AU646527B2 - Growing medium for plants - Google Patents

Description

r 1 6 dt;s 3 273 S F Ref: 191040

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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o a eo Name and Address of Applicant: Frank Wesley Moffett, Jr.

Peppermint Run Hawks Road Naples New York 14512 UNITED STATES OF AMERICA a 0 6 ae 00 Bo S. B.

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so go Actual Inventor(s): Address for Service: Invention Title: Frank Wesley Moffett, Jr.

Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Growing Medium for Plants The following statement is a full description of this invention, including the best method of performing it known to me/us:- I The present invention pertains to the art of growing plants and artificial media useful for growing the plants.

BACKGROUND INFORMATION Various types of compositions have been developed for germinating seeds and growing plants. Generally, these compositions provide an environment for plant growth which stimulates, to varying degrees, the conditions found in the natural or native soil. Compositions of this type were developed because it is not always desirable to use native soil for germinating seeds or growing plants. Native soil often contains many ingredients, some of which may actually hinder the growth of the plants.

Disease organisms may also be present in native soil and these organisms are difficult to eliminate. Also, the soils from one location to another may vary considerably, thus making a uniform product difficult to s: formulate from native soil sources. Additionally, the structure of the native soil does not always provide the optimum environment for plant growth. Often times the native soil is too compact for many types of 99~S plants. For these reasons, different types of synthetic growing media have been developed for the purpose of providing uniform, predictable growth conditions which can be modified in accordance with the particular growth requirements of any plant being cultivated.

Ideally, a synthetic plant growth medium should provide proper soil structure for plant growth. This structure should be sufficiently porous for moisture retention and it should have the ability to contain sufficient air therein to satisfy the plant root requirements for S. 25 oxygen. It should also be able to provide the proper chemical environment, such as pH, for optimum growth. It should be flowable for easy packaging, handling and use in different types of containers while, at the same time, it should be lightweight and capable of providing adequate anchorage for the roots so that the plants are not easily knocked over.

The materials used in the composition should be sufficiently cohesive so that they do not easily spill out of their container.

However, this quality of cohesiveness should not be optimized at the expense of the property of flowability.

The ingredients should be free of disease or toxic materials. They should be compatible with each other and be capable of releasing the necessary plant nutrients for optimum growth. It should be easily manufactured and the ingredients should be inexpensive. Finally, it LMM/622Z 2 should not decompose, be durable and retain its structure and properties for a long time.

It has generally not been possible to combine all the ideal features spoken of above, in a single composition. Usually, one or a few qualities are stressed at the sacrifice of others. For example, water adsorption has been optimized in some compositions by the use of certain porous ingredients while the ability to provide root anchorage has been sacrificed.

For example, one type of plant growth medium comprises shredded styrofoam. U.S. Patent 2,891,355 typifies compositions of this type.

The shredded styrofoam requires the addition of a detergent to provide the necessary water adsorbency so that the medium is able to contain sufficient moisture to sustain plant growth. Compositions of this type 0 generally do not provide a complete medium for optimum plant growth 15 conditions. The shredded styrofoam lacks the type of soil structure required for proper anchoring of the plants and, thus, the plants tend to o. be weak and can easily fall over due to insufficient anchorage. Also, any plant nutrients incorporated into the styrofoam are easily leached out of the zone of growth when the plant is watered.

Patent No. 4,174,957 provides a synthetic growing mixture which comprises a mixture of urea-formaldehyde foam granules, powdered peat or humus and a wetting agent to help promote water adsorption. The compositioi of this patent lacks sufficient structure to provide for effective root anchorage. Also, the composition of this patent requires 25 peat or humus which is a naturally occuring organic soil additive which will eventually break down. Thus, after a period of time, only the urea-formaldehyde will remain in the composition since the other components will either break down or be leached away. Furthermore, the peat or humus, being a naturally occuring soil component, could easily introduce disease organisms into the growing medium.

Other plant growth mediums have concentrated on select features without providing a truely balanced medium which approaches the idea as discussed above. Patent No. 3,441,400 uses an angular porous mineral carrier in a plant growth media. This material serves as a soil adjuvant and as a nitrogen containing ingredient which resists leaching. Patent No. 3,831,317 uses a polymeric pulp material as a plant growth medium.

