WO2007142497A1

WO2007142497A1 - Vegetation basement board, vegetation mat and method for manufacturing the vegetation basement mat

Info

Publication number: WO2007142497A1
Application number: PCT/KR2007/002806
Authority: WO
Inventors: Dae Young Kim; Choong Hyeon Oh
Original assignee: Industry Academic Cooperation Foundation of Dongguk University
Current assignee: Industry Academic Cooperation Foundation of Dongguk University
Priority date: 2006-06-09
Filing date: 2007-06-11
Publication date: 2007-12-13
Anticipated expiration: 2008-12-09
Also published as: KR100828167B1; JP2009531574A; KR20070118052A; JP4769892B2

Abstract

A lightweight vegetative base and a vegetative mat are provided. The vegetative base comprises a number of densely packed wood chips and a filler filled in spaces between the wood chips to maintain the densely packed wood chips in a planar structure. The vegetative base and the vegetative mat can be used in a simple manner to grow various plants thereon without requiring any vegetative soil, such as soil or artificial soil. In addition, the vegetative base and the vegetative mat are lightweight and are thus very useful in the afforestation of artificial grounds, particularly building roofs.

Description

[DESCRIPTION]

[Invention Title]

VEGETATION BASEMENT BOARD, VEGETATION MAT AND METHOD FORMANUFACTURINGTHEVEGETATIONBASEMENTMAT

[Technical Field]

The present invention relates to a vegetative base. More specifically, the present invention relates to a lightweight vegetative base composed of materials obtained from waste wood and waste paper, a vegetative mat comprising the vegetative base and that is easy to install, change and repair, and a method for manufacturing the vegetative mat.

[Background Art]

Recent rapid urbanization has resulted in a gradual decrease in the green space of cities. Many efforts have been made to overcome the lack of green space in cities. For example, city dwellers have actively participated in gardening, creation of ecological parks and tree planting. However, it is practically difficult to protect and increase green space in cities due to many buildings and residential facilities in the cities. As an alternative to solve the difficulty, an afforestation plan using existing building roofs has attracted more and more attention in recent years. Afforestation of building roofs is currently employed in many buildings due to its advantages in terms of space recycling, establishment of urban ecosystem, air purification, reduction of the urban heat island, energy saving of buildings and environmental improvements through microclimate control.

FIG. 1 is a cross-sectional view of a conventional vegetation structure 10 for afforestation of an artificial ground. The vegetation structure 10 comprises a vegetative soil layer 11, a filter layer 12, a drainage layer 13, a root barrier layer 14 and a waterproof layer 15. The vegetation structure 10 is installed on an artificial ground 20, such as the roof of a building.

The vegetative soil layer 11 acts as a base on which plants continuously grow.

Since the weight fraction of the vegetative soil layer 11 in the vegetation structure 10 is the highest among the constituent layers, the vegetation structure 10 suffers from high load.

The filter layer 12 serves to prevent fine-grained soil of the vegetative soil layer from being washed away during rainfall. The drainage layer 13 is responsible for the drainage of water from the vegetative soil layer 11, and the root barrier layer 15 protects the waterproof layer 15 and the building 20 from attack by the roots of plants. The waterproof layer 14 plays a role in blocking leakage of water into the building 20 from the vegetation structure 10. As a consequence, the conventional vegetation structure 10 has disadvantages in that its structure is complex and its total weight is large due to the high load of the vegetative soil layer 11.

The vegetative soil layer 11 must have a soil depth sufficient to allow various plants to grow on the vegetation structure 10. However, as the soil depth of the vegetative soil layer increases, the load of the vegetative soil layer applied to the building increases. From the viewpoint of the structural safety of the building, the soil depth of the vegetative soil layer must be limited, resulting in a limitation of the species of plants growing on the vegetation structure. Accordingly, the conventional vegetation structure 10 applies a high load to the building. Particularly, when the vegetative soil layer has a deep soil depth, the conventional vegetation structure 10 cannot be installed on weak buildings. As shown in FIG. 1, the vegetation structure 10 comprises various layers necessary for vegetation, which make the vegetation structure 10 inconvenient to install on the building roof 20 and difficult to partially change and repair. Further, since the vegetative soil layer 11 as a vegetative base includes soil or artificial soil, the vegetation structure 10 must be installed on flat artificial ground only.

[Disclosure] [Technical Problem]

The present invention has been made in view of the above problems, and it is a first object of the present invention to provide a vegetative base that has a simple structure and is lightweight due to the absence of a vegetative soil layer.

It is a second object of the present invention to provide a vegetative mat comprising the vegetative base and that is easy to install, manage and repair.

