2.

The cross-sectional shape perpendicular to the longitudinal direction of the bent portion is, for example, rectangular. The cross-sectional shape perpendicular to the longitudinal direction of the bent portion is not limited to this, and may be an inverted triangle shape in which the groove width dimension decreases from the open side of the bent portion to the outside toward the opposite side, or a U-shape.

The agricultural water stop sheet 1 is constructed so that it can be easily folded along the thin folded parts. As shown in FIG. 2, the agricultural water stop sheet 1 is folded at the folded parts 1a, 1b, and 1c with the part where the folded part 1a is formed being inserted into the groove part 2a of the frame member 2, and is fixed to the groove part 2a by being pressed against the inner walls on both sides of the groove width direction of the groove part 2a by the spring 3 made of a metal wire formed to meander in a plan view.

Here, FIG. 5 is a cross-sectional view of the agricultural water stop sheet 101 and the frame member 2 when a part of the conventional agricultural water stop sheet 101 is placed in the groove portion 2a of the frame member 2. When fixing the agricultural water stop sheet 101 to the frame member 2, the installer, for example, indents the agricultural water stop sheet 101 and places a part of the agricultural water stop sheet 101 in the groove portion 2a of the frame member 2, and then inserts a spring 3 (see FIG. 3) that is biased in the groove width direction of the groove portion 2a into the inside of the groove portion 2a, and presses the agricultural water stop sheet 101 against the inner wall of the groove portion 2a in the groove width direction. This fixes the agricultural water stop sheet 101 to the frame member 2.

However, the agricultural water stop sheet 101 may have a high stiffness and a relatively large restoring force. As shown in FIG. 5, in this case, when the agricultural water stop sheet 101 is folded and inserted into the groove 2a of the frame member 2, the agricultural water stop sheet 101 may pop out of the groove 2a of the frame member 2 due to the rebound caused by the folding. Therefore, the installer is required to fix the agricultural water stop sheet 101 to the groove 2a of the frame member 2 with the spring 3 while holding a part of the agricultural water stop sheet 101 inside the groove 2a of the frame member 2, which reduces workability and increases the workload. This problem of reduced workability becomes more noticeable, for example, as the restoring force of the agricultural water stop sheet 101 increases.

In contrast, the agricultural water stop sheet 1 according to the present invention has the above-mentioned folds formed, and when folded at each fold, the restoring force is reduced. Therefore, by placing the part of the agricultural water stop sheet 1 with the folds formed in the groove 2a of the frame member 2 and folding the agricultural water stop sheet 1 at the fold within the groove 2a, the agricultural water stop sheet 1 can be folded relatively easily, and it is easy to maintain the state in which a part of the agricultural water stop sheet 1 is inserted in the groove 2a of the frame member 2. This improves the workability when fixing the agricultural water stop sheet 1 in the groove 2a of the frame member 2 with the spring 3.

In addition, when a conventional agricultural water stop sheet 101, which has a high stiffness, is fixed in the groove portion 2a of the frame member 2 by the spring 3, the agricultural water stop sheet 101 may wrinkle or bend in and around the groove portion 2a, or a gap may form between the agricultural water stop sheet 101 and the frame member 2.

In contrast, the agricultural water stop sheet 1 of the present invention is folded at the folding portion, so that excessive force is not applied to the agricultural water stop sheet 1, and wrinkles and warping are less likely to occur. In addition, gaps are less likely to occur between the agricultural water stop sheet 1 and the frame member 2. As a result, the agricultural water stop sheet 1 can be properly fixed in the groove portion 2a of the frame member 2 by the spring 3, and the aesthetic appearance of the agricultural greenhouse can be prevented from being reduced by wrinkles and warping of the agricultural water stop sheet 1. In addition, the heat retention of the agricultural greenhouse can be prevented from being reduced by the above-mentioned gaps.

The agricultural water stop sheet 1 is manufactured, for example, based on the T-die extrusion molding method as shown in FIG. 4, by continuously manufacturing a sheet member 1' made of a resin material using a T-die, and processing the sheet member 1' by pressing rotary stamping blades 4a, 4b, and 4c against the surface of the sheet member 1' before the sheet member 1' is cooled and molded to form the folds 1a, 1b, and 1c. Note that the manufacturing method of the agricultural water stop sheet 1 is not limited to this.

The bend forming device 4, which is equipped with rotary stamping blades 4a, 4b, and 4c, can be appropriately adjusted so that the mutual spacing between the rotary stamping blades 4a, 4b, and 4c, the height of the convex portion, etc., are within a preferred range.

As explained above, the agricultural water stop sheet 1 according to the present invention is easily folded in the thickness direction at the folding portions, so that it can be easily folded at the folding portions even with a small force. Therefore, for example, when placing a part of the agricultural water stop sheet 1 in the groove portion 2a of the frame member 2, the part of the agricultural water stop sheet 1 where each folding portion is formed can be placed inside the groove portion 2a, so that a part of the agricultural water stop sheet 1 can be easily placed inside the groove portion 2a. This makes it possible to prevent the agricultural water stop sheet 1 from jumping out of the groove portion 2a due to the rebound force caused by folding. Therefore, it is possible to easily fix the agricultural water stop sheet 1 to the frame member 2 within the groove portion 2a of the frame member 2.

In addition, the agricultural waterproof sheet 1 has a folding section in which multiple convex portions are arranged in parallel, making it easy to fold at the folding section and maintaining good durability.

As described above, the present invention has the excellent effect of effectively preventing a decrease in workability when fixing an agricultural water stop sheet to a frame member. Therefore, it is beneficial to widely apply this effect as an agricultural water stop sheet.

Reference Signs List 1, 101: Agricultural water stop sheet 1a, 1b, 1c: Folding portion 2: Frame member 2a: Groove portion 2b: Main body portion 2c: Side portion 3: Spring 4: Folding portion forming device

Claims (1)

The first folded portion, the second folded portion, and the third folded portion extend linearly in one direction along the surface, and a part of the surface is easily folded in the thickness direction,
The first bent portion, the second bent portion, and the third bent portion are arranged in parallel in this order from one end side,
The agricultural waterproof sheet, wherein each of the first fold portion, the second fold portion and the third fold portion is composed of three or more parallel convex portions protruding from one surface side .

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