Background of the Invention For the most part, consolidated products such as oriented strand board (OSB) are manufactured using wood flakes and formaldehyde-based thermosetting binders such as phenyl formaldehyde. Although such formaldehyde-containing consolidated products are characterized by acceptable physical properties, formaldehyde-based binders require an extended cure time, do not possess moisture resistant properties and exhibit a formaldehyde emission hazard.

Isocyanate-based binders, particularly diphenylmethane diisocyante (MDI) binders, offer some significant advantages over formaldehyde-based binders, including improved cure time (i. e. , substantially faster cure speed), superior physical moisture resistance and the elimination of the formaldehyde emission hazard. Despite these advantages, isocyanate-based binders have not gained full acceptance, because such isocyanate-containing consolidated products stick to the equipment used for their manufacture (sometimes referred to as the isocyanate-containing composite sticking problem). The removal of these isocyanate-containing consolidated products from the manufacturing equipment damages panels, specifically the panel surfaces.

In an attempt to overcome the isocyanate-containing composite sticking problem, producers use a phenyl formaldehyde-based binder for the surface portions and isocyanate-based binders for the core portion of the product. However, this generally results in a lower quality product than one that is bonded entirely with an isocyanate-based binder.

In another attempt to overcome the isocyanate-containing composite sticking problem, producers have used release agents. For example, soap-based release agents such as potassium oleate have been sprayed on the surface of a wood flake mat forming a thin physical barrier to prevent sticking. However, soaps do not provide release memory (e. g. , if a mat enters the press without a coating, sticking will occur immediately).

Polyolefin-based release waxes have also been tried as a release agent. Unfortunately, such waxes build up on the surfaces of equipment resulting in maintenance downtime.

Other limitations of release agents include reduction in product quality as a result of an undesirable darkening of the surface of the consolidated product, and high production costs.

Thus, there remains a need for a new and improved molding system that provides a surface to facilitate a substantial self-release of the consolidated product from the molding system without reducing finished product quality.

Summary of the Invention The present invention is directed to a molding system for working an assemblage including a polymeric component and an isocyanate-based binder into a consolidated product. The molding system includes a molding mechanism and a moveable member having a self-releasing surface for contacting the assemblage while the assemblage is worked into the consolidated product. The self-releasing surface is substantially free of sites capable of reacting with the isocyanate-based binder thereby facilitating a substantial self-release of the consolidated product from the moveable member. Preferably, the self- releasing surface is made from a material having a standard oxidation potential greater than that of iron.

The molding mechanism of the molding system can include a batch press, a continuous press, an extruder or an injection molder. The batch press of the present invention contains an opening for receiving an assemblage and a moveable member. The batch press may further include a plurality of openings for receiving multiple assemblages and a corresponding plurality of moveable members.

The continuous press includes an advancement-consolidation mechanism for simultaneously conveying and consolidating the assemblage. The number of moveable members in the continuous press corresponds to the number of advancement- consolidation mechanisms. Examples of advancement-consolidation mechanisms are a chain or a belt.

The injection molder in the present invention may include a reaction injection molder.

The consolidated product of the present invention may be an engineered lumber product including an oriented strand board (OSB), medium density fiberboard (MDF), or a hard board. Likewise, the engineered lumber product may be shaped as an I-beam, for

example, for use as a joist. Alternatively, the engineered lumber product may include a laminated veneer.

The polymeric component of the assemblage can include a natural polymer such as a cellulosic, preferably a lignocellulosic. Alternative cellulosics may be, for example, agricultural products. The polymeric component can also include a bark, chip, cork, fiber, flour, particulate, shaving, sheet, strand, wafer, wood wool, and combinations thereof. Preferably, the polymeric component is any one form of a fiber, particulate, strand, wafer or combinations thereof.

Alternatively, the polymeric component of the assemblage may be a synthetic polymer such as a polyolefin. A preferred polyolefin is post consumer waste including textile waste, preferably, fiber.

The isocyanate-based binder includes an organic polyisocyanate generally having at least two isocyanate groups. The isocyanate-based binder may further include an additive. Examples of an additive that may be added to the assemblage include a mineral filler such as a mica, a glass fiber, and a rubber.