It is a third object of the present invention to provide a method for manufacturing a lightweight and easy-to-install vegetative mat. [Technical Solution]

To accomplish the first object of the present invention, there is provided a vegetative base comprising a number of densely packed wood chips and a filler filled in spaces between the wood chips to maintain the densely packed wood chips in a planar structure.

According to a preferred embodiment of the present invention, the wood chips are wood pieces obtained by crushing waste wood.

According to another preferred embodiment of the present invention, the filler contains waste paper pulp. According to another preferred embodiment of the present invention, the filler may contain a colorant, powdered activated carbon, a wet-strengthening agent for papermaking or a surface sizing agent for papermaking.

According to still another preferred embodiment of the present invention, the vegetative base may further comprise a reinforcing material composed of coconut fiber. To accomplish the second object of the present invention, there is provided a vegetative mat comprising: the vegetative base as a vegetative layer; a planting layer including seeds sown on the vegetative layer and a coating layer formed on the vegetative layer to immobilize the seeds; and a drainage layer disposed under the vegetative layer, the drainage layer including a non-woven fabric sheet and a drainage plate disposed under the non- woven fabric sheet and provided with drainage grooves.

According to a further embodiment of the present invention, the coating layer may contain oxidized starch.

To accomplish the third object of the present invention, there is provided a method for manufacturing the vegetative mat, the method comprising the steps of (a) preparing wood chips, (b) preparing a paper pulp slurry, (c) mixing the wood chips with the paper pulp slurry, (d) providing an apparatus for producing a vegetative base, the apparatus comprising a mold provided with drainage holes and a push plate matched with the mold, (e) feeding a mixture of the wood chips and the paper pulp slurry into the mold, and (f) pressurizing the mixture using the push plate to mold the mixture into a vegetative base.

According to a preferred embodiment of the present invention, in step (c), 40- 60% by weight of the wood chips are mixed with 40-60% of the paper pulp slurry, based on the total weight of the mixture. A colorant, powdered activated carbon, a wet- strengthening agent for papermaking or a surface sizing agent for papermaking may be further added to the mixture of the wood chips and paper pulp slurry. According to another embodiment of the present invention, in step (e), a reinforcing material composed of coconut fiber may be further added to the mixture.

According to another preferred embodiment of the present invention, the mold used in step (d) has a first side portion having a first protrusion/depression pattern and a second side portion opposite to the first side portion and having a second protrusion/depression pattern matched with the first protrusion/depression pattern.

The method of the present invention further comprises the step of, after step (f), planting seeds on the upper portion of the vegetative base as a vegetative layer. Preferably, the seed planting step includes the sub-steps of sowing seeds on one surface of the vegetative layer and coating the surface with an aqueous solution of oxidized starch. Preferably, the method of the present invention further comprises the step of, after step (f), immersing the vegetative base in liquid manure, followed by drying.

[Advantageous Effects]

The vegetative base and the vegetative mat of the present invention are lightweight due to the absence of any vegetative soil (e.g., artificial soil). Therefore, the light vegetative base and vegetative mat of the present invention can be used to afforest artificial grounds even in weak buildings and enable vegetation requiring a deep soil depth by simply increasing their thickness. Based on these advantages, the use of the vegetative mat according to the present invention can achieve diversification of vegetation when compared to the use of a conventional vegetation structure, which comprises vegetative soil having the same load as the vegetative base. In addition, the need to provide additional layers, such as a filter layer, a drainage layer and a waterproof layer of a conventional vegetation structure, is eliminated in the vegetative mat of the present invention. Therefore, the vegetative mat of the present invention has a simple structure, can be installed anywhere without particular limitation, and is easy to install and repair.

Furthermore, the vegetative mat of the present invention is advantageous in terms of resource recycling because it uses materials obtained from waste wood and waste paper.

[Description of Drawings]

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view of a conventional vegetation structure for afforestation of an artificial ground;

FIG. 2 is a perspective view of a vegetative base according to the present invention;

FIG. 3 is a perspective view of a vegetative mat according to the present invention;

FIG. 4 is a cross-sectional view of a vegetative mat according to the present invention installed on an artificial ground; FIGs. 5a to 5c are explanatory diagrams illustrating a method for preparing raw materials for a vegetative mat of the present invention;

FIG. 6 is a perspective view of a mold for producing a vegetative base of the present invention;

FIGs. 7a to 7f are explanatory diagrams illustrating the procedure of a method for manufacturing a vegetative mat according to the present invention;

FIGs. 8a to 8e are explanatory diagrams illustrating a method for providing unit vegetative mats in accordance with the present invention;

FIGs. 9 to 11 are diagrams illustrating afforestation of artificial grounds using unit vegetative mats in accordance with the present invention; FIG. 12 is a photograph of grass seeds germinated and grown on a vegetative mat of the present invention; and

FIG. 13 is a photograph showing a side view of a vegetative mat according to the present invention on which grass seeds are germinated and grown.

