Soy flour dispersions for medium density fiberboard and high-density fiberboard

Abstract

The present disclosure relates to an aqueous dispersion binding agent for use in the manufacture of medium density fiberboard (MDF) and high-density fiberboard (HDF). The aqueous binding agent comprises a polyol component, soy flour, a sulfite agent, a surfactant, and an anti-foam agent. The present disclosure also provides a method for making MDF and HDF using an aqueous binding agent.

Description

PT-1866-WO-PCT SOY FLOUR DISPERSIONS FOR MEDIUM DENSITY FIBERBOARD AND HIGH- DENSITY FIBERBOARD CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 562,032, filed March 6, 2024, and U.S. Provisional Application No.63 / 763,509, filed February 26, 2025, each of which is incorporated by reference herein in its entirety. BACKGROUND

[0002] Medium density fiberboard (MDF) and high-density fiberboard (HDF) are engineered wood products that are utilized in furniture, flooring, cabinetry, and other end-use applications. Historically, wood adhesives such as phenol-formaldehyde resins (PF) and urea- formaldehyde resins (UF) have been utilized. There are at least two concerns with PF and UF resins. First, volatile organic compounds (VOC), such as formaldehyde, are generated during the manufacture of MDF and HDF. Additionally, formaldehyde may be released from boards made from UF when the boards are exposed to high heat and humidity. The formaldehyde released from board made from PF and UF are undesirable. SUMMARY OF THE INVENTION

[0003] In one aspect, an aqueous dispersion binding agent is described for use in the manufacture of MDF and HDF engineered wood products (collectively “Fiberboard”). The binding agent has a low viscosity that is necessary for the binding agent to effectively be added just prior to or into the blow-line of a Fiberboard production facility. The aqueous dispersion binding agent exhibits a relatively long settling time to allow it to effectively be used in a Fiberboard manufacturing line. The aqueous dispersion binding agent comprises: at least 40 total weight percent based on the dry substance content of the binding agent of a polyol component (selected from the group consisting of a glycerol component, sorbitol, and mixtures thereof) based on the dry substance content of the binding agent (for example, at least 42 weight percent, at least 43 weight percent, at least 44 weight percent based on the dry substance content of the binding agent); the Glycerol and sorbitol in a weight ratio of from 0:1 to 1:0 glycerol to sorbitol (for example, from 1:1 glycerol to sorbitol to 4:1 glycerol to sorbitol (and sometimes a weight ratio of from 3:2 to 3.6:1 glycerol to sorbitol);PT-1866-WO-PCT at least 37 weight percent based on the dry substance content of the binding agent of soy flour (e.g., from 40 weight percent to 60 weight percent, from 42 weight percent to 55 weight percent, from 45 weight percent to 54 weight percent based on the dry substance content of the binding agent); the soy flour having a protein dispersibility index (PDI) of at least 70 (for example, at least 75, at least 80, at least 85, or at least 90) and having a protein content of from 35 wt% to 65 wt% (for example, from 40 wt% to 60 wt%); a sulfite agent, selected from the group consisting of: sodium sulfite, sodium bisulfite, sodium metabisulfite, or mixtures thereof; a surfactant; and an anti-foam agent; wherein aqueous dispersion binding agent has a dry substance content of from about 38 percent by weight to about 47 percent by weight (for examples, from 39 percent by weight to 46 percent by weight, from 40 percent by weight to 45 percent by weight), wherein the aqueous dispersion binding agent has a pH from about 6 to about 10, or from about 7 to about 9 (for example, from about 7.5 to 8.5), and wherein the aqueous dispersion binding agent has a viscosity less than 2000 centipoise at 23°C (for example, less than 1500 centipoise, or less than 1000 centipoise at 23°C, less than 400 centipoise at 23°C).

[0004] The pH of the aqueous dispersion binding agent is achieved by the addition of a base. Typically, the base comprises NaOH, magnesium oxide, KOH or mixtures thereof. Preferably, the base comprises NaOH present at concentrations of from 0 to 0.5 wt% of the aqueous dispersion binding agent, preferably present at concentrations of from 0.00 to 0.2 wt%. In some aspects the base can include another strong base (for example, Ca(OH)2or another base that completely dissociates in solution) or sodium carbonate. In some aspects ammonium or ammonia hydroxide can be used as the base, but these are not preferred because of their propensity to generate gaseous ammonia.

[0005] Soy flour has a tendency to make very high viscosity aqueous dispersions that do degrade / partition fairly quickly. The above-described aqueous dispersion binding agent not only has a relatively lower viscosity, but also remains stable without significant degradation / partition for a relatively long time, even at relatively high dry substance content levels described herein. Typically, the dispersion will remain stable for at least 1 hour, preferably at least 2 hours and more preferably at least 3 hours. In some preferred aspect the dispersion will remain stable, meaning without visible phase separation for at least 24 hours, and preferably at least 2 weeks. Due to the thixotropic behavior of the dispersion, it is beneficial to stir the dispersion for at least 10 minutesPT-1866-WO-PCT at low to moderate shear before processing. After around 1 week first molding phenomena can be observed, at least if the conservation is not optimized. Additionally, the aqueous dispersion binding agent can be readily agitated or mixed and put back into a well dispersed form, even if the dispersion has degraded / partitioned.

[0006] The sulfite agent cleaves disulfide bond present in the soy protein contained in the soy flour; and the surfactant lowers the viscosity of the overall composition and stabilizes the aqueous dispersion. Both these factors contribute to lowering the viscosity of the aqueous dispersion binding agent to the desired levels.