The self-releasing surface of the moveable member can be a metal, an alloy or a metalloid, and preferably has a potential greater than about-0.44 volts on the normal hydrogen or standard hydrogen scale. The self-releasing surface may be applied in the molding system as a coating.

These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings.

Brief Description of the Drawings FIGURE 1 is a schematic of a molding system according to the present invention; FIGURE 2 is a diagram of the galvanic series of various metals and alloys and the region within the series usable as the moveable member of the molding system of FIGURE 1 ; FIGURE 3A is a schematic illustration of using a batch press as the molding mechanism in the molding system of FIGURE 1; FIGURE 3B is a magnified schematic illustration of the batch press FIGURE 3A; FIGURE 4A is a schematic illustration of using a continuous press as the molding mechanism in the molding system of FIGURE 1;

FIGURE 4B is a magnified schematic illustration of a continuous press as may be used in FIGURE 4A; FIGURE 4C is a magnified schematic illustration of an alternative continuous press as may be used in FIGURE 4A; FIGURE 5 is a schematic illustration of an extruder useable as the molding mechanism in the molding system of FIGURE 1 ; FIGURE 6 is a schematic illustration of a reaction injection molder useable as the molding mechanism in the molding system of FIGURE 1; FIGURE 7 is a photograph of various metal coupons after 10 pressings showing wood remaining thereon; FIGURE 8 is a graph of weight gain per unit area for various coupons as a function of the number of pressings; FIGURE 9 is a graph of average weight gain per unit area for various metal coupons under various conditions as a function of the metal's potential ( S. H. E); and FIGURE 10 is a graph of average weight gain under various conditions as a function of the metal's potential (« S. H. E).

Detailed Description of the Preferred Embodiment In the following description, like reference characters designate like or corresponding parts throughout the several views. Also, in the following description, it is to be understood that such terms as"forward,""rearward,""left,""right,""upwardly," "downwardly, "and the like are words of convenience and are not to be construed as limiting terms.

Referring now to the drawings in general to Figure 1 in particular, it will be understood that the illustrations are for the purpose of describing a preferred embodiment of the invention and are not intended to limit the invention thereto. As best described in Figure 1, a molding system, generally designated 10, is shown schematically according to the present invention. The molding system 10 includes a moveable member 12 having a self-releasing surface 14. The moveable member 12 may be any one of integral with and additional to a molding mechanism 20.

One optional feature of the molding system 10 includes a mixer 40 for combining a polymeric component with an isocyanate-based binder to form an assemblage 16.

Further, a polymer supply 42 and a binder supply 44 may come before and be connected to the mixer 40. Following mixer 40 may be a dispensing station 46 and a

transporting mechanism 48 (both not shown in Figure 1) for preparing and transporting the assemblage 16 to the molding mechanism 20. Examples of dispensing stations 46 and transporting mechanisms 48 are described and illustrated in U. S. Patent Nos. 4,058, 210; 4,284, 595; 4,454, 940; 4,479, 428; 4,506, 778; and 4,508, 772, the disclosure of each being hereby incorporated by reference herein in its entirety.

With respect to the self-releasing surface 14 of the moveable member 12, we have unexpectedly discovered that the release performance of the moveable member 12 is related to the material making up its surface and may be related to a substantial absence of sites capable of reacting with the isocyanate-based binder. Without wishing to be bound by any particular explanation or scientific theory, applicants believe that materials having surfaces that include a metal hydroxide (MOH) or hydrated metal hydroxide (MOHHOH) have the capability of reacting with an isocyanate group (R-NCO). A first possibility involves a reaction between an isocyanate group and a metal hydroxide to make a urethane metal complex (R-NH-CO-O-M) according to the equation A that follows: MOH + R-NCO ~ R-NH-CO-O-M. (A) A second possibility involves a reaction between an isocyanate group and a hydrated metal hydroxide to make a polyurea (R-NH-CO-NH-R) n according to the equation B that follows: n (MOHHOH) + 2n (R-NCO) (R-NH-CO-NH-R) n + n (MOH) + nC02. (B) Through reaction (A) or through reaction (B) followed by reaction (A) an isocyanate-based binder may bond directly to the material making up the surface of the moveable member, and when used in the molding system 10, would exhibit the isocyanate containing composite sticking problem.