[Best Mode]

The present invention will now be described in detail with reference to the accompanying drawings.

The vegetative mat of the present invention is lightweight due to the absence of any vegetative soil. In addition, no need to provide additional layers, such as a filter layer and a waterproof layer, is required in the vegetative mat of the present invention, thus contributing to simplification of the structure of the vegetative mat. Furthermore, seeds, a vegetative layer, a planting layer and a drainage layer are integrally provided in the vegetative mat of the present invention, thus making the vegetative mat easy to install.

FIG. 2 is a perspective view of the vegetative base according to the present invention. The vegetative base 100 comprises a number of densely packed wood chips 110 and a filler 120 filled in spaces or voids between the wood chips to maintain the densely packed wood chips in a planar structure.

The vegetative base 100 has a planar structure as a whole. The thickness of the vegetative base 100 may be suitably determined depending on the kind of plants to be grown on the vegetative base so as to ensure a soil depth necessary for the growth of the plants. The planar shape of the vegetative base 100 is rectangular as shown in FIG. 2, but is not limited thereto. For example, the vegetative base 100 may have a circular, triangular or polygonal planar shape.

The wood chips 110 are wood pieces obtained by crushing wood. Preferably, the wood chips 110 are obtained by crushing waste wood produced after tree thinning/cutting or construction into pieces having a predetermined size (e.g., 1.5-2 cm). The wood chips 110 are porous in view of their characteristics. The wood chips 110 may retain various nutrients necessary for the growth of plants planted on the vegetative base 100. The content of the wood chips 110 within the vegetative base 100 is preferably from 40 to 60% by weight, based on the total weight of the wood chips and paper pulp slurry. When the content of the wood chips is less than 40% by weight, the ability of the wood chips to retain nutrients necessary for the growth of plants unfavorably drops. Meanwhile, when the content of the wood chips exceeds 60% by weight (i.e. when the content of the filler 120 is relatively low), there is a risk that the strength of the vegetative base 100 may be decreased. The filler 120 immobilizes the densely packed wood chips 110 to maintain the wood chips 110 in a planar structure. The filler 120 is composed of a material capable of permitting seeds to root. That is, the filler 120 is composed of a material that allows the roots of plants to penetrate therethrough, can contain an appropriate amount of water, and can maintain the planar structure of the vegetative base 100.

The filler 120 of the vegetative base 100 is preferably composed of paper pulp. The filler 120 may be prepared by dehydrating a mixture of the paper pulp slurry and the wood chips 110 to cause the paper pulp fibers to be adhered to each other and to hold the wood chips 110. As a result, the filler 120 can maintain the planar structure of the densely packed wood chips 110. The filler 120 composed of paper pulp may be prepared from a paper pulp slurry, which is prepared by digesting a mixture of waste paper, e.g., wood-free paper, and water.

The filler 120 is highly water absorptive because of its constituent material (i.e. paper pulp). Accordingly, the filler 120 serves to supply an appropriate amount of water to plants planted on the vegetative base 100. Water is essential for the growth of the plants. The filler 120 may contain at least one functional additive to improve the durability of the vegetative base 100 and to provide advantageous effects on the growth of plants. As the functional additive, there may be used powdered or granular activated carbon that inhibits decay of the vegetative base and provides soil improvement effects, an anti-corrosion agent, a colorant that enhances the aesthetic effects of the vegetative base without damage to vegetation, a wet-strengthening agent for papermaking that increases the wet strength of the paper pulp and acts as a binder, or a surface sizing agent for papermaking that permits the wood chips and the filler to retain an appropriate amount of water. The functional additive is contained in the filler 120 by adding the functional additive to the paper pulp slurry. The surface sizing agent for papermaking may be directly added to the paper pulp slurry or may be applied to the surface of the vegetative base 100.

The vegetative base of the present invention may further comprise a reinforcing material composed of coconut fiber. Any reinforcing material that is composed of coconut fiber and is commonly used in the art can be used in the present invention. The reinforcing material serves to increase the wet durability of the vegetative base, and particularly, to enhance the durability of the vegetative base when the vegetative base becomes thick. That is, when a deep soil depth is required for vegetation (i.e. when the vegetative base is required to have a large thickness for vegetation), the vegetative base must be more durable to endure the increased vegetation load. The reinforcing material is added to reinforce the durability of the vegetative base. Coconut fiber pieces may be mixed with the filler 120. Nets composed of coconut fiber are more preferably used in terms of durability. The thickness of the nets composed of coconut fiber may be properly varied, without any particular limitation, taking into consideration the thickness of the vegetative base. The number of the nets composed of coconut fiber is also not especially restricted. The nets composed of coconut fiber may be laminated at a certain distance apart from each other within the vegetative base.

