Recycle full rail ties by coating them with a polyurethane

Abstract

A method of preparing a wood railroad tie having a surface of a cured adhesive, a treated wood railroad tie and to a wood railroad tie recycling system are described. The method includes applying, to at least one surface of a wood railroad tie, an adhesive system containing: i) an isocyanate component; and ii) an isocyanate reactive component.

Description

[0001]DOCKET NO.: 005763WO TITLE OF THE INVENTION RECYCLE FULL RAIL TIES BY COATING THEM WITH A POLYURETHANE BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present disclosure generally related to a coated wood railroad tie and more specifically to a wood railroad tie coated with a polyurethane adhesive system. DESCRIPTION OF RELATED ART Railroad ties are used to position rails and have historically been made of wood. Wood has inherent properties that makes it the number one choice for over 93% of all track applications in North America and most of the world today. It is stiff but forgiving. It can be easily spiked or drilled for rail fastening systems, and it holds up under millions of gross tons of traffic. Typically, a variety of softwood and hardwoods timbers are used as ties, including oak, jarrah and karri. Nevertheless, despite their functionality, there are numerous problems associated with the utility of railroad ties made from wood. In order to prevent rot and damage such as splitting, insect infestation, plate-cutting and spike-pull, due to harsh conditions such as weather and other stresses, railroad ties are often treated with chemicals and preservatives. While creosote is the most common preservative for railway ties, other preservatives also used include pentachlorophenol, chromated copper arsenate, and other preservatives. The use of such chemicals and preservatives can result in unintended consequences such as negative environmental impact. In addition to necessary application of chemicals, environmental exposure drastically affects life cycle costs and durability for railroad ties. Other wood-based products also subject to such problems include structures such as fencing, railing, piers, marine pilings, utility and electric poles, lumber, and decking. Furthermore, the use of treated wood such as pressure treated wood creates a potential for toxins to leach into the ground as the chemicals injected into pressure treated wood are released into the soil and create potentially hazardous conditions. Moreover, the production of creosote often generates additional byproducts that are highly regulated as being potentially hazardous. An additional problem associated with railroad ties, and other wood-based components is that due to forestry restrictions imposed on forestry operations around the world, the supply of wood is becoming increasing limited. In light of the declining areas of mature forests and environmental need to protect trees, products using recycled materials to replace products presently using these protected hardwoods are needed. It is becoming increasingly apparent that there is a serious need for recycling and repurposing such wood related articles and structures. Rather than allowing worn out wooden articles, such as railroad ties to become unusable garbage, what is necessary is a method to re-process the wood, break it down and convert it to a useful article. Preferably, such a process results in the production of articles having improved functionality, and articles that are reinforced and engineered such that they overcome the limitations resulting from wood that has been pre-treated with undesirable chemicals. Theoretically, binder compositions may be used for making wood-based composite articles including phenol formaldehyde (PF) resins, urea formaldehyde (UF) resins and isocyanate resins. Binder compositions based on isocyanate chemistry are commercially desirable because they have low water absorption, high adhesive and cohesive strength, flexibility in formulation, versatility with respect to cure temperature and rate, excellent structural properties, the ability to bond with wood-based materials having high water contents, and importantly, zero formaldehyde emissions. Resulting composite articles utilizing such binder compositions are imparted with corresponding properties / benefits. Wood-based materials can be treated with polymethylene poly(phenyl isocyanates) (also known as polymeric MDI or pMDI) to improve the strength of the composite article. Typically, such treatment involves applying the isocyanate to the material and allowing the isocyanate to cure, either by application of heat and pressure or at room temperature. While it is possible to allow the pMDI to cure under ambient conditions, residual isocyanate (NCO) groups remain on the treated articles for weeks or even months in some instances. Toluene diisocyanate (TDI) can also be utilized for such purposes but is generally less acceptable from an environmental standpoint. Isocyanate prepolymers are among the preferred isocyanate materials that have been used in binder compositions to solve various processing problems, particularly, in reducing adhesion to press platens and for reducing reactivity of the isocyanates. Unfortunately, disadvantages of using isocyanates in place of PF and / or UF resins include difficulty in processing due to adhesion to platens, lack of tack or cold tack (i.e., the isocyanates are not “tacky” or “sticky”), and the need for special storage in certain scenarios. In addition, isocyanates can also have extended cure times, which reduces manufacturing output of composite articles utilizing the same. Further, some isocyanates and related components can have very high viscosities, which impairs handling of the same, and increases cost of manufacture of composite articles utilizing such components. U.S.2023 / 295370 discloses fiber reinforced polyurethane or polyisocyanurate foams which may be used as railroad ties. U.S.2021 / 0238425 discloses a wood composite article including a plurality of wood pieces and an adhesive system disposed on or dispersed among a plurality of wood pieces for bonding. The adhesive system includes a binder component of a thermosetting resin and a fiber component. The composite article may be formed into various objects such as railroad ties, fencing and the like. U.S.2023 / 0228040 discloses multi-layer articles for use as a rail tie footings comprising, as the tie, an elongate rigid body having a substantially planar surface, and on the substantially planar surface comprising a microcellular foam elastomeric pad, for example, of a substantially organic solvent free polyurethane, wherein the substantially planar surface has a peripheral landing on which there is no elastomeric pad and the elastomeric pad has a bulk density (ASTM D3676) of from 600 to 2000 Kg / m3(0.6 to 2.0 g / cm3). U.S.11,613,851 discloses a railroad tie formed of a polymeric or polymeric composite material and configured for enhanced mechanical interaction with an underlying ballast. The tie includes at least a top longitudinal surface, a pair of side longitudinal surfaces, a bottom longitudinal surface, and two end faces. Accordingly. there remains an opportunity to provide improved recycling systems useful for forming wood composite articles. There also remains an opportunity to provide improved wood composite articles and improved methods of forming such wood composite articles. Furthermore, there remains an opportunity to provide novel and productive methods that enable the recycling of wood-based materials such as railroad ties, resulting in products and articles with improved utility and enhanced material functionality. BRIEF SUMMARY OF THE INVENTION In view of the need to replace aging wood railroad tie, Applicant has discovered that treatment of at least one surface of a wood railroad tie with an adhesive composition comprising the reaction product of an isocyanate component and an isocyanate reactive component allows for the extended use of a wood railroad tie. Applicant has also discovered that the useful lifetime of a used wood railroad tie may be extended by encapsulating a used wood railroad tie in an adhesive composition comprising the reaction product of an isocyanate component and an isocyanate reactive component allows for the