This material is said to have enhanced capillary action which aids in the plants water and fertilizer requirements. Patent No. 4,241,537 uses an LMM/622Z 3 aqueous polyurethane gel as a plant growth medium. This material is described as useful for supplying water to the plants. None of the compositions described in the above cited patents address all the factors which make a soil composition ideal.

Other examples include U.S. Patents 3,524,279; 4,168,962 and 4,196,543. All of these provide growing mediums which are rigid or shaped self-supporting structures. As such, all of these lack some of the features found in the ideal multipurpose media.

Accordingly, there remains a need in the art for a plant growth media which provides a low cost composition which optimizes the features of the ideal plant growth media and can be produced anywhere in the world. Peat, for example, is only found in temperate zones.

SUMMARY OF THE INVENTION The present invention relates to a plant growth media suitable for germinating seeds, growing plants and other related uses that plant growth media are typically used in the field of horticulture.

The invention comprises a blend of ingredients which provides a combination of properties for an ideal plant growing environment.

According to a first embodiment of this invention, there is 20 provided a plant growth composition which comprises a blend of mineral wool substantially in the form of fibers, and particles of acidic phenol-formaldehyde resin.

According to a second embodiment of this invention, there is provided a method of making a plant growth composition which comprises 25 mixing mineral wool fibers with powdered phenol-formaldehyde resin having an acidic pH; said mixing being continued until the mineral wool forms tufts of about 1 inch in diameter having interstitial space therein and thereafter subjecting the mixture to a milling procedure to reduce the size of the tufts and disperse the resin powder within the interstitial space in the tufts.

According to a third embodiment of this invention, there is provided a method of growing plants which comprises planting a plant in a composition according to the first embodiment and feeding fertilizer and water to the plant in a growth stimulating amount.

The final blend of the composition of the invention appears to the naked eye as tufts of cotton (actually mineral wool) about 1/8" to 1/2" in diameter with phenolic resin powder dispersed throughout the mixture.

The tufts of mineral wool take on a grey-green color due to the fine L particles of phenolic resins dispersed in and on the network of mineralI 'I4 particles of phenolic resins dispersed in and on the network of mineral -4wool fibers.

Each of the ingredients plays an important role in providing a plant growth medium having a broad spectrum of ideal features.

Furthermore, the combination of ingredients provides additional water adsorbency not found in any of the individual ingredients. Additionally, the form and structure of the final product, being composed of tufts of broken mineral wool fibers with phenolic foam powder dispersed therein, makes the mixture flowable, lightweight, highly adsorbent without sacrificing the qualities of cohesiveness and the ability to anchor the roots. The composition also has an enhanced ability to hold and release nutrients to the growing plant. Furthermore, the composition is sufficiently cohesive in the wet state so that it can be periodically washed or leached with water to remove unwanted accumulation of 15 contaminants such as salts, without the media itself being washed away.

o 15 The phenolic resin is particularly useful because it provides for a particular pH level over a long period of time without the necessity of S"adding conventional pH adjuvants such as lime or sulfur. The powdered ,phenolic resin provides a stable pH level while also providing enhanced

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adsorbency of the water when combined with the other ingredient. The phenolic resin is used in the form of particulates, preferably in the form of a powder. Most preferably the powder is made by pulverizing a mass of phenol-formaldehyde foamed resin.

The fine particles of phenolic resin have adsorption qualities without the addition of detergent or surfactant compositions. In S" 25 addition, the powdered phenolic foam resin adheres to the tufts of mineral wool. Thus, the powdered foam resin provides for certain advantages such as longer pH regulation than that obtainable by simply adding conventional pH adjuvants such as lime or sulfur to the composition, and the raising of water by capillary action.

The mineral wool in the form of tufts of broken fibers allows the material to be flowable while providing for sufficient cohesiveness which prevents the composition from being easily spilled from its container.

This property is particularly important when the product is used in certain types of planters which have vertical walls containing a plurality of openings for plants, such as strawberry pots. The tufts of mineral wool also provide the uniform dispersal of the fine phenolic foam powder particles. The dispersal property is augmented by the surface adhesion which causes the powder to adhere to the multitude of fibers in LMM/622Z each tuft. This adhesion prevents the segregation and loss of the fine powder. The structure also results in the ability to adsorb greater quantities of water without sacrificing the optimization of other factors. Additionally, the mineral wool, being essentially inert in the mixture, is not subject to decay and thus it will provide uniform results over an extended period of time and should last as long as rocks would last.