To that end, applicants have unexpectedly discovered that materials being substantially free of sites capable of reacting with the isocyanate-based binder metal are free of the isocyanate containing composite sticking problem. Such materials include components substantially free of hydroxides and hydrated metal hydroxides. Included among such materials are metals, alloys, and metalloids having a standard oxidation potential greater than that of iron.

A material's potential is typically expressed with reference to a hydrogen electrode (i. e., 2H+ + 2e~ ~ H2) in which case the material's potential is expressed as volt on the normal hydrogen or standard hydrogen scale, sometimes expressed #H or b S. H. E.

Applicants have unexpectantly discovered that materials having a potential greater than about-0.44 volts on the normal hydrogen or standard hydrogen scale work well as the self-releasing surface 14 when in contact with an isocyanate containing assemblage.

Figure 2 depicts a galvanic series in flowing seawater (about 8-13 ft/s) and a temperature range of about 50-80°F (about 10-27°C) for a variety of metals, alloys, and metalloids. The potential or range of potentials of the metals, alloys, and metalloids are presented on the normal hydrogen or standard hydrogen scale, on the copper-copper sulfate reference electrode scale (i. e., 2H+ + 2e~ ~ H2), the saturated copper-copper sulfate reference electrode scale (i. e., Cu° ~ Cu++ + 2e), and the saturated calomet reference electrode scale (i. e. , 2Hg + 2Cl ~ Hg2 + 2e). Materials situated to the left of the low alloy steel are within the scope of the present invention. By way of example, such materials include, but are not limited to, brasses, copper bronzes, nickel and its alloys, and titanium.

Table 1 below lists alloys in order of the potential (Volts vs. b S. H. E. Half-Cell Reference Electrode) they exhibit in flowing seawater.

TABLE 1. CORROSION POTENTIALS IN FLOWING SEAWATER, (VOLTS as + S. H. E.) Range (volts) Alloy +0. 3+0. 2 Graphite +0. 26+0. 18 Platinum +0. 09 0. 03 Ni-Cr-Mo alloy C +0. 06 0. 04 Titanium +0. 04 0. 02 Nickel-Iron-Chromium alloy 825 +0. 06 0. 04 Alloy"20"Stainless Steels, cast & wrought 0-0. 1 *Stainless Steel-Type 316, 317 (passive) - 0. 03-0. 14 g Nickel-CoPDer alloes 400 K-500 - 0. 10-0. 15 Silver - 0. 04-0. 10 *Stainless Steel-Types 302 304 321 347 (passive) - 0. 10-0. 2 Nickel 200 - 0. 09-0. 2 Silver Braze Alloys - 0. 13-0. 18 *Nickel-Chromium alloy 600 (passive) - 0. 14-0. 22 Nickel-Aluminium Bronze - 0. 17-0. 24 70-30 Copper-Nickel - 0. 19-0. 25 Lead - 0. 20-0. 28 *Stainless Steel-Type 430 (passive) - 0. 21-0. 27 80-20 Copper-Nickel - 0. 22-0. 28 90-10 Copper-Nickel TABLE 1. CORROSION POTENTIALS IN FLOWING SEAWATER, (VOLTS as + S. H. E.) Range (volts) Alloy - 0. 24-0. 28 Nickel Silver - 0. 23-0. 35 *Stainless Steel-Type 410 416 (passive) -0. 24-0. 32 Tin Bronzes (G&M) - 0. 25-0. 29 Silicon Bronze - 0. 26-0. 34 Manganese Bronze - 0. 26-0. 36 Admiralty Brass, Aluminum Brass - 0. 27-0. 36 Pb-Sn Solder (50/50 - 0. 30-0. 37 Copper - 0. 30-0. 33 Tin - 0. 31-0. 40 Naval Brass, Yellow Brass, Red Brass - 0. 31-0. 40 Aluminum Bronze - 0. 33-0. 46 *Stainless Steel-Type 316 317 (active) - 0. 34-0. 46 *Nickel-Chromium alloy 600 (active) - 0. 43-0. 54 Austenitic Nickel Cast Iron - 0. 44-0. 58 *Stainless Steel-Type 302 304 321 347 (active) - 0. 45-0. 57 *Stainless Steel-Type 410 416 430 (active) - 0. 57-0. 63 Low Alloy Steel - 0. 60-0. 72 Mild Steel, Cast Iron - 0. 70-0. 74 Cadmium - 0. 76-1. 00 Aluminum Alloys - 0. 98-1. 03 Zinc - 1. 60-1. 63Magnesium