re-use a used wood railroad tie. According to one aspect of the present invention is a method, comprising: applying, to at least one surface of a wood railroad tie, an adhesive system comprising: i. an isocyanate component; and ii. an isocyanate reactive component. According to another aspect of the present invention is a method, wherein said adhesive system is applied to only one surface of said wood railroad tie, said one surface having the greatest surface area of said wood railroad tie. According to another aspect of the present invention is a method, wherein said wood railroad tie has not been used in a rail bed. According to another aspect of the present invention is a method wherein said adhesive system is applied to six faces of said wood railroad tie. According to another aspect of the present invention is a method, wherein said wood railroad tie has been used in a rail bed. According to another aspect of the present invention is a method, wherein said adhesive system is applied in a closed mold. According to another aspect of the present invention is a method, further comprising treating said wood railroad tie by at least one of drying, cleaning and scrubbing prior to applying said adhesive system. According to another aspect of the present invention is a method, wherein said adhesive system is applied placing the wood tie in a mold and pouring the adhesive system around the wood railroad tie. According to another aspect of the present invention is a method, further comprising subjected said adhesive system to curing, heating or combination thereof. According to another aspect of the present invention is a method, wherein the isocyanate component of the adhesive system is selected from polyisocyanate, ethylene diisocyanate, 1,4- tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-and -1,4-diisocyanate, 1-isocyanato-3,3,5- trimethyl-5-isocyanatomethyl-cyclohexane ("isophorone diisocyanate"), 2,4- and 2,6- hexahydrotoluene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate ("hydrogenated MDI", or "HMDI"), 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-toluene diisocyanate ("TDI"), diphenylmethane-2,4'- and / or -4,4'-diisocyanate ("MDI"), naphthylene-1,5-diisocyanate, triphenyl-methane-4,4',4''-triisocyanate, polyphenyl-polymethylene-polyisocyanates ("crude MDI"), norbornane diisocyanates, m- and p-isocyanatophenyl sulfonylisocyanates, perchlorinated aryl polyisocyanates, carbodiimide-modified polyisocyanates, urethane-modified polyisocyanates, allophanate-modified polyisocyanates, isocyanurate-modified polyisocyanates, urea-modified polyisocyanates, biuret-containing polyisocyanates, isocyanate-terminated prepolymers, or combinations thereof. According to another aspect of the present invention is a method, wherein the isocyanate reactive component of the adhesive system comprises at least one isocyanate reactive compound selected from polyols, polyethers, polyesters, polyacetals, polycarbonates, polyester ethers, polyester carbonates, polythioethers, polyamides, polyester amides, polysiloxanes, polybutadienes and polyacetones. According to another aspect of the present invention is a method, wherein the isocyanate reactive component of the adhesive system comprises a mixture of isocyanate-reactive compounds having a number averaged molecular weight of 300 to 6000 and a number averaged functionality of 1 to 6. According to another aspect of the present invention is a method, wherein the isocyanate- reactive component further comprises at least one catalyst, wherein the catalyst comprises organometallic tin catalysts, amino alcohols, metal chlorides, triazines, alkali metal hydroxides, alkali metal salts, trimerization catalysts, and tertiary amine catalysts. According to another aspect of the present invention is a method, wherein said adhesive system further comprise at least one additive selected from the group consisting of fillers, surfactants, light stabilizers, colorants, pigments, mold release agents, fungicides, mildewcides, or rheology control agents, fiber component or combination thereof. According to another aspect of the present invention is a method, wherein said additive is at least one filler selected from calcium carbonate, glass, sand, aggregate, silicates, rubber crumb, fly ash, or carbon black. According to another aspect of the present invention is a method, wherein said additive is at least one fiber component selected from fiberglass, E-glass, A-glass, C-glass, D-glass, R-glass, or S-glass, graphite, aramid, TPU, PBT, carbon fiber, nylon, or combinations thereof. According to another aspect of the present invention is a coated wood railroad tie obtained by a method of applying, to at least one surface of a wood railroad tie, an adhesive system. According to another aspect of the present invention is a coated wood railroad tie, comprising a wood railroad tie having disposed on at least one surface an adhesive system comprising: i) an isocyanate component; and ii) an isocyanate reactive component. According to another aspect of the present invention is a method of recycling a wood railroad tie, comprising griding the wood railroad comprising a wood railroad tie having disposed on at least one surface an adhesive system comprising: i) an isocyanate component; and ii) an isocyanate reactive component and binding with a binder composition. Applicant has also discovered a wood railroad tie produced by a method of applying an adhesive composition comprising the reaction product of an isocyanate component and an isocyanate reactive component. Applicant has also discovered a recycling method for wood railroad ties which have been treated with an adhesive composition comprising the reaction product of an isocyanate component and an isocyanate reactive component by grinding a wood railroad tie which has been treated with an adhesive composition comprising the reaction product of an isocyanate component and an isocyanate reactive component and binding a ground wood railroad tie with binder composition. DETAILED DESCRIPTION OF THE INVENTION Wood Railroad Ties The wood railroad tie to receive application of an adhesive system may be any wood cuboid having a length greater than a width. A suitable wood railroad tie has a length of 7-10 feet, preferably 8-9 feet, more preferably 8.5 feet. A suitable wood railroad tie has a width of 7-11 inches, preferably 8-10 inches, more preferably 9 inches. A suitable wood railroad tie has a height of 5-9 inches, preferably 6-8 inches, more preferably 7 inches. The wood railroad tie may be of any wood type such as hardwood or softwood. Preferably the wood railroad tie is a hardwood. The wood railroad tie may have never been used before as a railroad tie and thus would have no rail tie spike holes. The wood railroad tie may be a previously used railroad tie and thus would have at least one rail spike hole. In a preferred embodiment, the wood railroad tie has at least two rail spike holes. Encapsulation resin system The adhesive system is a polyurethane comprising at least one isocyanate compound and an isocyanate-reactive component containing at least one isocyanate-reactive compound. In certain embodiments the adhesive system may further optionally include additives such as fillers, pigments, colorants, light stabilizers, mold release agents, pesticides, fungicides, mildewcides, rheology control agents, formaldehyde resins, protein-based adhesives, or a combination thereof. If utilized, the isocyanate component is typically a polymeric diphenylmethane diisocyanate (pMDI); however, other isocyanates can also be utilized as described below. The adhesive system generally adheres to the surface of the wood railroad tie, once cured. For example, the reaction product of the isocyanate component and the isocyanate-reactive component can bond to the surface of the wood railroad tie via linkages, e.g., urea linkages. General mechanisms of adhesion, for wood composites, are detailed in pages 397 through 399 of The Polyurethanes Handbook (David Randall & Steve Lee eds., John Wiley & Sons, Ltd. 2002). The isocyanate component is typically a polyisocyanate having two or more functional groups, e.g., two or more isocyanate (NCO) groups. Said another way, the isocyanate component can just be an isocyanate or a combination of