CN86103668Y - Meltblown and conformal materials used as seedbeds - Google Patents

Abstract

The present invention generally accomplishes the provision of a seedbed of meltblown material in which seeds are incorporated. Preferably, in addition to the seeds, absorbent materials such as cellulosic fibers and superabsorbent materials (eg, hydrogels) are also blended.

Description

[0001] The present invention relates to measures and applications of nonwovens as seedbeds. In particular, it relates to the provision of meltblown materials that have blended seeds with a nutrient substrate for germinating the seeds, such as fertilizers and superabsorbents, and the like.

[0002] Jute fiber woven and synthetic netting has been used for erosion control for several years. Flat nets are difficult to adequately fix the soil, difficult to grasp, and prone to tearing when set aside. Closed nets are too expensive and are non-degradable, easily lifted by grass growing under the net, can be lifted from the ground by the wind, and must eventually be removed rendering erosion control ineffective.

[0003] Existing nets have been used or have been proposed for applications such as construction and maintenance of roads, landscaping and separation of open pit mining. All of these uses, with the possible exception of certain landscaping-type applications, require a system that does not require much maintenance once the area covered by the net is set up. It would be ideal if a product would both be sufficiently degraded to allow full plant development and provide constant erosion control.

[0004] U.S. Patent 3,315,408 (Fisher) is an early example of artificial woven fabrics for soil erosion control. Although this patent suggests the use of different types of yarns, including biodegradable yarns, and yarns with tubular or porous cores containing agents or substances to be released (eg, fertilizers, pesticides, herbicides, etc.) The woven material mentioned in the patent has the disadvantage of insufficient woven material, needs to have a certain flexibility, and needs to be a woven thread. Furthermore, the described fabric is not sufficiently versatile to provide a complete agro-horticultural system.

Contrary to the net type, other types of covering materials or ground coverings using material sheets have been

Disclosure, for example, U.S. Patent 3,205,619 (Henry), U.S. Patent 3,303,323 (Popa), U.S. Patent 3,467,142 (Boyle), U.S. Patent 3,511,694 (Lippoldt et al. al), U.S. Patent 3,427,194 (Lippoldt et al.), and U.S. Patent 3,516,196 (Lippoldt et al.). The Henry, Popa, and Boyle et al. patents teach the use of such sheets for irrigation or liquid diversion. Others suggest placing seeds, fungicides, fertilizers, pesticides, herbicides and growth hormones on the floor covering to promote the planting and growth of grasses or other plants. See U.S. Patent 3,557,491 (Franklin et al.), U.S. Patent 3,160,986 (Watson et al.). However, it has not been previously possible to provide such a composition and a floor covering with a mesh structure suitable for the requirements, especially a floor covering with sufficient adaptability and other essential characteristics, to provide a complete system for agro-horticulture.

[0007] U.S. Patent 3,848,359 (Seitn et al.) discloses woven mulch for erosion control landscaping and other agricultural uses. It is disclosed that a degradable seed bag may be included in the fabric. The disadvantage of this product is that it is complicated to form, and furthermore, the seed bag does not retain moisture easily, must be fastened to the fabric, and is easily displaced.

U.S. Patent No. 4,429,001 (Kolpan) and British Patent Application GB2,113,731 (Minto et al.) disclose the use of strong absorbent materials in meltblown substrates to make an adsorbent layer. It is disclosed in the UK patent application that the absorbent material may be clay, sponge or superabsorbent.

[0009] U.S. Patent No. 4,100,324 (Anderson et al.) discloses a nonwoven made from a meltblown blend of polymeric fibers and cellulosic fibers.

There remains a need for an agriculturally useful woven fabric that will be stable during sowing

[0011] Degraded within a reasonable time frame, and further will provide protection and nutrition to the seeds during germination and germination.

One object of the present invention is to overcome the shortcomings of previous artificial materials, processes and equipment.

Another object of the present invention is to provide an artificial seedbed or mulch that requires less watering than previous seedbeds.

Another object of the present invention is to provide a kind of low-cost technological process and equipment for making artificial seedbed.

These and other objects of the present invention can be achieved by providing a meltblown material in which existing seeds are blended. In addition to the blended seeds, absorbent materials such as cellulosic fibers and superabsorbent materials (eg, hydrogels) and the like are preferably blended. Additionally, it is preferred that the meltblown polymer be degraded by sunlight and/or water in the soil.