FIG. 3 is a perspective view of the vegetative mat according to the present invention.

The vegetative mat 200 of the present invention comprises the vegetative base 100 as a vegetative layer 210, which is explained with reference to FIG. 2. The vegetative layer 210 includes a number of densely packed wood chips 211 and a filler 212 composed of paper pulp and filled in spaces or voids between the wood chips to maintain the densely packed wood chips in a planar structure. It is understood that the vegetative layer 210 is in the form of a broad plate of the vegetative base 100. The vegetative layer 210 may have a rectangular or square shape in cross section whose width and length are from several centimeters to several meters, but is not limited to the shape. The wood chips 211 and the filler 212 are the same as those of the vegetative base 100, and descriptions thereof are omitted.

The vegetative mat 200 may further comprise a planting layer 220 formed on the vegetative layer 210. The planting layer 220 includes seeds 221 sown on the vegetative layer 210 and a coating layer 222 formed on the vegetative layer 210 to immobilize the seeds.

The seeds 221 may be sown at suitable intervals on the vegetative layer 210. The kind of the seeds 221 may be selected in consideration of the soil depth for vegetation, i.e. the depth of the vegetative layer 210. Contrary to this, the depth of the vegetative layer 210 may be determined after the kind of the seeds 221 is selected.

The coating layer 222 contains oxidized starch. For example, the coating layer 222 may be formed by coating the vegetative layer 210, on which the seeds 221 are sown, with a solution of oxidized starch. The oxidized starch constituting the planting layer 220 is used as a nutrient for the initial germination of the sown seeds 221, serves to better adhere the seeds 221 to the vegetative layer 210, and acts as a protective layer of the seeds. The coating layer 222 may be formed over the entire surface of the vegetative layer 210, as shown in the figure, or may be formed such that the sown seeds 221 only are covered.

The vegetative mat 200 of the present invention comprises the planting layer 220 including the seeds 221, and the vegetative layer 210 acts as a base for the vegetation of the seeds 221 and serves to supply water necessary for the vegetation of the seeds 221, thus allowing the vegetative mat 200 to possess all elements necessary for the vegetation of the seeds 221.

The planting mat 200 of the present invention may further comprise a drainage layer 230 underlying the vegetative layer 210 when installed to afforest artificial grounds.

The drainage layer 230 may consist of a drainage plate 231 provided with drainage passages (not shown) and a non- woven fabric sheet 232 disposed on the drainage plate

231.

The drainage plate 231 is made of a synthetic resin, such as polystyrene. A number of drainage grooves may be formed in length and width directions on the surface of the drainage plate 231. Alternatively, conical protrusions may be formed on the surface of the drainage plate 231 to form drainage passages through which water flows out. On the other hand, the non-woven fabric sheet 232 is disposed just below the vegetative layer 210 and is responsible as a root barrier layer to prevent the roots of the seeds 221 from penetrating and growing through the drainage plate 231. The non- woven fabric sheet 232 may be placed in direct contact with the surface of the drainage plate 231. In this case, the drainage layer 230 may be provided as a "drainage plate integrated with non- woven fabric", which is commercially available.

FIG. 4 is a cross-sectional view of the vegetative mat 200 installed on an artificial ground 20. As shown in FIG. 4, two nets composed of coconut fiber 400 are laminated. The artificial ground 20 may be the roof or outer wall of a building or a cut slope of an express highway. The drainage layer 230 is fixed to the artificial ground 20 or located so as not to move on the artificial ground 20. The drainage plate 231 of the drainage layer 230 may have a base plate 231a, a number of protrusions 231b formed on the base plate 231a, and drainage passages 231c formed between the respective protrusions 231b.

According to the present invention, the vegetative layer 210 integrally formed with the planting layer 220 is disposed on the drainage layer 230. The vegetative layer 210 may be simply seated on the drainage layer 230 or may be fixed to the drainage layer 230 by means of a fixing means.

The wood chips 211 and the filler 212 composed of paper pulp, which constitute the vegetative layer 210, are light in weight. Accordingly, the load of the vegetative mat 200 applied to the artificial ground 20 is much lower than that of the conventional vegetation structure 10 using soil as a vegetative layer. As a result, intended vegetation requiring a deep soil depth can be attained without applying an excessively large load to the artificial ground 20 by simply increasing the thickness of the vegetative layer 210 as needed. In addition, the filler 212 composed of paper pulp can contain water in an amount sufficient to be supplied to the roots of the growing seeds 221. Therefore, no need to form unnecessary elements, such as the filter layer 12 and the waterproof layer 15 of the vegetation structure 10, is required in the vegetative mat of the present invention, thus realizing a simple-structured and lightweight integral vegetation structure.

