Formaldehyde-free mineral wool growth medium

Abstract

Various exemplary aspects relate to a mineral wool plant substrate comprising mineral wool fibers bound by a binder, the binder formed from an aqueous binder composition comprising: a crosslinking agent comprising at least two carboxylic acid groups; a polyol component having at least two hydroxyl groups; a nitrogen-based protective agent; and 0.05 wt% to 0.7 wt% of a nonionic surfactant. Methods of making such fiber-based plant substrates can include collecting a plurality of inorganic fibers on a substrate; applying an aqueous binder composition to the aggregate of inorganic fibers, thereby forming a binder coated inorganic fiber; and curing the aqueous binder composition at a temperature below 510 DEG F to form a fiber-based plant substrate wherein the aqueous binder composition is free of formaldehyde.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of U.S. Provisional Patent Application No. 63 / 406,484, filed on September 14, 2022, the entire content of which is incorporated herein by reference. Technical field

[0003] The present disclosure relates to mineral wool growth media, and more particularly to formaldehyde - free mineral wool growth media for crop or plant applications. Background art

[0004] Substrates for supporting plant growth in the absence of soil, such as those in the form of plugs, blocks, and slabs, are known in the art. For example, U.S. Patent No. 6,389,748 (the entire disclosure of which is incorporated herein by reference) discloses a cube having a laminated structure of mineral wool fibers oriented parallel to each other. The mineral wool fibers are held together by a cured binder to form the cube. One such conventional cube is a laminated structure of Z - shaped fiber layers, having plant openings formed in the upper surface of the cube and a plurality of grooves formed in the lower surface of the cube. The shape and size of the plant openings are designed to receive plugs containing seeds that have already started the growth process. The dimensions of the cube are designed to allow the plants to continue growing without soil.

[0005] Water and nutrients are typically delivered to the cube by applying (e.g., dripping) a source of supply water to the upper surface of the cube. This supply water containing nutrients is spread through the cube in such a way that it can be absorbed by the roots of the plants. Excess supply water eventually reaches the lower surface of the cube, where the grooves facilitate its drainage.

[0006] Mineral fiber products generally include man - made vitreous fibers (MMVF), such as, for example, glass fibers, ceramic fibers, basalt fibers, slag wool, mineral wool, and rock wool, which are bonded together by a polymeric binder composition. Conventional binder compositions for mineral fiber insulation products are based on phenol - formaldehyde (PF) resins and PF resins extended with urea (PUF resins). However, while such binder compositions provide suitable properties for the growth media, binder compositions containing formaldehyde may have various drawbacks, including the risk of the leachate of formaldehyde being absorbed by plants, rendering the resulting products unable to be labeled as "organic", and environmental considerations.

[0007] As an alternative to formaldehyde-based binders, certain formaldehyde-free formulations have been developed for use as binders in horticultural products. However, when used with mineral wool, existing formaldehyde-free binders tend to lack the strength of PF binders, and the products formed therefrom exhibit inadequate performance, particularly in terms of puncture resistance, compressibility, and bond strength.

[0008] Accordingly, there is a need for a mineral wool growing medium formed using a formaldehyde-free binder composition that maintains sufficient performance characteristics. SUMMARY OF THE INVENTION

[0009] Various exemplary aspects of the present inventive concept relate to a mineral wool plant substrate comprising mineral wool fibers bonded by a binder formed from an aqueous binder composition comprising: a crosslinking agent comprising at least two carboxylic acid groups; a polyol component having at least two hydroxyl groups; a nitrogen protecting agent; and 0.05 wt% to 0.7 wt% of a nonionic surfactant;

[0010] In certain embodiments, the nonionic surfactant comprises an ethoxylated propoxylated polyaryl phenol ether. In certain embodiments, the nitrogen protecting agent comprises at least one of an amine protecting agent or an ammonium protecting agent. In certain embodiments, the mineral wool plant substrate is substantially free of formaldehyde. In certain embodiments, the mineral wool plant substrate has a density in the range of 30 kg / m 3 to 150 kg / m 3 range.

[0011] In certain embodiments, the mineral wool plant substrate has a loss on ignition of 1.0% to 5.0%. In certain embodiments, the mineral wool plant substrate exhibits a bond strength of about 150 lb / ft 2 to about 250 lb / ft 2 In certain embodiments, for a 6 pcf product, the mineral wool plant substrate exhibits a settlement time of less than 30 seconds. In certain embodiments, the mineral wool plant substrate exhibits a water absorption of greater than 50%.

[0012] In certain embodiments, the mineral wool plant substrate exhibits a compressive strength of at least 100 lb / ft 2 In certain embodiments, the mineral wool plant substrate exhibits a puncture resistance of at least 2.5 lb / ft 2 of puncture resistance.

[0013] In certain embodiments, a method of manufacturing a fiber-based plant substrate is provided. The method may include collecting multiple inorganic fibers on a substrate; applying an aqueous binder composition to the aggregate of inorganic fibers to form binder-coated inorganic fibers; and curing the aqueous binder composition at a temperature below 510°F to form a fiber-based plant substrate, wherein the aqueous binder composition is free of formaldehyde. In certain embodiments, the aqueous binder composition comprises: a crosslinking agent comprising at least two carboxylic acid groups; a polyol component having at least two hydroxyl groups; a nitrogen protecting agent, wherein the nitrogen protecting agent comprises at least one of an amine protecting agent or an ammonium protecting agent; and a nonionic surfactant in an amount of 0.05 wt% to 0.7 wt% based on the total weight of the aqueous binder composition;

[0014] In certain embodiments, the polyol component includes sugar alcohols, alkanolamines, pentaerythritol, or mixtures thereof. In certain embodiments, the nitrogen protecting agent includes ammonium hydroxide. In certain embodiments, the aqueous binder composition has an uncured pH of 4.2 to 6.5. In certain embodiments, the nonionic surfactant includes ethoxylated propoxylated polyaryl phenol ether. In certain embodiments, the aqueous binder composition is cured at a temperature of about 450°F to 480°F.

[0015] In certain embodiments, a mineral wool plant substrate comprising mineral wool fibers bonded by a binder is provided. The binder is formed from an aqueous binder composition comprising at least 50 wt% of polyacrylic acid, a salt of polyacrylic acid, an acid anhydride of polyacrylic acid, or a resin based on polyacrylic acid, based on the total weight of solids in the aqueous binder composition; about 5 wt% to about 50 wt% of sugar alcohol based on the total weight of solids in the aqueous binder composition; ammonium hydroxide; and about 0.05 wt% to about 0.7 wt% of ethoxylated propoxylated polyaryl phenol ether.

[0016] In certain embodiments, the mineral wool plant substrate is in the form of plugs, blocks, or slabs. In certain embodiments, for a 6 pcf product, the mineral wool plant substrate exhibits a settlement time of less than 25 seconds, a water absorption rate of greater than 90%, a compressive strength of at least 400 lb / ft 2 and a puncture resistance of at least 7 lb / ft 2

[0017] Many other aspects, advantages, and / or features of the general inventive concept will become more apparent from the following detailed description of exemplary embodiments and the accompanying drawings submitted herewith. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] ​The general inventive concept and its exemplary embodiments and advantages are described in more detail below by way of example with reference to the accompanying drawings, in which:

[0019] Figure 1 Perspective view of a fibrous substrate in the form of a cube for promoting plant growth according to one or more embodiments shown and described herein;

[0020] Figure 2 Illustrates an exemplary esterification reaction in limited crosslinking due to the formation of a metal carboxylate complex between mineral wool fibers and an unprotected carboxylic acid;

[0021] Figure 3 Illustrates an exemplary esterification reaction using a partially protected carboxylic acid-based binder;

[0022] Figure 4 Illustrates an exemplary method for producing a mineral wool product according to one or more embodiments shown and described herein;

[0023] Figure 5 Graph showing the water absorption (in %) of a mineral wool product prepared using various formaldehyde-free binder formulations without surfactant within 5 minutes according to Example 1 herein;

[0024] Figure 6 Graph showing the bond strength (in lb / ft 2 per unit) of a mineral wool product prepared using various formaldehyde-free binder formulations without surfactant according to Example 1 herein;

[0025] Figure 7 Graph showing the bond strength (in lb / ft 2 per unit) of a mineral wool product according to one or more embodiments shown and described herein;

[0026] Figure 8 Graph showing the sedimentation time (in seconds) of a mineral wool product according to one or more embodiments shown and described herein;

[0027] Figure 9 Graph showing the water absorption (in %) of a mineral wool product within 5 minutes according to one or more embodiments shown and described herein;

[0028] Figure 10 Graph showing the compressive strength (in lb / ft 2 per unit) of a mineral wool product at 25% deformation according to one or more embodiments shown and described herein;

[0029] Figure 11A graph showing the puncture resistance (in lb / ft 2 units) of a mineral wool product according to one or more embodiments shown and described herein; and

[0030] Figure 12 A graph showing the change of the surface tension (Y-axis, in N / m) of a mineral wool product according to one or more embodiments shown and described herein over time (X-axis, in seconds). Detailed Description

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which these exemplary embodiments belong. The terms used in the description herein are for the purpose of describing exemplary embodiments only and are not intended to limit the exemplary embodiments. Thus, the general inventive concept is not intended to be limited to the specific embodiments shown herein. Although other methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, the preferred methods and materials are described herein.

