JP7684680B2 - Vegetation Sheet - Google Patents

Description

The present invention relates to a vegetation sheet that is effective for vegetation of grass, for example, and can be used and installed in park green spaces, riverbeds, and slopes.

The applicant previously proposed a vegetation sheet made of nonwoven fabric with water repellency on the front side and water absorbency on the back side (Patent Document 1). When this vegetation sheet is laid on the ground with the front side facing up and the back side facing down, the front side (upper side) of the nonwoven fabric dries easily due to its water repellency, providing a weed control effect that inhibits the establishment of airborne seeds, while the back side (lower side) absorbs and retains moisture from the ground due to its water absorbency, making it easy to create an environment suitable for the growth of vegetation.

JP 2019-201552 A

However, in order to ensure the weed control effect of the above-mentioned vegetation sheet, it is preferable to increase the basis weight of the nonwoven fabric so as to prevent the penetration of the roots of the seeds that have flown in. In this case, however, there is a problem in that the nonwoven fabric itself tends to inhibit the penetration of the sprouts of the target seeds for vegetation that are placed on the back (lower side) of the nonwoven fabric.

The present invention was made with the above in mind, and its purpose is to provide a vegetation sheet that can enhance the weed control effect while ensuring the growth of the target species.

In order to achieve the above-mentioned object, the vegetative sheet of the present invention has a target species of vegetative base sandwiched between stacked upper cotton and lower cotton , the basis weight of the upper cotton is smaller than the basis weight of the lower cotton, the total basis weight of the upper cotton and the lower cotton combined is 150 g/m2 or ^more , and the ratio of the basis weight of the lower cotton to the basis weight of the upper cotton is 1.1 to 2.0 ( Claim 1).

In the above-mentioned vegetative sheet, a net-like member may be present above the upper cotton (Claim 2).

In the above-mentioned vegetation sheet, fertilizer or a surfactant may be present on at least one surface of the upper cotton or the lower cotton (claim 3).

In the above-mentioned vegetation sheet, between the core in which the vegetation base is sandwiched between the stacked upper cotton and lower cotton and the net-like member or below the core, there is a thin net which has the function of holding fertilizer together with the core and has a basis weight smaller than either the upper cotton or the lower cotton, and fertilizer may be present between the core and the thin net (Claim 4).

In the above vegetation sheet, a silicon-based or cationic softener may be in contact with the upper cotton and the lower cotton (claim 5).

In the above vegetation sheet, the target species can be Japanese lawn grass (Claim 6).

In the above vegetation sheet, the vegetation base may be a zoysiagrass seed or runner (Claim 7).

The present invention provides a vegetation sheet that can enhance weed control effects while ensuring the growth of target species.

In other words, the vegetation sheet of the invention according to each claim of this application can enhance the weed control effect by increasing the total basis weight of the top cotton and the bottom cotton. In addition, the vegetation base of the target species (e.g. seeds, bulbs, runners, etc.) is located between the top cotton and the bottom cotton, and of the top and bottom cottons, only the top cotton is subject to sprout penetration, and only the bottom cotton is subject to root penetration, so it is possible to ensure sprout penetration and root penetration, and therefore to ensure the growth of the target species.

The vegetation sheet of the present invention also has excellent heat retention properties because the vegetative base of the target species is sandwiched between cotton, and this high level of heat retention is particularly effective when the target species is, for example, lawn grass, which requires a relatively long period of heat retention before germination even after germination promotion treatment.

Furthermore, the cotton used in the vegetation sheet of the present invention is not a synthetic fiber and is white in color, so it is unlikely to become excessively hot even under direct sunlight in the summer, and it is possible to prevent the sandwiched vegetation base from dying due to heat. Furthermore, because cotton is naturally derived, it is completely biodegradable, so there is no burden on the environment, and there is also the advantage that it does not need to be removed, which helps reduce maintenance work.

In the vegetation sheet of the invention according to claim 2, unabsorbed cotton is used for each cotton, so a degreasing process is not required compared to when absorbent cotton is used, and it is expected that manufacturing costs will be reduced. In addition, unabsorbed cotton is water repellent, so there is an advantage that the cotton is less likely to absorb water or moisture and become heavy when the vegetation sheet is transported, etc.

In the vegetation sheet of the invention of claim 1 , taking into consideration that the root penetration ability of vegetation base is generally greater than the sprout penetration ability, the basis weight of the upper cotton is relatively small and the basis weight of the lower cotton is relatively large, thereby making it possible to achieve both sprout and root penetration of the target species, and thereby promoting its growth.