Alloys marked"*"may become active and exhibit a potential near-0. 5 volts in low-velocity or poorly aerated water and at shielded areas. Alloys having a potential greater than about-0.44 volts on the normal hydrogen or standard hydrogen scale may be suitable for use as the self-releasing surface 14 when making isocyanate containing consolidated product 18.

Table 2 lists materials in the order of their relative activity in seawater. The list begins with the more active (anodic) metal and proceeds down to the least active (cathodic) metal of the galvanic series. The list below is the latest galvanic table from MIL-STD-889 where the materials have been numbered according to how they interact in a galvanic couple in the seawater environment. Table 2 is the galvanic series of metals in seawater from Army Missile Command Report RS-TR-67-11,"Practical Galvanic Series." TABLE 2: GALVANIC TABLE FROM MIL-STD-889 Most Anodic (#1) Most Cathodic #92 1. Magnesium 26. AI 5052-H16 51. Brass (plated) 76. Stainless steel 316L (passive) 2. Mg alloy AZ-31B 27. Tin (plated) 52. Nickel-silver (18% NO 77. AM355 (active) 3. Mg alloy HK-31A 28. Stainless steel 430 I (active) 53. Stainless steel 78. Stainless steel 202 4. Zinc (hot-dip, die 316L (active) (passive) cast, or plated) 29. Lead 54. Bronze 220 79. Carpenter 20 5. Beryllium (hot 30. Steel 1010 (passive) pressed) 55. Copper 110 31. Iron (cast) 80. AM355 (passive) 6. Al 7072 clad on 56. Red Brass 7075 32. Stainless steel 410 81. A286 (passive) (active) 57. Stainless steel 347 7. Al 2014-T3 (active) 82. Titanium 5A1, 2. 5 33. Copper (plated, Sn 8. Al 1160-H14 cast, or wrought) 58. Molybdenum, Commercial pure 83. Titanium 13V, 9. Al 7079-T6 34. Nickel (plated) 11Cr, 3Al 59. Copper-nickel 715 (annealed) 10 Cadmium (plated) 35 Chromium (Plated) 60. Admiralty brass 84. Titanium 6Al, 4V 11. Uranium (solution treated 36. Tantalum 61. Stainless steel 202 and aged) 12. Al 218 (die cast) (active) 37. AM350 (active) 13. Al 5052-0 85. Titanium 6Al, 4V 38. Stainless steel 310 62. Bronze, Phosphor (anneal) 14. Al 5052-H12 (active) 534 (B-1) 15. Al 5456-0, H353 39. Stainless steel 301 63. Monel 400 86. Titanium 8Mn 39. Stainless steel 301 16. Al 5052-H32 (active) 64. Stainless steel 201 87. Titanium 13V, (active) 11Cr 3Al (solution 17. Al 1100-0 40. Stainless steel 304 heat treated and (active) 65. Carpenter 20 aged) 18. At 3003-H25 41. Stainless steel 430 (active) 88. titanium 75A 19. Al 6061-T6 (active) (active) 89. AM350 (passive) 20. Ai A360 (die cast) 42. Stainless steel 410 (active) 67. Stainless steel 316 21. Al 7075-T6 (active) 91. Gold 43. Stainless steel 17- 22. Al 6061-0 7PH (active) 68. Stainless steel 309 92. Graphite (active) 23. Indium 44. Tungsten 69. Stainless steel 17- 24. Al 2014-0 45. Niobium (columbium) 1% 25. Al 2024-T4 Zr 70. Silicone Bronze 655 46. Brass, Yellow, 268 71. Stainless steel 304 47. Uranium 8% Mo (passive) 48. Brass, Naval, 464 72. Stainless steel 301 49. Yellow Brass (passive) 50. Muntz Metal 280 73. Stainless steel 321 (passive) 74. Stainless steel 201 (passive) 75. Stainless steel 286 (passive)

As described in Figures 3A and B, the molding system 10 may include a batch press 22 having at least one opening 24 for receiving the assemblage 16 as part of the molding mechanism 20. In a batch press 22, the moveable member 12 may be a platen, a caul plate or both. Also shown in Figure 3A are a dispensing station 46 and transporting mechanism 48. Figure 3B depicts a batch press having multiple openings for receiving assemblage 16 and multiple moveable members 12; the number of moveable members 12 being equal to the number of openings 24. Examples of batch presses 22 usable with the present invention are described and illustrated in U. S. Patent Nos.