isocyanates. Suitable organic polyisocyanates include, but are not limited to, conventional aliphatic, cycloaliphatic, araliphatic and aromatic isocyanates. In certain embodiments, the isocyanate component is chosen from diphenylmethane diisocyanates (MDIs), polymeric diphenylmethane diisocyanates (pMDIs), and combinations thereof. Polymeric diphenylmethane diisocyanates can also be called polymethylene polyphenylene polyisocyanates. In other embodiments, the isocyanate component is an emulsifiable MDI (eMDI). Examples of other suitable isocyanates include, but are not limited to, toluene diisocyanates (TDIs), hexamethylene diisocyanates (HDIs), isophorone diisocyanates (IPDIs), naphthalene diisocyanates (NDIs), and combinations thereof. In a specific embodiment, the isocyanate component is MDI. In another specific embodiment, the isocyanate component is pMDI. In further specific embodiments, the isocyanate component is a combination of MDI and pMDI. In yet another specific embodiment, the isocyanate component is Elastoflex® W which is a soft foam system derived from MDI, TDI and / or their mixture in tailor-made formulations with densities from 30 to 80 kg / m.sup.3 according to article specifications. Elastoflex® W is available from BASF Corporation of Florham Park, N.J. In certain embodiments, the isocyanate component is an isocyanate-terminated prepolymer. The isocyanate-terminated prepolymer is a reaction product of an isocyanate and a polyol and / or a polyamine. The isocyanate may be any type of isocyanate in the polyurethane art, such as one of the polyisocyanates. If utilized to make the isocyanate-terminated prepolymer, the polyol is typically chosen from ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butane diol, glycerol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, and combinations thereof. The polyol may also be a polyol as described and exemplified further below with discussion of the isocyanate-reactive component. If utilized to make the isocyanate- terminated prepolymer, the polyamine is typically chosen from ethylene diamine, toluene diamine, diaminodiphenylmethane and polymethylene polyphenylene polyamines, aminoalcohols, and combinations thereof. Examples of suitable aminoalcohols include ethanolamine, diethanolamine, triethanolamine, and combinations thereof. The isocyanate- terminated prepolymer may be formed from a combination of two or more of the aforementioned polyols and / or polyamines. The isocyanates or isocyanate-terminated prepolymers may also be used in the form of an aqueous emulsion by mixing such materials with water in the presence of an emulsifying agent. The isocyanate component may also be a modified isocyanate, such as, carbodiimides, allophanates, isocyanurates, and biurets. Other suitable isocyanates include those described in U.S.4,742,113 to Gismondi et al.; U.S.5,093,412 to Mente et al.; U.S.5,425,976 to Clarke et al.; U.S.6,297,313 to Hsu; U.S. 6,352,661 to Thompson et al.; U.S.6,451,101 to Mente et al.; U.S.6,458,238 to Mente et al.; U.S.6,464,820 to Mente et al.; U.S.6,638,459 to Mente et al.; U.S.6,649,098 to Mente et al.; U.S. No.6,822,042 to Capps; U.S.6,846,849 to Capps; U.S.7,422,787 to Evers et al.; U.S. 7,439,280 to Lu et al.; and U.S.8,486,523 to Mente; and U.S.2005 / 0242459 to Savino et al. Additional specific examples of suitable isocyanate components are commercially available from BASF Corporation of Florham Park, N.J., under the trademark LUPRANATE®, such as LUPRANATE® M, LUPRANATE® M20, LUPRANATE® M1, LUPRANATE® M20SB, LUPRANATE® M20HB, and LUPRANATE® M20FB isocyanates. In one embodiment, the isocyanate component is LUPRANATE® M20. In another embodiment, the isocyanate component is LUPRANATE® M20FB. It is to be appreciated that the isocyanate component may include any combination of the aforementioned isocyanates and / or isocyanate- terminated prepolymers. If utilized, the isocyanate component typically has a viscosity which is suitable for specific applications of the isocyanate component to the wood pieces, such as by spraying, coating or molding. Typically, the isocyanate component has a viscosity of from about 100 to about 5,000, about 100 to about 2,500, or about 100 to about 1,000, cps at 25° C. according to ASTM D2196, or any subrange in between. Regardless of the application technique, the viscosity of the isocyanate component should be sufficient to adequately coat the wood railroad tie. The adhesive system can include the reaction product of the isocyanate component and the isocyanate-reactive component. In one embodiment, the isocyanate-reactive component is water, which may be applied to and / or already present on surface of the wood railroad tie, e.g., as a preexisting moisture content (or a portion thereof). In other embodiments, the isocyanate- reactive component includes a polyol and / or a polyamine. In certain embodiments, the isocyanate-reactive component includes a polymer polyol, which may also be referred to as a graft polyol. The isocyanate-reactive component can include a combination of the aforementioned isocyanate-reactive components, e.g., water and a polyol. If utilized, the polyol is typically chosen from conventional polyols, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butane diol, glycerol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, and combinations thereof. Other suitable polyols include, but are not limited to, biopolyols, such as soybean oil, castor-oil, soy- protein, rapeseed oil, etc., and combinations thereof. It is believed that certain polyols impart plasticization and / or film formation, and tackiness, which may increase with pressure. For example, some polyols may act as a plasticizer, especially in conjunction with the compatibilizer component. Suitable polyether polyols include, but are not limited to, products obtained by the polymerization of a cyclic oxide, for example ethylene oxide (EO), propylene oxide (PO), butylene oxide (BO), or tetrahydrofuran in the presence of polyfunctional initiators. Suitable initiator compounds contain a plurality of active hydrogen atoms, and include water, butanediol, ethylene glycol, propylene glycol (PG), diethylene glycol, triethylene glycol, dipropylene glycol, ethanolamine, diethanolamine, triethanolamine, toluene diamine, diethyl toluene diamine, phenyl diamine, diphenylmethane diamine, ethylene diamine, cyclohexane diamine, cyclohexane dimethanol, resorcinol, bisphenol A, glycerol, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, and combinations thereof. Other suitable polyether polyols include polyether diols and triols, such as polyoxypropylene diols and triols and poly(oxyethylene-oxypropylene)diols and triols obtained by the simultaneous or sequential addition of ethylene and propylene oxides to di- or trifunctional initiators. Copolymers having oxyethylene contents of from about 5 to about 90% by weight, based on the weight of the polyol component, of which the polyols may be block copolymers, random / block copolymers or random copolymers, can also be used. Yet other suitable polyether polyols include polytetramethylene glycols obtained by the polymerization of tetrahydrofuran. Suitable polyester polyols include, but are not limited to, hydroxyl-terminated reaction products of polyhydric alcohols, such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentylglycol, 1,6-hexanediol, cyclohexane dimethanol, glycerol, trimethylolpropane, pentaerythritol or polyether polyols or mixtures of such polyhydric alcohols, and polycarboxylic acids, especially dicarboxylic acids or their ester-forming derivatives, for example succinic, glutaric and adipic acids or their dimethyl esters sebacic acid, phthalic anhydride, tetrachlorophthalic anhydride or dimethyl terephthalate or mixtures thereof. Polyester polyols obtained by the polymerization of lactones, e.g., caprolactone, in conjunction with a polyol, or of hydroxy carboxylic acids, e.g., hydroxy caproic acid, may also be used. Suitable polyesteramides polyols may be obtained by the inclusion of aminoalcohols such as ethanolamine in polyesterification mixtures. Suitable polythioether polyols include products obtained by condensing thiodiglycol either alone or with other glycols, alkylene oxides, dicarboxylic acids, formaldehyde, aminoalcohols or aminocarboxylic