Abstract: Aromatic alcohol-lignin-aldehyde resins and process for making and using same. In some examples, a process for making a resin can include heating a first mixture that includes a lignin, an aromatic alcohol, and a base compound to produce a second mixture that can include an activated lignin, the aromatic alcohol, and the base compound. The second mixture can be heated with an aldehyde to produce a third mixture that can include an aromatic alcohol-lignin-aldehyde resin and unreacted free aldehyde. In some examples, an aromatic alcohol-lignin-aldehyde resin can be or include a co-polymer of an activated lignin, an aromatic alcohol, and an aldehyde. A weight ratio of the activated lignin to the aromatic alcohol can be about 20:80 to about 95:5.

Abstract: A lignin-phenol-formaldehyde resin, which is obtained by polycondensation of formaldehyde, phenol and lignin in the presence of a basic or acidic catalyst, is characterized in that the lignin is a lignin that is not chemically modified at the available functional groups. This lignin has a low molecular mass and includes available functional groups chosen from the group including aliphatic hydroxyls and phenolic hydroxyls. The degree of substitution by weight of phenol with the lignin is between 50% and 60%. The weight proportion of the lignin and of phenol in the resin is equal to the weight proportion of phenol in a lignin-free phenol-formaldehyde (PF) resin.

Abstract: A method for transforming selected plant or plant-derived materials, and optionally selected waste plastics, into a plurality of phenolic reaction products having a lower sulphur content than the original feedstock, via supercritical water is disclosed. The method comprises: conveying the selected plant or plant-derived materials, and optionally waste plastic material, through an extruder, wherein the extruder is configured to continuously convey the selected feedstock to a supercritical fluid reaction zone; injecting hot compressed water into the supercritical fluid reaction zone, while the extruder is conveying the selected plant and/or plant-derived mixture and optionally waste plastic material into the supercritical fluid reaction zone so as to yield a water-containing mixture; retaining the mixture within the reaction zone for a period of time sufficient to yield the plurality of phenolic reaction products having a lower sulphur content than the original feedstock.

Abstract: A method for transforming selected renewable oils and fats, and optionally polyester waste plastic materials, into a plurality of reaction products via supercritical water is disclosed. The method comprises: conveying the selected oils and fats material through an extruder, wherein the extruder is configured to continuously convey the selected oils and fats material to a supercritical fluid reaction zone; injecting hot compressed water into the supercritical fluid reaction zone, while the extruder is conveying the selected oil and fats material into the supercritical fluid reaction zone so as to yield a mixture; retaining the mixture within the reaction zone for a period of time sufficient to yield the plurality of reaction products.

Abstract: Particulate binder compositions and methods for making and using same are provided. The binder composition for producing composite lignocellulose products can include an aldehyde based resin and a filler, an extender, or a combination thereof. The binder composition can be in the form of particulates. The particulates can each comprises the filler, the extender, or the combination thereof and the aldehyde based resin.

Abstract: A plate member for a housing has a wood part including a plurality of wood plates that are stacked, and a resin part adhered on the wood part and including a plurality of resin sheets that are stacked. Each of the plurality of resin sheets includes a plurality of pores.

Abstract: Reinforced wood flooring according to one embodiment includes: a surface layer having a plurality of wood sheets and a resin-impregnated paper sheet interposed between the wood sheets, in which each of the wood sheets has a predetermined thickness and a plate shape, and the wood sheets and the resin-impregnated paper sheets are bonded together into a unitary body through hot-pressing; an adhesive layer formed beneath the surface layer to serve as an adhesive; and a plywood arranged beneath the adhesive layer and attached to a lower side of the surface layer by the adhesive lay.

Abstract: The invention relates to a veneered panel (1) having a supporting panel (2) and a veneer which is joined to at least one surface of the supporting panel (2). An overlay (4) is provided on the side of the veneer (3) facing away from the supporting plate.

Abstract: A device for supporting equipment on a wall panel having protruding ribs. Channels are mounted perpendicular to the ribs. The channel has a base wall, and a pair of side walls extending outward from the base wall. The channel also has an outward wall portion communicating with the side walls at a distance from the base wall. Several apertures are defined in each channel. The apertures have a pair of side wall portions and a base wall portion. When the channel is positioned on the wall panel, the apertures receive the protruding ribs. A fastening structure is located on the base wall of the channel for mounting the channel to the wall panel. A fastening plate is also located on the outward wall portion of the channel for mounting the equipment to the channel.