The sown seeds 221 utilize oxidized starch of the coating layer 222 as a nutrient and are rooted within the vegetative layer 210. First, the seeds are rooted through the filler 212 at the initial rooting stage. Thereafter, the seeds are rooted through the wood chips 211 while decomposition of the wood chips 211 proceeds with the lapse of time. The porous wood chips 211 may contain nutrients necessary for the growth of plants. Also, the porous wood chips 211 may supply nutrients necessary for the growth of plants while being decomposed. Explanations of a method for producing the vegetative base and a method for manufacturing the vegetative mat according to the present invention will be provided below.

FIGs. 5a to 5c are explanatory diagrams illustrating a method for preparing raw materials for the vegetative base (i.e. vegetative layer) of the vegetative mat according to the present invention.

Waste wood 311a produced after tree thinning/cutting or construction is dried until the water content reaches about 11% and crushed into fine wood pieces using a crusher 311b. The wood pieces have a size of about 1.5 cm to about 2 cm. The wood pieces are used as wood chips 311 (FIG. 5a).

Next, waste paper, e.g., wood-free paper 312a, is collected and cut into pieces and charged together with water into a digester 312b. The digester 312b is rotated at about 5,000 rotations to obtain a paper pulp slurry 312. The concentration of paper pulp in the paper pulp slurry 312 is adjusted to about 2.5% to about 3.5% (FIG. 5b).

Thereafter, as shown in FIG. 5c, the wood chips 311 are mixed with the paper pulp slurry 312 to obtain a mixture 310. It is preferred to mix the wood chips 311 and the paper pulp slurry 312 in a weight ratio ranging from 4:6 to 6:4. Water is supplied to the mixture 310, and then a functional additive 314 is added thereto to improve the functions of a final vegetative base.

As described above, the functional additive 314 may be powdered or granular activated carbon, an anti-corrosion agent, a colorant harmless to vegetation, a wet- strengthening agent for papermaking, a surface sizing agent for papermaking, etc. The powdered or granular activated carbon inhibits decay of a final vegetative base and effectively improves the functions of the vegetative layer. The anti-corrosion agent performs the same role as the activated carbon. Any anti-corrosion agent that is commonly used in the art and does not adversely affect the growth of plants can be used without particular limitation. The wet-strengthening agent for papermaking inhibits further digestion of the paper pulp slurry, increases the wet strength of the paper pulp, and acts as a binder. The wet-strengthening agent for papermaking is preferably added in an amount of 5 to 30% by weight, based on the total dry weight of a finished vegetative mat. When the wet-strengthening agent is added in an amount of less than 5% by weight, its addition effect is trivial, resulting in poor durability against water. Meanwhile, when the wet-strengthening agent is added in an amount greater than 30% by weight, the growth of plants may be unfavorably affected. Any wet-strengthening agent for papermaking that is commonly used in the art and does not adversely affect the growth of plants can be used without particular limitation. The surface sizing agent for papermaking serves to prevent rapid drying of a final vegetative base, thus guaranteeing a filler, which is prepared by dehydration of the paper pulp slurry (FIGs. 2 and 3), and wood chips to retain an appropriate amount of water. A preferable amount of the surface sizing agent for papermaking is between 5% and 30% by weight, based on the total dry weight of a finished vegetative mat. The addition of the surface sizing agent in an amount of less than 5% by weight has little or no effect. Meanwhile, the addition of the surface sizing agent in an amount exceeding 30% by weight causes the risk that the physical properties, such as strength, of a final vegetative base may be deteriorated. In an alternative embodiment, the surface sizing agent for papermaking may be applied to the surface of a final vegetative base 330 (FIG. 7c).

The mixture 310 thus prepared is charged into an apparatus 320 for producing a vegetative base or a vegetative layer of a vegetative mat. A perspective view of the apparatus 320 is shown in FIG. 6. Referring to FIG. 6, the apparatus 320 comprises a mold 321 into which the mixture 310 is charged, a push plate 322 matched with the mold 321, and a tub 323 for supporting the mold 321 and receiving water discharged from the mold 321. The mold 321 is in the form of a rectangular box and is provided with a number of drainage holes 324, through which water contained in the mixture 310 are discharged, on its lower surface. A number of crossbars 325 for supporting the mold 321 are arranged in the upper portion of the tub 323.

FIGs. 7a to 7f are explanatory diagrams illustrating the procedure of a method for producing a vegetative base or a vegetative layer of a vegetative mat according to the present invention.

