IE47069B1 - Mat for growing lawns and other vegetation - Google Patents

Abstract

A laminated mat for growing lawns or other vegetation on soil comprises a base sheet 13 of water pervious, biodegradable web material. Joined to the base sheet 13 by an adhesive binder 15 is a bed 21 of seeds and dried compressed peat particles. Secured to the bed 21 of seeds and peat particles by adhesive 23 is an upper laminate comprising a fibrous porous biodegradable veil 25 which protects and retains the bed 21 therebelow. The upper veil 25 is water pervious to permit water to pass therethrough to the bed 21 of peat particles 19 and seeds 17. The biodegradable veil 25 also easily expands to retain the wet, expanded peat particles and the seeds retained by the peat particles and the veil.

Description

There are already known, in the prior art, many forms of mat or carpet products which are intended for growing lawns and other forms of vegetation. These products generally include some sort of fibrous material which provides struct5 ural integrity to the mat, and a mulch material which is often mixed with seeds to he germinated. These products also include some form of joining these various materials together, including stitching, adhesives, and the like.

Generally speaking, the known products have not gained 10 wide acceptance due to failures in some aspects of their designs. For example, most mulch material used in these products expands upon watering. Often, the expansion of the mulch material breaks whatever bond is provided with the fibrous structural material of the mat, with the result that significant portions of the mulch and seed mixture are washed away from the mat. atitching methods for joining the materials to form a mat tend to limit the expansion of the mulch material, forming an irregular surface and also decreasing the survival rate of the germinating seeds.

Also, many of the prior art mat products rail to protect properly the seeds during the germinating and sprouting periods. As the seeds are covered tr- only a ti'.:? ’, yer of mulch material, they are prey to birds, winds, and rain, and the deleterious effects of strong sunlight. 70 6 9 The present invention provides an improved mat for growing lawns or other vegetation upon soil, having the advantage of an unique construction which retains the mulch material after it is watered and expanded, which also allows free water flow therethrough, and which protects the seeds and mulch material during the vital germination and sprouting periods.

Pursuant hereto, the present invention provides an improved laminated mat for growing vegetation on soil, comprising: an outer lower base sheet laminate of pervious web material, said material being quickly biodegradable to become part of the soil after coming into contact therewith; a bed of seeds and dried compressed peat particles and means adhesively securing said bed to said base sheet, said particles being expansible upon wetting to surround and form a mulch for said seeds; and an outer upper veil laminate of fibrous unwoven porous web material and means adhesively securing said veil to said bed, said veil comprising means for expanding with said expansible peat particles and retaining said particles and seeds integrally in said mat after biodegradation of said base sheet, said veil being slowly biodegradable to become part of the soil after germination and rooting of said seeds.

A preferred embodiment of the mat of the present invention includes a base sheet of web material which is - 3 4 7 0 6S easily degradable upon wetting, and which quickly becomes part of the underlying soil. An adhesivo binder joins a bed of seeds mixed with dried, compressed neat narticles to the base sheet. The peat particles are also prescreened to remove smaller particles and dust which interfere with the adhesion of the binder.

Joined to the top of the bed of seeds and peat particles by an adhesive binder is a fibrous veil comprising an unwoven, porous fabric formed of bio-degradable synthetic fibres. The veil is bonded to the bed of seeds and peat particles to provide structural integrity to the mat after the mat has been placed on soil and watering has substantially dissolved the base sheet.

The fibrous veil serves other important functions. It protects the seeds and seedlings from direct sunlight, and also greatly ameliorates the eroding effects of wind, water, and the like. The veil is particularly characterized by its ability to expand laterally in concert with the expanding wotted peat particles, so that the particles and seeds are well secured during the germination and sprouting phases.

Affier the mat is applied to a soil surface, water is applied either by irrigation or natural rain-fall to initiate swelling of the peat perticles, which subsequently 7 0 6 9 surround and protect the germinating seeds. The water passes through tho fibrous veil and the bed of seeds and peat particles as well as the base sheet, the base sheet quickly dissolving. The sprouting seeds easily may send roots through the deteriorated base sheet, and may send shoots upwardly through the fibrous veil. The fibrous veil biodegrades after a period of months, after the seedlings are well established in the underlying soil.