2,543, 582; 2, 728, 468; 3,565, 725; 3,619, 450; 3,611, 482 ; 3, 824, 058; 4,412, 801; and 4,846, 925, the disclosure of each being hereby incorporated by reference herein in its entirety.

Figures 4A, 4B, and 4C depict the molding system 10 as including a continuous press 26 having a molding mechanism and an advancement-consolidation mechanism 28 for simultaneously conveying and consolidating the assemblage 16. The advancement-consolidation mechanism 28 may include a belt 32 or a chain 30. Likewise, in a continuous press 26, the moveable member 12 may be the advancement-consolidation mechanism 28 having a continuous belt, a chain or mesh, a platen, a caul plate or combinations thereof. Also shown in Figure 4A are a dispensing station 46, transporting mechanism 48, and cutting station 50 for cutting the consolidated product 18 into panels or sheets. Examples of continuous presses 26 usable with the present invention are described and illustrated in U. S. Patent Nos. 3,120, 862 ; 3,723, 230; 3,792, 953 ; 3,851, 685; 3,993, 426; 4,043, 732; 4,213, 748; 4,802, 837; 5,085, 812; 5, 185, 114; 5,224, 367; 5,762, 980; 5,788, 892 ; 6,007, 320; and 6,190, 588B1, the disclosure of each being hereby incorporated by reference herein in its entirety.

Figure 5 depicts the molding system 10 as including an extruder 34 as a part of the molding mechanism 20. In extruder 34, the moveable member 12 can include a die 52, a mold 54 or both. Also shown in Figure 5 is a transporting mechanism 48 for advancing the assemblage into the die 52 or mold 54. An example of an extruder 34 believed to be usable with the present invention is described and illustrated in U. S. Patent Nos.

6,247, 913; 4,913, 863 and 3,095, 608, the disclosure of each being hereby incorporated by reference herein in its entirety.

As described in Figure 6, the molding system 10 may include an injection molder 38, preferably a reaction injection molder, as a part of the molding mechanism 20. In an injection molder 38, the moveable member may be a die, a mold or both. Also depicted

in Figure 6 is polymer supply 42, binder supply 44 and mixer 40 for supplying and combining the polymeric component with the isocyanate-based binder to form the assemblage. The injection molder 38 can further include a dispensing station and a transporting mechanism for advancing the assemblage into the die or mold. An example of an injection molder believed to be usable with the present invention is described and illustrated in U. S. Patent No. 5,770, 141, the disclosure being hereby incorporated by reference herein in its entirety.

The organic polyisocyanates useful in the isocyanate-based binder according to the present invention generally include any organic polyisocyanate compound or mixture of organic polyisocyanate compounds provided the compounds have at least two isocyanate groups. Suitable organic polyisocyanates include diisocyanates, particularly aromatic diisocyanates, and isocyanates of higher functionality.

Preferred isocyanates of the present invention include those wherein the isocyanate is an aromatic diisocyanate or polyisocyanate of higher functionality, such as pure diphenylmethane diisocyanate or mixture of methylene bridged polyphenyl polyisocyanates containing diisocyanates, triisocyanates and higher functionality polyisocyanates. Such materials are prepared by the phosgenation of corresponding mixtures of polyamines obtained by condensation of aniline and formaldehyde. For convenience, polymeric mixtures of methylene bridged polyphenyl polyisocyanates containing diisocyanate, triisocyanate and higher functionality polyisocyanates are referred to hereinafter as"polymeric MDI". Both polymeric MDI and emulsifiable MDI or aqueous emulsions thereof can be used. Preferably the polyisocyanate is liquid at room temperature.

