Abstract:
New composite members, for example, useful in decks or decking systems, rail or railing systems and window-coverings or blinds and the like, as well as methods for producing the same or like items have been discovered. The composites or composite members are easy to manufacture in a variety of configurations using relatively inexpensive materials. In addition, the composites are sturdy, lightweight and have excellent weatherability properties. In addition, the composites or composite members have many of the desirable properties of natural wood products such as fences and decks and railings. For example, the composites of the invention can be made to have a wood-like look and texture, for example, without having any wood content. Moreover, unlike solid wood fences and decks, the composites of the present invention preferably are highly resistant to effects of weathering.

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to composite members and more specifically relates to compositions, pellets and composite members made therefrom and useful as or in the form of deck elements, window blind (covering) elements, rail (railing) elements, and the like, and methods for producing same. 
     Traditionally, decks, window blinds and railing systems have been made of components fashioned from solid wood. Such wood elements are often considered more aesthetically appealing than those made of metal or cement. However, construction of wood decks or wood window blinds (window coverings) or wood railing systems is labor intensive. Solid wood components are heavy and cumbersome. In addition, maintenance of wood decks, blinds or railings is expensive. 
     After a period of time, solid wood components naturally begin to break down from weather and/or light exposure and/or pest infestations. It is known that this deterioration can be tempered by treating such wood components with widely available weather resistant coatings, paints, varnishes, finishes and the like. Unfortunately however, it is often only a matter of time before such treated wood components deteriorate requiring partial or complete replacement. 
     In addition, solid wood materials that are suitable for decks, window blinds and rails are costly. Also, because of natural variations in wood, replacement of individual components may result in an inconsistent, uneven appearance to the deck, window blinds or railing system. 
     Plastic components have been developed as alternatives or supplements to traditional, natural wood structures. 
     For example, U.S. Patent Publication No. 2007/0148429 (McGrath et al) discloses tri-extruded thermoplastic profiles which are reinforced and not homogeneous. This publication discloses a first polymeric composition in the form of a structural frame including: reinforcing fibers coated with a sizing composition that contains a film forming agent, a coupling agent, a lubricant, and one or more additives. A second polymeric composition fills the recess of the structural frame and a third polymeric composition is a cap or coating. The polymers used may include high density polyethylene (HDPE). 
     The second polymeric composition may be a foamed composition or filler. The reference discloses that the addition of wet use chopped strand (WUCS) fiberglass may enhance strength of the foamed composition; and that wood flour (WF) may be used in any of the three polymeric compositions. 
     McGrath et al does not disclose that the finished profiles may be used for decking and fence railing; see paragraphs [0037] and [0087]-[0080]. 
     McGrath et al implies, at paragraph [0102] that the incorporation of glass fiber into foamed boards does not successfully improve their mechanical properties due to insufficient adhesion of the glass fibers with the polymeric materials. The reference purports to overcome this problem with the use of a size composition and WUCS. 
     U.S. Patent Publication No. 2003/0082338 (Baker) discloses a composite material comprising a thermoplastic polymer, for example, polyethylene, and a fiber material, for example, wood. 
     Baker discloses that the composite material contains about 40% to about 70%, preferably about 50%, by weight, of the fiber material. Baker does not disclose the use of fiberglass. 
     U.S. Patent Publication No. 2012/0077890 (Mancosh et al) discloses composite profiles made using recycled carpet waste, including carpet fibers and adhesive, and fly ash. Mancosh et al discloses that carpet waste is an essential ingredient in the composites of this reference. Mancosh et al discloses that wood fiber and fiberglass fibers may optionally be used. The compositions may also contain a base polymer, which may comprise HDPE. In other embodiments no base polymer is included. 
     U.S. Patent Publication No. 2003/0198780 (Campese et al) discloses a pultruded composite comprising a matrix and coated hollow microspheres. Campese et al discloses that the composite may be reinforced with fiberglass mat. The composite may include polyethylene or “vinyl” and wood fibers may be present. Campese et al does not disclose extruded products or extrusion; and also does not disclose foamed composites. 
     Other references include: U.S. Patent Publication No. 2004/0126515 (Yarmoska); U.S. Pat. No. 5,100,109 (Robbins, III); U.S. Pat. No. 5,404,685 (Collins); U.S. Pat. No. 6,827,995 (Hughes et al); and U.S. Pat. No. 6,890,965 (Johnson et al). 
     There still remains a need in the market today for inexpensive, lightweight decking components, window coverings, and rail components that are sturdy, weather resistant, lightweight, and aesthetically appealing, and easy to manufacture using simple manufacturing techniques. Further, there remains a need for compositions, including pellets and formulations for making such components, and coverings. 