A particularly preferred form of the present invention is that the article is made with an apparatus and process in which a structure of air-formed polyolefin fibers and cellulosic fibers is created and in which seeds and superabsorbents are formed granules are incorporated into it. Articles produced in this form contain seeds embedded in the lofty structure of the nonwoven meltblown material, where the seeds are free to germinate and not easily shake loose or be pecked by birds.

Brief description of drawings

1 is a cross-sectional fragment of an article of the present invention.

Figure 2 is a cross-sectional fragment of a product of the present invention after germination.

[0020] FIG. 3 is a diagrammatic illustration of an apparatus for forming an article of the present invention.

4 is a schematic illustration of a forming apparatus for making a multilayer article in accordance with the present invention.

[0022] Figures 5, 6 and 7 are cross-sectional fragments of a multilayer article according to the present invention.

[0023] FIG. 8 is a diagrammatic illustration of another forming apparatus in accordance with the present invention.

[0024] FIGS. 9 and 10 are cross-sectional fragments of multilayer articles according to the present invention, which can also be made on the apparatus of FIG. 8 .

MODE FOR IMPLEMENTING THE INVENTION

[0026] The apparatus, process, and articles of manufacture of the present invention have many advantages over those of existing methods, apparatus, and articles of manufacture. The artificial seedbed made by the invention can ensure that the seeds are dispersed evenly. Because the seeds are embedded in the material, they will not be washed away from the seedbed. The product of the present invention does not require any covering to prevent drying out after sowing. In addition, since straw or other materials are not required, the problem of being blown all over the place and making them unsightly when using these materials is reduced. Another advantage of the present invention is that it provides conditions for bird protection when the seeds are in the germination stage. The materials of the present invention will further degrade rapidly, and this degradation can be controlled by the structure of the polymer used. The present invention reduces the number of times the seedbed is watered and allows sowing on steep slopes. In addition, sowing on slopes in the shade is greatly improved compared to using turf, where grass does not grow well on the shady side. The material is light in weight, and it is much easier to lay down and sow than to use sod. The articles of the present invention may also contain additives, such as pesticides or herbicides, to inhibit weed growth, and may even be dyed to give the grass the appearance of grass before it grows. Combined with grass seeds with superabsorbents, the long grass season can go beyond the normal fall and spring planting times. These and other advantages of the present invention will become more apparent from the detailed description that follows.

[0027] FIG. 1 is a cross-sectional fragment of an article in accordance with the present invention. The article 10 of FIG. 1 is a web composed of air-formed polymer fibers 12 and wood fibers 14 . Article 10 also contains seeds 16 and superabsorbent 18. Both the dry superabsorbent 18 and the seed 16 are firmly trapped within the web of fibers 12 and 14 . Fibers 12 and 14 are mechanically bound together by mixing immediately after extrusion during air forming. Melt blowing of mixtures of thermoplastic polymers and wood pulp fibers is known, as in U.S. 4,100,324

[0028] As disclosed in (Anderson et al.), cf. Air-formed combinations of cellulosic fibers and meltblown polymers are commonly referred to as coforms. A system for incorporating superabsorbents into meltblown blends is disclosed in U.S. Patent Application No. 602,993, filed on April 23, 1984, (Inventor Mcfarland et al.), which is related to The present invention was co-designed and is therefore hereby referenced.

2 illustrates a seedbed 20 according to the present invention. The seed 24 has grown a bud 26 and a root 28. The roots 28 penetrate into the soil 30 . The combined polymer fibers 32 and wood fibers 34 have not degraded to a significant degree. The superabsorbent 18 has absorbed the water and swelled.