In the vegetation sheet of the invention according to claim 3 , by providing a net-like member, it is possible to prevent the entire vegetation sheet from being damaged or turned over by the wind.

In the vegetation sheet of the invention according to claim 5, the growth of the target species can be promoted by holding fertilizer on one side of either the upper or lower cotton. In addition, if the upper or lower cotton is unabsorbed cotton, coating one side of either cotton with a surfactant will impart water absorption properties to the cotton, making it easier to create an environment suitable for the growth of the target species.

In the vegetation sheet of the invention according to claim 6, the growth of the runners of the Japanese lawn grass, protected by the cotton above and below, is less likely to be inhibited by weeds, so vigorous reproduction of the Japanese lawn grass can be expected.

In the vegetation sheet of the invention according to claim 7, the seeds of the Japanese zoysia grass are oval in shape and the runners are elongated, so neither of them are likely to roll around. Once they are evenly distributed over the entire vegetation sheet, this state is easy to maintain, and uneven distribution during transportation and construction is unlikely to occur, allowing for good growth of the Japanese zoysia grass.

1A and 1B are exploded perspective views of a vegetation sheet according to a first embodiment and a second embodiment of the present invention. 1A and 1B are a cross-sectional view and a plan view showing the applied state of the vegetation sheet of the first embodiment. (A) and (B) are photographs of the conventional vegetation sheet and the vegetation sheet of this example used in the comparative test, (C) and (D) are photographs of both vegetation sheets about one month after the start of the test, and (E) and (F) are photographs of both vegetation sheets about two months after the start of the test.

The following describes an embodiment of the present invention.

The vegetation sheet S of the first embodiment shown in Figure 1 (A) is intended to promote the growth of the target species of vegetation base 1 while not promoting, and in fact suppressing, the growth of plants other than the target species by laying it on the ground G (a slope in the illustrated example, but flat ground, etc.) as shown in Figure 2 (A), for example.

The vegetation sheet S has a long, roughly rectangular shape, specifically measuring 1 m in width and 10 m in length, and is advantageous in terms of portability and space-saving storage when rolled up lengthwise. For example, as shown in Figure 2 (A), when laying a rolled vegetation sheet S on a slope, it can be easily unfolded by fixing one end to the slope top with an anchor pin A, a bamboo skewer, or other fastening member and rolling it toward the foot of the slope, and in this unfolded state, its longitudinal direction faces from the slope top to the foot of the slope. Note that Figure 2 (B) shows (part of) a state in which multiple vegetation sheets S are laid out side by side.

As shown in FIG. 1(A), the vegetation sheet S has, in this order from the bottom, a core 4 in which the target species of vegetation base 1 is sandwiched between stacked upper cotton 2 and lower cotton 3, fertilizer 5, a thin sheet 6, and a net-like member 7. This vertical positional relationship is when the vegetation sheet S is laid on the ground, and does not apply during the manufacture, transportation, or storage of the vegetation sheet S. Also, in this example, the planar dimensions of the core 4 (upper and lower cotton 2, 3), the thin sheet 6, and the net-like member 7 when laid are approximately the same (width 1 m, length 10 m).

The structure of the vegetation sheet S is explained in detail below.

The vegetation base 1 is made up of, for example, the seeds, bulbs, runners, etc. of the target species, and has functions suitable for composing plants and promoting vegetation. Specific examples include warm-climate turfgrass such as Japanese lawn grass, seeds and runners of bamboo grass, and seeds of Imperata cylindrica, Miscanthus sinensis, Artemisia anguicida, and Japanese quince. If Japanese lawn grass runners are used, the vegetation base 1 can be loosened and used as turf. From the perspective of biodiversity conservation, it is preferable to use vegetation base 1 of native plants that are traditionally native to Japan rather than invasive or foreign plants whenever possible.

Upper cotton 2 and lower cotton 3 are made from unbleached raw cotton.

It is preferable that the basis weight of the upper cotton 2 is as large as possible, with the upper limit not inhibiting sprout growth in the vegetation base 1 of the target species, and the basis weight of the lower cotton 3 is as large as possible, with the upper limit not inhibiting root growth in the vegetation base 1 of the target species. On the other hand, it is preferable that the total basis weight of the upper cotton 2 and the lower cotton 3 combined is limited to a lower limit that ensures weed control effect, and specifically, 150 g/ ^m2 or more is preferable. It is preferable that the total basis weight is as large as possible to increase the weed control effect and the effect of preventing weeds from being overwhelmed.