     SUMMARY OF THE INVENTION 
     New composite members, for example, useful in decking elements or decking systems, rail elements or railing systems, and window coverings or blinds, and the like, as well as compositions and methods for producing the same or like items have been discovered. The present composite members are easy to manufacture in a variety of configurations using relatively inexpensive and readily available materials. In addition, the composite members are both sturdy and lightweight compared to solid wood elements, and have excellent weatherability properties. The present composite members have many of the desirable properties of natural wood products such as decks, window blinds (coverings) and railings, including fences. The composites and composite members of the invention can be made to have a wood-like look and texture, for example, without having any wood content. Moreover, unlike solid wood elements, the composites and composite members of the present invention preferably are highly resistant to effects of weathering, for example, are weatherable. In other examples, such composites and component members may comprise a wood or other filler. 
     Methods for producing composite members are provided, as are compositions, including, without limitation, fused and compacted pellets, for making the same. 
     In one example, such a method comprises forming a mixture comprising high density polyethylene (HDPE), for example, at least about 40% or at least about 45%, or at least about 50% by weight of HDPE, and a chopped fiberglass component. The fiberglass component is selected from the group consisting of chopped fiberglass mat, chopped fiberglass strand, and mixtures thereof in an amount equal to or less than about 20% by weight of the total mixture, the mixture being substantially free of carpet waste; and processing the mixture to produce the composite member. By “mat” is meant fiberglass strand of any geometric shape, which is at least partially woven. As intended in this application the term “fiberglass component”, when used to refer to the present invention (and the mat and/or strand comprising it) shall, unless specifically excluded, always include a coupling agent, such as a coating comprising a coupling agent. The composite member has increased strength relative to a reference composite member produced by identically processing an identical mixture without the chopped fiberglass component. 
     The processing may include any suitable step or steps effective to produce the composite member. In one example, the processing comprises extruding the mixture. The processing may preferably comprise foaming the mixture, for example, to form a substantially homogeneous foamed composite. 
     Compositions of the present invention may comprise fused or compacted pellets, or powdered, chopped or granulated compositions to be used in formulating and forming the composites and components described herein. 
     The method may further comprise applying a weatherable cap to the composite member. 
     In one example, the method further comprises forming the composite member into a shape of one of a decking element, a window blind element (a window covering element) or a rail element (an element of a railing assembly). 
     In one example, a deck is provided comprising a plurality of composite members, as described herein, in combination. For example, the composite members, each in the form of a decking element, may be linked, secured or otherwise used, together to form a deck. 
     A window blind, for example, a window covering, may be provided comprising a plurality of composite members, as described herein. For example, the plurality of composite members, each in the form of a window blind element, may be linked together, for example, in a conventional manner, to form a window blind or window covering. 
     One or more elements of a rail (railing) system, for example, a rail system (e.g., rail posts, ballisters and/or railings) for a stair case, a swimming pool, a walkway and the like, may be provided comprising a plurality of composite members in the form of railing elements, as described herein. For example, the composite members, each in the form of a railing element, may be linked or otherwise used together to form a railing system. 
     Various examples and embodiments of the present invention are described in detail in the detailed description and claims herein. Any feature or combination of features described herein are included within the scope of the present disclosure provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. In addition, any feature or combination of features may be specifically excluded from any example or embodiment of the present disclosure. Additional advantages and examples are apparent in the following detailed description, claims and drawings in which like parts bear like reference numbers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-section view, in perspective, of a composite member of the present invention in the form of a rail post. 
         FIG. 2  is a cross-section view, in perspective, of a composite member of the present invention in the form of a decking board. 
         FIG. 3  is a cross-section view, in perspective, of a composite member of the present invention in the form of a window blind element. 
     
    
    
     DETAILED DESCRIPTION 
     The present composite members and/or materials may be used in various forms, to form, for example, structural materials or articles such as decking elements, rail or railing elements, window coverings and the like. The present composite members/compositions may be weatherable, strong and impact resistant. 
     As used herein, the term “weatherable” refers to the ability or property of a material, such as a composite member, to effectively withstand the conditions of an out-of-doors environment over a long period of time, for example, at least five years and preferably at least seven years, with substantially no degradation, decomposition, and/or loss of structural strength. 