First, the mixture 310 is charged into the mold 321 (FIG. 7a). Thereafter, the mixture 310 is pressurized using the push plate 322. During the pressurization, water contained in the mixture 310 is discharged into the tub 323 through the drainage holes 343 formed within the mold 321. By the dehydration and pressurization of the mixture 310 using the push plate 322, the wood chips 311 present within the mixture 310 are densely packed in a rectangular planar shape corresponding to the rectangular shape of the mold 321, and at the same time, paper pulp fibers contained in the paper pulp slurry 312 are adhered to each other while water is discharged from the paper pulp slurry 312 to fill spaces between the wood chips 311, thereby maintaining the densely packed wood chips 311 in a planar structure. That is, the paper pulp acts as a filler (FIGs. 2 and 3). The pressurization of the mixture using the push plate 322 may be achieved by a power press or by installing a body having an appropriate weight on the push plate 322 (FIG. 7b).

After completion of the pressurization and dehydration for a predetermined time, a finished vegetative base is released from the mold 321. The finished vegetative base 330 is shown in FIG. 7c. The vegetative base 330 undergoes drying at room temperature for a predetermined time.

As already mentioned, a reinforcing material composed of coconut fiber may be further added to the mixture 310 or one or more nets composed of coconut fiber may be added while the mixture 310 is charged into the mold to be laminated within the vegetative base.

The dried vegetative base 330 comprises a number of wood chips 331 densely packed in a rectangular planar shape and a filler 332 filled in spaces between the wood chips 331 to maintain the densely packed wood chips 331 in a planar shape. Since the filler 332 and the wood chips 331 contain water, the vegetative base 330 can be directly used as a vegetative layer of a vegetative mat.

When it is intended to manufacture a vegetative mat using the vegetative base, the dried vegetative base 330 is additionally immersed in liquid manure and dried so as to contain nutrients necessary for vegetation. If liquid manure is directly added to the mixture 310, the durability of the vegetative base may be deteriorated. Further, effects attained when liquid manure is added to the mixture 310 are insignificant compared to those attained when the vegetative base 330 is immersed in liquid manure in the same amount as the liquid manure added to the mixture 310. As a result of the immersion, the liquid manure penetrates into the vegetative base 330 so that the vegetative base 330 contains nutrients necessary for vegetation. For better immersion efficiency, the immersion is more preferably performed at reduced pressure.

Depending on the size of the mold 321, the vegetative base 330 may have a rectangular or square shape in cross section whose width and length are from several centimeters to several meters. For example, afforestation of an artificial ground can be achieved by laying one or more vegetative bases 330 having a size of several meters on the artificial ground. Alternatively, afforestation of an artificial ground can be achieved by assembling a number of vegetative bases 330 having a size of several tens of centimeters on the artificial ground.

The vegetative bases having a size of several tens of centimeters may have the following dimensions:

(1) Width = 200 mm, length = 200 mm, height = 50 mm, total dry weight = 25Og, the amount of water added to form a mixture = 2,000 ml

(2) Width = 200 mm, length = 200 mm, height = 20 mm, total dry weight = 150g, the amount of water added to form a mixture = 2,000 ml

Next, seeds 341 are sown on the dried vegetative base 330 (FIG. 7d). The seeds 341 used herein require a soil depth corresponding to the thickness of the vegetative base 330.

Thereafter, an aqueous solution 343 of oxidized starch is applied to the surface of the vegetative base 330, on which the seeds 341 are sown. The aqueous solution of oxidized starch is evaporated to leave oxidized starch on the vegetative base 330. The oxidized starch serves to fix the sown seeds 341 on the upper surface of the vegetative base 330. The aqueous solution 343 of oxidized starch may be applied over the entire surface of the vegetative base 330 or may be applied such that the sown seeds 341 only are covered (FIG. 7e).

A planting layer 340 including the seeds 341 and the vegetative base 330 as a vegetative layer constitute a vegetative mat 350 (FIG. If). The vegetative layer 330 acts as a base for the vegetation of the seeds and serves to supply water and nutrients necessary for the vegetation of the seeds.

On the other hand, the vegetative mat may be divided into smaller vegetative mat pieces (hereinafter, referred to as 'unit vegetative mats'). The unit vegetative mats commonly have a size of several tens of centimeters. Workers can easily afforest an artificial ground by assembling a number of unit vegetative mats on the artificial ground.

In addition, workers can install and repair the unit vegetative mats in a simple manner.

[Mode for Invention]

FIGs. 8a to 8e are explanatory diagrams illustrating a method for providing unit vegetative mats in accordance with the present invention.

Unit vegetative mats may be provided by cutting the finished vegetative mat 350 (FIG. 7f) having a size of several meters to a predetermined shape.