acids. Suitable polycarbonate polyols include products obtained by reacting diols such as 1,3-propanediol, 1,4- butanediol, 1,6-hexanediol, diethylene glycol or tetraethylene glycol with diaryl carbonates, e.g., diphenyl carbonate, or with phosgene. Suitable polyacetal polyols include those prepared by reacting glycols such as diethylene glycol, triethylene glycol or hexanediol with formaldehyde. Other suitable polyacetal polyols may also be prepared by polymerizing cyclic acetals. Suitable polyolefin polyols include hydroxy-terminated butadiene homo- and copolymers and suitable polysiloxane polyols include polydimethylsiloxane diols and triols. Specific examples of suitable polyols are commercially available from BASF Corporation under the trademark of PLURACOL®. It is to be appreciated that the isocyanate- reactive component may include any combination of two or more of the aforementioned polyols. In certain embodiments utilizing the polymer polyol, the polymer polyol is a graft polyol. Graft polyols may also be referred to as graft dispersion polyols or graft polymer polyols. Graft polyols often include products, i.e., polymeric particles, obtained by the in-situ polymerization of one or more vinyl monomers, e.g., styrene monomers and / or acrylonitrile monomers, and a macromer in a polyol, e.g., a polyether polyol. In one embodiment, the isocyanate-reactive component is a styrene-acrylonitrile (SAN) graft polyol. In other embodiments, the polymer polyol is chosen from polyharnstoff (PHD) polyols, polyisocyanate polyaddition (PIPA) polyols, and combinations thereof. It is to be appreciated that the isocyanate-reactive component can include any combination of the aforementioned polymer polyols. PHD polyols are typically formed by in-situ reaction of a diisocyanate with a diamine in a polyol to give a stable dispersion of polyurea particles. PIPA polyols are similar to PHD polyols, except that the dispersion is typically formed by in-situ reaction of a diisocyanate with an alkanoamine instead of a diamine, to give a polyurethane dispersion in a polyol. The article is not limited to any particular method of making the polymer polyol. If utilized, the polymer polyol can serve as a sizing agent substitute, e.g., a sizing wax or wax sizing agent substitute, specifically by imparting a certain degree of water repellency to the article, once formed. Paraffin, for example, is a common wax sizing agent for OSB and OSL applications. In certain embodiments, the article is substantially free of a wax component, such as paraffin. By “substantially free”, it is meant that in these embodiments, the wax component is typically present in an amount no greater than about 5, no greater than about 2.5, no greater than about 1.5, or approaching or equaling 0, parts by weight, based on 100 parts by weight of the wood pieces, or any subrange in between. In certain embodiments, the article is completely free of a wax component. One method by which the polymer polyol can impart water repellency is by at least partially coating a surface of the wood railroad tie, thus decreasing surface tension of the surface. Another method by which the polymer polyol imparts water repellency is that the polymer polyol at least partially fills capillaries within the wood railroad tie, thus providing a barrier to capillary uptake of water. Further, it is believed that the polymer polyol reduces formation of micro- and / or nano-cracks from forming within the article, for example, within the adhesive, during or after cure to form the reaction product. Yet further, if such cracks are already present in the wood pieces, the polymer polyol at least partially fills such cracks, as with description of the capillaries. It is believed that the blocking of water and filling of cracks reduces de-lamination and swelling problems when the article is exposed to moisture during use. It is further believed that such “filling” largely occurs due to the polymeric particles of the polymer polyol. In various embodiments, the polymer polyol includes a continuous phase and a discontinuous phase. The continuous phase of the polymer polyol is not generally miscible with the isocyanate component, which provides for increased coverage of the polymeric particles with reactive groups, such as hydroxyl (OH) groups. Such reactive groups can further impart crosslinking in the article, once the reactive groups are reacted. The polymeric particles are further described below. In certain embodiments, the polyol of the polymer polyol is a hydrophobic polyol. In a specific embodiment, the polyol is a hydrophobic polyether polyol. In another specific embodiment, the polyol is a hydrophobic polyester polyol. The hydrophobic polyol contains alkylene oxides. In these embodiments, the hydrophobic polyol typically has from about 0 to about 50, about 2 to about 20, or about 5 to about 15, parts by weight of ethylene oxide (EO), based on 100 parts by weight of the alkylene oxides of the hydrophobic polyol, or any subrange in between. In other embodiments, the hydrophobic polyol typically has at least 60, at least 70, or at least 80, parts by weight propylene oxide (PO), based on 100 parts by weight of the alkylene oxides, or any subrange in between. Accordingly, in these embodiments, the hydrophobic polyol is a propylene oxide rich polyol, which imparts the hydrophobic polyol with hydrophobicity, and therefore further imparts the article with hydrophobicity. In certain embodiments, the alkylene oxides of the hydrophobic polyol include a mixture of EO and PO. In another embodiment, the alkylene oxides of the hydrophobic polyol include only PO, i.e., the hydrophobic polyol does not include other alkylene oxides, such as EO. In certain embodiments, the hydrophobic polyol includes other types of alkylene oxides known in the art, e.g., butylene oxide (BO), in combination with PO, and optionally, in combination with EO. The alkylene oxides of the hydrophobic polyol may be arranged in various configurations, such as a random (heteric) configuration, a block configuration, a capped configuration, or a combination thereof. For example, in one embodiment, the hydrophobic polyol includes a heteric mixture of EO and PO. In certain embodiments, the hydrophobic polyol is terminally capped with EO. The hydrophobic polyol typically has a terminal cap of from about 5 to about 25, about 5 to about 20, or about 10 to about 15, parts by weight EO, based on 100 parts by weight of the hydrophobic polyol, or any subrange in between. In certain embodiments, the EO may only be present in the terminal ethylene oxide cap; however, in other embodiments, the EO may also be present along with the PO, and optionally, with other alkylene oxides, e.g., BO, in the alkylene oxides of the hydrophobic polyol. Generally, it is thought that increasing the PO content of the hydrophobic polyol is preferred in order to impart increased hydrophobicity to the article. Suitable hydrophobic polyols include, but are not limited to, glycerine-initiated, trimethylolpropane-initiated, propylene glycol-initiated, and sucrose-initiated polyether polyols, and combinations thereof. In one embodiment, the hydrophobic polyol is a glycerine-initiated polyether polyol. The alkylene oxides of the hydrophobic polyol generally extend from the respective initiator portion of the hydrophobic polyol. The discontinuous phase of the graft polyol includes polymeric particles. If micro- and / or nano-cracks are present in the wood pieces, it is believed that the polymeric particles of the discontinuous phase of the polymer polyol at least partially fill these cracks. The polymeric particles are generally large in size due to their macromer constituents, i.e., the polymeric particles have micrometer or larger dimensions, e.g., micrometer or larger diameters. In certain embodiments, the polymeric particles have average diameters ranging from about 0.1 to about 10 microns, alternatively from about 0.1 to about 1.5 microns, or any subrange in between. In other embodiments, the polymeric particles have average diameters less than 0.1 microns, which imparts the polymer polyol with nano-polymeric particles. Blocking of water and filling of cracks reduces de-lamination and swelling problems when the article is exposed to moisture during storage