Abstract: A layered composite product for use as a floorboard, a door, a cabinet, a wall, etc. is disclosed. The product is a layered structure that includes a rigid substrate layer having two substantially planar sides, a resin-saturated sheet layer disposed on each of the substantially flat sides, and a veneer layer disposed on at least one of the sheet layers. Also provided is a method of making the aforementioned product, the method comprising the steps of forming the layered structure, and then compressing the structure in a pressing apparatus for a time sufficient to cure the resin at under heat and pressure.

Abstract: A method of producing formaldehyde laden layered products, the products having reduced emission of formaldehyde, of at least 2 layers, at least one of the layers being a veneer, comprising a step of treating at least one of the surfaces of said veneer, prior to bonding the layers together, with a solution comprising an ammonium salt. The invention also relates to a flooring material obtained by the method.

Abstract: A method of producing formaldehyde laden layered products, the products having reduced emission of formaldehyde, of at least 2 layers, at least one of the layers being a board or veneer, comprising a step of treating at least one of the surfaces of said board or veneer, prior to bonding the layers together, with a solution comprising an inorganic sulphur containing salt. The invention also relates to a flooring material obtained by the method.

Abstract: Disclosed is a floor-covering material, in which a phenol composite resin comprising phenol resin of resorcinol-formaline and polyurethane resin is incorporated with paper and dried, to form a prepreg, which is then thermally compressed to the upper side of a PVC base or a waterproof plywood layer, yielding a transparent protective layer and a shaping layer. In the flooring material, the transparent layer and the shaping layer are made of phenol composite resin, and thus low in heat- and moisture-distortion, with no curling. Further, since a surface layer of the floor-covering material is hardly distorted by heat, a balance layer for the suppression of such distortion is not additionally required.

Abstract: Weatherable building materials particularly well suited for entry door skins and other exterior building components are prepared by compression molding lignocellulosic fibers digested under conditions such that partial breakdown of hemicellulosic and other components produces an in situ binder, together with a secondary phenol/formaldehyde binder resin, followed by impregnating the product with a non-fugitive tertiary binder.

Abstract: Coated articles having improved chemical resistance comprising an article formed from a moldable polymer coated on at least one surface with a coating composition comprising at least one vinyl ether oligomer compound, and at least one photoinitiator are disclosed. Coatings which also contain at least one acrylate compound and/or at least one epoxy compound are also disclosed. The articles are preferably made from polyesters. Methods for coating such articles are also disclosed.

Abstract: A veneer-based product is made of a plurality of veneer layers, a resin binding the layers, and a filler having a high thermal conductivity.

Abstract: A pharmaceutical composition containing an extract from inflammatory tissue inoculated with vaccinia virus may be used to suppress the death of cells caused by endotoxin, and suppress excessive production of nitrogen monoxide induced by endotoxin. The extract may also be used to relieve hypotension induced by endotoxin. In sepsis and other serious bacterial infectious diseases, endotoxin (an intracellular toxin) is produced and a shock symptom is induced by its action. The extract, having an excellent inhibitory action toward endotoxin-induced toxicity, is quite useful for the treatment or the prevention of endotoxin-induced shock symptoms, sepsis and various symptoms accompanied thereby. In addition, the extract has an inhibitory action towards abnormal nitrogen monoxide production during the diseased state and, therefore, it is also useful as a therapeutic and preventive agent for diseases wherein an excessive nitrogen monoxide production occurs, such as acute hypotension.

Abstract: The invention is a method of gluing wood using a reactive two component thermosetting adhesive such as a phenol-resorcinol-formaldehyde (PRF) condensation product. One component is first coated on one of the members to be bonded. The second component is then spread directly on top of the first in a manner to minimize mixing; e.g., by spraying. When the mating member to be bonded is placed against the adhesive coated first member and pressure is applied the components are mixed. This begins the curing reaction between the components so that a thermosetting adhesive bond is formed. With selected adhesives very rapid curing times are possible. A preferred adhesive has a first component comprising a PRF resin mixed with a methylene group donor hardener such as paraformaldehyde. The second part is also a PRF resin. No hardener is present in the second part. Instead an oxygen and nitrogen containing heterocycle is used as an accelerator. Morpholine is a preferred compound.