[0007] The defoaming agent decreases the viscosity of the aqueous dispersion by reducing the foaming tendencies of the aqueous dispersion binding agent as it is being made and in use for making fiberboard panels and other articles of manufacture.

[0008] In another aspect, a method is described for making fiberboard using the aqueous dispersion binding agent. The method comprises: a) contacting the aqueous dispersion binding agent with a plurality of wood fibers; b) forming the composition from a) into a desired shape: and c) heating and applying pressure to the composition from step b) to form a fiberboard.

[0009] Preferably, the aqueous dispersion binding agent is contacted with the plurality of wood fibers by introducing the binding agent into the blowline upstream of the pressure reducing section of the blowline, or introducing the binding agent downstream of the refiner, but upstream of the blowline.

[0010] Typically, the aqueous dispersion binding agent is present in a range of from 3 parts to 25 parts per 100 parts dry weight of the dry weight of the plurality of wood fibers, or from 7 parts to 17 parts dry weight per 100 parts of the dry weight of the plurality of wood fibers, or from 8 parts to 17 parts dry weight per 100 parts of the dry weight of the plurality of wood fibers, or from 9 parts to 15 parts dry weight per 100 parts of the dry weight of the plurality of wood fibers.

[0011] Preferably, the method further comprises adding a swell-retardant component during the manufacture of fiberboard. Typically, the swell-retardant component comprises a wax. The wax typically in the form of an emulsion.

[0012] Typically, pressure is applied to the shape from step b) prior to, during or after heating step c); and preferably pressure is applied simultaneously with heat during step c).

[0013] Typically, the composition is heated to from 140°C to 260°C, preferably from 200°C to 250°C (for example, from 220°C to 240°C).PT-1866-WO-PCT

[0014] Heating the composition and applying pressure compacts the composition to form a board (or other shaped fiberboard item) and cure the binding agent.

[0015] Water is removed from the composition during step c). BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein.

[0017] FIG.1 is a description of the typical production process for a fiberboard. DETAILED DESCRIPTION OF THE INVENTION

[0018] Reference will now be made in detail to certain embodiments of the disclosed subject matter. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0019] In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0020] The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 90%, 95%, 99.5%, or 100%. The term “substantially free of” as used herein can mean having none or having a trivial amount of, such that the amount of material present does not affect the material properties of the composition including the material, such that about 0 wt% to about 5 wt% of the composition is the material, or about 0 wt% to about 1 wt%, or about 5 wt% or less, or about 0 wt%.

[0021] According to various aspects of the instant disclosure, an aqueous dispersion binding agent is described together with fiberboard and method for making such fiberboard (e.g., MDF and HDF).

[0022] The fiberboard can be used to make flooring, furniture, cabinets, etc.PT-1866-WO-PCT The aqueous dispersion binding agent:

[0023] The aqueous dispersion binding agent comprises: a polyol component; soy flour of at least 37 wt% to based on the dry substance content of the binding agent (e.g., from 40 weight percent to 60 weight percent of soy flour, from 42 weight percent to 55 weight percent, from 45 weight percent to 54 weight percent based on the dry substance content of the binding agent), the soy flour has a PDI of at least 70 (for example, at least 75, at least 80, at least 85, or at least 90) and has a protein content of from 35 wt% to 65 wt% (for example, from 40 wt% to 60 wt%); a sulfite agent, selected from the group consisting of: sodium sulfite, sodium bisulfite, sodium metabisulfite, or mixtures thereof; a surfactant; and an anti-foam agent; a biocide wherein the aqueous dispersion binding agent has a dry substance content of from about 38 percent by weight to about 47 percent by weight (for examples, from 39 percent by weight to 46 percent by weight, from 40 percent by weight to 45 percent by weight), wherein the aqueous dispersion binding agent has a pH from about 6 to about 10, or from about 7 to about 9 (for example, from about 7.5 to 8.5), and wherein the aqueous dispersion binding agent has a viscosity less than 2000 centipoise at 23°C (for example, less than 1500 centipoise, less than 1000 centipoise at 23°C, less than 400 centipoise at 23°C). Polyol component:

[0024] The polyol component is selected from the group consisting of a glycerol component, sorbitol, and mixtures thereof. The polyol component comprises at least 40 total weight percent based on the dry substance content of the aqueous dispersion binding agent (for example, at least 42 weight percent, at least 43 weight percent, at least 44 weight percent based on the dry substance content of the binding agent).

[0025] The glycerol component and sorbitol typically are present in a weight ratio of from 0:1 to 1:0 glycerol component to sorbitol (for example, from 0.1:1 to 1:0.1 glycerol component to sorbitol). In some instances, there is no sorbitol present, only glycerol component. And, in some instances, sorbitol is used at a glycerol component to sorbitol weight ratio of from 1:1 to 4:1 glycerol component to sorbitol (and sometimes a weight ratio of from 3:2 to 3.6:1 glycerolPT-1866-WO-PCT component to sorbitol)). The glycerol lowers the viscosity of the resulting aqueous dispersion binding agent, while assisting to maintain a higher dry solids content of the aqueous dispersion binding agent (e.g., the glycerol and a polyol in general also improves the bioresistance in the dispersion, the water resistance of the boards and reduces the viscosity of the dispersion without lowering the dry content.

[0026] The glycerol component may be in the form of crude glycerol. An example of a crude glycerol is a mixture including 10 to 20 wt% water (for example, 15 wt%), 3 wt% to 7 wt% NaCl (for example, 4 wt% to 5 wt%) and 75 wt% to 95 wt% glycerol (for example, 80 wt% to 90 wt%). A crude glycerol may include additional materials known to one of skill in the art.