Fig. 3 illustrates equipment and technological process of the present invention, and it is made up of melt-blown material extrusion equipment 40, and melt-blown material fiber 44 is settled on the moving belt 42 with small holes. The extrusion apparatus 40 includes a polymer feed hopper 46 into which the polymer is fed into an extrusion device 48 . The polymer is extruded from the central nozzle 50 into a series of thin streams. These thin streams must pass through the high velocity air flow from nozzle ports 52 and 54, which breaks the continuous stream and forms the meltblown material. Immediately below nozzle 56, seed 60 is injected from nozzle 62 into the air flow. Seeds are blown out of reservoir 64 by blower 66 . Underneath the seed unit is a high-grade absorbent 68 fed from a nozzle 70. Superabsorbent 68 is introduced from hopper 72 via blower 74 . Immediately below extrusion nozzle 56, the shed wood fibers from fiberizer 78 are added. Although there should be a clear distance between the nozzles of the seeds, wood fibers and superabsorbents, the best device is to place the three nozzles very close together, immediately after the meltblown extrusion. below the pressure nozzle 56 . The slurry is introduced by rollers 80 into fiberizer 78 where it is broken up and joined with the air stream from passage 82, blowing fibers 84 into the formed stream of material containing meltblown material 81 , Super Absorber 68 and Seed 60. Meltblown with Super Absorber 68 and Seed 60

[0031] The material is settled onto a perforated conveyor belt 42, depicted with a row of fan units 44. A perforated conveyor belt 42 moved by drive rollers 47 and 49 transports the web 5 to a device 53 where it is wound into rolls for storage. The roll 55 may be recut to size for use in a variety of different applications.

[0032] The apparatus shown in FIG. 4 can be used to illustrate that certain changes and modifications to the process, equipment and products are possible with the present invention. The system of FIG. 4 has three meltblown extrusion tanks 110 , 112 , and 114 . As shown, each tank is equipped with a feed hopper for feeding specific materials in accordance with the present invention. In the multifunctional system of FIG. 4, any one to three of tanks 110, 112, and 114 can be used to make a single-layer, double-layer, or three-layer product through the hoppers 116, 118, and 120. . In addition, each tank can be filled with the same material or supplied with different additives through feed hoppers 116, 118, and 120. Notably, in each case, fiberizers 122, 124, and 126 are used to deliver shed cellulosic fibers to meltblown streams 128, 130, and 132, respectively. For example, extruder 110 may extrude meltblown polypropylene to which shed wood fibers will be added at 134 . The hopper 116 will supply the superabsorbent 136 so that the layup is a single layer meltblown containing the superabsorbent 140 . The single layer of matrix 140 will then pass under the meltblown extruder 112, before blowing the cellulosic fibers 144 into the meltblown stream 130, where the seeds 142 will be blown into the meltblown stream 130, where the The spray stream 130 will be spread as a seed layer containing the meltblown 146 on top of the superabsorbent layer containing the meltblown 140 . The two-layer mixture of 140 and 146 will then move under the meltblown hopper 114 where another meltblown stream of polypropylene 132 will be added, and the fine-grained fertilizer will be added immediately prior to the addition of the shed wood fibers 150. 148 join from here. This meltblown stream 132 will be spread over the preceding layer 146 as layer 152 . This three-layer mixture contains

Moisture-maintaining superabsorbent, seeds, and fertilizers for seed germination. The hybrid layer 156 formed from layers 140, 146, and 152 may then be rolled or cut to a suitable shape after being released from the forming equipment. It is not necessary to introduce ingredients such as seeds, fertilizers, and superabsorbents where indicated, they may be introduced in any order. Also, in some cases it may be better to have seeds, superabsorbent and fertilizer mixed in each layer. It is also possible to activate the meltblown material feeder 110 and only make the co-type or meltblown polymer without adding other special substances. This may be advantageous if the particles are small and easily sucked down by the fan arrangement 160 . It seems unlikely that the particles will be picked up by the next fans 162 and 164 because the particles are collected in the first cambium 140 .

[0034] FIG. 5 is a cross-section of a panel 156 of the present invention composed of layer 140, layer 146, and layer 152. Particles 136 are superabsorbent in the lowest layer. Particles 142 are seeds in the middle layer 146 and particles 148 are fertilizer in the uppermost layer 152 .

[0035] The structure of FIG. 6 is another double-layer structure made according to the present invention. The two-layer structure of Figure 6 is made with a starting layer 170 consisting of exfoliated wood fibers and meltblown material. Seed 174 and fertilizer 176 and superabsorbent 178 are all added from upper layer 172 . It is worth noting that some particles, such as seeds 175, have migrated to the lower layers due to the air expelling the seeds through the structure while forming. The structure of Figure 6 can be made with a two-can forming system, or a system like that of Figure 4, in which one can is not used.