[0032] As used in the specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0033] The term "substantially free of" means that the composition contains less than 1.0 wt%, including not more than 0.8 wt%, not more than 0.6 wt%, not more than 0.4 wt%, not more than 0.2 wt%, not more than 0.1 wt%, and not more than 0.05 wt% of the said component. In any of the exemplary embodiments, "substantially free of" means that the composition contains not more than 0.01 wt% of the said component.

[0034] Unless otherwise indicated, all numbers expressing amounts of ingredients, chemical and molecular properties, reaction conditions, etc. used in the specification and claims should be understood to be modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and appended claims are approximations that may vary depending on the desired properties sought to be obtained by the exemplary embodiments herein. To the extent possible, each numerical parameter should be construed in light of the number of significant figures and the ordinary rounding method.

[0035] Unless otherwise specified, any element, property, feature, or combination of elements, properties, and features can be used in any embodiment disclosed herein, whether or not the element, property, feature, or combination of elements, properties, and features is explicitly disclosed in that embodiment. It should be readily understood that the features described with respect to any particular aspect herein can be applied to other aspects described herein, provided that the features are compatible with that aspect. Specifically: the features described herein related to the method can be applied to fiber products and vice versa; the features described herein related to the method can be applied to aqueous binder compositions and vice versa; and the features described herein related to fiber products can be applied to aqueous binder compositions and vice versa.

[0036] Each numerical range given throughout the specification and claims will include every narrower numerical range that falls within such broader numerical ranges, as if such narrower numerical ranges were all explicitly written herein.

[0037] The present disclosure relates to formaldehyde-free or "formaldehyde-free added" aqueous binder compositions for use with inorganic fibers such as glass or mineral wool fibers. As used herein, the terms "binder composition", "aqueous binder composition", "binder formulation", "binder", and "binder system" are used interchangeably herein and are synonymous.

[0038] The present general concept of the invention relates to a fiber-based substrate for supporting plant growth in the absence of soil. The use of mineral wool fibers and the like in the substrate avoids problems associated with conventional growth substrates and / or provides advantages and features not achievable with previous conventional growth substrates.

[0039] In one exemplary embodiment, Figure 1 a fiber-based substrate in the form of a cube 100 is shown. The cube 100 has a fixed volume defined by an upper surface 102, a lower surface 104, and four side surfaces 106 located between the upper surface 102 and the lower surface 104. The cube 100 can have any dimensions suitable for supporting the growth stage of a plant. In some exemplary embodiments, the cube 100 has a width c in the range of 2 inches to 8 inches w ; a length c in the range of 2 inches to 8 inches l , and a height c in the range of 2 inches to 8 inches h . In some exemplary embodiments, c w = c l = c hAlthough the reference cube 100 is described for various embodiments herein, it is contemplated that in other embodiments, the fiber-based matrix may take another form, such as a plug (e.g., generally cylindrical, where the end faces of the cylinder form the top and bottom surfaces of the growth matrix) or a thick plate.

[0040] Fibers suitable for use in the fiber products of the present disclosure include, but are not limited to, mineral fibers (e.g., mineral wool, rock wool, rock wool, slag wool, etc.), glass fibers, carbon fibers, ceramic fibers, natural fibers, and synthetic fibers. In certain exemplary embodiments, the plurality of randomly oriented fibers are mineral wool fibers, including but not limited to mineral wool fibers, rock wool fibers, slag wool fibers, rock wool fibers, or combinations thereof.

[0041] The fiber-based matrix may be formed entirely of one type of fiber, or they may be formed of a combination of two or more types of fibers. For example, depending on the desired application, the fiber-based matrix may be formed of a combination of various types of mineral fibers or various combinations of different inorganic fibers and / or natural fibers. In certain exemplary embodiments, the fiber-based matrix is formed entirely of mineral wool fibers.

[0042] In some exemplary embodiments, the mineral wool fibers are oriented horizontally to be substantially parallel to each other. In some exemplary embodiments, the mineral wool fibers are oriented vertically to be substantially parallel to each other. In some exemplary embodiments, the mineral wool fibers are randomly distributed within the body of the cube 100. In some exemplary embodiments, the mineral wool fibers are oriented in a first direction in one region of the cube 100 and in a second direction in another region of the cube 100. The cube 100 has a density in the range of 30 kg / m 3 to 150 kg / m 3 range.

[0043] In any of the exemplary embodiments, the mineral wool fibers may have an average fiber diameter in the range of 1 μm to 20 μm. In some exemplary embodiments, the mineral wool fibers are formed to have an average fiber diameter in the range of 3 μm to 8 μm. In some exemplary embodiments, the mineral wool fibers are formed to have an average fiber diameter less than or equal to 5 μm.

[0044] In some exemplary embodiments, the length of the mineral wool fibers is in the range of 0.1 inches to 21.0 inches, 0.1 inches to 15 inches, 0.1 inches to 10 inches, 0.1 inches to 5 inches, or 0.1 inches to 3 inches.

[0045] Compared to fiberglass, mineral wool typically has a higher percentage of divalent and trivalent metal oxides. Table 1 provides ranges of typical glass wool formulations and typical stone (or mineral) wool formulations. Guldberg, Marianne et al., “The Development of Glass and Stone Wool Compositions with Increased Biosolubility” Regulatory Toxicology and Pharmacology 32, 184 - 189 (2000). As shown below, glass wool has a total weight percentage of divalent and trivalent oxides (CaO / MgO / Al2O3 / FeO) of no greater than 25 wt%. In contrast, mineral wool or rock wool contains at least 25 wt% of divalent and trivalent metal oxides, or in some cases, greater than 30 wt% of divalent and trivalent metal oxides, and in some cases, at least 50 wt% of divalent and trivalent metal oxides. Such metal oxides (especially aluminum) have a strong tendency to complex with acidic functional groups such as carboxylic acids, which inhibits the wetting of the binder on the fibers and prevents sufficient esterification and crosslinking. Thus, traditional acid - free formaldehyde binders show reduced performance with mineral wool fibers.

[0046] Table 1 :

[0047]

[0048] Within the cube 100, the mineral wool fibers are held together by a binder. Upon curing, the binder “locks” the fibers together to form a matrix capable of mechanically supporting a plant during at least a portion of its growth stage.

[0049] In any of the exemplary embodiments, the binder composition may include an acidic cross - linker suitable for cross - linking with a polyol component via an esterification reaction. The cross - linker may have a number - average molecular weight greater than 90 Daltons, such as from about 90 Daltons to about 10,000 Daltons, or from about 190 Daltons to about 5,000 Daltons. In any of the exemplary embodiments, the cross - linker may have a number - average molecular weight of from about 2,000 Daltons to 5,000 Daltons or about 4,000 Daltons.

[0050] Non-limiting examples of suitable crosslinking agents include materials having one or more carboxylic acid groups (-COOH), such as monomeric polycarboxylic acids and polymeric polycarboxylic acids, including their salts or acid anhydrides and mixtures thereof. In any of the exemplary embodiments herein, the polycarboxylic acid may be a polymeric polycarboxylic acid, such as a homopolymer or copolymer of acrylic acid. The polymeric polycarboxylic acid may include polyacrylic acid (including its salts or acid anhydrides) and polyacrylic acid-based resins such as QR-1629S and Acumer 9932 (both commercially available from Dow Chemical Company), polyacrylic acid compositions (commercially available from CH Polymer), and polyacrylic acid compositions (commercially available from Coatex). Acumer 9932 is a polyacrylic acid / sodium hypophosphite resin having a molecular weight of about 4000 and a sodium hypophosphite content of 6 wt% to 7 wt% based on the total weight of the polyacrylic acid / sodium hypophosphite resin. QR-1629S is a polyacrylic acid / glycerol resin composition.

[0051] In any of the exemplary embodiments disclosed herein, based on the total solids content of the binder composition, the crosslinking agent may be present in the binder composition at at least 50 wt%, including but not limited to at least 55 wt%, at least 60 wt%, at least 63 wt%, at least 65 wt%, at least 68 wt%, at least 70 wt%, at least 71 wt%, at least 73 wt%, and at least 75.0 wt%. In any of the exemplary embodiments herein, based on the total solids content of the binder composition, the crosslinking agent may be present in the binder composition in an amount of 50 wt% to 85 wt%, including but not limited to 60 wt% to 82 wt%, 65 wt% to 80 wt%, and 68 wt% to 78 wt% (including all endpoints and sub-combinations therebetween).