[0027] In some aspects, the glycerol component can include less than 3 wt%, less than 2 wt%, or less than 1 wt% NaCl. In some aspects, the glycerol can be a technical grade glycerol that includes a high concentration of glycerol and less than 1 wt% methanol, less than 0.5 wt% methanol, or less than 0.1 wt% methanol and less than 1 wt% NaCl, less than 0.5 wt% NaCl, or less than 0.1 wt% NaCl. In some aspects, the technical glycerol includes at least 98 wt% glycerol. Crude glycerol is preferred because it is cheaper and the higher concentration of sodium chloride acts as a denaturant to the protein. Preferably sodium chloride concentration below 5% to prevent corrosion phenomena.

[0028] In some aspects, the glycerol need not be highly purified or refined. Crude forms of glycerol may also be employed. Soy Flour:

[0029] The soy flour typically comprises at least 37 weight percent based on the dry substance content of the aqueous dispersion binding agent (e.g., from 40 weight percent to 60 weight percent of soy flour, from 42 weight percent to 55 weight percent, from 45 weight percent to 54 weight percent based on the dry substance content of the binding agent). The soy flour typically has a protein dispersibility index (PDI) of at least 70 (for example, at least 75, at least 80, at least 85, or at least 90, and typically a PDI less than 95 (for example, a PDI of 90 or less) and typically has a protein content of from 35 wt% to 65 wt% (for example, from 40 wt% to 60 wt%).

[0030] Typically, soy flour is selected from one that passes through a screen sized 100- mesh screen to a 635-mesh screen or a 100-mesh screen to a 400-mesh screen. For example, the soy flour typically has a mesh size of from 100 to 300, or from 100 to 200.PT-1866-WO-PCT

[0031] The soy flour includes non-protein constituents such as a carbohydrate. It has been surprisingly and unexpectedly found that aqueous dispersion binding agent produces fiberboard panels having competitive properties to fiberboard made using UF Binder. Sulfite agent:

[0032] The sulfite agent typically comprises sodium sulfite, sodium bisulfite, sodium metabisulfite, or mixtures thereof. The sulfite agent typically comprises from 0.1 to 2.0 wt% of the dry substance content of the aqueous dispersion binding agent (for example, from 0.1 to 1.0 wt%, from 0.1 to 0.8 wt%, from 0.14 to 0.8 wt% of the dry substance content of the aqueous dispersion binding agent).

[0033] In addition to lowering the viscosity of the aqueous dispersion binding agent, the sulfite agent can help to increase the strength of the resulting fiberboard and help, for example, increase the modulus of rupture, modulus of elasticity, internal bond strength, or a combination thereof of the Fiberboard panes. Where present, a ratio of sodium sulfite to soy flour is in a range of from 1:100 to 12:100 or 1:100 to 4:100. Surfactant:

[0034] The surfactant typically comprises from 0.1 to 2.0 wt% of the dry substance content of the aqueous dispersion binding agent, preferably, from 0. 2 to 1.0 wt% of the dry substance content of the aqueous dispersion binding agent.

[0035] The surfactant comprises an ionic or a non-ionic surfactant. Examples of surfactants useful include, but are not limited to, ethoxylated sugar, ethoxylated sugar alcohol, ethoxylated sugar fatty acid ester, polyoxyethylenesorbitan fatty acid ester (such as polysorbate 20 and 80), polyoxyethylene (100) stearyl ether, sodium dodecyl sulfate, sodium stearyl lactylate, soy lecithin, maleic acid / olefin copolymer Na-salt (e.g., TRADENAME Sokalan CP 9 available from BASF).

[0036] Preferably, the surfactant is a non-ionic surfactant comprising an ethoxylated (or propoxylated) sugar fatty acid ester, or an ethoxylated (or propoxylated) sugar alcohol, or polyoxyethylenesorbitan fatty acid ester (such as polysorbate 20 and 8) having a non-polar carbon chain length from 12 to 20 carbons (C12-C20) (e.g., from C16 to C18); or an ethoxylated (or propoxylated) sorbate. In some aspects, the non-ionic surfactant is sorbitan monolaurate.PT-1866-WO-PCT

[0037] The use of a sulfite agent together with a surfactant and anti-foam agent provides a relatively low viscosity that provides for a binding agent with high dry substance content that can be effectively utilized in existing fiberboard panel manufacturing equipment. Anti-foam agent:

[0038] The anti-foam agent typically comprises from 0.1 to 2.0 wt% (preferably, from 0.3 to 1.0 wt%) of the dry substance content.

[0039] The anti-foam agent reduces the foaming that may occur when the aqueous dispersion binding agent is being made and when it is in used to manufacture the fiberboard panels. The anti-foam agent can all be added at once as the aqueous dispersion binding agent is being made (for example, prior to or at the start of the making of the aqueous dispersion). Alternatively, in one preferred aspect, a portion of the anti-foam agent is added at the start of making the aqueous dispersion (for example, initially add 30 to 70 percent of the total anti-foaming agent to be utilized at the beginning and add the rest of the total anti-foam agent to be utilized after the ingredients have been initially mixed and begin to foam during the mixing. In some aspects, the anti-foam agent is an ester of a fatty acid, or a polyalkylene glycol, or a monofunctional alcohol alkoxylate.