The invention will be described further, by way of 10 example, with reference to the accompanying drawings, in which each of the figures is an enlarged diagrammatic cross-sectional elevation, and in whichsFig. 1 illustrates a base sheet and an adhesive material used in forming a preferred embodiment of the improved mat of the present invention; Fig.2 illustrates the application of seed to the structure shown in Fig. 1; Fig. 3 illustrates the application of compressed, screened peat particles to the structure shown in Fig. 2; Fig. 4 illustrates the structure of Fig. J after the application of adhesive material over the bed of seeds and compressed peat particles of the structure shown in Fig. 3; and - 5 47 0 6 9 Fig. 5 illustrates the resultant preferred embodiment of the improved mat of the present invention, obtained by the application of a fibrous veil to the structure as shown in Fig. 4.

The preferred embodiment of the present invention generally comprises a mat-like laminated structure 11, as shown in Fig. 5» which is adapted to grow lawns or similar vegetation on a soil surface. The mat 11 includes seeds of the desired vegetation, a mulch material which provides protection for the seeds and a growth medium for the seeds, and structural material which maintains the integrity of the mat and protects the seeds and mulch during germination and sprouting of the seeds.

The mat 11 comprises laminated layers of selected materials which are assembled in a sequence depicted in Figs. 1 to 5« As shown in Fig. 1, the fabrication of the mat 11 begins with a base sheet 13 which comprises a biodegradable material. In the preferred embodiment, the base sheet 13 is formed of light tissue paper weighing from 8 to 11 pounds per three thousand square feet, or about 1.25 to 1.80 kilos per 100 square metres. This tissue paper is mechanically roughed or scarfed to increase the bonding thereto of subsequent laminations. Al..o, the tissue paper may be perforated to increase water flow through the mat 11, It should be noted that the tissue paper provides substantial structural integrity to the mat 11 prior to use - 6 of the product. However, after the mat is emplaced and watered, the tissue paper base sheet 13 deteriorates rapidly, losing a substantial portion of Its strength upon initial wetting.

An adhesive binder material 15 is then applied to the scarfed surface of the base sheet 13. Preferably, the adhesive binder comprises a water base rubber adhesive compound which is easily bio-degradable and which provides a high tack factor, the water base adhesive losing most of its binder properties upon wetting. The adhesive material 15 Is sprayed onto the base sheet by conventional techniques.

Next, seeds 17 of the desired kind of vegetation are dispersed upon the adhesive material 15, as shown in A'ig. 2. Following this step, particles Of dried, compressed peat 19 are spread in a thin layer over the adhesive binder 15 and the seed layer 17 to form a bed 21 of seeds mixed with tlie compressed peat particles. The peat particles are formed b_, firstly drying the peat to a moisture content of 20.; or less, and then compressing the peat to form dense cylinders. The cylinders are then cut up and passed through a grinder or hammer mill to form particles of compressed peat. The particles are screened on l/8 inch (appx. 3 mm) mesh to obtain particles in the size range of l/16th inch (appx. 1.5 mm) to 3/8th inch (appx. 10 mm). The screenin’ step removes smaller, dust-like particles which would otherwise be absorbed by the adhesive binder and would reduce the adhesion of the laminations. - 7 4 7 0 6 9 It should be noted that upon wetting, dried peat expands greatly. If the compressed peat particles are larger than the aforementioned size range, they will expand upon watering to produce an uneven and irregular upper surface. Further, dried, compressed peat forms a lamination which is structurally superior t Also, the dried peat increases the shelf life of the mat 11, as it does not provide sufficient moisture for germination of the seeds 17.

Another adhesive binder material layer 23 is then applied over the bed 21 of seeds and peat particles, as shown in Fig. 4. This adhesive binder material may also comprise a water base rubber adhesive, or any other similar adhesive material.

As shown in Fig. 5, a fibrous veil 25 of unwoven fabric having a cotton like texture is then applied to the adhesive layer 23· The adhesive material 23 binds the fibrous veil 25 to the bed 21 of seeds and dried, compressed neat particles. The veil 25 serves a multitude of functions in the mat 11 of the present invention. The fibres of the mat permit water to pass therethrough, while protecting the bed 21 from destruction from excessive water run_eff or high winds. Also, the fibrous veil 25 controls evaporation of water from the bed 21 so that a moist growing medium is maintained. The veil also protects the seeds - 8 4 7 0 6 9 from direct sun, and helps prevent severe temperature change: in the bed 21.