[0052] Optionally, all or a certain percentage of the acid functional groups in the polycarboxylic acid may be temporarily blocked with a protecting agent that temporarily prevents the acid functional groups from complexing with the mineral wool fibers and is subsequently removed by heating the binder composition to a temperature of at least 150 °C during the curing process to release the acid functional groups for crosslinking with the polyol component and complete the esterification process. In any of the exemplary embodiments herein, 10% to 100% of the carboxylic acid functional groups may be temporarily blocked by the protecting agent, including ranges between about 25% to about 99%, about 30% to about 90%, and about 40% to 85%, including all sub-ranges and combinations of ranges therebetween. In any of the exemplary embodiments herein, at least 40% of the acid functional groups may be temporarily blocked by the protecting agent.

[0053] The protecting agent may be capable of reversibly binding to the carboxylic acid groups of the crosslinking agent. In any of the exemplary embodiments, the protecting agent includes any compound of a molecule capable of forming at least one reversible ionic bond with a single acid functional group. In any of the exemplary embodiments, the protecting agent may include nitrogen-based protecting agents such as ammonium-based protecting agents; amine-based protecting agents; or mixtures thereof. Exemplary ammonium-based protecting agents include ammonium hydroxide. Exemplary amine-based protecting agents include alkylamines and diamines such as, for example, ethylenimine, ethylenediamine, hexamethylenediamine; alkanolamines such as ethanolamine, diethanolamine, triethanolamine; ethylenediamine-N,N'-disuccinic acid (EDDS), ethylenediaminetetraacetic acid (EDTA), etc., or mixtures thereof. Additionally, it has surprisingly been found that alkanolamines can be used as both a protecting agent and a participant in the crosslinking reaction to form esters in the cured binder. Thus, alkanolamines have a bifunctionality of a protecting agent and a polyol for crosslinking with polycarboxylic acids via esterification.

[0054] As Figure 2 shown, if unprotected, the carboxylic acid groups in the polycarboxylic acid component will form carboxylic acid-metal complexes with metal ions (Mg 2+ , Al 3+ , Ca 2+ , Fe 3+ , Fe 2+ ) from the mineral wool fibers. In such cases, when the binder composition cures, the polyol will have very limited availability to crosslink with the carboxylic acid groups, resulting in weak binder properties. In contrast, Figure 3 illustrates the pre-reaction of a polycarboxylic acid with a nitrogen-based protecting agent such as ammonium hydroxide or an amine. Such a pre-reaction temporarily prevents the acid functional groups from permanently reacting with the metal ions. When the binder cures, ammonia is released, releasing the acid functional groups to react with the polyol via esterification.

[0055] The function of the protecting agent is different from that of a conventional pH regulator. As defined herein, the protecting agent only temporarily and reversibly caps the acid functional groups in the polymeric polycarboxylic acid component. In contrast, a conventional pH regulator (such as sodium hydroxide) permanently terminates the acid functional groups, which prevents crosslinking between the acid and hydroxyl groups due to the capped acid functional groups. Thus, including a conventional pH regulator (such as sodium hydroxide) does not provide the desired effect of temporarily capping the acid functional groups and then releasing these groups during curing to allow crosslinking via esterification. Thus, in any of the exemplary embodiments disclosed herein, the binder composition may be free or substantially free of conventional pH regulators such as, for example, sodium hydroxide and potassium hydroxide. Such conventional pH regulators for high-temperature applications will permanently bind to the carboxylic acid groups and will not release the carboxylic acid functional groups to allow crosslinking esterification.

[0056] In addition to providing a temporary capping function, the protective agent also increases the pH of the binder composition to provide compatibility with the pH of the mineral wool fibers. If the pH of the binder composition is significantly lower than the pH of the fibers, the binder composition can damage the mineral fibers, which changes the composition and weakens the fibers. The function of the binder composition is to adhere the fibers together and should not react with the fibers themselves.

[0057] The pH of the binder composition in the uncured state can be adjusted according to the intended application to promote the compatibility of the components of the binder composition or to function with various types of fibers. In any of the exemplary embodiments disclosed herein, when in the uncured state, the binder composition has a pH of at least about 4. In such exemplary embodiments, when in the uncured state, the pH of the binder composition can be from about 4.0 to 7.0, including from about 4.2 to 6.8 and from about 4.5 to 6.5. After curing, the pH of the binder composition can increase to a pH of at least 6.5 and up to a pH of 8.5. In any of the exemplary embodiments disclosed herein, the cured pH of the binder composition is between 7.2 and 7.8.

[0058] Based on the total solids in the binder composition, the protective agent can be present in the binder composition in an amount of 1.25 wt% to 50.0 wt%, including but not limited to 2.50 wt% to 25.0 wt%, or 3.0 wt% to 15.5 wt%. In any of the exemplary embodiments disclosed herein, the protective agent is present in the binder composition in an amount of at least 3.5 wt%, including at least 4.0 wt%, at least 5.0 wt%, at least 6.0 wt% and at least 8.0 wt%. In any of the exemplary embodiments, the protective agent can be used in an amount sufficient to cap at least 40% of the acid functional groups of the polycarboxylic acid.

[0059] In any of the exemplary embodiments, the ratio of carboxylic acid groups to amine groups in the binder composition ranges from about 6:1 to about 1:1, or from about 4:1 to about 1.5:1.

[0060] In any of the exemplary embodiments, the binder composition further comprises at least one polyol having two or more hydroxyl groups (also referred to herein as a polyhydroxy compound). In any of the exemplary embodiments, the polyol includes one or more of monomeric polyhydroxy compounds or polymeric polyhydroxy compounds.

[0061] Exemplary polyols include pentaerythritol, alkanolamines, mixtures thereof, or derivatives thereof. In any of the exemplary embodiments, the alkanolamine may include triethanolamine or derivatives thereof. Thus, in some exemplary embodiments, the polyol includes one or more of pentaerythritol, triethanolamine, derivatives thereof, or mixtures thereof.

[0062] In an exemplary embodiment, the polyol may include one or more sugar alcohols. Sugar alcohols should be understood to mean compounds obtained when the aldehyde group or ketone group of a sugar is reduced (e.g., by hydrogenation) to the corresponding hydroxyl group. The starting sugar may be selected from monosaccharides, oligosaccharides, polysaccharides, and mixtures of those products, such as syrups, molasses, and starch hydrolysates. The starting sugar may also be a dehydrated form of the sugar. Although sugar alcohols are highly similar to the corresponding starting sugars, they are not sugars. Thus, for example, sugar alcohols do not have reducing ability and cannot participate in the Maillard reaction of typical reducing sugars. In any of the exemplary embodiments, the sugar alcohol includes any of the following: glycerol, erythritol, arabitol, xylitol, sorbitol, maltitol, mannitol, iditol, isomaltitol, lactitol, cellobiitol, palatinol, maltotriitol, their syrups, and mixtures thereof. In various exemplary embodiments, the sugar alcohol is selected from glycerol, sorbitol, xylitol, and mixtures thereof. In any of the exemplary embodiments, the polyol may be a dimeric condensation product or an oligomeric condensation product of a sugar alcohol. In any of the exemplary embodiments, the condensation product of the sugar alcohol may be isosorbide. In any of the exemplary embodiments, the sugar alcohol may be a diol or ethylene glycol.

[0063] In any of the exemplary embodiments, the binder composition may be free of reducing sugars. Reducing sugars are a class of carbohydrates or sugars that include free aldehyde or ketone groups and are capable of donating electrons to another molecule. Since the binder composition is free of reducing sugars, the binder composition cannot participate in the Maillard reaction, which is a process that occurs when a reducing sugar reacts with an amine. The Maillard reaction produces a brown binder composition, which is undesirable for the subject binder composition.

[0064] In any of the exemplary embodiments, the polyol may include at least one carbohydrate that is of natural origin and derived from renewable resources. For example, the carbohydrate may be sourced from plant sources such as beans, maize, corn, waxy corn, sugar cane, sorghum, white sorghum, potatoes, sweet potatoes, cassava, rice, glutinous rice, peas, sago, wheat, oats, barley, rye, amaranth, and / or tapioca, as well as other plants with high starch content. The carbohydrate may also be sourced from products containing crude starch that are derived from plants containing residues of proteins, polypeptides, lipids, and low molecular weight carbohydrates. The carbohydrate may be selected from monosaccharides (e.g., xylose, glucose, and fructose), disaccharides (e.g., sucrose, maltose, and lactose), oligosaccharides (e.g., glucose syrup and fructose syrup), and polysaccharides and water-soluble polysaccharides (e.g., pectin, dextrin, maltodextrin, starch, modified starch, and mixtures thereof).