The materials used to make the composition of this invention are free of contamination of toxic agents and are substantially sterile with respect to larvae insects germs such as plant pathogens. The composition also contains a sufficient amount of air to supply the oxygen requirements for roots growing in the media. Furthermore, this air is retained even after overwatering so long as means are provided for excess o water to drain from the composition. Also, the materials used in this 15 composition are non-reactive with fertilizer materials. Fol example, 0000 .e nitrogen will not be used up as it might be in a composition which .00 contains various types of decomposable organic materials such as sawdust 00 0o So0. and peat.

00 The above ingredients are low in cost and readily available and lightweight for easy shipping, thus making them particularly suitable for formulation into this new composition.

.o:It is an object of this invention to provide a composition useful ,n processes of growing plants.

It is also an object of this invention to provide a low cost pH S 25 adjusted plant growth media which optimizes the ideal features of a plant growth media without compromising or sacrificing any of the ideal features.

It is also an object of this invention to provide a low cost, lightweight, pH adjusted plant growth media which is highly adsorbent while retaining the ability to anchor the plant roots; and is flowable for easy handling yet is sufficiently cohesive to prevent unwanted spilling from plant containers.

It is also an object to provide a plant growth media having the above mentioned properties and which is also non-toxic and free of disease causing agents.

It is also an object to provide a method of making a plant growth media having the above mentioned properties.

It is also an object to provide a method of growing plants in the LMM/622Z -6above described plant growth media.

These objects and other objects will become apparent to those skilled in the art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The composition contains powdered phenolic foam resin and mineral wool. The ingredients and their form and structure contribute to the unique properties of this invention.

In the preferred embodiment, the composition contains ninety parts of mineral wool and thirty-eight parts of foamed phenolic resin. All parts given in this specification are parts by weight unless indicated otherwise. The amounts of each ingredient can vary to suit particular plants, especially the needs of particular plants being used with the composition. In general, the major ingredient is the mineral wool which provides the bulk of the final product. Lesser or greater quantities of S 15 the resin can be blended with the mineral wool. For most plant growing *0S0 needs, the formulation will vary from the above mentioned preferred S* embodiment by as much as plus or minus ten percent of the weight of each ingredient.

The structure of the ingredients in the final product of the preferred embodiment is also important. The mineral wool is in the form of tufts. The tufts are formed by taking conventional mineral wool and subjecting it to forces which pull apart and break the mineral fibers 4 into short length fibers and mixing the broken fibers to form tufts. The .4 0 fibers are pulled apart and broken up into lengths which are long enough 25 so that they are capable of forming the tufts.

a In a preferred embodiment, the fibers are subjected to breaking and mixing forces to break and mix the fibers to such an extent that tufts :0o• are formed which are about 1/8" to 1/2" in diameter. Larger or smaller tufts can be used but this size range is found to be particularly convenient for most planting purposes.

1he breaking and mixing action can be carried out in any conventional device known to those skilled in the art for this purpose.

It is also possible to pull apart and break the fibers by hand to form the tufts. In a preferred embodiment, the mineral wool is first placed in a mixing apparatus for mixing and breaking the fibers. The mineral wool is mixed until tufts of about 1" in diameter are formed.

Thereafter, the 1" tufts are placed in a hammer mill for further processing until tufts of about 1/8" to 1/2" in diameter are formed.

LMM/622Z -7- Conventional mineral wool or rock wool is used in the invention.

Mineral wool, sometimes referred to as rock wool, is a common ingredient used in many fields of technology such as the field of insulation. It is a fine fibrous "wool like" material made by forming fine filaments of mineral fiber from a molten rock. Many processes are known for making the mineral wool. Examples of this type of product are disclosed in US Patents 2,193,982; 2,051,279 and 2,155,107, the specifications of which are incorporated herein by reference.

Preferably the mineral wool for the present invention is made from a silica containing mineral such as basalt. Other types of mineral are permissible so long as they do not contain harmful ingredients. Even fiberglass of the type used in typical home insulation is acceptable but is not preferred because it is less adsorbent and is somewhat irritable to personnel who handle it. For the purposes of this invention, the term 6 l 15 "mineral wool" includes glass wool and the like.

The phenolic resin is a phenol-formaldehyde resin. Preferably it is a foamed resin in the form of a block or mass which is then pulverized into a powder. The resin may be foamed by any conventional method. The powder is made sufficiently fine so that it adheres to the mineral wool tufts within the interstices thereof and does not become segregated from the tufts during ordinary handling.