Abstract: The invention comprises a method of densifying lignocellulosic material such as wood. The wood is impregnated with a maltodextrin solution under vacuum and/or pressure and the maltodextrin is then cross linked to insolubilise the maltodextrin. A wood-polymer composite is formed. Suitable cross linking agents include compounds having at least one hydroxyl group. Maltodextrins having a dextrose equivalent in the range 15 to 30 are preferred. The resulting composite material has improved appearance, hardness, impact resistance, strength and water repellency.

Abstract: The present invention provides a wood board, and a flooring material using this, which uses thin wooden strands as a raw material, has superior surface smoothness, and possesses sufficient strength and rigidity. The wood board in accordance with the present invention comprises a core layer 1 comprising a strand board, and a surface layer 2 comprising a oriented strand board which is laminated on at least one surface of the core layer 1; the surface layer 2 comprises thin wooden strands which are thinner than the thin wooden strands comprising the core layer, and furthermore, the flooring material of the present invention is obtained by laminating a decorative single sheet onto at least one of the surface layers 2 of the wood board. The wood board and flooring material in accordance with the present invention have high strength and superior surface smoothness.

Abstract: The invention relates to the use of a resorcinol-glutaraldehyde reaction product as an accelerator for thermosetting phenolic resin and to a method of making the accelerator. Further, the invention relates to a resin blend comprising phenol-formaldehyde and the accelerator and a process for making cellulosic board, oriented strandboard and plywood wherein the binder for the cellulosic board, oriented strandboard and plywood in its uncured form comprises the resin blend of the invention. In another embodiment the accelerator for thermosetting resin comprises resorcinol and glutaraldehyde.

Abstract: A rapid curing adhesive for wood finger jointing and laminating and a method of its use are disclosed. The adhesive consists of two parts that are used as a honeymoon system. One part is used on one side of the joint being formed and the other part on the other side. When the parts are joined under pressure a very rapid reaction occurs resulting in a durable weather resistant joint. Wood finger joints bonded with the adhesive can be handled for further processing within as little time as 15 seconds. The first part of the adhesive is a conventional resorcinol-formaldehyde or phenol-resorcinol formaldehyde resin containing a hardener such as an alkylene group donor. The second part is a similar resin lacking any hardener but containing a modifier which is a heterocyclic oxygen and nitrogen containing compound. Morpholine has proved to serve well as the modifier. The hardener in the first part is used in a sufficient amount to effect a thermosetting cure for the resin used in both parts.

Abstract: A composite board which includes a core and inner and outer surface layers, said core and surface layers each including cellulose material and a cured resin binding said cellulose material together, wherein the resin in the core of the composite is an acid setting resin and the core includes a low steam volatile weak acid in an amount of between 2 to 8% by weight to the dry weight of the cellulose material in the core.

Abstract: An intumescent fire-resistant coating and a fire-resistant material using the same are disclosed, the coating essentially including (A) at least one inorganic compound selected from the group consisting of a carbide, boride, nitride, carbonitride, or carboboride of titanium, zirconium, vanadium, niobium, tantalum, molybdenum, tungsten, silicon or chromium and a carbide, nitride or carbonitride of boron, (B) a synthetic resin, and (C) at least one phosphorus and/or sulfur compound capable of forming a Lewis acid on heating.

Abstract: A composite wood product made from discrete wood particles secured together by a cured bisphenol A formaldehyde resin cured from an A-stage bisphenol A formaldehyde resin having an A-stage bisphenol A to formaldehyde mole ratio of 1 to between 2.5 and 4 and between 3 and 11% of caustic measured as sodium hydroxide based on the weight of resin solids. Preferably the resin will include 2 to 10% urea based on the resin solids. The cured bisphenol A formaldehyde resin secures the wood particles together to form a composite wood product having light colored glue lines that substantially corresponds in color with the wood so that the glue lines tend to be unnoticeable.

Abstract: A fusible phenolic resin and a dialkyl-N, N-bis (hydroxyalkyl) aminoalkyl phosphonate are condensed to form a water-insoluble resin having fire retardant properties. Fire resistant materials are made by causing the condensation to occur in situ when a normally flammable material and the reactants are mixed and the mixture is heated at 250.degree. F. to 480.degree. F. Wooden articles such as molded hardboard roofing shingles of this invention do not lose their fire resistance after being soaked with rain repeatedly.