[0065] The carbohydrate may be a carbohydrate polymer having a number average molecular weight of from about 1,000 to about 8,000. Additionally, the carbohydrate polymer may have a dextrose equivalent (DE) value of from 2 to 20, from 7 to 11, or from 9 to 14. In at least one exemplary embodiment, the carbohydrate is a water-soluble polysaccharide such as dextrin or maltodextrin.

[0066] The polyol may be present in the binder composition in an amount up to about 50% by total solids weight, including but not limited to amounts up to about 40%, about 35%, about 30%, about 28%, and about 25% by total solids weight. In any of the exemplary embodiments, the polyol may be present in the binder composition in an amount of from 5.0% to about 50% by total solids weight, including but not limited to amounts of from 10% to 45%, from 15% to 40%, from 18% to 38%, from 20% to 35%, from 22% to 32%, from 20% to 50%, and from 17% to 27% (including all endpoints and subcombinations therebetween) by total solids weight. In any of the exemplary embodiments, the polyol may be present in an amount providing a ratio of carboxylic acid groups to hydroxyl groups of from 10:1 to 0.2:1 or from 3:1 to 0.5:1.

[0067] In various embodiments, the binder composition may include a surfactant. One or more surfactants may be included in the binder composition to aid in binder atomization, wetting, and interfacial adhesion.

[0068] The surfactant is not particularly limited and includes surfactants such as, but not limited to, ionic surfactants (e.g., sulfates, sulfonates, phosphates, and carboxylates); sulfates (e.g., alkyl sulfates, ammonium lauryl sulfate, sodium lauryl sulfate (SDS), alkyl ether sulfates, sodium lauryl polyoxyethylene ether sulfate, and sodium myreth sulfate); amphoteric surfactants (e.g., alkyl betaines such as lauryl betaine); sulfonates (e.g., sodium diisooctyl sulfosuccinate, perfluorooctane sulfonates, perfluorobutane sulfonates, and alkylbenzene sulfonates); phosphates (e.g., alkyl aryl ether phosphates and alkyl ether phosphates); carboxylates (e.g., alkyl carboxylates, fatty acid salts (soaps), sodium stearate, sodium lauroyl sarcosinate, carboxylate fluorosurfactants, perfluoromethyl formate, and perfluorooctanoate); cations (e.g., alkylamine salts such as laurylamine acetate); pH-dependent surfactants (primary amines, secondary amines, or tertiary amines); permanently charged quaternary ammonium cations (e.g., alkyltrimethylammonium salts, cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, cetylpyridinium chloride, and isooctylphenoxyethoxyethyl benzyldimethylammonium chloride); and zwitterionic surfactants, quaternary ammonium salts (e.g., lauryltrimethylammonium chloride and alkylbenzyldimethylammonium chloride), polyoxyethylene alkylamines, and mixtures thereof.

[0069] Suitable nonionic surfactants that can be used with the binder composition include polyethers (e.g., ethylene oxide and propylene oxide condensates, which include linear and branched alkyl and alkaryl polyethylene glycol and polypropylene glycol ethers and thioethers); alkylphenoxypoly(ethoxy)ethanol having an alkyl group containing about 7 to about 18 carbon atoms and having about 4 to about 240 ethyleneoxy units (e.g., heptylphenoxypoly(ethyleneoxy)ethanol and nonylphenoxypoly(ethyleneoxy)ethanol); polyoxyalkylene derivatives of hexitols, including sorbitan, sorbitol anhydride, mannitol sesquianhydride, and mannitol dianhydride; partial long-chain fatty acid esters (e.g., polyoxyalkylene derivatives of sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, and sorbitan trioleate); condensates of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol; sulfur-containing condensates (e.g., these condensates prepared by the condensation of ethylene oxide with a higher alkyl mercaptan such as nonyl, dodecyl, or tetradecyl mercaptan or an alkylphenol, wherein the alkyl group contains about 6 to about 15 carbon atoms); ethylene oxide derivatives of long-chain carboxylic acids (e.g., lauric acid, myristic acid, palmitic acid, and oleic acid, such as tall oil fatty acid); ethylene oxide derivatives of long-chain alcohols (e.g., octanol, decanol, lauryl alcohol, or cetyl alcohol); and ethylene oxide / propylene oxide copolymers. In one specific embodiment, the binder includes a nonionic surfactant in the form of an ethoxylated propoxylated polyaryl phenol ether block copolymer.

[0070] In any of the exemplary embodiments, the surfactant can include 1500, which is an ethoxylated propoxylated polyaryl phenol ether block copolymer commercially available from Stepan. Specifically, it has surprisingly been found that 1500 provides the desired hydrophilicity, which increases the water absorption capacity of the fiber-based product, while also having the thermal stability that enables it to withstand the heat treatment of the fiber-based product. Additionally, when compared to a fiber-based product that is otherwise identical but does not contain a surfactant, including 1500 in the fiber-based product demonstrates an improvement in bond strength and reduces the energy required to cure the binder. For example, when adding as little as 1.0% by weight of glass of 1500, an oven temperature of 460°F effectively achieves the same level of cure as a fiber-based product that is otherwise identical but does not contain a surfactant and is cured at 520°F. In addition to or alternatively, the surfactant can include one or more of the following: Dynol 607, which is 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol; 420, 440, and 465, which is an ethoxylated 2,4,7,9 - tetramethyl - 5 - decyne - 4,7 - diol surfactant (commercially available from Evonik Corporation, Allentown, Pa.); Stanfax (sodium lauryl sulfate); Surfynol 465 (ethoxylated 2,4,7,9 - tetramethyl - 5 - decyne - 4,7 - diol); Triton TM GR - PG70 (sodium 1,4 - bis(2 - ethylhexyl)sulfosuccinate); and Triton TM CF - 10 (poly(oxy - 1,2 - ethanediyl), α - (phenylmethyl)-ω-(1,1,3,3 - tetramethylbutyl)phenoxy).

[0071] Based on the total solids content in the binder composition, the surfactant may be present in the binder composition in an amount of from 0 wt% to about 10 wt%, from about 0.01 wt% to about 5.0 wt%, from about 0.05 wt% to about 2.5 wt%, from about 0.05 wt% to about 0.7 wt% or from about 0.1 wt% to about 0.7 wt%.

[0072] Optionally, the binder composition may contain an esterification catalyst, also known as a curing promoter. The catalyst may include inorganic salts, Lewis acids (i.e., aluminum chloride or boron trifluoride), Bronsted acids (i.e., sulfuric acid, p - toluenesulfonic acid, and boric acid), organometallic complexes (i.e., lithium carboxylate, sodium carboxylate) and / or Lewis bases (i.e., polyethyleneimine, diethylamine, or triethylamine). Additionally, the catalyst may include alkali metal salts of phosphorus - containing organic acids; specifically, alkali metal salts of phosphoric acid, hypophosphorous acid, or polyphosphoric acid. Examples of such phosphorus catalysts include, but are not limited to, sodium hypophosphite, sodium phosphate, potassium phosphate, disodium pyrophosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, potassium phosphate, potassium tripolyphosphate, sodium trimetaphosphate, sodium tetrametaphosphate, and mixtures thereof. Further, the catalyst or curing promoter may also be a fluoroborate compound, such as fluoboric acid, sodium tetrafluoroborate, potassium tetrafluoroborate, calcium tetrafluoroborate, magnesium tetrafluoroborate, zinc tetrafluoroborate, ammonium tetrafluoroborate, and mixtures thereof. Additionally, the catalyst may be a mixture of phosphorus and fluoroborate compounds. Other sodium salts (such as sodium sulfate, sodium nitrate, sodium carbonate) may also be used as catalysts or alternatively as co - catalysts.

[0073] The catalyst may be present in the binder composition in an amount of from about 0% to about 10% by weight of the total solids in the binder composition, including but not limited to from about 0 wt% to about 5 wt%, or from about 0.5 wt% to about 4.5 wt%, or from about 1.0 wt% to about 4.0 wt%, or from about 1.15 wt% to about 3.8 wt%.

[0074] Optionally, the binder composition may comprise at least one coupling agent. In at least one exemplary embodiment, the coupling agent is a silane coupling agent. The coupling agent may be present in the binder composition in an amount of from about 0.01% to about 5%, from about 0.01 wt% to about 2.5 wt%, from about 0.05 wt% to about 1.5 wt%, or from about 0.1 wt% to about 1.0 wt% based on the weight of the total solids in the binder composition.