Phenol-formaldehyde foam resins are well known to those skilled in a the art. Typical examples are described in U.S. Patent 2,728,741 and S4,166,162, the specifications of which are incorporated herein by 25 reference. In the preferred embodiment, the phenol-formaldehyde resin is a o formulated so that it has an acidic pH. A particularly useful resin for this embodiment is the phenol-formaldehyde described in U.S. Patent 2,753,277, the specification of which is incorporated herein by reference.

S. 8 In a preferred embodiment of this invention, the foamed phenolformaldeh Je resin described in U.S. Patent 2,753,277, is pulverized into a powder and mixed in with the mineral wool as defined above. It is not necessary, however, for the incorporation of any wetting agent or surfactant into the phenol-formaldehyde because the structure of the final composition does not require a wetting agent to achieve its unusually high water adsorption.

In a preferred embodiment, the final product is obtained by mixing the mineral wool with acidic phenol-formaldehyde foam which has been previously pulverized to a powder. The ingredients are mixed until the LMM/622Z -8mineral wool breaks up and forms tufts of about 1" in diameter. At that point, the entire mixture is subjected to the action of a hammer mill until tufts are generally reduced in size to about 1/8" to about 1/2" in diameter, it being realized that -he hammer mill process will result in a distribution of sizes with some tufts being smaller than 1/8" in diameter and some which may be slightly larger.

The material of the above described preferred embodiment is flowable and is capable of adsorbing large quantities of water. It is also capable of providing superior anchorage for the plant roots due to the nature of the tufts. The property of root anchorage is provided without sacrificing the properties of flowability or water adsorption.

The presence of the powdered acidic phenolic resin in the interstices of the tufts provides a long lasting means of assuring p'oper pH for acid to loving plants such as strawberries (a pH of 6.2 is ideal for most oVa S 15 plants). Furthermore, since the resin adheres to the mineral fiber, it Iq~d 8 does not become segregated therefrom nor is it easily washed from the composition.

a Although the composition is flowable, it is sufficiently cohesive so that it is not easily lost through the holes in the planters.

The composition is suitable for a wide variety of horticultural uses. As such, any of the usual adjuvants may be added to the composition to accomplish their intended purposes. For example, fertilizer, both liquid and solid, are desirably used with the composition. Biocidal compositions for efficient disease or insect 25 control may also be added.

pa The composition of this invention is particularly suitable for acid O080e loving plants such as strawberries. Strawberries are often grown in special receptacles such as pots which have a plurality of side holes.

S Typically, a strawberry plant grows out of each of these holes. However, due to the positions of the holes, it is very easy for the soil or other growing medium to spill out of the holes, especially immediately after planting since the roots have not fully developed to a point where they can hold in the soil. The unique cohesiveness of the growing medium of this invention prevents the soil from spilling out of the holes yet it is sufficiently flowable so that no difficulty is encountered when filling the pot with the medium.

The composition is also useful for germinating seeds. Seeds can be planted in this material and treated with any suitable adjuvant which LMM/622Z -9aids in seed germination. Thereafter, the developing plant can be grown in accordance with accepted methods of horticulture.

Although the composition of this invention comprises mineral wool and acidic phenolic resin, suitable compositions may be made wherein the composition further comprises vermiculite or perlite, or the acidic phenolic resin is replaced by vermiculite or perlite. A composition containing tufts of mineral wool in combination with vermiculite or perlite would be preferred if an acid artificial soil were not desired, for example, as when one wishes to grow plants which require a neutral or somewhat alkaline soil.

EXAMPLE

The following example is given as a preferred embodiment of the invention.

o e Thirty-eight (38) pounds of acidic phenol-formaldehyde foam resin o 15 was pulverized to a powder. The foam is identified as "Oasis" which is an acidic phenol-formaldehyde foam resin sold by Smithers Company of Kent 'e Ohio. The powdered phenolic resin was mixed with ninety (90) pounds of a mineral wool. The mineral wool was purchased from U.S. Mineral Wool Company in New Jersey. The composition was mixed until the mineral wool was broken up sufficiently to form tufts of about 1" in diameter. At that point, the materia& was transferred to a hammer mill for further ease*: processing until tufts of about 1/8" to 1/2" diameter were formed. The *eoe final product was grey-green in colour and had the appearance of tufts of C cotton.