Furthermore, since the root penetration ability of the vegetation base 1 is generally greater than the sprout penetration ability, it is possible to achieve both sprout penetration and root penetration of the target species, and thus promote growth, by making the weight of the upper cotton 2 smaller than that of the lower cotton 3. Specifically, it is desirable to set the ratio of the weight of the lower cotton 3 to that of the upper cotton 2 to about 1.1 to 2.0, and in this example, the weight of the upper cotton 2 is 85 g/ ^m2 , and the weight of the lower cotton 3 is 100 g/ ^m2 . However, for example, in the case of wild grass, if the basis weight of the upper cotton 2 is 200 g/ ^m2 and the basis weight of the lower cotton 3 is 0 g/ ^m2 , germination is inhibited. However, the inventors have confirmed that stable germination can be achieved even if the total basis weight of the upper and lower cottons 2, 3 is maintained at 200 g/ ^m2 and the ratio of the basis weights of the upper cotton 2 and lower cotton 3 is 130:70, 140:60 or even 150:50 (i.e., even if the basis weight of the upper cotton 2 is 130 to 150 g/ ^m2 and the basis weight of the lower cotton 3 is 70 to 50 g/ ^m2 correspondingly).

In this example, the upper cotton 2 and the lower cotton 3, both of which are formed into rectangular sheets by the needle punching method into nonwoven fabric, are integrated by needle punching. During this integration (needle punching), the vegetative base 1 is placed between the two cottons 2 and 3, and the core 4 is formed by sandwiching the vegetative base 1 between the two cottons 2 and 3 that are stacked and integrated.

When using Japanese yew seeds as the vegetation base 1, the Japanese yew seeds are oval in shape and do not roll easily. Once they are distributed almost uniformly over the entire surface between the upper and lower cotton 2, 3, the fibers of the upper and lower cotton 2, 3 are intricately intertwined, and the Japanese yew seeds are unlikely to move between the upper and lower cotton 2, 3 during transportation or construction. In other words, the distribution is unlikely to become uneven (it is easy to maintain a dispersed state). Therefore, the Japanese yew seeds do not need to be glued to the upper and lower cotton 2, 3. However, this is not a limitation, and the vegetation base 1 may be glued to either or both of the upper and lower cotton 2, 3 before the upper and lower cotton 2, 3 are integrated (needle punched).

The fertilizer 5 may be any fertilizer that is effective in promoting the growth of the vegetation base 1; in this example, it is in granular or powder form (solid), and is attached with an adhesive (e.g., poval) to one side (top) of the top cotton 2 or to the bottom side of the thin sheet 6. Generally, germination tends to be delayed when fertilizer is placed in contact with the vegetation base 1 such as seeds, but in this example, by placing the top cotton 2 between the fertilizer 5 and the vegetation base 1 as described above and physically separating the two 5, 1, this tendency can be reduced and delays in germination can be prevented.

In addition, in this example, a surfactant is applied to the top surface of the upper cotton 2 to impregnate it, making it absorbent, and making it easier to create an environment suitable for the growth of the target species.

The thin and weak sheet 6 has a function of holding the fertilizer 5 together with the core 4 (upper cotton 2) until the vegetation sheet S is installed on the ground, and has a structure (thinness, strength, gaps, and basis weight) that does not inhibit germination of the vegetation base 1 after the vegetation sheet S is installed on the ground. The thin and weak sheet 6 is biodegradable and is preferably made of natural fibers or regenerated fibers made by chemically treating natural fibers rather than 100% synthetic fibers derived from petroleum, and for example, paper such as crepe paper or a thin cotton sheet can be used. In this example, a thin cotton sheet with a basis weight (20 g/ ^m2 ) smaller than both the upper cotton 2 and the lower cotton 3 is used as the thin and weak sheet 6.

As mentioned above, it is preferable to make the weight of the upper cotton 2 smaller than that of the lower cotton 3, but the thin sheet 6 compensates for the smaller weight of the upper cotton 2, thereby improving the heat retention and water retention of the vegetation base 1 and contributing to an improved germination rate.

The net-like member 7 is provided to prevent damage to the entire vegetation sheet S and to prevent the entire vegetation sheet S from being turned over by the wind, and is a mesh-like member that is easily deformed like the core 4 and the thin sheet 6, but has higher strength (tensile strength) than the core 4 and the thin sheet 6. The net-like member 7 is preferably made of a biodegradable material such as sliding door material (made by knitting or weaving 100% rayon flat yarn, paper yarn, etc.) or mosquito net material (coarsely woven hemp or cotton yarn), and is preferably made of natural fibers or regenerated fibers made by chemically treating natural fibers, rather than 100% synthetic fibers derived from petroleum.