[0075] Non-limiting examples of silane coupling agents useful in the binder composition may be characterized by functional groups alkyl, aryl, amino, epoxy, vinyl, methacryloxy, ureido, isocyanate, and mercapto. In an exemplary embodiment, the silane coupling agent includes a silane containing one or more nitrogen atoms having one or more functional groups such as amine (primary, secondary, tertiary, and quaternary amines), amino, imino, amido, imido, ureido, or isocyanato. Specific non-limiting examples of suitable silane coupling agents include, but are not limited to, aminosilanes (e.g., triethoxyaminopropylsilane; 3-aminopropyl-triethoxysilane and 3-aminopropyl-trihydroxysilane), epoxy trialkoxysilanes (e.g., 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane), methacrylyl trialkoxysilanes (e.g., 3-methacryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane), hydrocarbon trialkoxysilanes, aminotrihydroxysilanes, epoxy trihydroxysilanes, methacrylyl trihydroxysilanes, and / or hydrocarbon trihydroxysilanes. In one or more exemplary embodiments, the silane is an aminosilane such as γ-aminopropyltriethoxysilane.

[0076] Optionally, the binder composition may comprise one or more processing aids. The processing aids are not particularly limited as long as they function to facilitate the processing of fiber formation and orientation. The processing aids may be used to improve the uniformity of binder application distribution, reduce the binder viscosity, increase the post-formed ramp height, improve the uniformity of the vertical weight distribution, and / or accelerate the dehydration of the binder during formation and oven curing. Based on the total solids content in the binder composition, the processing aids may be present in the binder composition in an amount of from 0 wt% to about 15 wt%, from about 0.1 wt% to about 10.0 wt%, or from about 0.3 wt% to about 5.0 wt%, or from about 0.5 wt% to 2.0 wt%. In any of the exemplary embodiments, the aqueous binder composition may be substantially or completely free of any processing aids.

[0077] Examples of processing aids include defoamers such as emulsions and / or dispersions of mineral oil, paraffin oil or vegetable oil; dispersions of siloxanes, polydimethylsiloxane (PDMS) fluids and silica hydrophobized with polydimethylsiloxane or other materials. Other processing aids may include particles made of amide waxes such as ethylenebisstearamide (EBS) or hydrophobized silica.

[0078] Other processing aids may include viscosity modifiers which include, for example, glycerol, 1,2,4 - butanetriol, 1,4 - butanediol, 1,2 - propanediol, 1,3 - propanediol, poly(ethylene glycol) and combinations thereof.

[0079] Optionally, the binder composition may contain a dust inhibitor to reduce or eliminate the presence of inorganic and / or organic particles which may have an adverse effect in the subsequent manufacture and installation of the thermal insulation material. The dust inhibitor can be any conventional mineral oil, mineral oil emulsion, natural or synthetic oil, bio - based oil or lubricant such as, but not limited to, siloxanes and siloxane emulsions, polyethylene glycol, and any petroleum or non - petroleum oil with a high flash point to minimize the evaporation of the oil in the oven.

[0080] In any of the exemplary embodiments, the binder composition may contain up to about 10 wt% of the dust inhibitor, including up to about 8 wt% or up to about 6 wt% of the dust inhibitor. In any of the exemplary embodiments, the binder composition may contain between 0 wt% and 10 wt% of the dust inhibitor, including about 1.0 wt% to about 7.0 wt%, or about 1.5 wt% to about 6.5 wt%, or about 2.0 wt% to about 6.0 wt%, or about 2.5 wt% to 5.8 wt% of the dust inhibitor.

[0081] The binder composition further contains water to dissolve or disperse the active solids for application to the reinforcing fibers. The amount of water added is sufficient to dilute the binder composition to a viscosity suitable for its application to the reinforcing fibers and to obtain a desired solids content on the fibers. It has been found that the binder composition of the present invention may contain a lower solids content than conventional phenol - urea formaldehyde or carbohydrate - based binder compositions. Specifically, the binder composition may contain 3 wt% to 35 wt% of binder solids, including but not limited to 10 wt% to 30 wt%, 12 wt% to 20 wt% and 15 wt% to 19 wt% of binder solids.

[0082] The binder content on the product can be measured as loss on ignition (LOI). In any of the exemplary embodiments, the LOI on the mineral wool fibers can be from 0.1% to 50%, including but not limited to from 0.15% to 10%, from 0.2% to 10%, and from 0.3% to 5%. In some embodiments, the LOI on the mineral wool fibers can be from 1.0% to 5.0%, from 1.5% to 4.5%, from 2.0% to 4.0%, from 2.5% to 3.0%. As is known in the art, this loss on ignition can be considered the binder content / weight.

[0083] In any of the exemplary embodiments, the binder composition can further comprise one or more additives such as extenders, crosslink density enhancers, deodorants, antioxidants, dust inhibitors, biocides, moisture-proof agents, or combinations thereof. Optionally, the binder can comprise but is not limited to dyes, pigments, additional fillers, colorants, UV stabilizers, heat stabilizers, defoamers, emulsifiers, preservatives (e.g., sodium benzoate), corrosion inhibitors, and mixtures thereof. Other additives can be added to the binder composition for improving process and product performance. Such additives include lubricants, wetting agents, antistatic agents, and / or water repellents. The additives can be present in the binder composition in trace amounts (such as about 0.1 wt% of the binder composition) up to about 10% by weight of the total solids in the binder composition.

[0084] In any of the exemplary embodiments, the binder composition can be free or substantially free of monomeric carboxylic acid components. Exemplary monomeric polycarboxylic acid components include aconitic acid, adipic acid, azelaic acid, butanetetracarboxylic acid dihydrate, butanetricarboxylic acid, chlorendic anhydride, citraconic acid, citric acid, dicyclopentadiene-maleic acid adduct, diethylenetriaminepentaacetic acid pentasodium salt, dipentene-maleic anhydride adduct, endomethylenetetrachlorophthalic anhydride, fully maleated rosin, maleated tall oil fatty acid, fumaric acid, glutaric acid, isophthalic acid, itaconic acid, maleated rosin - oxidation of unsaturation to alcohol followed by oxidation to carboxylic acid with potassium peroxide, malic acid, maleic anhydride, mesaconic acid, oxalic acid, phthalic anhydride, polylactic acid, sebacic acid, succinic acid, tartaric acid, terephthalic acid, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, and benzene-1,3,5-tricarboxylic acid.

[0085] In any of the exemplary embodiments, the binder composition comprises at least one crosslinking agent, protective agent, polyol, nonionic surfactant, and has a pH of at least 4.

[0086] Table 2 :

[0087]

[0088] Figure 4An exemplary method for producing mineral wool products according to various embodiments is outlined. A melt of the raw mineral material is prepared in a reservoir 12, and the melt stream 14 is dropped into a spinner 16 (such as a centrifugal spinner), where the melt is fibrillated and blown into a collection chamber 18, thereby forming a mineral wool web on a collection belt 20. A binder composition containing a surfactant can be applied to the mineral wool fibers before collection onto the collection belt, during collection of the fibers, or after formation of the mineral wool web. The binder composition can be applied to the mineral wool fibers by known means (such as, for example, by spraying). Although Figure 4 not shown in, in some embodiments, the binder-coated mineral wool web can pass through a crimper to change the orientation of the fibers. The binder-coated mineral wool web is then heated in a conventional curing oven to cure the binder-coated mineral wool web, thereby forming a mineral wool product. The mineral wool web can be subjected to compression to obtain a desired final product thickness.

[0089] Curing can be carried out in a curing oven at a conventional temperature (such as, for example, from about 200 °C to about 600 °C, such as from about 225 °C to about 550 °C and from about 400 °C to about 525 °C). In a specific embodiment, curing is carried out at a temperature of about 450 °F to about 480 °F and effectively bonds the mineral wool fibers.

[0090] Returning to Figure 1 , during or after the formation of the cube 100, one or more holes 112 are formed in the upper surface 102 of the cube 100, and one or more grooves 114 or other channels are formed in the lower surface 104 of the cube 100. For example, the holes 112 and the grooves 114 can be formed by removing (such as, cutting) material from the cube 100. In some exemplary embodiments, the cube 100 includes a plurality of holes 112. In some exemplary embodiments, the first hole has a different size from the second hole. The shape and size of each of the holes 112 are designed to receive a plug containing seeds that may have started the growth process. The size of the cube 100 is designed to allow the plant to continue soilless growth.

[0091] Water and nutrients can be delivered to the cube 100 by applying (such as, dripping) a water supply source onto the upper surface 102 of the cube 100 or by adding water to a support tray on which the cube 100 is placed. This supply water containing nutrients is spread through the cube 100 in such a way that it can be absorbed by the roots of the plant. For example, when water is added to the support tray, the water moves into the cube 100 by capillary action and throughout the cube. The excess supply water eventually reaches the lower surface 104 of the cube 100, where the grooves 114 facilitate its drainage.

[0092] After the plant reaches a specific growth threshold, it is separated from the cube 100, and at least a portion of its root system remains in the cube 100.