25 While the present invention has been described in terms of certain preferred embodiments and exemplified with respect thereto, one skilled in the art will readily appreciate that various modifications, changes, l'•a omissions and substitutions may be made without departing from the spirit a 0 thereof. It is intended, therefore, that the present invention be S 30 limited solely by the scope of the following claims.

LMM/622Z

Claims (21)

1. A plant growth composition which comprises a blend of mineral wcol substantially in the form of fibers, and particles of acidic phenol-formaldehyde resin.

2. The composition of Claim 1 wherein said fibers are in the form of tufts having interstitial space contained therein.

3. The composition of Claim 2 wherein said tufts have air in said interstitial space whereby said composition contains sufficient air to supply the oxygen requirement for roots growing in said composition.

4. The composition of Claim 2 or Claim 3 wherein said tufts are about 1/8 inch to about 1/2 inch in diameter.

The composition of claim 2 or claim 3 wherein said tufts are less than about 1/8 inch in diameter.

6. The composition of any one of Claims I to 5 wherein said phenol-formaldehyde resin is in the form of a powder.

7. The composition of Claim 6 wherein said phenol-formaldehyde powder is pulverized phenol-formaldehyde foam.

8. The composition of Claim 6 or Claim 7 wherein said phenol-formaldehyde powder is substantially contained within said interstitial space of said mineral wool tufts.

9. The composition of any one of Claims 2 to 8 wherein said mineral wool tufts are present in an amount of about 60% to 78% by -'eight and said phenol-formaldehyde resin is present in a pH effective amount to provide an acidic growth medium for plants.

10. The composition of Claim 9 wherein said phenol-formaldehyde resin is present in an amount of about 22% to 40% by weight.

11. The composition of Claim 9 or Claim 10 wherein said mi.',ol wool tufts are present in an amount of about 70% by weight and said phenol-formaldehyde resin is present in an amount of about 30% by weight.

12. The composition of any one of Claims 2 to 11 wherein said mineral wool tufts and said phenol-formaldehyde resin form a flowable composition.

13. The composition of any one of Claims 1 to 12 which additionally contains a fertilizer in a plant growth stimulating amount.

14. A plant growth composition substantially as hereinbefore described with reference to the example.

A method of making a plant growth composition which comprises mixing mineral wool fibers with powdered phenol-formaldehyde resin having /STA/622Z 11 an acidic pH; said mixing being continued until the mineral wool forms tufts of about 1 inch in diameter having interstitial space therein and thereafter subjecting the mixture to a milli, rocedure to reduce the size of the tufts and disperse the resin powder within the interstitial space in the tufts.

16. The method of Claim 15 wherein said mineral wool fibers are present in an amount of about 72-108 parts by weight and said phenol- formaldehyde resin is present in an amount of about 30-47 parts by weight.

17. The method of Claim 15 or Claim 16 wherein said tufts are reduced in size to about 1/8 inch to about 1/2 inch in diameter.

18. A method of preparing a plant growth composition, which method is substantially as hereinbefore described with reference to the example.

19. The plant growth composition product when produced by the process of any one of Claims 15 to 18.

20. A method of growing plants which comprises planting a plant in a composition according to any one of Claims 1 to 14 or 19 and feeding *fertilizer and water to the plant in a growth stimulating amount.

21. The method of Claim 20 wherein said plant is in the form of a S: seed. DATED this SIXTH day of DECEMBER 1993 Frank Wesley Moffett, Jr. .Patent Attorneys for the Applicant SPRUSON FERGUSON ft /STA/622 TA /622 Z GROWING MEDIUM FOR PLANTS ABSTRACT The present invention relates to an artificial medium useful for growing plants and a method of growing plants using that medium. Accordingly, this invention provides a plant growth composition which comprises a blend of mineral wool and particles of acidic phenyl- formaldehyde resin. The invention also provides a method of making a plant growth composition which comprises mixing mineral wool fibres with powdered phenyl-formaldehyde resin having an acidic pH; the mixing being continued until the mineral wool forms tufts of about 1 inch in diameter having interstitial space therein and thereafter subjecting the mixture to a milling procedure to reduce the size of the tufts and disperse the resin powder within the interstitial space in the tufts. Additionally provided is a method of growing plants which comprises planting a plant in a composition as described above and feeding fertilizer and water to Q the plant in a growth stimulating amount. JO 06 0 Be e B a a B g e eg a «G«OB G B Be GB B Ga LMM/622Z