In this example, the thin sheet 6 is bonded to the core 4 (upper cotton 2) and the net-like member 7 with an adhesive (e.g., poval). Here, while the upper cotton 2 of the core 4 is a natural fiber, if either or both of the thin sheet 6 and the net-like member 7 are made of a material different from the upper cotton 2, such as a synthetic fiber derived from petroleum (e.g., polyester), the difference in the materials of the three components 2, 6, and 7 would lead to a decrease in adhesion, and there is a risk that the amount of adhesive required to bond the three components 2, 6, and 7 would increase. However, by using natural or recycled fibers for both the thin sheet 6 and the net-like member 7, the materials of the three components 2, 6, and 7 become homogenous, and the amount of adhesive required to bond them can be reduced, thereby reducing the environmental impact.

In addition, by making the mesh size and wire diameter of the net-like member 7 smaller, the contact area between the net-like member 7 and the thin sheet 6 when they are stacked increases, so the concentration of the adhesive used to bond the two 7, 6 can be reduced accordingly, and the thin sheet 6 is more likely to peel off from the net-like member 7 due to the action of raindrops and adhere to the ground together with the core 4. Specifically, for example, a net-like member 7 made of 20-80 count rayon single yarns plain woven to have a mesh size of 1-3 mm x 3-5 mm can be used.

Incidentally, the present inventors have confirmed that when a net is attached to the top of the vegetation sheet (nonwoven fabric) shown in Patent Document 1 with poval (adhesive) and laid on the ground, the nonwoven fabric eventually turns into cardboard. This cardboard-like phenomenon refers to the phenomenon in which the nonwoven fabric loses its elasticity and flexibility due to a combination of factors such as ultraviolet rays and temperature changes, and turns into a crunchy, board-like material. This cardboard-like texture reduces the mesh size of the nonwoven fabric, significantly impairing the germination and root penetration of seeds (plants) held on the underside of the nonwoven fabric. Furthermore, the nonwoven fabric shrinks and hardens starting from the poval at the boundary between the net and the nonwoven fabric, and eventually the bulk of the nonwoven fabric decreases in the direction of the taut net (the nonwoven fabric is pulled in the direction away from the ground). As the seeds held under the nonwoven fabric take root, the young, thin rootlets that have been lowered (stretched) to the ground begin to pop and break as the nonwoven fabric shrinks in the direction of the net, stopping further growth and preventing the vegetation of the target plant from progressing.

In this regard, the vegetation sheet S of this example can reduce the amount of poval used, which is thought to be one of the factors that causes the paper to become thick, making the upper cotton 2 and lower cotton 3 less likely to become thick.

In addition, in the vegetation sheet S of this example, a thin sheet 6 is interposed between the upper cotton 2 and the net-like member 7, so even if both cottons 2 and 3 are made into thick paper, the two cottons 2 and 3 (core 4) are less likely to be pulled in the direction of the net-like member 7, which means that both cottons 2 and 3 (core 4) can be easily attached to the ground (and can be easily maintained in contact with the ground).

It is also possible to prevent the initial thickening of the paper by contacting both cotton sheets 2 and 3 with a silicone or cationic softener, for example by spraying it on.

In the vegetation sheet S constructed as described above, the total basis weight of the upper cotton 2 and the lower cotton 3 can be increased to enhance the weed prevention effect. In addition, the vegetation base 1 of the target species is located between the upper cotton 2 and the lower cotton 3, and of the upper and lower cottons, only the upper cotton is subject to sprout penetration, and only the lower cotton is subject to root penetration, so it is possible to ensure sprout penetration and root penetration, and therefore the growth of the target species.

The vegetation sheet S also has excellent heat retention properties because the vegetation base 1 of the target species is sandwiched between cotton 2 and 3. This high level of heat retention is particularly effective when the target species is, for example, lawn grass, which requires a relatively long period of heat retention before germination even after germination promotion treatment.

Furthermore, the cotton 2, 3 used in the vegetation sheet S is not synthetic and is white in color, so it is unlikely to become excessively hot even under direct sunlight in the summer, and it is possible to prevent the sandwiched vegetation base 1 from dying due to heat. Furthermore, since the cotton 2, 3 is naturally derived, it is completely biodegradable, so there is no environmental burden, and there is also the advantage that it does not need to be removed, which helps reduce maintenance work.

In addition, because unbleached raw cotton is used for the upper cotton 2 and the lower cotton 3, a degreasing process is not required compared to when absorbent cotton is used, and it is expected that manufacturing costs will be reduced. Furthermore, unbleached cotton is water repellent, so there is also the advantage that the cotton is less likely to absorb water or moisture and become heavy when the vegetation sheet is transported, etc.