or use. In addition to filling cracks, in certain embodiments, the polymeric particles are reactive with the isocyanate component, which may increase internal bond (IB) strength of the article. The polymeric particles typically include the reaction product of monomers chosen from styrenes, e.g., alpha-methyl styrene, acrylonitriles, esters of acrylic and methacrylic acids, ethylenically unsaturated nitriles, amines, amides, and combinations thereof. In certain embodiments, the polymeric particles include the further reaction of a macromer, such as a polyol having an unsaturation, which permits chemical incorporation of the polymeric particle. In these embodiments, it is believed that the polymeric particles can impart crosslinking in the article, due to reactive groups attached to the polymeric particles, e.g., OH groups, which can react with the isocyanate component. It is also believed that the polymeric particles can serve as a “hot melt” adhesive depending on their specific chemical makeup, e.g., polymeric particles formed from styrene and acrylonitrile monomers. In one embodiment, the polymeric particles include styrene acrylonitrile (SAN) copolymers, which are the reaction product of styrene monomers and acrylonitrile monomers. Typically, the SAN copolymers have a weight ratio of styrene to acrylonitrile of from about 30:70 to about 70:30, about 40:60 to about 60:40, about 45:55 to about 60:40, about 50:50 to about 60:40, or about 55:45 to about 60:40, or any subrange in between. In one embodiment, the SAN copolymers have a weight ratio of styrene to acrylonitrile of about 66.7:33.3. In another embodiment, the polymeric particles are urea, which are the reaction product of an amine monomer and an isocyanate (NCO) group, such as an NCO group of a diisocyanate. In yet another embodiment, the polymeric particles are urethane, which are the reaction product of an alcohol monomer and an isocyanate (NCO) group, such as an NCO group of a diisocyanate. Typically, the polymeric particles are present in the polymer polyol in an amount of from about 5 to about 70, about 15 to about 55, or about 25 to about 50, parts by weight, based on 100 parts by weight of the polymer polyol, or any subrange in between. In one embodiment, the polymeric particles are present in the polymer polyol in an amount of about 65 parts by weight based on 100 parts by weight of the graft polyol. Generally, increasing the amount of polymeric particles increases the water repellency of the article. The polymer polyol typically has a molecular weight of from about 400 to about 20,000, about 500 to about 10,000, about 600 to about 5,000, or about 700 to about 3,000, or any subrange in between. In one embodiment, the polymer polyol has a molecular weight of about 730. In another embodiment, the polymer polyol has a molecular weight of about 3,000. Other suitable polymer polyols and methods of making the same include those described in U.S.4,522,976 to Grace et al.; U.S.5,093,412 to Mente et al.; U.S.5,179,131 to Wujcik et al.; U.S.5,223,570 to Huang et al.; U.S.5,594,066 to Heinemann et al.; U.S.5,814,699 to Kratz et al.; U.S.6,034,146 to Falke et al.; U.S.6,103,140 to Falke et al.; U.S.6,352,658 to Chang et al.; U.S.6,432,543 to Harrison et al.; U.S.6,472,447 to Lorenz et al.; U.S.6,649,107 to Harrison et al.; and U.S.7,179,882 to Adkins et al. Specific examples of suitable polymer polyols are commercially available from BASF Corporation, under the trademark PLURACOL®, such as PLURACOL® 1365, PLURACOL® 4600, PLURACOL® 4650, PLURACOL® 4800, PLURACOL® 4815, PLURACOL® 4830, and PLURACOL® 4850 graft polyols. In a specific embodiment, the isocyanate-reactive component includes PLURACOL® 4650. In another embodiment, the isocyanate-reactive component is PLURACOL® 2086 and / or PLURACOL® 593. The isocyanate-reactive component may include any combination of the aforementioned polymer polyols. Detailed information on polymer polyols is described on pages 104 and 105 of The Polyurethanes Handbook (David Randall & Steve Lee eds., John Wiley & Sons, Ltd.2002). If utilized, the polymer polyol typically has a viscosity which is suitable for specific applications of the polymer polyol to the wood railroad tie, such as by spraying, coating or molding. Typically, the polymer polyol has a viscosity of from about 100 to about 10,000, about 500 to about 5,000, or about 500 to about 3,000, cps at 25° C. according to ASTM D2196, or any subrange in between. Regardless of application technique, the viscosity of the polymer polyol should be sufficient to adequately coat the wood railroad tie. If utilized, the polymer polyol is typically utilized in an amount of from about 5 to about 40, about 10 to about 30, or about 15 to about 25, parts by weight, based on 100 parts by weight of the adhesive system, or any subrange in between. The isocyanate-reactive component may include any combination of the aforementioned polyols, polymeric particles, and / or types of polymer polyols. The adhesive system may further include an auxiliary polyol, different than the polyol in the polymer polyol, if the isocyanate component is utilized as the binder component. Suitable polyols for use as the auxiliary polyol are as described with the isocyanate-terminated prepolymer. The auxiliary polyol can be used for various purposes. For example, an auxiliary polyol having a higher functionality (relative to the polyol of the polymer polyol) can be utilized to provide additional reactive groups for reaction with the isocyanate component, or an auxiliary polyol can be utilized to increase or decrease viscosity of the adhesive system. The auxiliary polyol may be utilized in various amounts. Additives to the adhesive system In certain embodiments, the additive component includes a catalyst component. In one embodiment, the catalyst component includes a tin catalyst. Suitable tin catalysts include tin(II) salts of organic carboxylic acids, e.g. tin(II) acetate, tin(II) octoate, tin(II) ethylhexanoate and tin(II) laurate. In one embodiment, the organometallic catalyst includes dibutyltin dilaurate, which is a dialkyltin(IV) salt of an organic carboxylic acid. Specific examples of suitable organometallic catalyst, e.g., dibutyltin dilaurates, are commercially available from Air Products and Chemicals, Inc. of Allentown, Pa., under the trademark DABCO®. The organometallic catalyst can also include other dialkyltin(IV) salts of organic carboxylic acids, such as dibutyltin diacetate, dibutyltin maleate and dioctyltin diacetate. In an embodiment, the adhesive system may further comprise a catalyst, wherein the catalyst includes but is not limited to tin carboxylate, amines, 1-methylimidizole, Fomrez® UL- 29, Fomrez® UL-28, a blowing catalyst (i.e. Dabco® BL-19, DMDEE), a blocked catalyst (i.e. Toyocat® DB30, Polycat® SA-102), or combinations thereof. In some embodiments the binder component includes: castor oil, such as T31; polyether / polyester polyols such as Sovermol® 750, commercially available from BASF; aromatic polyester polyols such as Terol® 258, aromatic polyester commercially available from Huntsman; and grafted polyether polyols such as NIAX 31-28 commercially available from Union Carbide; or any combination thereof. Examples of other suitable catalysts include iron(II) chloride; zinc chloride; lead octoate; tris(dialkylaminoalkyl)-s-hexahydrotriazines including tris(N,N-dimethylaminopropyl)-s- hexahydrotriazine; tetraalkylammonium hydroxides including tetramethylammonium hydroxide; alkali metal hydroxides including sodium hydroxide and potassium hydroxide; alkali metal alkoxides including sodium methoxide and potassium isopropoxide; and alkali metal salts of long-chain fatty acids having from 10 to 20 carbon atoms and / or lateral OH groups. Further examples of other suitable catalysts, specifically trimerization catalysts, include N,N,N-dimethylaminopropylhexahydrotriazine, potassium, potassium acetate, N,N,N-trimethyl isopropyl amine / formate, and combinations thereof. A specific example of a suitable trimerization catalyst is commercially available from Air Products and Chemicals, Inc. under the trademark POLYCAT®. Yet further examples of other suitable catalysts, specifically tertiary amine catalysts, include