As shown in FIG. 8a, the rectangular finished vegetative mat 350 having a size of several meters is cut along the orthogonal dashed lines to provide rectangular or square unit vegetative mats 361 having a size of several tens of centimeters. As shown in FIG. 8b, the rectangular finished vegetative mat 350 having a size of several meters is cut along the dashed lines parallel to each other in the widthwise direction and the wave-shaped dashed lines in the lengthwise direction to provide unit vegetative mats 362 having a size of several tens of centimeters. In this case, each of the unit vegetative mats 362 has a protruded side portion 362a and a depressed side portion 362b opposite to and matched with the protruded side portion 362a. Afforestation of an artificial ground using the unit vegetative mats is achieved in such a manner that the protruded side portion 362a of one unit vegetative mat 362 is matched with the depressed side portion 362b of the adjacent unit vegetative mat 362.

As shown in FIG. 8c, the rectangular finished vegetative mat 350 having a size of several meters is cut along the wave-shaped dashed lines in the widthwise and lengthwise directions to provide unit vegetative mats 363 having a size of several tens of centimeters. In this case, each of the unit vegetative mats 363 has left and right portions 363a and 363b in a matchable protrusion/depression pattern and upper and lower portions 363c and 363d in a matchable protrusion/depression pattern. Afforestation of an artificial ground using the unit vegetative mats 363 is achieved in such a manner that the protruded/depressed left portion 363a of one unit vegetative mat 363 is matched with the protruded/depressed right portion 363b of the adjacent unit vegetative mat 363 and the protruded/depressed upper portion 363c of one unit vegetative mat 363 is matched with the protruded/depressed lower portion 363d of the adjacent unit vegetative mat 363. The cutting of the vegetative mat 350 having a size of several meters into unit vegetative mats is not limited to the patterns shown in FIGs. 8a to 8c. The vegetative mat 350 may be cut in such a manner that unit vegetative mats can be assembled one another or have a shape that creates an aesthetic feeling.

The unit vegetative mats 361, 362 and 363 may also be provided by cutting the vegetative base 330 having a size of several meters shown in FIG. 7c into one of the patterns shown in FIGs. 8a to 8c to form unit vegetative bases, sowing seeds on the unit vegetative bases, and applying an aqueous solution of oxidized starch thereto.

Alternatively, a mold can be used to directly provide unit vegetative mats having a size of several tens of centimeters. Such molds are illustrated in FIGs. 8d and 8e.

FIG. 8d shows a mold 321' and a push plate 322' to provide the unit vegetative mat 362 illustrated in FIG. 8b. The mold 321' has a protruded side portion 321 'a and a depressed side portion 321 'b opposite to and matched with the protruded side portion 321'a.

FIG. 8e shows a mold 321" and a push plate 322" to provide the unit vegetative mat 363 illustrated in FIG. 8c. The mold 321" has left and right portions 321 "a and 321"b in a matchable protrusion/depression pattern and upper and lower portions 321"c and 321"d in a matchable protrusion/depression pattern.

Molds that can be used to provide unit vegetative mats are not limited to those illustrated in FIGs. 8d and 8e. For example, a rectangular or square mold having a size of several tens of centimeters may be used to provide unit vegetative mats. In addition, a mold may be used in such a manner that unit vegetative mats can be assembled one another or have a shape that creates an aesthetic feeling.

FIGs. 9 to 11 are diagrams illustrating afforestation of artificial grounds using unit vegetative mats.

Referring to FIG. 9, the drainage plate 231 is installed on a flat artificial ground 21, such as the roof of a building, and then the non- woven fabric sheet 232 is installed thereon. As stated earlier, the drainage plate 231 and the non-woven fabric sheet 232 may also be integrally provided. Next, a number of the unit vegetative mats 362 are assembled and arranged on the non-woven fabric sheet 232, thus achieving afforestation of the flat artificial ground in a simple manner. Accordingly, since the unit vegetative mats 362 are lightweight, workers can easily afforest an artificial ground by assembling the unit vegetative mats 362 on the artificial ground. Further, afforestation of the artificial ground can be achieved by simply laying the unit vegetative mats, each of which includes the vegetative layer 330 and the planting layer 340, on the non-woven fabric sheet. That is, the unit vegetative mats can be installed in a simple manner to afforest the artificial ground. After the passage of time from the initial afforestation of the artificial ground, the unit vegetative mats may be damaged. The maintenance and management of afforestation can be accomplished in a simple and convenient manner by simply changing the damaged unit vegetative mats with new unit vegetative mats.

Referring to FIG. 10, a number of unit vegetative mats can be used to afforest an inclined artificial ground 22 (e.g., a cut slope of an express highway). The unit vegetative mats 361 can be installed on the inclined artificial ground 22 because no material is lost or washed away from the unit vegetative mats 361 in view of the structural characteristics of the unit vegetative mats 361.

Referring to FIG. 11, a number of unit vegetative mats can be used to afforest a vertical artificial ground 23 (e.g., an outer wall of a building). In this case, the unit vegetative mats may be fixed to the vertical artificial ground 23 by means of fixing units.