[0040] In some aspects a biocide may be include in the formulation. Biocides are known in the art and commercially available. Any functional and acceptable biocide may be utilized. pH:

[0041] The aqueous dispersion binding agent typically has a pH from about 6 to about 10, or from about 7 to about 9 (for example, from about 7.5 to 8.5 or 9.5). While not intending to be limited to any theory, it is believed that a neutral to basic pH results in a pH environment that enhances the reaction between the carbohydrates present, polypeptides present, and wood component to form a biopolymer network enveloping the wood fiber. Preferably, the pH is from 6.50 to 8. Therefore, when wood fibers and the solids of the aqueous dispersion binding agent are heated and pressed under pressure, better adhesion and interlocking between the components of the binding agent and the wood fibers can be achieved. High Dry Substance Content:

[0042] An aqueous dispersion binding agent having a high dry substance content of from 38 percent by weight to 47 percent by weight (for examples, from 39 percent by weight to 46 percent by weight, from 40 percent by weight to 45 percent by weight), will provide sufficientPT-1866-WO-PCT binder to produce a fiberboard panel having excellent physical properties (such as MOE, MOR, Internal bond strength and swell behavior). Substantially-free of urea formaldehyde:

[0043] The aqueous dispersion binding agent is substantially free of a urea-formaldehyde. For example, the binding agent typically includes less than 5 wt% of urea-formaldehyde, less than 2 wt% of urea-formaldehyde, or less than 11 wt% urea-formaldehyde. This will enable the board to be manufactured with low emissions during manufacture and provide a fiberboard that does not emit significant formaldehyde when exposed to high temperatures and high humidity.

[0044] There are a number of disadvantages associated with using urea-formaldehyde. For example, absorption of water, at high temperature, cured urea-formaldehyde can hydrolyze and release formaldehyde, this weakens the glue bond and can be toxic. Additionally, urea- formaldehyde adhesives both during and before curing can release formaldehyde and other volatiles. This will require urea-formaldehyde to be used in well ventilated areas and can cause air emission issues.

[0045] The materials described herein can address at least some of these drawbacks and, in particular, prevent the outgassing of substantially any formaldehyde. Making the Aqueous Dispersion Binding Agent:

[0046] The aqueous dispersion binding agent typically is made as follows: i) First the desired mass of sulfite agent (such as disodium sulfite (Na2SO3)) is added to water; ii) Glycerol and, if desired, sorbitol are next added together with a surfactant and anti- foam agent (defoamer); iii) The mixture is agitated / mixed slowly while soy flour is added; iv) After all soy flour added and mixed to a sufficient consistency, the agitation / mixing is increased to provide high shear mixing for an appropriate amount of time to evenly disperse the material into an aqueous dispersion; and v) A base such as sodium hydroxide is added under agitation to provide an aqueous dispersion having the desire pH, dissolved solids content, and viscosity.

[0047] If desired, a portion of the total desired defoamer can be added during step ii), with the remaining portion of the defoamer being added during or just prior to step iv).PT-1866-WO-PCT Making the Fiberboard:

[0048] A fiberboard manufacturing process includes the following described main equipment and unit operations, together with additional unit operations and equipment known to one of ordinary skill in the art.

[0049] Referring to FIG.1, the major unit operations of a fiberboard panel manufacturing line are shown. A conveyor 11 typically transfers large wood chips that were previously washed to plug screw 13 that compresses the large wood chips to form a plug of wood chips that are transferred into cooker 15. The water content of the large wood chips carried by the conveyor is typically high (e.g., 50-60%, depending on season, storage time and source). The plug of wood chips helps maintain a back pressure on the cooker to prevent blowback of wood chips and other materials present in cooker 15 into plug screw 13. Plug screw 13 also removes much of the water from the wood chips and sends the water removed (squeeze water) to waste-water treatment.

[0050] In cooker 15, the wood chips typically are cooked at pressure (about 7-9 bar) and at around 170°C for 3-4-10 minutes through the direct introduction of steam into cooker 15. The cooked wood chips exit cooker 15 and are sent through refiner 19.

[0051] Typically, a swell-retardant agent, such as a wax emulsion, (from 0.5 wt% to 1.5 wt% on a dry basis of the wood chips and wax) is added after cooker 15 and prior to refiner 19. Alternatively, a swell-retardant agent may be added to blow line 21.

[0052] Refiner 19 typically comprises a disc refiner with a gap of 0.12 mm to 0.16 mm. As the cooked wood chips pass through refiner 19 they are converted to refiner wood fibers that have a greatly reduced size compared the wood chips that entered refiner 19. The processes that occur in refiner 19 are sometimes referred to as defibration process. The aspect ratio of the refiner wood fibers existing refiner 19 is large, the refiner wood fibers are fine, and the fibers are relatively homogeneous in size with respect to each other. Optionally, additional water can be added to the cooker, if the wood is too dry, e.g., due to the summer season.

[0053] Refiner wood fibers exist refiner 19 and are sent through an outlet line to a “blowline 21”.

[0054] The aqueous dispersion binding agent typically is introduced downstream of refiner 19 and prior to the pressure drop taking place in blowline 21. This can be achieved by introducing the aqueous dispersion binding agent in the piping that connects refiner 19 to blowline 21, or alternatively, directly into blowline 21 upstream of the area where the pressure drop and steam explosion takes place.PT-1866-WO-PCT

[0055] In blowline 21, the pressure is greatly reduced rapidly, thereby causing a steam explosion of water present with the refiner wood fibers and water that may be introduced into blowline 21 (such as water present within the aqueous dispersion binding agent). The steam explosion further reduces the sizing variability of the fibers to produce glued wood fibers that are much finer than the refiner wood fibers exiting refiner 19 (and have aqueous dispersion binding agent on them).