[0093] In some exemplary embodiments, the sheath 110 or other wrapping material or container surrounds at least a portion of the cube 100, such as the side surface 106. The sheath 110 can contribute to the strength of the cube 100 (i.e., mechanical support) and / or provide other beneficial effects, such as retaining water within the cube 100. In some exemplary embodiments, the sheath 110 is made of a rigid or semi-rigid material that is easy to compost. For example, a thick paper or cardboard outer shell can be used.

[0094] In some exemplary embodiments, the sheath 110 is a sheet or wrapping material that is dissolvable over time, such as a degradable polymer (e.g., PVOH)-based film. In this case, the sheath 110 is formed to maintain its strength during the growth period associated with the plant and / or the useful life of the cube 100 (e.g., about 3 months), and then decomposes during a subsequent time period (e.g., about 3 months to about 6 months). Different plants have different growth periods. In some exemplary embodiments, the growth period associated with the plant ranges from 1 week to 19 months. In some exemplary embodiments, the growth period associated with the plant ranges from 8 days to 15 days, 2 months to 19 months, or 3 months to 4 months. In some exemplary embodiments, the growth period associated with the plant ranges from 14 months to 18 months. The useful life of the cube 100 is typically engineered to correspond to (if not exceed) the growth period of the specific plant to be cultivated therein.

[0095] Compared to competing products that include alternative binder compositions, the fiber-based matrix products produced according to the various embodiments described herein exhibit comparable or improved bond strength, compressive strength, and puncture resistance. It has been found that the bond strength is related to the processability of the board. Specifically, boards with low bond strength tend to fray during cutting, stick to the cutting tool, and cause fibers to be left behind, rather than leaving a clean cylindrical hole when cutting a hole in the middle of a fiber-based product. Compressive strength is important for enabling the fiber-based matrix product to withstand handling during use without significant damage. For example, both automated inoculation and selection can involve the use of machines that can subject the growth substrate to significant pressure and force, making compressive strength an important mechanical property of fiber-based products. Additionally, it has been found that compressive strength affects the water retention capacity of the final product.

[0096] In addition, to optimize plant growth, growers typically pre-set rooms with different lighting, temperature, humidity, and nutrient solution conditions. To provide these conditions to the plants, the grower grabs each growth medium on which a plant is growing one by one and moves it to a different room. A puncture test can simulate finger puncture in the product. Puncturing can break the fibers and thus damage the roots growing thereon, which can affect plant health.

[0097] The bond strength is measured by gluing a 6"×6" sample from side to side to two 6"×7" wooden boards using hot melt adhesive. The sample is then placed in an Instron equipped with a 1 kN load cell and pulled in opposite directions. The reported result is the amount of lb / ft2 required to break the bond, as evidenced by the sample breaking in the middle. In various embodiments, the bond strength of the fiber-based substrate product is greater than about 150 lb / ft 2 . For example, the bond strength can be about 150 lb / ft 2 to about 250 lb / ft 2 , about 150 lb / ft 2 to about 225 lb / ft 2 , about 160 lb / ft 2 to about 225 lb / ft 2 , about 170 lb / ft 2 to about 225 lb / ft 2 , or about 170 lb / ft 2 to about 200 lb / ft 2 .

[0098] The compressive strength of the sample is measured and tested using the standard ASTM C165 test method. The fiber-based substrate products formed according to the various embodiments described herein exhibit at least 100 lb / ft 2 , including at least 200 lb / ft 2 , at least 300 lb / ft 2 , at least 400 lb / ft 2 , at least 500 lb / ft 2 or at least 600 lb / ft 2 of compressive strength.

[0099] The puncture resistance of the sample is measured and tested using a dual-column Instron with a 10 KN load cell. A 1 / 2-inch diameter puncture fixture is placed in the Instron and the sample is punctured one by one on each side. The puncture fixture travels 1 inch deep into the material. The reported value is the amount of lb / ft2 required to break / puncture the fibers. The fiber-based substrate products formed according to the various embodiments described herein exhibit at least 2.5 lb / ft 2, including at least 3 lb / ft 2 , at least 4 lb / ft 2 , at least 5 lb / ft 2 , at least 6 lb / ft 2 or at least 7 lb / ft 2 of puncture resistance.

[0100] In addition, for a 6 pcf board, a fiber-based matrix product formed according to various embodiments described herein may exhibit an average settling time of less than or equal to 30 seconds. The settling time is tested by measuring the amount of time it takes for a 4 in. x 4 in. x 4 in. sample to settle in water at room temperature, a 6 in. x 6 in. x 6 in. sample to settle in water at room temperature, or a 2.5 in. x 4 in. x 4 in. sample to settle in water at room temperature, in triplicate, and is a measure of the rate at which the fiber-based matrix product absorbs water, and the reported value is the average of the samples tested in triplicate. For example, for a 6 pcf board, a mineral wool growing medium product has a settling time of less than or equal to 30 seconds, including less than or equal to 29 seconds, less than or equal to 28 seconds, less than or equal to 27 seconds, less than or equal to 26 seconds, less than or equal to 25 seconds, less than or equal to 24 seconds, or less than or equal to 23 seconds. In some exemplary embodiments, the mineral wool growing medium product has a settling time of from about 5 seconds to about 30 seconds, from about 6 seconds to about 28 seconds, from about 7 seconds to about 26 seconds, from about 8 seconds to about 24 seconds, or from about 8 seconds to about 23 seconds (including any and all ranges and subranges therein).

[0101] In addition, when measured using the free drainage test method, a fiber-based matrix product formed according to various embodiments described herein may exhibit a water retention capacity of at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90% or at least 95% of the water volume. For this test, the product is saturated (allowed to settle until fully submerged), and then drained on a grid without applying any mechanical stress that could affect drainage. These values are calculated by weight.

[0102] Free drainage and thick plate drainage use the following equation:

[0103]

[0104] where w f is the final weight of the sample after drainage in g, w i is the dry weight of the sample in g, l is the length of the sample in cm, w is the width of the sample in cm, t is the thickness of the sample in cm, and v c is the diced volume in cm 3 3 (if a finished product).

[0105] Example

[0106] The present invention has been generally described and can be further understood by reference to certain specific embodiments illustrated below. These embodiments are provided for illustrative purposes only and are not intended to be comprehensive or restrictive, unless otherwise stated.

[0107] Example 1

[0108] Six different binder compositions were applied to the mineral wool fibers at a throughput of 4.5 tons per hour via a typical mineral wool production line. Each of the binder compositions is formaldehyde-free, but none of these binder compositions contain a surfactant. Each of the binder compositions contains polyacrylic acid and sorbitol and contains a certain amount of ammonium hydroxide to bring the pH to 5. Each of the binder compositions (Binder A - Binder F) is listed in Table 3 below:

[0109] Table 3 :

[0110] Polyacrylic acid Sorbitol Citric acid Glycerol Binder A 70 30 0 0 Binder B 70 30 0 10 Binder C 60 40 0 0 Binder D 60 40 0 10 Binder E 50 50 0 0 Binder F 30 40 30 0

[0111] In Table 3, the polyacrylic acid, sorbitol, and citric acid in the binder compositions are reported in parts by weight based on solids.

[0112] The mineral wool boards were then fed into a curing oven. The curing oven temperature was set to 232 °C to 287 °C (450 °F to 550 °F). The final mineral wool boards were approximately 76.2 mm (3 inches) thick and had a density of approximately 96 Kg / m 3 (6 pcf).

[0113] The mineral wool boards were collected and the water absorption and bond strength tests were performed in triplicate. As Figure 5 shown, in the absence of a surfactant, each of the binder compositions exhibited a water absorption of less than 10%. This is important because even though the chemical compositions of these binders are hydrophilic in nature, they do not provide the desired wettability for the product. Additionally, as Figure 6 shown, the bond strength of each of the binder compositions was less than 90 lb / ft 2 , where only Binder E exhibited a bond strength greater than 55 lb / ft 2 . This demonstrates that the individual binders do not provide the desired mechanical strength.

[0114] Next, to determine whether adding a surfactant to the binder composition can help distribute the binder throughout the mineral wool fibers, 0.7 wt% of STEP-FLOW 1500 (an ethoxylated propoxylated polyaryl phenol ether (nonionic) surfactant from Stepan) was added to Binder B. Boards containing the surfactant-containing binder were prepared as described above, except that Sample 1 was cured at a curing temperature of 500°F, while Comparative Sample 1 (Binder B only; no surfactant) and Sample 2 were cured at a curing temperature of 550°F. As Figure 7 shown, adding 0.7 wt% of the nonionic surfactant increased the bond strength of both Sample 1 and Sample 2 compared to Comparative Sample 1. More specifically, comparing Sample 2, which was cured at the same temperature, with Comparative Sample 1, the nonionic surfactant increased the bond strength of the binder by more than four times.