Other examples of organic polyisocyanates which may be used in the process of the present invention include aliphatic isocyanates such as hexamethylene diisocyanate; aromatic isocyanates, such as m-and p-phenylene diisocyanate, tolylene-2, 4- and-2, 6- diisocyanate, diphenylmethane-4,4'-diisocyanate, chlorophenylene-2,4-diisocyanate, naphthylene-1, 5-diisocyanate, diphenylene-4,4'diisocyanate, 4,4'-diisocyanate-3, 3'- dimethyldiphenyl, 3-methyldiphenylmethane-4,4'-diisocyanate and diphenyl ether diisocyanate; and cycloaliphatic diisocyanates such as cyclohexane-2, 4- and-2, 3- diisocyanate, 1-methylcyclohexyl-2, 4- and-2, 6-diisocyanate and mixtures thereof and bis- (isocyanatocyclohexyl) methane and triisocyanates such as 2,4, 6-triisocyanatotoluene and 2, 4,4-triisocyanatodiphenylether.

Modified polyisocyanates containing isocyanurate, carbodiimide or uretonimine groups may also be used according to the present invention. Furthermore, blocked polyisocyanates, such as the reaction product of a phenol or an oxide and a polyisocyanate, having a deblocking temperature below the temperature applied when using the polyisocyanate composition may be utilized as the organic polyisocyanate binder in the present process. The organic polyisocyanate may also be an isocyanate- ended prepolymer prepared by reacting an excess of a diisocyanate or a higher functionality polyisocyanate with a polyol.

Water-emulsifiable organic polyisocyanates like those described in UK Patent No.

1,444, 933; in European Patent Publication No. 516361; and in PCT Patent Publication No. 91/03082 can also be used.

Mixtures of isocyanates may also be used in the present process. For example, a mixture of tolylene diisocyanate isomers, such as the commercially available mixtures of 2, 4- and 2,6-isomers and also the mixture of di-and higher polyisocyanates produced by phosgenation of aniline/formaldehyde condensates may be utilized as the organic polyisocyanate binder according to the present invention. Such mixtures further include the crude phosgenation products containing methylene bridged polyphenylpolyisocyanates, including diisocyanate, triisocyanate and higher polyisocyanates together with any phosgenation by-products.

The isocyanate-based binder may further comprise additives conventionally used in the art such as flame retardants, lignocellulosic preserving agents, fungicides, waxes, sizing agents, fillers, catalysts, surfactants and other binders such as formaldehyde condensate adhesives.

The isocyanate-based binder is generally applied to the polymeric component, which is preferably a natural polymer. The natural polymer can include material such as a cellulosic, preferably a lignocellulosic, in an amount of about 0. 1% to about 25%, preferably about 1% to about 12% and most preferably about 2% to about 8% by weight based upon the dry weight of the lignocellulosic material.

According to one aspect of the present invention, the lignocellulosic material is treated with the isocyanate-based binder material by means of, for example, mixing, blending, spraying and/or spreading the isocyanate-containing composition with or onto the lignocellulosic material. Such application may generally take place in a conventional blender. Thereafter, the treated lignocellulosic material is formed into a mat, preferably upon a screen. The lignocellulosic-containing mat may then be conveyed to a press

where pressure is applied thereto at elevated temperatures. The pressing operation generally includes pressing at temperatures of about 120°C to 260°C and at pressures of about 2 to 6 MPa. It will be recognized by those skilled in the art that the consolidation operation may be modified as needed for a particular operation.

While the process is particularly suitable for the manufacture of waferboard known extensively as oriented strand board and would largely be used for such manufacture, the process should not be regarded as limited in this regard. The present process can also be used in the manufacture of various types of engineered lumber products, such as, for example, medium density fiberboard, hardboard, particle board (also known as chipboard), plywood, laminated veneer lumber and beams, composite I- beams, and finger jointed lumber.

The cellulosic material suitable for use in the present process includes all types known in the industry, such as wood strands, wood chips, wood fibers, shavings, veneers, wood wool, cork, bark, sawdust and similar waste products of the woodworking industry as well as other materials having a lignocellulosic basis such as paper, bagasse, straw, flax, sisal, hemp, rushes, reeds, rice hulls, husks, grass, nutshells and the like. Moreover, the cellulosic material may be mixed with other particulate or fibrous materials such as mineral fillers, glass fiber, mica, rubber, and textile waste such as plastic fibers, fabrics and plastic particles.