[0056] The glued wood fibers typically are dried further in a drier 23 (e.g., to a 7-12 preferably 8-10 wt% moisture level). The dried glued wood fibers may be stored in glued fiber storage. When desired, the dried resinated wood fibers are evenly distributed on a continuously running conveyor belt or similar spreading operation 25 (typically in random directions) to form a mat. The mat comprising resinated wood fibers is further shaped and typically pre-pressed 26 (at lower temperatures and pressures than used in final press 27) before being introduced to a final press 27 where high heat and pressure cure the mat comprising glued wood fibers into a fiberboard. The temperatures utilized to form and cure the panels in the final pressing operations are well known in the art and by those in industry. The two main types of final presses utilized are a continuous press and multi-opening presses.

[0057] Additional finishing steps, such as calibration of the raw panels, sanding, trimming, and sizing of the fiberboard to produce the final fiberboard panels using techniques known to one of skill in the art. Typically, a coating or laminate is applied to the fiberboard near the end of the manufacturing process. Physical Properties of the Fiberboard Panels: Density [kg / m³] - EN323 Internal bond [N / mm²] - EN 319 MOE [N / mm²] - EN310 MOR [N / mm²] - EN310 Water absorption 24h [%] - DIN 52351 Thickness swell 24h [%] - EN317

[0058] Examples of desirable physical properties of the fiberboard described herein can include the product’s density, internal bond strength (IB), modulus of rupture (MOR), modulus of elasticity (MOE), thickness swell percent (thickness swell%), or a combination thereof as measured for example in the Working Examples. The modulus of rupture of the fiberboard product measures the amount of force required to result in rupturing the fiberboard product. The modulusPT-1866-WO-PCT of rupture can be measured, for example, according to EN310 While the modulus of rupture value can depend on a variety of factors, including the fiberboard product’s density, length, width, thickness, or a combination thereof. EN 622-5 in part 5 specifies the requirements for dry process boards (MDF).

[0059] The modulus of elasticity is a quantity that measures fiberboard product’s resistance to being deformed elastically (e.g., non-permanently) when a stress is applied to it. The modulus of elasticity can be measured, for example, according to EN310 as described in the examples herein. The modulus of elasticity value typically depends on a variety of factors, including the fiberboard product’s density, length, width, thickness, or a combination thereof.

[0060] The thickness swell% and the water absorption% are both quantities that measure the fiberboard product’s resistivity to water penetration. The higher the values, the greater the amount of water that is penetrated. This can result in the fiberboard product swelling or otherwise deforming. For example, the fiberboard product may expand past a desired amount. This can be undesirable, if the fiberboard product has precise features such as bore holes, flanges, grooves, or the like, that are designed to fit precisely with a corresponding feature on another product. The thickness swell% and water absorption% values can be measured, for example, according to EN317 and DIN 52351 as described in the examples herein. According to some aspects, the thickness swell% and water absorption% after soaking the fiberboard in water for twenty-four hours can be as low as zero. EN 622-5 in part 5 specifies the requirements for dry process boards (MDF).

[0061] As discussed above, a swell-retardant agent may be introduced onto to refiner fibers. The swell-retardant agent typically can include a wax that can sustain (e.g., remain stable) even the pHs being used and high temperature environment as utilized in the manufacture of Fiberboard panels described herein. Where present, the swell-retardant can be from 0.1 wt% to 2 wt% or typically from 0.5 wt% to 1.5 wt% of the dry weight of the swell retardant agent and wood fiber present.

[0062] The internal bond strength is a quantity that measures a material’s ability to resist rupturing in the direction perpendicular to the plane of the material’s surface. The internal bond strength can be measured byEN319, as described in the examples herein. EN 622-5 in part 5 specifies the requirements for dry process boards (MDF).

[0063] A benefit of using the aqueous dispersion binder agent and the methods described herein to manufacture fiberboard panels, is that the properties of the fiberboard panels, typicallyPT-1866-WO-PCT are generally comparable to those of fiberboard panels that are made using a urea-formaldehyde (UF) binder.

[0064] The wood used to make the fiberboard described herein can include one or more wood particles, one or more wood components, one or more wood chips, or one or more wood strands. The wood can include a wood material such as pine, hemlock, spruce, aspen, birch, maple, or mixtures thereof. All the wood is treated by a fiberboard manufacturing process as described above and as further known to one of ordinary skill in the art. WORKING EXAMPLES

[0065] Various aspects of the present disclosure can be better understood by reference to the following Working Examples which are offered by way of illustration. The present disclosure is not limited to the Working Examples given herein. The weight percentages (wt%) indicated refer to weight percent of the indicated component based on the total weight of the material or formulation being referred to, unless otherwise indicated. Table 1. Materials Name Supplier a - lePT-1866-WO-PCT available from Cargill, Incorporated, Wayzata, MN th 5Preparation of the Aqueous dispersion binding agent:

[0066] The method described above for “Making the Aqueous Dispersion Binding Agent” is utilized to prepare an Aqueous Dispersion Binding Agent as set forth below in Table 2.PT-1866-WO-PCT Table 2. Components CAS# Wt % Water 56.35as ADBA-1. Making Medium Density Fiberboard (MDF) Panels: Example 1 1.1 Process

[0068] Medium Density Fiberboard panels are manufactured at pilot scale using the method described above for fiberboard and as depicted in FIG. 1., and as more fully described below. The average throughput of materials used to make the MDF through the equipment was 40 kg / h.

[0069] Wood Chips are loaded into a hopper and carried by an elevator / conveyor to a plug flow screw, where the Wood Chips as they move forward are compressed into a plug. As the Wood Chips move forward through the screw, water (squeeze water) is removed from the Wood Chips to lower the moisture content from 50%-60% to 30-40%. The starting level is strongly depending on the season, storage time and source of the wood and will have an effect on the squeeze water and the end moisture content.