An important characteristic of the veil 25 is that it is easily laterally expansible, As the peat particles are wetted and caused to expand, the fibrous veil 25 expands with the particles to retain and protect the peat particles and the seeds.

In the preferred embodiment, the fibrous veil has a loft ranging between l/8tli inch (appx. 3 and 1/4 inch (appx. 6 mm), t ;is loft being sufficient to retain the expanding peat particles within its non-woven structure, Tho veil is composed of biodegradable synthetic fibres having a denier of approximately 6-1/2, and a weight in the range of 4/lOs per ounce per square yard to 8/lOs per ounce per square yard. The synthetic fibres are biodegradable in a period 12 to 18 months after planting, so that the seedlings are well established before the veil disintegrates. It may be appreciated that the germinating seedlings may easily pass through the unwoven fibre: of the veil, while the roots of the germinating seedlings easily may pas through tlie peat particles and tissue paper to penetrate the soil therebelow.

The light absorption associated with the colour of the fibres forming the fibrous veil may be very important in areas having extreme climates. In localities having hot - 9 4 7 0 69 climates and little water, the fibres may he white to reflect a substantial portion of incident sunlight and prevent the mat 11 from overheating and damaging the seeds. Conversely, in cold climates, the fibres may be a dark colour or black to absorb more sunlight and maintain a temperature in the mat sufficient to foster germination.

The mat of the present invention is easily used to form a lawn or the like merely by unrolling the mat onto a prepared soil surface and then watering the mat. Upon waterihg, the tissue paper base sheet begins to degrade immediately, and the dried peat particles expand to several times their dry size. The fibrous veil 25 expands with the f peat particles, providing structural strength to maintain the bed 21 as an integral unit while the seeds begin to germinate. It should be noted that after the initial watering, the fibrous veil provides the primary structural strength for the mat 11, although the loft, non-woven nature, and placement of the veil above the bed 21 provides this structural function without any interference with the germination and rooting of the seeds.

The finished mat 11 weighs approximately 15 to 20 pounds per one hundred square feet (or approximately '/ to 10 kilos per 10 square metres). This relatively light weight is due to the use of light materials and compressed, dried peat particles, and facilitates easy handling of large pieces of the mat 11 when configured in a spiral wound roll.

Claims (11)

1. Cl aims :1. An improved laminated mat for growing vegetation on soil, comprising: an outer lower base sheet laminate of waterpervious web material, said material being quickly biodegradable to become part of the soil after coming into contact therewith; a bed of seeds and dried compressed peat particles and means adhesively securing said bee', to said base sheet, said particles being expansible upon wetting to surround and form a mulch for said seeds; and an outer upper veil laminate of fibrous unwoven porous web material and means adhesively securing said veil to s. id bed, said veil comprising means for expanding with said expansible peat particles and retaining said particles and seeds integrally in said mat after biodegradation of said base sheet, said veil being slowly biodegradable to become part of the soil after germination and rooting of said seeds.

2. A mat as claimed in claim 1, wherein said means adhesively securing comprises a water base adhesive material which dissolves upon wetting.

3. A mat as claimed in claim 1 or 2, wherein said dried compressed peat particles range in size from 1/16 inch to 3/8 inch.

4. A mat as claimed in claim 1, 2 or 3 wherein said peat particles are treated to remove dust entrained therewith prior to lamination in said mat. 11 4 7 0 6 9

5. A mat as claimed in any preceding claim wherein said peat particles contain 20,ό moisture or less.

6. A mat as clai .ed in any preceding claim wherein said veil has a loft of 1/8 inch to 1/4 inch. 5

7. A mat as claimed in any preceding claim wherein said veil biodegrades 12 to 18 months after said mat is placed on the soil.

8. O A mat as claimed in any preceding claim wherein said base sheet comprises tissue paper weighing S to 11 pounds 10 per 3000 square feet.

9. A mat as claimed in any preceding claim wherein said mat weighs approximately 15 to 20 pounds per 100 square feet.

10. A mat as claimed in any ..receding claim wherein said veil includes means for controlling the absorption of incident 15 sunlight and maintaining a proper temperature range in said bed for germination of said seeds.

11. A laminated mat for growing vegetation on soil substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.