Abstract: The invention is a board of non-timber hardwood-replacement lumber. The primary constituent is rinds of a grass selected from the group of grasses consisting of sugarcane and sorghum. The board has an integral mass of parallel elongate flattened rinds aligned along the length of the board, parallel to a board surface and joined together by adhesive bonding. A "cant" (from which the boards are made) is also disclosed and like the boards sawed from it, the cant is substantially void-free and of substantially constant density throughout its cross-section. The board is furniture-grade and exhibits grain characteristics very closely similar to natural hardwood.

Abstract: A laminated veneer lumber product utilizes low density veneers and is able to provide an edge stiffness value or MOE of at least 2,000,000 psi. This is the same strength as attained with high density veneers. The product has adjacent surface layers formed of low density incised veneer sheets having a moisture content of at least about 6% or adjacent surface layers formed of low density incised veneer sheets impregnated with phenolic resin and dried to a moisture content not exceeding about 5%. The surface layers are positioned on both sides of adjacent core layers which are either formed of high density veneer sheets or are formed of low density incised veneer sheets impregnated with a phenolic resin and dried to a moisture content not exceeding about 5%. The surface layers of low density incised veneer sheets having a moisture content of at least about 6% are densified against the core layers by at least about 5%.

Abstract: A process for preparing phenol-formaldehyde resole resins by fractionating organic and aqueous condensates made by fast-pyrolysis of biomass materials while using a carrier gas to move feed into a reactor to produce phenolic-containing/neutrals in which portions of the phenol normally contained in said resins are replaced by a phenolic/neutral fractions extract obtained by fractionation.

Abstract: A process for preparing phenol-formaldehyde novolak resins and molding compositions in which portions of the phenol normally contained in said resins are replaced by a phenol/neutral fractions extract obtained from fractionating fast-pyrolysis oils. The fractionation consists of a neutralization stage which can be carried out with aqueous solutions of bases or appropriate bases in the dry state, followed by solvent extraction with an organic solvent having at least a moderate solubility parameter and good hydrogen bonding capacity.Phenolic compounds-containing/neutral fractions extracts obtained by fractionating fast-pyrolysis oils from a lignocellulosic material, is such that the oil is initially in the pH range of 2-4, being neutralized with an aqueous bicarbonate base, and extracted into a solvent having a solubility parameter of approximately 8.4-9.11 [cal/cm.sup.3 ].sup.1/2 with polar components in the 1.8-3.0 range and hydrogen bonding components in the 2-4.

Abstract: A phenol-formaldehyde resole resin solution useful in adhesives for preparing wood laminates from a plurality of wood veneers, prepared by reacting at least an equal molar amount of formaldehyde with phenol in the presence of sodium hydroxide and a water-soluble potassium salt selected from the group consisting of potassium choloride, potassium sulfate and mixtures thereof.

Abstract: A process for preparing phenol-formaldehyde resole resins and adhesive compositions in which portions of the phenol normally contained in said resins are replaced by a phenol/neutral fractions extract obtained from fractionating fast-pyrolysis oils.

Abstract: An improved method for providing a smooth, abrasion resistant surface substantially free of surface irregularities on a solid substrate possessing surface irregularities, the method comprising the steps of: (a) forming an uncured and unbonded laminate overlay of at least two sheets of cellulose impregnated with a thermosettable resin; (b) substantially curing the thermosettable resin to form a laminate overlay that is both precured and bonded; and (c) adhering the precured bonded laminate overlay to a solid substrate possessing surface irregularities so as to substantially bridge the irregularities. The method has particular application to the manufacture of concrete forms.

Abstract: It has now been found that when there is a partial or complete replacement of the sodium hydroxide that is used to make a sodium phenolate resole resin by a molar equivalent of potassium hydroxide, a far faster curing resin is obtained. Such potassium-modified phenolic resins exhibit significant improvement in cure speed without loss of flowability. To the contrary, these resins act as though they were lower molecular weight condensation products. Reduced application rates are possible. The combination of faster cure and lower application rates has allowed such resins to be used as effective adhesives for plywood, for example, with veneer and interior plies having a higher moisture content than was previously possible. Generally, resins according to the invention may contain from about 1% to about 14%, and preferably from about 1% to about 7% by weight, of potassium hydroxide, or more.