[0070] The wood chip plug flows into the cooker where direct steam is introduced at 170 ºC and 8 to 9 bar. The wood chip plug prevents the material in the cooker from backflowing into the plug flow screw. The wood chips remain in the cooker for from 3 to 4 minutes and are then transported to the refiner (having a 0.14 mm gap) where a defibration process acts on the cookedPT-1866-WO-PCT wood chips to produce refiner wood fibers. Prior to entering the refiner, one weight percent (1 wt%) (on a dry basis) Wax Emulsion is added to the cooked Wood Chips.

[0071] The refiner wood fibers exit the refiner and are transported toward the blowline. Prior to entering the blowline, the binder system (e.g., Aqueous Dispersion Binging Agent or UF- Binder control) are added to the refiner wood fibers. Twelve weight percent of each of the binders based on dry weight of the wood and other materials was used for the manufacture of each of the MDF panels, and a control was also made that was binder free. In the blowline, the pressure is dropped rapidly to atmospheric pressure and thereby causes the water present to flash to steam and further fiberize the wood to reduce the size of the glued wood fibers.

[0072] The glued wood fibers are dried using heat to a moisture content of from 7-10 wt%. The glued wood fibers are manually loaded into wooden forming frames (580 mm by 520 mm). The glued wood fibers are pre-pressed to compact the glued wood fibers and then pressed at a pressure of 15 bar for sixty seconds using a Höfer OK 426 press and heated to a temperature of 185°C for 8 to 10 second. The final MDF panels measure 580 mm by 520 mm by 3 mm thick and have a target density of 820 kg / m3. The panels are trimmed and tested for mechanical properties. 1.2 Properties evaluation

[0073] The properties of the resulting panels are set forth below in Table 3. Table 3. Liquid 91,2 ,7PT-1866-WO-PCT

[0074] As can be seen from Table 3, fiberboards made with the aqueous dispersion binding agent (ADBA-1) performed competitively with fiberboards made with the incumbent UF binder. For example, the thickness swell (TS), internal bond (IB) and water adsorption (WA) properties for fiberboard panels made with ADBA-1 were better than the same properties of fiberboard panels made with UF Binder. And, the MOE and MOR of the fiberboard panels made with ADBA- 1 were only slightly lower than the MOE and MOR exhibited by fiberboard panels made with UF Binder. Example 2

[0075] In this example, a modified Aqueous Dispersion Binding Agents, ADBA-2, is studied with ADBA-1 and UF binder. ADBA-2 has very similar composition as ADBA-1 except sorbitol is absent in ADBA-2. Composition of ADBA-2 is set forth in Table 4. Table 4. Components CAS# Wt %2.1 Process

[0076] Medium Density Fiberboard panels are manufactured at pilot scale using the method described above for fiberboard and as depicted in FIG. 1., and as more fully described below. The average throughput of materials used to make the MDF through the equipment was 40 kg / h.

[0077] Wood Chips are loaded into a hopper and carried by an elevator / conveyor to a plug flow screw, where the Wood Chips as they move forward are compressed into a plug. As thePT-1866-WO-PCT Wood Chips move forward through the screw, water (squeeze water) is removed from the Wood Chips to lower the moisture content from 50%-60% to 30-40%. The starting level is strongly depending on the season, storage time and source of the wood and will have an effect on the squeeze water and the end moisture content.

[0078] The wood chip plug flows into the cooker where direct steam is introduced at 170°C and 8 to 9 bar. The wood chip plug prevents the material in the cooker from backflowing into the plug flow screw. The wood chips remain in the cooker for from 3 to 4 minutes and are then transported to the refiner (having a 0.14 mm gap) where a defibration process acts on the cooked wood chips to produce refiner wood fibers. Prior to entering the refiner, one weight percent (1 wt%) (on a dry basis) Wax Emulsion is added to the cooked Wood Chips.

[0079] The refiner wood fibers exit the refiner and are transported toward the blowline. Prior to entering the blowline, the binder system (e.g., Aqueous Dispersion Binging Agent or UF- Binder control) are added to the refiner wood fibers. Twelve weight percent of each of the binders based on dry weight of the wood and other materials was used for the manufacture of each of the MDF panels, and a control was also made that was binder free. In the blowline, the pressure is dropped rapidly to atmospheric pressure and thereby causes the water present to flash to steam and further fiberize the wood to reduce the size of the glued wood fibers.

[0080] The glued wood fibers are dried using heat to a moisture content of from 7-10 wt%. The glued wood fibers are manually loaded into wooden forming frames (580 mm by 520 mm). The glued wood fibers are pre-pressed to compact the glued wood fibers and then pressed at a pressure of 15 bar for sixty seconds using a Höfer OK 426 press and heated to a temperature of 185°C for 8 to 10 second. The final MDF panels measure 580 mm by 520 mm by 3 mm thick and have a target density of 820 kg / m3. The panels are trimmed and tested for mechanical properties. 2.2 Properties Evaluation

[0081] The properties of the resulting panels are set forth below in Table 5.PT-1866-WO-PCT Table 5. Liquid 9 component into13715,7

[0082] , ith the aqueous dispersion binding agent without sorbitol (ADBA-2) performed competitively with fiberboards made with the incumbent UF binder, its performance was worse than that of the fiberboard made with the aqueous dispersion binding agent (ADBA-1). For example, the thickness swell (TS) and internal bond (IB) properties for fiberboard panels made with ADBA-2 were worse than the same properties of fiberboard panels made with ADBA-1. This study demonstrates the importance of sorbitol in the aqueous dispersion binding agent in contributing desirable benefits to the fiberboards. Example 3