[0036] FIG. 7 is another alternative structure. In the structure of FIG. 7 , the upper layer 180 is provided with fertilizer 184 . The middle layer 182 is provided with superabsorbent 186 , while the next layer 188 contains grass seeds 190 . This structure is ideal since the superabsorbent above keeps the seeds constantly moist. The fertilizers supplied to the seeds when they germinate are of the soluble type. Another variation of this approach is the polymer fiber 192 of the upper layer, which can do

[0037] The greening polymer is extruded or the pulp is dyed green before use to provide an artificial seedbed that is more desirable prior to germination. Other variations of the present invention include variations in the number of squeeze tanks, the number of pellet feed tubes, and the addition of materials.

[0038] Another alternative in accordance with the present invention is the 199 device of FIG. 8 . The apparatus of FIG. 8 is equivalent to that of FIG. 4, except that there are two particle feeders 208 and 210. Furthermore, a feed tank 192 is provided with a permeable matrix material 194 . Feeders 208 and 210 are adapted to deliver particles 200 and 202 from particle storage devices 204 and 206 onto layers 140 and 146 . This system is particularly suitable for settling seeds that are too fragile to be thrown into the meltblown stream. These granular spreaders for heat-sensitive materials can also be used to spread live heat-sensitive substances such as fungal spores, yeast, larvae, eggs of beneficial insects or bacteria, etc., for non-chemical organic pest control in seedbeds. The particle spreader is also suitable for intermittently spreading a colorant or other marker to indicate changes in the properties of the material being spread. The apparatus of Figure 8 allows for a large variation in the additive, either in each of the three meltblown layers, or between two meltblown layers. The permeable substrate 194 can be used to provide a base layer that is easy to handle and reduces additive loss during forming. A good permeable material is a spunbond polypropylene fiber matrix. Apparatus 199 can operate without the use of certain additive dispensers or without additional base layer 194.

9 and 10 are cross-sections of articles made in accordance with the present invention. These articles are similar to the articles of Figures 5 and 7, but have fine particulate material added by particulate feeders 208 and 210 between the two layers. In FIG. 9 the layered structure 220 has a base layer of an additive-free conformal 222 to which the surface 224 of layer 222 has been applied with slowly dissolving fertilizer macroparticles 226. The middle layer 228 is a conformal type with superabsorbent 230 added. Seeds 234 have been placed 232 on the surface of layer 228. The top layer 236 is containing

Typical of externally added superabsorbent 238.

10 illustrates another three-layer structure 240, which is made on a permeable polypropylene spunbond material 241 (such as the material used for diamond backing). Bottom layer 242 is a layer of meltblown polypropylene fibers 244 . Slow growing grass seed 248 is dropped from feeder 208 onto interface 245 between layer 242 and layer 246 comprising a co-type of meltblown polypropylene and wood fibers to which superabsorbent hydrogel 250 is added. Fast-growing grass seeds (eg, annual ryegrass) are dropped onto the interface 252 between the middle layer 246 and the top layer 254 via the loader 210, and the seeds are then covered with the layer 254, which is composed of the same common layer as the layer 246. Type plus superabsorbent 256 particles. The mixed layer 240 is particularly desirable because the fast-growing ryegrass will act as ground cover when slow-growing grasses (eg, bluegrass) are slow-growing. The apparatus of Figure 8 can be operated in different ways, thereby making great changes in structure, using different additives within each layer, and between layers, and using different types of slurries as base layers.

The polymer raw material that makes meltblown material in the present invention can be any suitable polymer. Polyethylene and polypropylene are preferred as they can be made in a degradable form. Degradation of polyethylene and polypropylene can be controlled by increasing or decreasing UV inhibitors in a known manner. In addition, it is known to make a polyolefin as disclosed in U.S. Patent 3,795,654 containing a water-soluble stabilizer which will be leached from the polyolefin by water without exposure to sunlight. Linear polyolefins can be degraded by water. Other polymers that can be used in the present invention are also polyesters such as nylons, where the polymer may be very slowly degrading or not degrading. The use of stabilizing polymers may be beneficial on some slopes prone to leaks.