dimethylaminoethanol, dimethylaminoethoxyethanol, triethylamine, N,N,N′,N′- tetramethylethylenediamine, N,N-dimethylaminopropylamine, N,N,N′,N′,N″- pentamethyldipropylenetriamine, tris(dimethylaminopropyl)amine, N,N-dimethylpiperazine, tetramethylimino-bis(propylamine), dimethylbenzylamine, trimethylamine, triethanolamine, N,N-diethyl ethanolamine, N-methylpyrrolidone, N-methylmorpholine, N-ethylmorpholine, bis(2-dimethylamino-ethyl)ether, N,N-d imethylcyclohexylamine (DMCHA), N,N,N′,N′,N″- pentamethyldiethylenetriamine, 1,2-dimethyl imidazole, 3-(dimethylamino) propyl imidazole, and combinations thereof. Specific examples of suitable tertiary amine catalysts are commercially available from Air Products and Chemicals, Inc. under the trademark POLYCAT®. The catalyst component can be utilized in various amounts. The catalyst component may include any combination of the aforementioned catalysts. The adhesive system may also include a fiber component. As used herein fiber may refer to a variety of materials, including but not limited to chopped fiber, continuous filament mat, dry use chopped woven mats, chopped strand mat, multi-end roving, non-wovens, single-end roving, technical fabrics and wet-use chopped strand or combinations thereof; including but not limited to, fiberglass, E-glass, A-glass, C-glass, D-glass, R-glass, or S-glass, graphite, aramid, TPU, PBT, carbon fiber, basalt fibers, nylon, or combinations thereof. In some embodiments the fibers include Owens 995 chopped strand, commercially available from Owens Coming, NEG-T249H chopped glass strands, commercially available from Nippon Electric Glass, or any combination thereof. The fiber component may include most common types of glass fiber used in fiberglass such as E-glass, an alumino-borosilicate glass with less than 1% w / w alkali oxides. Other types of glass fibers used may include A-glass (alkali-lime glass with little or no boron oxide), E-CR- glass (Electrical / Chemical Resistance; alumino-lime silicate with less than 1% w / w alkali oxides, with high acid resistance), C-glass (alkali-lime glass with high boron oxide content, used for glass staple fibers and insulation), D-glass (borosilicate glass, named for its low Dielectric constant), R-glass (alumino silicate glass without MgO and CaO with high mechanical requirements as reinforcement), and S-glass (alumino silicate glass without CaO but with high MgO content with high tensile strength). Glass fiber components are available in numerous embodiments including chopped strand mat, continuous filament mat, dry-use chopped strand, multi-end roving, non-wovens, single-end roving, technical fabrics and wet-use chopped strand. The selection of the glass fiber component is based upon several factors, including but not limited to choppablility, dispersion, durability, mechanical and hydrolysis resistance property of the finished product, resistance to mechanical cracking, shrinkage resistance, static control, strength of finished composite products, molding ability, compatibility with polyurethane and aesthetic and design flexibility. In an embodiment, the glass fiber component comprises fiberglass roving ER13-2400- 180 (Jushi Group Co., Ltd. California, USA). In an alternative embodiment, the glass fiber component may be selected from any commercially available products, including but not limited to a variety of glass fiber products available from companies such as Jushi Group Co., Ltd. California, USA, or Owens Corning Ohio, USA (for example, Anti-CRAK® Chopped Strands / HD, Anti-CRAK® Chopped Strands HP / HD Anti-CRAK® Fibers, HydroStrand® chopped strands 258 for PA, and HydroStrand® chopped strands 276 for PBT). In an embodiment, the isocyanate-reactive component further comprises at least one additive, wherein the additive includes but is not limited to fillers, surfactants, light stabilizers, colorants, pigments, mold release agents, fungicides, mildewcides, or rheology control agents. The filler may comprise calcium carbonate, glass, sand, aggregate, silicates, rubber crumb, fly ash, or carbon black. In an embodiment, the fiber of the binder component comprises fiberglass, E-glass, A- glass, C-glass, D-glass, R-glass, or S-glass, graphite, aramid, TPU, PBT, carbon fiber, nylon, or combinations thereof. The fiber component may comprise chopped fiber, continuous filament mat, dry use chopped woven mats, chopped strand mat, multi-end roving, non-wovens, single- end roving, technical fabrics and wet-use chopped strand or combinations thereof. Furthermore, the fiber component may comprise continuous strands of fiber or fragments of fiber having lengths of about 1 / 16″ to 40 ft, ½″-20 ft, ¾″-5 ft, 1″ to 1 ft, 1.5″ to 5″. In an embodiment, the adhesive system further comprise additives, such as fillers, pigments, colorants, light stabilizers, mold release agents, pesticides, fungicides, mildewcides, rheology control agents. The fillers may comprise calcium carbonate, glass, sand, aggregate, silicates, rubber crumb, fly ash, shredded closed-cell foam jounce bumper, PA66 nylon, F311 fiberglass, F410 fiberglass, polypropylene microfilaments, carbon black or any combinations thereof. In certain embodiments, the adhesive system comprises in whole, or in part, as additive components an isocyanate, a hydrophobic polyol, an agent for increasing cross link density and improving homogenization, a chain extender and a catalyst. In one embodiment the adhesive composition is comprised of 35-80, preferably 38-75, more preferably 38.73-72.57 wt. % of a hydrophobic polyol such as castor oil T31 3-18, preferably 5-15, more preferably 6.42-12 wt. % of a polyol such as Pluracol P-736; 5-20, preferably 7-17, more preferably 8.02-15.0 wt. % of a difunctional crosslinker such as dipropylene glycol; 0.05-1.5, preferably 0.1-1, more preferably 0.37-0.50 wt. % of a water absorbent such as 3Å molecular sieve powder; 0.01-0.1, preferably 0.02-0.08, more preferably 0.03-0.05 wt. % of a defoamer such as Xiameter ACP1000; and 20-65, preferably 25-62, more preferably 46.54-87.05 wt. % of an isocyanate such as Elastolite G 20114T Iso, a total wt.% adding up to 100 wt. % In one embodiment, the adhesive system has a Tg of 100-170°F, preferably 120-170 °F, more preferably 130-160°F, even more preferably 135-145°F, and specifically, 140 F. In another embodiment, the Tg ranges from 150-160°. In one embodiment, the adhesive system has an elongation of 12-62%, preferably 15-60 %., more preferably 16-20%, even more preferably 16-18% and includes 17.3%. The adhesive properties of Tg and elongation may be adjusted according to known parameters to one of ordinary skill in the art, without undue experimentation. In one embodiment, the adhesive system has a density which is greater than that of said wood railroad tie. Encapsulation conditions The present invention is applicable to a previously unused wood railroad tie to which the adhesive is applied to only one surface of a cuboid wood railroad tie, a surface having the greatest surface area. Independent of the degree of encapsulation (1 or more faces receiving adhesive) the adhesive is applied to an average thickness of 1-5, mm, preferably 1.5-4 mm on each face. Railroad ties will not necessarily have even / flat surfaces, so some areas will have dips / cracks / holes, etc. Accordingly an “average thickness” may be calculated based on the exposed surface area of the face of the wood railroad tie. The adhesive may penetrate the surface of the wood railroad tie to a maximum depth of 9, mm, 10,mm 11 mm, 12 mm, 13 mm, 14 mm, 15 mm and even 16 mm. Given a heterogeneity of a recycled wood railroad tie, and the possible presence of cracks and holes, adhesive penetration is based on an average depth of penetration on intact section of the wood railroad tie, excluding the depth of penetration through cracks and into holes. The present invention is also applicable to a previously used wood railroad tie wherein the adhesive is applied to at least one surface and preferably encapsulates the previously used wood railroad tie. The wood railroad tie is preferably pretreated prior to application of the adhesive by drying, such as to a moisture level of <1.0 w t.