[0083] In this example, different process conditions, as set forth in Table 6, are studied in using the aqueous dispersion binding agent (ADBA-1) to manufacture fiberboards. An incumbent MUF binder (a UF binder having about 6% melamine) is used as reference. Composition of ADBA-1 is set forth in Table 2 above. Table 6. Trial Binder Binder dosage Press factor Press temperaturePT-1866-WO-PCT 2 MUF 14,0 10 185 3 ADAB-1 11,0 10 185

[0084] Medium Density Fiberboard panels are manufactured at pilot scale using the method described above for fiberboard and as depicted in FIG. 1., and as more fully described below. The average throughput of materials used to make the MDF through the equipment was 40 kg / h.

[0085] Wood Chips are loaded into a hopper and carried by an elevator / conveyor to a plug flow screw, where the Wood Chips as they move forward are compressed into a plug. As the Wood Chips move forward through the screw, water (squeeze water) is removed from the Wood Chips to lower the moisture content from 50%-60% to 30-40%. The starting level is strongly depending on the season, storage time and source of the wood and will have an effect on the squeeze water and the end moisture content.

[0086] The wood chip plug flows into the cooker where direct steam is introduced at 170°C and 8 to 9 bar. The wood chip plug prevents the material in the cooker from backflowing into the plug flow screw. The wood chips remain in the cooker for from 3 to 4 minutes and are then transported to the refiner (having a 0.14 mm gap) where a defibration process acts on the cooked wood chips to produce refiner wood fibers. Prior to entering the refiner, one weight percent (1 wt%) (on a dry basis) Wax Emulsion is added to the cooked Wood Chips.

[0087] The refiner wood fibers exit the refiner and are transported toward the blowline. Prior to entering the blowline, the binder system (e.g., Aqueous Dispersion Binging Agent or UF- Binder control) are added to the refiner wood fibers. Twelve weight percent of each of the binders based on dry weight of the wood and other materials was used for the manufacture of each of the MDF panels, and a control was also made that was binder free. In the blowline, the pressure is dropped rapidly to atmospheric pressure and thereby causes the water present to flash to steam and further fiberize the wood to reduce the size of the glued wood fibers.

[0088] The glued wood fibers are dried using heat to a moisture content of from 7-10 wt%. The glued wood fibers are manually loaded into wooden forming frames (580 mm by 520 mm). The glued wood fibers are pre-pressed to compact the glued wood fibers and then pressed at aPT-1866-WO-PCT pressure of 15 bar for sixty seconds using a Höfer OK 426 press and heated to a temperature of 185°C for 8 to 10 second. The final MDF panels measure 580 mm by 520 mm by 3 mm thick and have a target density of 820 kg / m3. The panels are trimmed and tested for mechanical properties. 3.2 Properties Evaluation

[0089] The properties of the resulting panels are set forth below in Table 7. Table 7. Liquid 9 component into13

[0090] As can be seen from Table 7, fiberboards made with the aqueous dispersion binding agent (ADBA-1) under different tested process conditions performed competitively with fiberboards made with the incumbent MUF binder. For example, the thickness swell (TS) property for fiberboard panels made with ADBA-1 was better than that of fiberboard panels made with MUF Binder. The tested process conditions also impacted the properties of the fiberboards.

Claims

PT-1866-WO-PCT CLAIMS What is claimed is:

1. An aqueous dispersion binding agent for use in the manufacture of an engineered wood product comprising medium density fiberboard, high density fiberboard, or ultra low density fiberboard, comprising: at least 40 total weight percent based on the dry substance content of the binding agent of a polyol component selected from the group consisting of a glycerol component, sorbitol, and mixtures thereof based on the dry substance content of the binding agent (for example, at least 42 weight percent, at least 43 weight percent, at least 44 weight percent based on the dry substance content of the binding agent), the glycerol component and sorbitol in a weight ratio of from 0:1 to 1:0 glycerol to sorbitol (for example, from 1:1 glycerol to sorbitol to 4:1 glycerol to sorbitol (and sometimes a weight ratio of from 3:2 to 3.6:1 glycerol to sorbitol)); at least 37 weight percent based on the dry substance content of the binding agent of soy flour (e.g., from 40 weight percent to 60 weight percent, from 42 weight percent to 55 weight percent, from 45 weight percent to 54 weight percent) based on the dry substance content of the binding agent), the soy flour having a protein dispersibility index (PDI) of at least 70 (for example, at least 75, at least 80, at least 85, or at least 90) and having a protein content of from 35 wt% to 65 wt% (for example, from 40 wt% to 60 wt%); a sulfite agent, selected from the group consisting of: sodium sulfite, sodium bisulfite, sodium metabisulfite, or mixtures thereof; a surfactant; and an anti-foam agent; wherein aqueous dispersion binding agent has a dry substance content of from about 38 percent by weight to about 47 percent by weight (for examples, from 39 percent by weight to 46 percent by weight, from 40 percent by weight to 45 percent by weight), wherein the aqueous dispersion binding agent has a pH from about 6 to about 10, from about 7 to about 9 (for example, from about 7.5 to 8.5), and wherein the aqueous dispersion binding agent has a viscosity less than 2000 centipoise at 23°C (for example, less than 1500 centipoise, less than 1000 centipoise at 23°C, less than 400 centipoise at 23°C.PT-1866-WO-PCT 2. The aqueous dispersion binding agent of claim 1, wherein sulfite agent comprises from about 0.1 to 2.0 wt% of the dry substance content (for example, from 0.1 to 1.0 wt%, from 0.1 to 0.8 wt%, from 0.14 to 0.8 wt% of the dry substance content).