[0115] Example 2

[0116] Based on the observations of Example 1, the STEP-FLOW 1500 surfactant was added at 0.7 wt% to other Binder B or Binder E. Boards including the surfactant-containing binder were prepared as described above and cured at the temperatures reported in Table 4.

[0117] Table 4 :

[0118] Binder composition Curing temperature (℉) Sample 3 Binder B 510 Sample 4 Binder B 450 Sample 5 Binder E 450 Sample 6 Binder E 510

[0119] The water absorption, water retention capacity, compressibility, and compressive resistance of each of Samples 3 to 6 were measured, and the results are shown in Figures 8 to 11 . Each of the cured samples had a pH between about 7.0 and about 7.6.

[0120] As Figure 8As shown, when cured at 450°F, the mineral wool boards (Samples 4 and 5) prepared with Binders B and E and 0.7 wt% surfactant exhibited a settling time of less than 30 seconds. However, Samples 3 and 6 cured at 510°F exhibited significantly longer settling times. Thus, it was noted that curing the fiber-based matrix product at a temperature between about 450°F and about 480°F would result in a suitable settling time. Notably, no smoke was observed at 510°F. Smoke typically appears at higher curing oven temperatures. Specifically, in the case of conventional PUF binders, smoke can be observed at curing temperatures greater than 480°F. In the manufacturing facility, the temperature and fan settings were increased to compensate for products with insufficient curing that may be caused by furnace belt blockages. However, the ability to increase the temperature and fan settings was limited based on the increase in smoke. Thus, for the various embodiments, the absence of smoke up to 510°F gives a larger window within which the settings can be adjusted to achieve a balance between the manufacturing process and the final product performance.

[0121] Go to Figure 9 , the water retention capacity of Samples 3 to 6 is given. Different from the settling time, the water retention capacity of the mineral wool boards is not affected by the curing temperature, and each of Samples 3 to 6 exhibited a water retention of greater than 90%. From Figure 8 the results shown, this indicates that the curing temperature affects the water absorption rate, but once the mineral wool product is saturated, it can retain the same amount of water as other aspects of the mineral wool product cured at different temperatures. It is assumed that the surfactant contributes to the water absorption rate, but the material porosity supports the water retention capacity. In addition, the water retention capacity of each of Samples 3 to 6 is similar to that of commercially available mineral wool products prepared with formaldehyde-containing binders.

[0122] The compressive strength of the samples is shown in Figure 10 , and the puncture resistance of the samples is shown in Figure 11 . Each of Samples 3 to 6 exhibited a compressive stress greater than 100 lb / ft 2 , and more specifically greater than about 395 lb / ft 2 , and a puncture resistance greater than 2.5 lb / ft 2 , and more specifically greater than 6 lb / ft 2 . The puncture resistance of each of Samples 3 to 6 is up to three times that exhibited by commercially available mineral wool products prepared with formaldehyde-containing binders.

[0123] Considering that surfactants are amphiphilic molecules (e.g., they have a hydrophilic side and a hydrophobic side), surfactants can be mixed with other liquids and disrupt their intermolecular interactions, thus helping them spread over the surface more quickly. They can also adsorb at the interfaces of different molecules to provide the same effect. The above binder composition is known to be hydrophilic, but lacks a suitable sedimentation time without the inclusion of surfactants. The surface tension of various samples was measured to confirm that the addition of surfactants to the binder composition is the main factor in reducing the surface tension of water when water comes into contact with the product.

[0124] Comparative Sample 2 contains the formaldehyde-free binder as described above without the addition of surfactants. Samples 7, 8, and 9 contain the STEP-FLOW 1500 surfactant at concentrations of 1.5%, 2.25%, and 3% respectively. At a temperature between 70°F and 75°F and a humidity between 40% and 60%, for samples with a volume of approximately 8 μL, the surface tension was measured in triplicate using the pendant drop method over a time period of 0 seconds to 180 seconds (3 minutes). The average value (in N / m) for each sample is shown in Figure 12 the

[0125] As Figure 12 shown, an increase in surfactant concentration directly corresponds to a decrease in surface tension. Thus, without being bound by theory, it is believed that surfactants improve the water absorption rate and sedimentation time of the product by reducing the surface tension.

[0126] Example 3

[0127] To further evaluate the performance of the fiber-based substrate product in horticultural applications (e.g., as a plant substrate), growth tests were conducted using the fiber-based substrate product according to the embodiments herein and two commercially available mineral wool / rock wool products with phenol-urea formaldehyde binders. The growth tests were conducted by Summit Concentrates, a third-party licensed cultivation facility in central Colorado. All samples were collected in accordance with the 2021 Colorado Department of Public Health and Environment Sampling Requirements.

[0128] The experimental design included three groups of growth media on six vertical hydroponic benches evenly distributed in a growth chamber. The vertical hydroponic benches adjacent to the walls were excluded from the study to minimize the risk of microclimate effects associated with the test space. All samples were treated the same and managed equally. These three groups included 564 plants of six different varieties. The control group (Group A) included VIDA WOOL with a diameter of 1.2" and a height of 1.5"TM Plants that start in a cylindrical plug and, after the cloning stage, are transplanted into VIDAWOOL TM In Block 190 (6"×6"×5.3") (both are commercially available from Owens Corning, Toledo, OH). Group B includes plants that start in another commercially available mineral wool / rock wool product that has a phenol-urea formaldehyde binder and is in the form of 1.5" blocks, and after the cloning stage, the plants are transplanted into 6" blocks formed with the same binder as the 1.5" blocks. Group C includes plants that start in a cylindrical plug with a diameter of 1.2" and a height of 1.5" formed with the above-mentioned binder E and, after the cloning stage, are transplanted into a block (6"×6"×5.3") formed with binder E.

[0129] Each stage of plant growth requires a specific set of conditions (such as fertilizers, pH adjustment solutions, temperature, humidity, and water / block saturation) to achieve optimal growth performance. To illustrate these differences, each stage is carried out in a different room. A fixed fertilizer formulation mixture is used to irrigate the plants from a reservoir throughout the automated system. The fertilizer mixture includes a mixture of silica and key nutrients, which include but are not limited to calcium nitrate, ammonium nitrate, nitric acid, potassium hydroxide, phosphoric anhydride, and magnesium sulfate. Dilute sulfuric acid is used to adjust the pH. Tap water from Aurora is used after being filtered through a 1μm sediment filter and an activated carbon filter.

[0130] Six cultivars were selected for the study. All clones were obtained from mother plants. The selected cultivars represent a cross-section of the typical ranges of internode spacing, product yield, leaf surface area, and other variations expected in the market and are cultivar-specific. The cultivars selected are commercially known as Apple Fritter (APP), Divine Kush Breath (DKB), IceCream Cake (ICC), Melon Juice (MLJ), Tropical Banana (TBN), and Tropical Diesel (TOD).

[0131] During the cloning stage, all clones are covered with a humidity hood for the first 48 hours and the humidity hood is removed for the remainder of the cloning stage. The temperature and relative humidity are kept constant. The cloning stage lasts approximately two weeks. The healthiest clones are selected from the group according to conventional cultivation practices to eliminate any potential confounding effects of genetically inferior plants on the final test results. At the end of the cloning stage, the plants have developed roots from the plugs and are transplanted into blocks and then moved to the vegetative room.

[0132] During the vegetative stage, the temperature and relative humidity are kept constant, and carbon dioxide is added to the air. The vegetative stage lasts for about six weeks.

[0133] Finally, the plants enter the flowering stage and are moved to the flowering room. The temperature and humidity levels are varied, each decreasing during the final stage of the entire growth cycle. The air is supplemented with carbon dioxide. All plants are harvested within three days. Each sample is cut at the base of the stem and weighed using an OHAUS TM RANGER TM 3000 scale, accurate to 0.1 g. Each plant is treated individually after harvest, and data for each individual plant are captured until they are dry. After drying for seven to nine days, the individual plants are pooled into bins after additional data capture. The bins are treated in the same way to achieve consistent final product quality and uniformity.

[0134] More specifically, for each plant, the stem diameter at the base of the plant before harvest (from diameter), the total wet weight of the above-ground portion of each plant immediately after harvest, the dry available mass (dry flowers processed for extraction). Statistical analysis is performed using JMP TM Pro statistical software. The results are shown in Table 5.

[0135] Table 5 :

[0136]

[0137] * Significantly different from the other two groups.

[0138] ** Significantly different from Group A, but not significantly different from Group B.

[0139] As shown in Table 5, JMP TM Pro analysis (using one-way analysis of variance (ANOVA) test) shows a statistically significant effect of the growth medium on the average stem diameter (F-ratio = 6.8099, p = 0.0012, N = 564). After further analysis, using Tukey-Kramer HSD, there is a significant difference between Group C and Group A and Group B (p = 0.0042). However, there is no significant difference between Group A and Group B (p = 1.00).