FIGs. 12 and 13 are photographs of grass seeds that were germinated and grown on the vegetative mat of the present invention. The photographs indicate that grass densely grew well on the vegetative mat.

As apparent from the above description, the vegetative base and the vegetative mat of the present invention can be used anywhere without particular limitation. In addition, afforestation of artificial grounds can be achieved by simply installing the vegetative mat of the present invention on the artificial grounds. The vegetative mat of the present invention comprises a planting layer, on which seeds are sown, and a vegetative layer necessary for the growth of the seeds. Accordingly, seeds satisfying consumers' tastes can be sown on the vegetative mat of the present invention. In addition, the vegetative mat of the present invention is custom-made that is easy to install. Furthermore, the unit vegetative mats of the present invention can be used to afforest artificial grounds in a simple manner. Moreover, when it is required to repair damaged unit vegetative mats after installation, the damaged unit vegetative mats are changed with new unit vegetative mats, thereby facilitating the maintenance and management of afforestation.

Although the present invention has been described herein with reference to the foregoing embodiments illustrated in the accompanying drawings, these embodiments are given for the purpose of illustration only and it will be apparent to those skilled in the art that various modifications and equivalents of the embodiments are possible in light of the above teachings. Thus, the genuine scope of the technical protection of the present invention should be defined according to the technical spirit of the attached claims.

[Industrial Applicability]

The vegetative base and the vegetative mat of the present invention are very useful in the afforestation of artificial grounds, particularly building roofs. In addition, the vegetative base and the vegetative mat of the present invention are advantageous in terms of space recycling, establishment of urban ecosystem, air purification, reduction of the urban heat island, energy saving of buildings and environmental improvements through microclimate control.

Claims

[CLAIMS] [Claim 1]

A vegetative base comprising a number of densely packed wood chips and a filler filled in spaces between the wood chips to maintain the densely packed wood chips in a planar structure.

[Claim 2]

The vegetative base according to claim 1, wherein the wood chips are wood pieces obtained by crushing waste wood.

[Claim 3]

The vegetative base according to claim 1, wherein the filler contains waste paper pulp.

[Claim 4]

The vegetative base according to claim 1, wherein the filler contains a wet- strengthening agent for papermaking.

[Claim 5] The vegetative base according to claim 1, wherein the filler contains an additive selected from colorants, powdered activated carbon, surface sizing agents for papermaking and mixtures thereof.

[Claim 6] The vegetative base according to claim 1, further comprising a reinforcing material composed of coconut fiber.

[Claim 7]

A vegetative mat comprising: the vegetative base according to any one of claims 1 to 6 as a vegetative layer; a planting layer including seeds sown on the vegetative layer and a coating layer formed on the vegetative layer to immobilize the seeds; and a drainage layer disposed under the vegetative layer, the drainage layer including a non-woven fabric sheet and a drainage plate disposed under the non-woven fabric sheet and provided with drainage grooves.

[Claim 8]

The vegetative mat according to claim 7, wherein the coating layer contains oxidized starch.

[Claim 9]

A method for manufacturing the vegetative mat, the method comprising the steps of:

(a) preparing wood chips;

(b) preparing a paper pulp slurry; (c) mixing the wood chips with the paper pulp slurry;

(d) providing an apparatus for producing a vegetative base, the apparatus comprising a mold provided with drainage holes and a push plate matched with the mold;

(e) feeding a mixture of the wood chips and the paper pulp slurry into the mold; and (f) pressurizing the mixture using the push plate to mold the mixture into a vegetative base.

[Claim 10]

The method according to claim 9, wherein, in step (c), 40-60% by weight of the wood chips are mixed with 40-60% of the paper pulp slurry, based on the total weight of the mixture.

[Claim 11]

The method according to claim 9, wherein, in step (c), a functional additive selected from powdered or granular activated carbon, colorants, wet-strengthening agents for papermaking and surface sizing agents for papermaking is further added to the mixture of the wood chips and paper pulp slurry.

[Claim 12]

The method according to claim 9, wherein, in step (e), a reinforcing material composed of coconut fiber is further added to the mixture.

[Claim 13]

The method according to claim 9, wherein the mold used in step (d) has a first side portion having a first protrusion/depression pattern and a second side portion opposite to the first side portion and having a second protrusion/depression pattern matched with the first protrusion/depression pattern.

[Claim 14]

The method according to claim 9, further comprising the step of, after step (f), planting seeds on the upper portion of the vegetative base as a vegetative layer, the seed planting step including the sub-steps of sowing seeds on one surface of the vegetative layer and coating the surface with an aqueous solution of oxidized starch.

[Claim 15] The method according to claim 9, further comprising the step of, after step (f), immersing the vegetative base in liquid manure, followed by drying.