The sheets and molded bodies produced according to the present invention have excellent mechanical properties and they may be used in any of the situations where such articles are customarily used.

Although the molding system 10 having a moveable member 12 with a self-releasing surface 14 of the present invention is directed to minimizing or eliminating the need for release agents, release agents may also still be used to enhance self-release of the assemblage. For example, release agents may be used internally, e. g. , as an emulsion or mixture with the organic polyisocyanate or externally, e. g. , applied to the self-releasing surface 14 of the moveable member 12 or to the polymeric component of the assemblage 16. According to another aspect of the invention the release agent can be used as an internal release agent, in conjunction with the use of an external release agent.

Examples of release agents include oil, wax polish, metallic soap, silicone such as polysiloxane having isocyanate reactive functional groups, and polytetrafluoroethylene.

A common external release agent is based upon fatty acid salts (e. g. , potassium oleate, sodium oleate, etc. ). Applicants believe that such fatty acid salts are to be used with care since at typical consolidation temperatures discoloration is observed in the consolidated product containing lignocellulosics. To that end the fatty acid salts may be used in an effective amount that is beneficial to the operation of the self-releasing surface 14 of the moveable member 12 while at the same time imparting substantially no discoloration to the consolidated product 18.

Common release agents are wax-based. The binding of lignocellulosic materials with polyisocyanates while using wax-based release agents is described in, for example, EP 46014 EP 57502, U. S. Patent No. 5,554, 438 and U. S. Patent No. 5,908, 496, the disclosure of each being hereby incorporated by reference herein in its entirety. Wax- based release agents may be used in an effective amount that is both beneficial to the operation of the self-releasing surface 14 of the moveable member 12 while imparting desirable frictional and/or adhesion properties to the surfaces of the consolidated product 18.

In general, release agents, whether used internally, externally, or internally and externally, are to be used in effective amounts that are beneficial both to the removal of consolidated product 18 from the self-releasing surface 14 of moveable member 12 while at the same time imparting little to no detriment to product physical properties (e. g., surface color, surface grip, surface roughness, surface adhesion, strength, moisture resistance, etc. ). Further, the use of release agent would be effective in amounts that provide good release memory and little or no build-up on the self-releasing surface 14 of the moveable member 12.

The following examples are provided to help illustrate certain aspects of the present invention and should be in no way viewed as limiting the scope of the present invention.

Examples Various metals were pressed on the surface of pMDI bonded consolidated product to evaluate a metal's propensity to stick to the consolidated product. Polymer-isocyanate- based assemblages were prepared using dried wood strands blended with about 4 weight percent (wt. %) pMDI (RUBINATE° M isocyanate, commerically available from Huntsman International LLC) in a rotary laboratory blender at a rate of 100 grams per

minute. A standard slack sizing wax was then spray atomized on the flakes. The mix comprised: about 5 Kg Aspen (Ainsworth Lumber) wood flakes (5.5% MC); about 200 grams pMDI (RUBINATE° M isocyanate); and about 50 grams slack paraffin wax.

Mats of the blended flakes measuring about 30 x 30 cm were hand formed in a box, on a screen. Prior to pressing, elementally pure metal samples (about 99.99 wt. % from Aldrich Chemical Company, Milwaukee, WI) were conditioned to simulate three moisture conditions; wet (about 18 hour water soak), dry (heated to about 200°C for about two minutes before each pressing), and no conditioning. After conditioning, the metal samples measuring about 25 x 25 x 0.25 mm were placed on the mat surface, where the largest and most uniform aspen flakes were situated. The mats were then pressed in a PLC controlled hotpress at a temperature of about 205°C using a pressing strategy of closing in about 20 seconds, holding for about 100 seconds, and decompressing in about 10 seconds. The mats were pressed to a thickness of about 6.4 mm directly to the steel platen surface that was pre-coated with a release agent. Following pressing, the panels were removed from the press. The metal samples were carefully removed in the direction of the wood grain, and the effort to remove the sample was noted. The weight of wood sticking to each metal sample was measured to about 0.0001 gram with an analytical balance. This was repeated nine times yielding a ten pressing series for each metal type and pre-conditioning.