[0140] Regarding the wet weight, the ANOVA test shows a statistically significant effect of the growth medium (F-ratio = 3.3266, p = 0.0366, N = 564). After further analysis, using Tukey-Kramer HSD, there is a significant difference between Group C and Group A (p = 0.0295). This indicates that the growth medium according to the various aspects described herein can increase plant biomass when compared to other commercially available growth medium alternatives.

[0141] In addition, ANOVA tests showed a statistically significant effect of the growth medium on the available plant dry weight (F-ratio = 3.8242, p = 0.0224, N = 532). After further analysis, using Tukey-Kramer HSD, there was a significant difference between Group C and Group A (p = 0.0320).

[0142] Using JMP TM Pro binary fitting to analyze any correlation between wet weight and available plant dry weight showed a strong correlation (R 2 = 0.852). When referring to their yields, since growers in the industry use available plant dry weight as a key metric, this supports the previous data, indicating statistically significantly higher performance relative to other commercially available mineral growth media.

[0143] Quality characteristics were also analyzed to examine the effect of the growth medium on the quality of the plants grown. Specifically, growers aim to optimize their operations to produce high THC concentrations and rich terpene profiles. THC is the main psychoactive component, and terpenes are the main components responsible for the plant's aroma. The highest concentrations of THC and terpenes are present in the trichome structures, which are resin glands highly accumulated in the flowers and surrounding leaves. The terpene profile gives each cultivar its unique odor and taste.

[0144] Terpene concentrations were measured and analyzed using gas chromatography - mass spectrometry (GC-MS). Gravimetric analysis of fifteen different terpenes in both APP and TBN plants grown in each type of growth medium (N = 162) showed no statistical significance in terpene concentrations across different growth media, indicating that the growth media described herein have no adverse effect on terpene profiles compared to other commercially available mineral growth media. The total terpenes in plants grown using Group A medium were 20.704 mg / g, Group B was 21.232 mg / g, and Group C was 21.670 mg / g. In addition, using JMP TM Pro's ANOVA test analyzed the total terpenes. The analysis showed no statistically significant effect of the growth medium on the total terpenes (F-ratio = 1.1536, p = 0.3181, N = 163). After further analysis, using Tukey-Kramer HSD, there were no significant differences in total terpenes between Group A to Group C (p = 0.0320).

[0145] The potencies of APP and TBN plants were measured and analyzed using high performance liquid chromatography (HPLC). Potency is a measure of the δ-9-THC concentration and is usually reported as a weight percentage. THC is the psychoactive component in the plant, however most THC exists in the form of the precursor molecule THCA (non-psychoactive). Potency (total THC%) is calculated from the concentrations of the two molecules according to the following equation:

[0146] Total THC% = THC% + (THCA% × 0.877).

[0147] This conversion factor accounts for the weight of CO2 lost through thermal decarboxylation during testing.

[0148] Using JMP TM Pro's ANOVA test analyzed the percentage of potency. The analysis showed that the growth medium had no statistically significant effect on the percentage of potency (F-ratio = 1.7168, p = 0.1829, N = 163). Specifically, Group A had a percentage of potency of 19.1%, Group B had a percentage of potency of 19.6%, and Group C had a percentage of potency of 19.6%. After further analysis, using Tukey-Kramer HSD, the data confirmed that there were no significant differences between Group A and Group C in terms of the percentage of potency, as indicated by a p-value less than 0.05.

[0149] Therefore, the analysis of the quality characteristics shows comparable performance of the growth medium formed using a formaldehyde-free binder and a non-ionic surfactant (e.g., 1500) compared to commercially available alternatives, thus demonstrating that the growth medium described herein is a suitable alternative for plant growth and provides plants of comparable quality while reducing or eliminating the presence of chemicals harmful to human consumption.

[0150] It should be understood that many more detailed aspects of the exemplified products and processes are largely known in the art and have been omitted for the purpose of presenting the general inventive concept concisely. Although the present invention has been described in connection with specific devices, materials, and embodiments, from the foregoing description, those skilled in the art can readily determine the basic features of the disclosure and can make various changes and modifications to adapt to various uses and characteristics without departing from the essence and scope of the invention as described above and set forth in the appended claims.

Claims

1. A mineral wool plant substrate, the mineral wool plant substrate comprising mineral wool fibers bonded by a binder, the binder being formed from an aqueous binder composition, the aqueous binder composition comprising: A crosslinking agent comprising at least two carboxylic acid groups; A polyol component having at least two hydroxyl groups; An amino protecting agent; and 0.05 wt% to 0.7 wt% of a nonionic surfactant.

2. The mineral wool plant substrate according to claim 1, wherein the nonionic surfactant comprises an ethoxylated propoxylated polyaryl phenol ether.

3. The mineral wool plant substrate according to claim 1 or claim 2, wherein the amino protecting agent comprises at least one of an amine protecting agent or an ammonium protecting agent.

4. The mineral wool plant substrate according to any one of claims 1 to 3, wherein the mineral wool plant substrate is substantially free of formaldehyde.

5. The mineral wool plant substrate according to any one of claims 1 to 4, wherein the mineral wool plant substrate has a density in the range of 30 kg / m 3 to 150 kg / m 3 range.

6. The mineral wool plant substrate according to any one of claims 1 to 5, wherein the mineral wool plant substrate has a loss on ignition of 1.0% to 5.0%.

7. The mineral wool plant substrate according to any one of claims 1 to 6, wherein the mineral wool plant substrate exhibits a bond strength of about 150 lb / ft 2 to about 250 lb / ft 2 .

8. The mineral wool plant substrate according to any one of claims 1 to 7, wherein for a 6 pcf product, the mineral wool plant substrate exhibits a settling time of less than 30 seconds.

9. The mineral wool plant substrate according to any one of claims 1 to 8, wherein the mineral wool plant substrate exhibits a water absorption rate of greater than 50%.

10. The mineral wool plant substrate according to any one of claims 1 to 9, wherein the mineral wool plant substrate exhibits a compressive strength of at least 100 lb / ft 2 3.

11. The mineral wool plant substrate according to any one of claims 1 to 10, wherein the mineral wool plant substrate exhibits a puncture resistance of at least 2.5 lb / ft 2 3.

12. A method for manufacturing a fiber-based plant substrate, the method comprising: Collecting multiple inorganic fibers on a substrate; Applying an aqueous binder composition to the aggregate of inorganic fibers to form binder-coated inorganic fibers, the aqueous binder composition comprising: A crosslinking agent comprising at least two carboxylic acid groups; A polyol component having at least two hydroxyl groups; An amino protecting agent, wherein the amino protecting agent comprises at least one of an amine protecting agent or an ammonium protecting agent; And 0.05 wt% to 0.7 wt% of a nonionic surfactant based on the total weight of the aqueous binder composition; Curing the aqueous binder composition at a temperature below 510°F to form a fiber-based plant substrate, wherein the aqueous binder composition is free of formaldehyde.

13. The method according to claim 12, wherein the polyol component comprises a sugar alcohol, an alkanolamine, pentaerythritol, or a mixture thereof.

14. The method according to claim 12 or claim 13, wherein the amino protecting agent comprises ammonium hydroxide.

15. The method according to any one of claims 12 to 14, wherein the aqueous binder composition has an uncured pH of 4.2 to 6.

5.

16. The method according to any one of claims 12 to 15, wherein the nonionic surfactant comprises an ethoxylated propoxylated polyaryl phenol ether.

17. The method according to any one of claims 12 to 16, wherein the aqueous binder composition is cured at a temperature of about 450°F to 480°F.

18. A mineral wool plant substrate, the mineral wool plant substrate comprising mineral wool fibers bonded by a binder, the binder being formed from an aqueous binder composition, the aqueous binder composition comprising: At least 50% by weight of polyacrylic acid, a salt of polyacrylic acid, an anhydride of polyacrylic acid or a resin based on polyacrylic acid, based on the total weight of solids in the aqueous binder composition; From about 5% to about 50% by weight of a sugar alcohol, based on the total weight of solids in the aqueous binder composition; Ammonium hydroxide; and From about 0.05% to about 0.7% by weight of an ethoxylated propoxylated polyaryl phenol ether.

19. The mineral wool plant substrate according to claim 18, wherein the mineral wool plant substrate is in the form of plugs, blocks, or slabs.

20. The mineral wool plant substrate according to claim 18 or claim 19, wherein for a 6 pcf product, the mineral wool plant substrate exhibits a settlement time of less than 25 seconds, a water absorption rate of greater than 90%, a compressive strength of at least 400 lb / ft 2 and a puncture resistance of at least 7 lb / ft 2 .

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