3. The aqueous dispersion binding agent of any of claims 1-2, wherein the surfactant comprises from 0.1 to 2.0 wt% of the dry substance content.

4. The aqueous dispersion binding agent of any of claims 1-3, wherein the sulfite agent comprises sodium sulfite.

5. The aqueous dispersion binding agent of any of claims 1-4, wherein the anti-foam agent comprises from 0.1 to 2.0 wt% (preferably, from 0.3 to 1.0 wt%) of the dry substance content.

6. The aqueous dispersion binding agent of any of claim 1-5, wherein the surfactant comprises a non-ionic surfactant.

7. The aqueous dispersion binding agent of any of claims 1-6, wherein the surfactant is selected from the group consisting of ethoxylated sugar, ethoxylated sugar alcohol, ethoxylated sugar fatty acid ester, polyoxyethylenesorbitan fatty acid ester (such as polysorbate 20 and 80), sodium dodecyl sulfate, polyoxyethylene (100) stearyl ether, sodium stearyl lactylate, lecithin, maleic acid / olefin copolymer Na-salt.

8. The aqueous dispersion binding agent of claim 6, wherein the non-ionic surfactant comprises an ethoxylated sugar fatty acid ester or an ethoxylated sugar alcohol.

9. The aqueous dispersion binding agent of claim 6, wherein the non-ionic surfactant comprises polyoxyethylenesorbitan fatty acid ester (such as polysorbate 20 and 80) having a nonpolar carbon chain length from C12 to C20 (e.g., from C16-C18), or an ethoxylated sorbate.

10. The aqueous dispersion binding agent of claim 8, wherein the non-ionic surfactant comprises a propoxylated sorbitol compound having a main carbon chain length from C12 to C20 (e.g., from C16-C18).PT-1866-WO-PCT 11. The aqueous dispersion binding agent of claim 9, wherein the non-ionic surfactant comprises polyoxyethylenesorbitan monolaurate.

12. The aqueous dispersion binding agent of any of claims 1-11, wherein the anti-foam agent comprises an esters of a fatty acid, a polyalkylene glycol or a monofunctional alcohol alkoxylate.

13. The aqueous dispersion binding agent of any of claims 1-12, wherein the soy flour used passes through a 200 screen size mesh.

14. The aqueous dispersion binding agent of any of claims 1-13, wherein the soy flour has a PDI of from 75 to 99 (for example, from 80 to 93).

15. The aqueous dispersion binding agent of any of claims 1-14.

16. The aqueous dispersion binding agent of any of claims 1-15, wherein the aqueous dispersion binding agent comprises less than 5 wt% of urea-formaldehyde, methylene diphenyl diisocyanate, or a mixture thereof.

17. The aqueous dispersion binding agent of any of claims 1-16, wherein the aqueous dispersion binding agent is substantially free of urea-formaldehyde, methylene diphenyl diisocyanate, or a mixture thereof.

18. The aqueous dispersion binding agent of any of claims 1-17, wherein the aqueous dispersion binding agent is substantially free of urea, ammonia, or mixtures thereof.

19. The aqueous dispersion binding agent of any of claims 1-18, wherein the aqueous dispersion binding agent of any of claims 1-18, wherein the aqueous dispersion binding agent is substantially free of borax.

20. The aqueous dispersion binding agent of any of claims 1-19, wherein the aqueous dispersion binding agent further comprises a biocide.PT-1866-WO-PCT 21. The aqueous dispersion binding agent of claim 20, wherein the biocide comprises from 0.05 to 2.0 wt% of the dry substance content (for example, from 0.1 to 1.0 wt%).

22. The aqueous dispersion binding agent of any of claims 1-21, further comprising borax in a range of from 1 wt% to 3 wt% based on the dry weight of the aqueous dispersion binding agent.

23. A method for manufacturing medium density fiberboard (MDF) or high-density fiberboard (HDF), the method comprising: a) contacting the aqueous dispersion binding agent of any of claims 1-22 with a plurality of wood fibers to obtain a composition, wherein aqueous dispersion binding agent is present in a range of from 3 parts to 25 parts per 100 parts dry weight of the dry weight of the plurality of wood fibers; and b) heating the composition from step a) to form the MDF or HDF.

24. The method of claim 23, wherein the aqueous dispersion binding agent is present in a range of from 7 parts to 17 parts dry weight per 100 parts of the dry weight of the plurality of wood fibers, or from 8 parts to 17 parts dry weight per 100 parts of the dry weight of the plurality of wood fibers, or from 9 parts to 17 parts dry weight per 100 parts of the dry weight of the plurality of wood fibers.

25. The method of any of claims 23 and 24, wherein the heating of step b) comprising heating the composition of step a) to a temperature from 140°C to 260°C, for example 200°C to 250°C.

26. The method of any of claims 23-25, wherein pressure is applied to the MDF or HDF prior to, during or after heating step b).

27. The method of any of claims 23-26, wherein the method further comprises applying a swell-retardant component during the manufacture of MDF or HDF.

28. The method of any of claims 23-27, wherein the method further comprises applying a wax emulsion during the manufacture of the MDF or HDF.PT-1866-WO-PCT 29. The method of claim 28, wherein the wax emulsion is applied prior to, during step a).

30. The aqueous dispersion binding agent of any of claims 1-22, or the method of any of claim 23-29, wherein the soy flour has from 40 wt% to 60 wt% protein, based on the total soy flour present.

Images