It was found that certain metals are more likely to"stick"to MDI bonded consolidated product. Wood fiber tore away from the consolidated products and adhered to the metal coupons resulting in weight gain as may be seen in Figure 7. The amount of wood adhering to a metal coupon surface is graphed versus the number of pressings in Figure 8.

When the data was regraphed as shown in Figures 9 and 10, it is observed that a relationship exists between a metal material's electrochemical potential (b S. H. E. ) and lignocellulosic consolidated product sticking. That is as the metal material's potential exceeded-0.44 volts, sticking was reduced. In addition, it is observed that as a metal coupon's conditions go from dry to wet, the propensity for sticking increases, and wood failure weight gain increases. For these reasons, applicants believe that the reactivity between metal hydroxides and adsorbed water (e. g. , hydrated metal hydroxides), and the

isocyanate group, play a role in the sticking of isocyanate-based binder consolidated products and, in particular, MDI bonded lignocellulosic consolidated products to metal surfaces.

Further, applicants believe that the use of the present invention produces a consolidated product that is substantially superior to that of the prior art. Table 3 contains a summary of properties for comparison of a consolidated product of the present invention with the prior art. Among the properties compared are surface discoloration, surface grip, surface roughness, and surface adhesion.

As mentioned above, the use of release agents may impart discoloration upon a product. The extent of surface discoloration may be rated as severe, in the worst case, to substantially none in the best case. Colorimetric analysis may be used to quantify the extent to which a product possesses an aesthetically pleasing, light colored surface.

Surface grip is inversely related to surface slipperiness. The use of release agents may impart surface slipperiness upon a product. For the most part, surface slipperiness is undesirable and may be accentuated when the product is wet by water. In contrast, surface grip slipperiness is desirable and may be rated as poor, in the worst case when a product is slippery, to excellent when even the wetting by water imparts substantially no slipperiness. Determination of the coefficient of friction may be used to quantify the extent to which a product possesses satisfactory surface grip.

As mentioned above, without the use of release agents, almost inevitably a product may be characterized by extensive polymer pullout. Even with the use of release agents, a product may be characterized by moderate polymer pullout. The extent of surface roughness may be rated as extensive, in the worst case, to substantially none in the best case. Surface roughness measurements such as from a profilometer, qualitative visual analysis and even surface sensitive physical properties measurement may be used to quantify the extent to which a product possesses satisfactory surface roughness.

Surface adhesion relates the ability of a coating and/or adhesive to remain on a product. The use of release agents may have adverse effects on surface adhesion. The extent of surface adhesion may be rated as poor, in the worst case, to tenacious in the best case. Paint adhesion testing and glue adhesion testing may be used to quantify the extent to which a product possesses satisfactory acceptance to paints and glues.

Table 3. Properties for Comparison with the Prior Art Property And Rating Description -.--,-. Surface , . Surface Roushness ,..... RATING Surface. Surface Grip. Surface Roughness Surface Adhesion Discoloration (e. g. pullout) 1 Severe Poor Extensive Poor 2 Severe-Moderate Poor-Moderate Extensive-Moderate Poor-Moderate 3 Moderate Moderate Moderate Moderate 4 Moderate-None Moderate-Excellent Moderate-None Moderate-Tenacious l 5 None Excellent None Tenacious

Table 4 contains a summary of a comparison of properties for a consolidated product of the present invention with the prior art. Among the properties compared are surface discoloration, surface grip, surface roughness, surface adhesion and surface performance. Surface performance is the product of surface discoloration, surface grip, surface roughness and surface adhesion. A consolidated product of the present invention including a polymeric component, an isocyanate-based binder, a surface essentially free of a release agent, and a surface performance rating of about 625 is clearly superior over the prior art that at best has a performance rating of about 48.

Table 4. Comparison of the Present Invention with the Prior Art -,, Surface,.. Surface Surface Surface Surface Discoloration Surface Grip Rouhness Adhesion Performance e.. pullout Present 5 5 5 5 625 Invention Soap Release 1 3 4 2 24 Agents v Wax Release 4 2 3 2 48 A ents Silicone Release 4 2 4 1 32 Agents CoMposite 4 3 4 48 Board

Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.