Abstract: The disclosure relates to a medium density overlay plywood panel used as an exterior trim product for a residential building having a relatively high number of plies to total board thickness, and exposed edges with void free sanded surfaces having a predetermined pattern coarseness, and in which said overlay and edge surfaces are covered with an acrylic paint, whereby the trim product is characterized with the appearance of a solid wood product and the painted surfaces as highly weather resistant.

Abstract: The invention is a solution of highly advanced phenolic resin with improved inherent foamability that is made from the reaction of phenol, aldehyde, water and alkali the improved foamability being brought about by the incorporation of up to 1.0% by weight, anhydrous basis, lime (calcium hydroxide) into the early stages of the reaction mix. In another embodiment, the invention is a plywood glue composition comprising a solution of lime-containing highly advanced phenolic resin, dried animal blood and preferably an aldehyde glue viscosity-lowering agent.

Abstract: There are disclosed a flame retardant for treatment of wood and a wood product coated with the flame retardent, which comprises (A) 3-(dialkylphosphono)propionamides respresented by the following general formula: ##STR1## (in which R.sub.1 and R.sub.2 each represents an alkyl group containing 1 to 3 carbon atoms; and R.sub.3 represents a hydrogen atom, a methyl group or a methylol group group) and/or methylolated derivatives thereof; (B) at least one resin selected from the group consisting of water-soluble or water-dispersible resins, melamine resins and copolycondensated urea-melamine resins; and (C) ammonium polyphosphates microcapsulated by melamine and/or epoxy resins.

Abstract: An improved phenol formaldehyde resin not requiring fillers or extenders and capable of bonding wafers or veneers having a moisture content of 10% or above is disclosed. The adhesive composition is prepared by mixing together a caustic solution of a high molecular weight PF resin, a dispersion of PF resin which is characterized in that it can swell in aqueous caustic medium but not go into solution, and alkylene carbonates or phenol resorcinol formaldehyde resins. Optionally, borax is utilized. The disperse phase is made by converting a solution of PF resin into a fine particle size particulate form by precipitation, spray drying or freeze drying, and partially cross-linking the resin during or subsequent to the formation of the fine particle size dispersion. The PF resin is partially cross-linked by (a) heat, by (b) acid catalysis, or by (c) a reaction with cross-linking chemicals.

Abstract: A temporary support with a transferable film composition coated on its surface is used in the manufacture of heat and pressure consolidated laminates to produce laminates of improved surface strength and functional properties. The film is composed of polyvinyl butyral resin and melamine resin. Additives may be included in the film composition for functional purposes and appearance.

Abstract: A method of manufacturing a liquified fiber-phenol-formaldehyde resin includes heating a mixture of phenol, formaldehyde, liquified cellulosic fiber and alkali at a temperature of 60.degree. C. to 100.degree. C. and a pH of 8-13. The liquified cellulosic fiber comprises about 5 to about 80 percent of the total weight of phenol, formaldehyde and liquified fiber. Also disclosed are fibrous articles manufactured using this resin as a binder, such as fiberboards, particle board, plywood, oriented strand board, and waferboard.

Abstract: Finely divided almond shell flour is used as an extender in plywood- and laminating-adhesives, alone or in combination with other, different, vegetable shell flours.

Abstract: It has now been found that when there is a partial or complete replacement of the sodium hydroxide that is used to make a sodium phenolate resole resin by a molar equivalent of potassium hydroxide, a far faster curing resin is obtained. Such potassium-modified phenoli resins exhibit significant improvement in cure speed without loss of flowability. To the contrary, these resins act as though they were lower molecular weight condensation products. Reduced application rates are possible. The combination of faster cure and lower application rates has allowed such resins to be used as effective adhesives for plywood, for example, with veneer and interior plies having a higher moisture content than was previously possible. Generally, resins according to the invention may contain from about 1% to about 15%, and preferably from about 1% to about 7% by weight, of potassium hydroxide, or more.