[0043] Any suitable additives can be combined with the nonwoven meltblown polymer and grass seed furnish to make the mixtures of the present invention. These additives are: pigments, pesticides (eg diazinon), herbicides

[0044] agents, fungicides (such as copper salts of naphthenic acid) and rodenticides and the like. Odor repellants can also be added to keep animals (such as dogs or cats) away from new growth. The preferred additives are superabsorbents, especially hydrogels, because they provide a moist seedbed for seeds and fertilizers for nutrients.

[0045] The seeds added to the substrate can be of any desired type. Typical seeds suitable for use on ground cover are fenugreek, clover, ivy, vetch, and flowers (eg, hydrangeas). The best material is grass seed because it grows widely and has a small kernel that can be handled by a typical pellet supply system.

[0046] After collection, the board product of the present invention can be further processed by pressing with heat and pressure to control the thickness of the board. In addition, the panels can be molded to increase their strength and wear resistance.

[0047] The blown fibers are preferably microfibers having an average diameter of less than about 10 microns because such fibers provide more points of contact with the particles per unit volume of the fiber. Very fine fibers with an average diameter of less than 5 or even 1 micron can also be used, especially with very fine seeds or hydrogel particles.

[0048] The superabsorbent or hydrogel particles are preferably capable of rapidly absorbing and retaining large amounts of liquid under pressure. Preferred granules would include modified starch, such a sample as described in U.S. Patent 3,981,100, and high molecular weight acrylic polymers containing hydrophilic groups. A wide variety of water-soluble superabsorbent particles are readily available on the market and can absorb more than 20 times their weight in water, and the best can absorb more than 100 times their weight in water. The particle size of the absorbent can vary widely, but generally between about 90 microns and about 425 microns is preferred for good retention in the seedbed and easy handling during shaping so that it does not become sluggish in the environment. Generate dust.

Particles of seeds, superabsorbents and other materials can be fed into any suitable place

in a meltblown stream of microfibers. Seeds can be introduced where the meltblown fibers have been slightly solidified so that the seeds are not damaged by high temperatures. However, even though the meltblown stream is somewhat molten, very high cooling rates during meltblown will prevent substantial damage to the seed, since cooling will take place before the heat energy is transferred to and damaged the seed, which is typically used for isolation of The skin protects. Mechanically sufficient to capture seeds and other particles, such polymeric binders generally do not need to hold the particles in place. Furthermore, as illustrated in Figure 8, too finely divided additive blown into the air stream may settle between the two layers.

[0051] The artificial covering of the present invention is combined with other products if required. Can be made into a mix of spunbond fabrics. In fact, this would be desirable since spunbond is sometimes used as a carrier during meltblown formation. In addition, it can also be made on tissue matrices or other permeable membranes. Forming on a tissue or spunbond substrate reduces the likelihood of superabsorbent or grass seed being expelled under a perforated conveyor belt as it passes through the forming air system.

[0052] The artificial bed of the present invention can be used in various ways. Typically, the mixing board is held in the ground and watered until the grass or other seed sprouts and takes root. The meltblown material and cellulosic fibers will then degrade and disperse. Alternatively, whole bundles of artificial seedbeds can be soaked and kept at a specific temperature until germination has begun. It can then be unfolded and laid on the ground for quicker equipping into a cover. Such a process would be beneficial for sowing fields, such as baseball fields or children's playgrounds, where rapid rooting and growth of grass is particularly desirable.

[0053] In addition, this substrate can be used as a decorative method, such as covering various figurative objects and sprouting grass to create a living sculpture.

[0054] The present invention has generally described the addition of shed wood fibers from pulp to meltblown materials, but on the other hand cellulosic fibers from other sources may also be utilized. Typical other sources are groundnut seeds, peat moss, and white newspapers. These and other cellulosic materials are

[0055] The present invention would all be suitable because the purpose of their use is to provide an absorbent structure as well as to give the matrix some strength.

Can obviously find out from above description, equipment of the present invention, technological process and product all can have many changes within the spirit scope of the present invention, and the scope of the present invention is only limited by the scope of claims.