% and cleaning such as by scrubbing to remove loose debris. Encapsulation may be by insertion in a 5-sided open mold. The mold has dimensions which are preferably at least 1-5, mm, preferably 1.5-4 mm greater than the dimensions of the wood railroad tie. The adhesive composition is poured into the open mold, whereby the wood railroad tie is secured to prevent floating within the confines of the mold. Thereafter, additional adhesive is poured into the mold from the open side until nearly filling the mold, followed by adhesive curing. Encapsulation may also be performed by injection through the bottom of a closed mold, followed by curing. The mold has dimensions which are preferably at least 1-5, mm, preferably 1.5-4 mm greater than the dimensions of the wood railroad tie. When injected into a closed mold, the system is optionally equipped with a transducer to monitor the pressure within the mold. Coating conditions are not particularly limited such that the ties may be treated and then coated, under ambient conditions for the coating process. Adjustment of the coating conditions may be made to accommodate local condition, under principles understood by one of ordinary skill in the art. Ambient humidity may affect coating performance such that adhesive is preferably applied under conditions of low humidity. Standard processing techniques for the components of the encapsulation system include a practice of applying an inert gas, such as nitrogen and / or air, to the head space of storage tanks. This can result in entrainment of gases in the components which can reduce the density of the encapsulating material, once cured. Encapsulated Tie properties The properties of an encapsulated wood tie may be measured by a spectrum of tests. In one embodiment, a modulus of elasticity (MOE) may be at least 150,000 psi, preferably at least 175,000 psi, more preferably at least 200,000, more preferably at least 250,000 psi. In another embodiment, the modulus of rupture (ROR) may be at least 4,000 psi, preferably at least 4,500 psi, more preferably at least 5,000 psi even more preferably at least 5,500 psi. In another embodiment a single tie lateral push property is at least 1,600 lbf, more preferably at least 1,700 lbf, even more preferably at least 1,800 lbf, even more preferably at least 1,900 lbf. In another embodiment, a spike insertion test property is at least 3,000 lbf, more preferably at least 3,500 lbf, even more preferably at least 4,000 lbf, even more preferably at least 4,500 lbf. In another embodiment, a spike withdrawal test property is >1,500 lbf, preferably >1,760 lbf, more preferably >1,800 lbf, even more preferably >2,000 lbf and even more preferably >2,250 lbf. In another embodiment, the spike withdrawal test property is <2,500 lbf, preferably < 2,400 lbf, more preferably <2,300 lbf. In another embodiment, electrical impendence is less than 30,000 ohms, preferably less than 25,000 ohms, more preferably less than 20,000 ohms, more preferably less than 19,000 ohms. In another embodiment, thermal conductivity is > 0.250 Watts / (Meter*Kelvin), preferably >0.269 Watts / (Meter*Kelvin), more preferably >0.270 Watts / (Meter*Kelvin), more preferably >0.280 Watts / (Meter*Kelvin). Recycling of treated wood railroad tie After the useful lifetime of the treated wood railroad tie, the treated wood railroad tie may be recycled by grinding into pieces and adhered with an adhesive system as described in co- pending U.S.17 / 054,568, the description of the binder system being hereby incorporated by reference. The binder component is typically chosen from thermosetting plastic material component and a fiber component, wherein the thermosetting plastic material component comprises thermosets, such as unsaturated polyesters, epoxy, polyurea, polyurethane or combinations thereof. The thermosetting plastic material component may comprise at least one isocyanate compound and an isocyanate-reactive component containing at least one isocyanate-reactive compound. In certain embodiments the binder may further optionally include additives such as fillers, pigments, colorants, light stabilizers, mold release agents, pesticides, fungicides, mildewcides, rheology control agents, formaldehyde resins, protein-based adhesives, or a combination thereof. If utilized, the isocyanate component is typically a polymeric diphenylmethane diisocyanate (pMDI); however, other isocyanates can also be utilized as described below. If utilized, the formaldehyde resin is typically a urea formaldehyde (UF) resin or a melamine UF resin, however, other formaldehydes can also be used, e.g., a phenol formaldehyde (PF) resin. If utilized, the protein-based adhesive is typically a soy-based adhesive, however, other protein-based adhesives can also be utilized, e.g., a casein-based adhesive. The binder component is utilized in an amount of from about 0.5 to about 50 parts, 5 to about 45 parts, 10 to about 30 parts, 1 to about 60, about 1 to about 40, about 1 to about 20, about 1 to about 15, about 2 to about 10, about 5 to 15, about 5 to 10, or about 5 to 12, parts by weight based on 100 part by weight of wood pieces. The adhesive system also includes a fiber component, such that the composite article further includes the fiber dispersed among the plurality of wood pieces. By “dispersed among”, it is meant that the fiber component is mixed in with at least a portion of the wood pieces. As used herein fiber may refer to a variety of materials, including but not limited to chopped fiber, continuous filament mat, dry use chopped woven mats, chopped strand mat, multi-end roving, non-wovens, single-end roving, technical fabrics and wet-use chopped strand or combinations thereof; including but not limited to, fiberglass, E-glass, A-glass, C-glass, D-glass, R-glass, or S- glass, graphite, aramid, TPU, PBT, carbon fiber, basalt fibers, nylon, or combinations thereof. In some embodiments the fibers include Owens 995 chopped strand, commercially available from Owens Coming, NEG-T249H chopped glass strands, commercially available from Nippon Electric Glass, or any combination thereof. Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified. EXAMPLES By way of non-limiting example an encapsulated wood railroad tie may be prepared as follows: Rail ties may be moved, using a forklift, one or two at a time. Rail ties are then placed on a metal cart that is approx.3ft high and rolled into an oven at 40-45°C for 16-24 hrs. The moisture content is tested and should be <1.0%. Screws are inserted (preferably #10 screws) into the ties at the 1) ends, 4 per side, 2) sides, 2, 7, and 12" away from the end a total of six screws per side, 3) top & bottom, 2, 7, and 12" away from the end a total of six screws per side. Screw heads will protrude, approximately by about 1 / 8". The weight and dimensions of each tie is made, then a photo document of the rail tie may be made, at this time. The marked top and side are removed, leaving the ends attached to one side and the bottom. The inside of a HDPE mold is coated with a mold release such as Frekote silicon. All sides and ends are coated then wipe off well. The rail tie is then slid into the mold, from a horizontal direction. The side of the mold is then attached with screws. The top is also closed then attached with screws. At this point it is ensured that the mold is secure in the KM-05 platent, engage press. An eflux hose at the far end of the mold is attached, the hose leads into an open top drum with a trash bag liner. A mix head is attached to the inlet. The mold is ready to be filled. While filling the mold with PU, the eflux hose is monitored and when PU starts flowing out of the hose, PU application is stopped. The mold containing the encapsulated wood railroad tie is allowed to sit in place for at least an hour prior to moving the mold. The mold is placed on a bench or large metal cart. The far end of the mold is first removed, and the composition is checked for cure. If ok, the top and marked side may be removed. The weight and dimensions of each tie after PU application is recorded and photo documentation of the encapsulated rail tie is made. The tie is then placed on a flat surface and allow for a post cure of at least 24 hrs. prior to moving it outside to the rail yard. The PU may be of the following formulation: I di t Wt Wt% R i F l Elastolite G 20114T Iso 87.05 46.54 Isocyanate 60 / 40 MP 102 / M20 Total 187.05 100.00 Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