In particular, when the target species to be grown on the vegetation sheet S is Japanese lantern grass, the growth of the Japanese lantern grass runners protected by the upper and lower cottons 2 and 3 is less likely to be inhibited by weeds, so vigorous reproduction of the Japanese lantern grass can be expected.

A comparative test using a conventional vegetation sheet and the vegetation sheet S of this example (first embodiment) will be described below. In this comparative test, the conventional vegetation sheet (see FIG. 3(A)) was a sheet in which a net (material: degradable resin, shape: raschel knit, mesh size: 15 mm x 20 mm) was attached to the upper surface of a nonwoven fabric made of unbleached cotton with a basis weight of 200 g/ ^m2 , and the lower surface was cut to a length of 50 cm and a width of 50 cm with wild zoysia grass seeds and fertilizer glued thereto. The vegetation sheet S of this example (see FIG. 3(B)) has the above-mentioned configuration, is 50 cm long and 100 cm wide, and uses wild zoysia grass seeds as the vegetation base 1. The retention amounts of wild zoysia grass seeds and fertilizer per unit area are approximately the same in both vegetation sheets.

The conventional and present vegetation sheets were laid in the field at the test site (Nihon Shokusei Co., Ltd. General Research Field, Shinjo, Misaki-cho, Kume-gun, Okayama Prefecture) on July 22, 2020 (the start of the test), and the growth of the Japanese lantern grass was observed for two months. The results are shown in Figures 3 (C) to (F).

Approximately one month after the start of the test (August 25, 2020), the vegetation coverage rate was 5% for the conventional vegetation sheet (see Figure 3 (C)), while it was 40% for the vegetation sheet S of this example (see Figure 3 (D)). In addition, approximately two months after the start of the test (September 28, 2020), the vegetation coverage rate was 10% for the conventional vegetation sheet (see Figure 3 (E)), while it was 60% for the vegetation sheet S of this example (see Figure 3 (F)). These results confirmed the effectiveness of the vegetation sheet S of this example.

The present invention is not limited to the above embodiment, and can be modified in various ways without departing from the spirit of the present invention. For example, the following modifications can be mentioned:

In the first embodiment described above, as shown in FIG. 1(A), fertilizer 5 (and surfactant) and a thin sheet 6 are provided between the core 4 and the net-like member 7 provided above the core 4, but this is not limiting. For example, as in the vegetation sheet S2 of the second embodiment shown in FIG. 1(B), fertilizer 5 (and surfactant) and a thin sheet 6 may be provided below the core 4.

The vegetation sheets S, S2 are not limited to having an overall rectangular shape, but may be, for example, square shaped.

The vegetation sheets S and S2 may be manufactured on-site by laminating and integrating each component.

In the vegetation sheet S, the fertilizer 5 and surfactant may be provided on the underside of the core 4 (lower cotton 3), or between the upper cotton 2 and the lower cotton 3.

It goes without saying that the above modifications may be combined as appropriate.

REFERENCE SIGNS LIST 1 Vegetation base 2 Upper cotton 3 Lower cotton 4 Core 5 Fertilizer 6 Thin sheet 7 Net-like member A Anchor pin G Ground S Vegetation sheet S2 Vegetation sheet

Claims (7)

The target species of vegetation is sandwiched between the upper and lower cotton layers .
The weight of the upper cotton is smaller than the weight of the lower cotton,
The total weight of the upper cotton and the lower cotton combined is 150 g/m2 ^or more,
A vegetative sheet characterized in that the ratio of the basis weight of the lower cotton to the basis weight of the upper cotton is 1.1 to 2.0 . The vegetative sheet according to claim 1, wherein a net-like member is present above the upper cotton . 3. The vegetation sheet according to claim 1 or 2, wherein a fertilizer or a surfactant is present on at least one surface of the upper cotton or the lower cotton . A vegetation sheet as described in any one of claims 1 to 3, wherein between the core in which the vegetation base is sandwiched between the stacked upper cotton and lower cotton and the net-like member or below the core, there is a thin net having a function of holding fertilizer together with the core and having a smaller basis weight than either the upper cotton or the lower cotton, and fertilizer is present between the core and the thin net . 5. The vegetative sheet according to claim 1, wherein a silicone or cationic softener is in contact with said upper cotton and said lower cotton . The vegetation sheet according to any one of claims 1 to 5, wherein the target species is Japanese zoysiagrass. The vegetative sheet according to any one of claims 1 to 6, wherein the vegetative base is a seed or a runner of Zoysiagrass.