File Name Page Line Before Correction After Correction

Instructions 2 2 3, 303, 323 3, 302, 323

14 Seitn Seith

6 2 stencils 5 stencils 51

9 7 Grass Seeds Grass Seeds 255

Claims (34)

1. A product consisting of a meltblown polymer and a plurality of seeds. 2. The article of claim 1, further comprising cellulosic fibers. 3. The article of claim 1, further comprising a superabsorbent. 4. The article of claim 1 comprising a plurality of layers. 5. The article of claim 1 comprising an additive in each of the multiple layers of the article. 6. The article of claim 1 further comprising cellulosic fibers and a superabsorbent. 7. The article of claim 1 comprising a base plate of a spunbond polymeric material. 8. The article of claim 1 wherein said meltblown polymer is a linear polyolefin and is susceptible to degradation by sunlight or water. 9. The article of claim 1 further comprising at least one ingredient selected from the group consisting of fertilizers, superabsorbents, colorants, herbicides, fungicides, rodenticides, Odor protectant for animals, bacteria and spores. 10. A process for making an artificial growth bed, characterized in that it comprises at least meltblowing a stream of a polymer material and depositing seeds into the meltblown material. 11. The process of claim 10, further comprising introducing seeds and superabsorbent into said formed stream. 12. The process of claim 10, further comprising introducing seeds and natural absorbent fibers into at least one of said streams of polymeric material. 13. The process of claim 10, further comprising at least two extrusion tanks for making the meltblown polymer and a moving orifice conveyor on which the meltblown fibers are collected. 14. The process of claim 10 wherein there is also a moving and orifice member for collecting the meltblown material. 15. The process of claim 13 wherein different additives are introduced into each polymer stream. 16. The process of claim 10, wherein the process comprises: a first tank is used to make a meltblown material containing cellulosic fibers, at least one of the other tanks is used to make a meltblown material containing particles, the particles Introduced into the material stream at the time of forming, the particles here include: seeds, fertilizers, superabsorbents, herbicides, fungicides, colorants, and mixtures thereof. 17. The process of claim 10 wherein said polymeric material is a linear polyolefin and is susceptible to degradation by sunlight. 18. The process of claim 14 wherein a permeable web is placed on the apertured member prior to collecting said meltblown material. 19. A process for making a hybrid product comprising providing a first stream of material having a meltblown into which shed wood fibers are introduced. Collecting the first stream of material to make a web, providing at least one-half of the stream of meltblown polymer containing the exfoliated wood fibers introduced therein, and converting the stream of meltblown material At least one-half of the seed is collected on the web, and the seed is added to at least one collection web and to the meltblown stream. 20. The process of claim 19 wherein said seeds are deposited onto the surface of said web and covered with a meltblown material derived from at least one-half of said material stream. 21. The process of claim 19 including adding a superabsorbent to at least one of said collection webs and to said meltblown stream. 22. The process of claim 19 including collecting said webs on a permeable spunbond material. 23. Equipment for making mixed melt-blown products, including an extrusion device capable of forming at least one melt-blown material flow; a feeding device for feeding cellulose fibers into at least one material flow of the melt-blown product in; a feeding device for injecting seeds into at least one of the streams formed by said meltblown material; and a device for collecting the mixture of meltblown polymer material, seeds, and cellulosic fibers. 24. The apparatus of claim 23, comprising a plurality of extrusion devices for the meltblown material, followed by deposition of the meltblown material into the same moving collection device. 25. The apparatus of claim 23, including a feeding device, at least one of the following ingredients, including superabsorbents, fertilizers, and colorants. 26. The apparatus of claim 23 wherein said means for introducing seeds and cellulosic fibers comprises means for delivering said seeds and superabsorbent into a stream of air. 27. The apparatus of claim 23 wherein said collection means is a moving perforated conveyor belt. 28. Apparatus for making mixed materials, comprising means for making meltblown polymer materials and means for applying seeds to said meltblown material. 29. The apparatus of claim 28 wherein said means for distributing seed comprises a spreader positioned above said collector of meltblown material. 30. A process for germinating seeds comprising providing a seedbed comprising a meltblown polymer, a plurality of seeds, placing said seedbed on a suitable substrate and moistening the seedbed. 31. The process of claim 30 wherein said seedbed further comprises a superabsorbent. 32. The process of claim 30, wherein said seedbed further comprises at least one material selected from the group consisting of superabsorbents, colorants, herbicides, sporicidal-fungicides, rodenticides, anti-animal and Odor protectant for bacteria. 33. The method of claim 30 wherein said polymer is ultraviolet light degradable polypropylene. 34. The method of claim 30 wherein said seedbed further contains exfoliated wood fibers.