CLAIMS:

1. A method, comprising: applying, to at least one surface of a wood railroad tie, an adhesive system comprising: i) an isocyanate component; and ii) an isocyanate reactive component.

2. The method according to claim 1, wherein said adhesive system is applied to only one surface of said wood railroad tie, said one surface having a greatest surface area of said wood railroad tie.

3. The method according to any of claims 1-2, wherein said wood railroad tie has not been used in a rail bed.

4. The method according to claim 1, wherein said adhesive system is applied to six faces of said wood railroad tie.

5. The method according to claims 1 or 4, wherein said wood railroad tie has been used in a rail bed.

6. The method according to any of claims 1, or 4-5, wherein said adhesive system is applied in a closed mold.

7. The method of any one of claims 1-6, further comprising: treating said wood railroad tie by at least one procedure selected from the group consisting of drying, cleaning and scrubbing prior to applying said adhesive system.

8. The method of any one of claims 4-7, wherein said adhesive system is applied placing the wood tie in a mold and pouring the adhesive system around the wood railroad tie.

9. The method of any one of claims 1-8, further comprising: subjected said adhesive system to curing, heating or combination thereof.

10. The method of any one of claims 1-9, wherein the isocyanate component of the adhesive system is selected from the group consisting of polyisocyanate, ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-and -1,4-diisocyanate, 1-isocyanato-3,3,5- trimethyl-5-isocyanatomethyl-cyclohexane ("isophorone diisocyanate"), 2,4- and 2,6- hexahydrotoluene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate ("hydrogenated MDI", or "HMDI"), 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-toluene diisocyanate ("TDI"), diphenylmethane-2,4'- and / or -4,4'-diisocyanate ("MDI"), naphthylene-1,5-diisocyanate, triphenyl-methane-4,4',4''-triisocyanate, polyphenyl-polymethylene-polyisocyanates ("crude MDI"), norbornane diisocyanates, m- and p-isocyanatophenyl sulfonylisocyanates, perchlorinated aryl polyisocyanates, carbodiimide-modified polyisocyanates, urethane-modified polyisocyanates, allophanate-modified polyisocyanates, isocyanurate-modified polyisocyanates, urea-modified polyisocyanates, biuret-containing polyisocyanates, isocyanate-terminated prepolymers, and combinations thereof.

11. The method of any one of claims 1-10, wherein the isocyanate reactive component of the adhesive system comprises at least one isocyanate reactive compound selected from the group consisting of polyols, polyethers, polyesters, polyacetals, polycarbonates, polyester ethers, polyester carbonates, polythioethers, polyamides, polyester amides, polysiloxanes, polybutadienes and polyacetones.

12. The method of any one of claims 1-11, wherein the isocyanate reactive component of the adhesive system comprises a mixture of isocyanate-reactive compounds having a number averaged molecular weight of 300 to 6000 and a number averaged functionality of 1 to 6.

13. The method of any one of claims 1-12, wherein the isocyanate-reactive component further comprises at least one catalyst, wherein the catalyst comprises organometallic tincatalysts, amino alcohols, metal chlorides, triazines, alkali metal hydroxides, alkali metal salts, trimerization catalysts, tertiary amine catalysts or a combination thereof.

14. The method of any one of claims 1-13, wherein said adhesive system further comprises at least one additive selected from the group consisting of fillers, surfactants, light stabilizers, colorants, pigments, mold release agents, fungicides, mildewcides, rheology control agents, fiber components and a combination thereof.

15. The method of claim 14, wherein said additive is at least one filler selected from the group consisting of calcium carbonate, glass, sand, aggregate, silicates, rubber crumb, fly ash, and carbon black.

16. The method according to claim 14, wherein said additive is at least one fiber component selected from the group consisting of fiberglass, E-glass, A-glass, C-glass, D-glass, R-glass, or S-glass, graphite, aramid, TPU, PBT, carbon fiber, nylon, and combinations thereof.

17. A coated wood railroad tie obtained by the method of any one of claims 1-16.

18. A coated wood railroad tie, comprising: a wood railroad tie having disposed on at least one surface an adhesive system comprising: i) an isocyanate component; and ii) an isocyanate reactive component.

19. A method of recycling a wood railroad tie, comprising: griding the wood railroad according to claim 18 and binding with a binder composition.

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