Abstract: Substitute lumber pieces having strengths and densities substantially equivalent to lumber are cut from single layer panels of over about 1 and normally less than 4 inches thickness made from wood wafers. The wafers are oriented with their lengths having a mean deviation to the longitudinal length of the panel measured in the major plane of the panel in the range of 0 to 10 degrees and a mean deviation measured in a minimum longitudinal plane perpendicular to the major plane from 0 to about 5 degrees and have an average effective length of at least 8 inches (200 mm), and preferably an average thickness less than 0.15 inches (4 mm) and a width of at least 0.25 inches (6 mm). Lumber is made by cutting the panel longitudinally. Preferably the panels are formed to have a substantially uniform density profile throughout their thicknesses.

Abstract: A dimensionally stable composite wood panel having wood veneer sheets with their grains disposed in the same direction, and a core of adhesively-bonded biomass particles is improved by including a third wood veneer sheet having its grain substantially perpendicular to the grains of the surface veneer sheets. Additional veneer sheets may lie intermediate the surface sheets and the intermediate sheet, with its grain structure oriented parallel to the surface sheets. The panel produced may be ripped or sawed to form laminated veneer lumber of such dimensions that it may be substituted for structural lumber. The laminated veneer lumber of the present invention has improved dimensional stability and may be nailed without splitting or cracking. A process of manufacturing continuous or indefinite lengths of the composite wood panel is disclosed.

Abstract: A method of manufacturing a lignosulfonate-phenol-formaldehyde resin includes heating a mixture of phenol, formaldehyde, lignosulfonate and alkali at a temperature of 60.degree. C. to 100.degree. C. and a pH of 8-13. The lignosulfonate comprises about 5 to about 80 percent of the total weight of phenol, formaldehyde and lignosulfonate and the lignosulfonate is mixed with said phenol and formaldehyde before substantial reaction between said phenol and said formaldehyde. Also disclosed are fibrous articles manufactured using this resin as a binder, such as fiberboards, particle board, plywood, oriented strand board, and waferboard.

Abstract: The disclosure relates to difficulty flammable wooden articles, especially chip boards comprising solid and pipe boards, prepared by extrusion from wooden chips and/or woody fibrous materials. The articles contain as a flame-retarding addend a product of(a) 50 to 99.5 weight % of a flame-retarding agent physically and chemically stable under extrusion conditions, preferably 75 to 99.5 weight % of a pulverulent, free-flowing ammonium polyphosphate of the general formulaH.sub.(n-m)+2 (NH.sub.4).sub.m P.sub.n O.sub.3n+1in which n stands for a whole number with an average value of about 20 to 800 and the ratio of m/n is about 1, and(b) about 0.5 to 50 weight % of a cured water-insoluble artificial resin encapsulating the individual particles of the flame-retarding agent or ammonium polyphosphate.The disclosure also relates to difficulty flammable boards veneered with wood or a laminate.

Abstract: An improved moisture-stable phenolic resin binder with calcium ions from the catalyst complexed with the phenolic resin and a process for its preparation and laminate boards with the said binder as the binding agent.

Abstract: Wood surfaces are bonded together by heating and pressing with a bonding composition containing, on a bonding agent solids basis, from 10-70% of one or more sugars and from 90-30% of an aminoplast, and the bonding composition being used in an amount equal to the amount of straight condensation resin which would normally be used, i.e. the sugar replaces a quantity of condensation resin normally used thereby reducing the total quantity of condensation resin, thereby reducing cost and formaldehyde emissions and without any disadvantages.

Abstract: A composite wood product, such as waferboard, is treated during manufacture with preservative chemicals to improve resistance to decay and insect organisms. The process avoids having to treat a finished product and is not limited to only surface protection. Molten slack wax is first applied to wood particles having a moisture content not greater than about 10%, the wax coated wood particles are then sprayed with an ammoniacal copper arsenate solution having a concentration of at least about 11% followed by blending with adhesive resin and forming a composite wood product.

Abstract: Substitute lumber pieces having strengths and densities substantially equivalent to lumber are cut from single layer panels of over about 1 and normally less than 4 inches thickness made from wood wafers. The wafers are oriented with their lengths having a mean deviation to the longitudinal length of the panel measured in the major plane of the panel in the range of 0 to 10 degrees and a mean deviation measured in a minimum longitudinal plane perpendicular to the major plane from 0 to about 5 degrees and have an average effective length of at least 8 inches (200 mm), and preferably an average thickness less than 0.15 inches (4 mm) and a width of at least 0.25 inches (6 mm). Lumber is made by cutting the panel longitudinally. Preferably the panels are formed to have a substantially uniform density profile throughout their thicknesses.