     In one example, the present composite members, such as decking elements, rail (or railing) elements, window covering or window blind elements, are substantially resistant to the effects of outdoor weather on a long term basis and, therefore, can be employed out-of-doors. The present composite members can be molded, pressed, extruded and/or otherwise formed into shapes and configurations useful in producing finished product articles. Such finished product articles can include only the compositions of the present invention or; other examples may include combinations of the present composite members (compositions) with other materials. In one example, certain of the compositions from which the present composite members are made (or other suitable compositions), in accordance with the present invention may be used to apply a cap to the finished article, such as (without limitation) through a co-extrusion process. Preferably, the cap has a thickness between about 20/1000 of an inch to about 30/1000 of an inch, or preferably less than about 1/16 of an inch, or preferably less than about ⅛ inch, do not comprise fiberglass, and/or are unfoamed. 
     In one example, one or more composite members are provided comprising a foamed composition, for example, a substantially homogenous foamed composition, comprising high density polyethylene, sometimes referred to herein as HDPE; chopped fiberglass mat in an amount less than about 20% by weight of the composition and being effective to increase the strength of the foamed composition and/or composite member. The present composite members may be substantially free of carpet waste. In one example, the present composite members may be substantially free of hollow microspheres (other than those used in foaming components). 
     The present composite members are preferably foamed and may be manufactured or otherwise provided and/or used in any suitable form. For example, and without limitation, the present composite members may be in the form of a decking element, a window blind or window covering element, a rail element (such as a ballister), that is at least one element of a railing system or assembly, and the like. 
     In one example, the chopped fiberglass component of the present composite members provides increased or added strength to the composite members. This is surprising since it has been believed that fiberglass, even relatively large amounts, for example, about 30% by weight or more, of fiberglass, did not substantially increase the strength of hydrocarbon polymer-containing articles containing such relatively large amounts of fiberglass. 
     Furthermore, it was previously thought that the addition of fiberglass to HDPE-containing compositions in weight amounts of less than about 20% had little or no advantage in the resulting composite&#39;s strength beyond that of less expensive fillers such as wood or talc. 
     However, It has now been surprisingly found that a relatively small amount, for example, less than about 20% by weight, or less than about 15% by weight, or less than about 12% by weight, or less than about 10% by weight, or less than about 8% by weight, or less than about 5% by weight, of a chopped fiberglass component, for example, fiberglass strand and/or mat, in the composite members of the present invention at least assists in providing or provides a significant, even synergistic, increase in strength to the present composite members, for example, relative to identical composite members without the chopped fiberglass component being present. Particularly surprising is that the strength of the foamed composite members of the present invention is particularly increased relative to an otherwise identical foamed composite member lacking the fiberglass component or to an otherwise identical foamed composite member lacking the fiberglass component but containing other conventional fillers at the same percentage by weight as that of the reference fiberglass-containing component. This benefit of the presence of chopped fiberglass mat advantageously occurs or is provided in composite members that are substantially free or free of carpet waste. 
     In one example, a chopped fiberglass component is present in an amount less than about 15% by weight of the composite member. In another example, the chopped fiberglass component is present in an amount less than about 10% by weight of the composite member. Benefits, for example, increased strength, may be provided to composite members in accordance with the present invention including as little as about 2% by weight, or even about 1% or less, by weight, of the chopped fiberglass component. 
     The high density polyethylene (HDPE) component of the present composite members may be any suitable such component having a density of at least about 0.94 to about 0.97 gm/cc, or about 0.95 gm/cc. The term “high density polyethylene” is well known and understood in the polymer processing and use arts. Low density polyethylene (LDPE), which may also be useful in the formations of the present invention, has a density below about 0.94 gm/cc, and may be in largely linear for; these are linear low destiny polyethylene (LLDPE). 
     In some examples, the composite members of the present invention are uncapped. In other examples, the composite members of the present invention may further comprise a weatherable cap or cover component, covering at least a portion of the composite member. In one example, the cap component is deposited on the composite member after the composite member (that is, the foamed composite member without the cap) is formed. In one example, the cap may comprise a polyester film (such as MYLAR®) or an acrylic composition wrapped around or glued or fused to the composite member. In other examples, the cap component may be co-extruded with the composite member, which is preferably foamed. The cap component may be provided to alter or change the outer surface, for example, the color or texture of the outer surface, of the composite member. The cap component may be made of the same material as the rest of the composite member or may be made of a different material, as the case may be. In preferred examples the cap component does not contain a fiberglass component. The cap may be, and in preferred examples is, made of unfoamed material. In one example, the cap component and the other components of the composite member may be, and preferably are, sufficiently compatible so that the cap component remains in place on the composite member for substantially the entire useful life of the composite member. 
     In one example, the cap component is not foamed and has substantially the same composition as the remainder of the composite member. In another example, the cap component includes substantially no chopped fiberglass component. Preferably the cap has a thickness of about ⅛″ or less, or about 1/32″ or less, or about 30/1000 inch or less, or between about 20/1000 inch to about 30/1000 inch. In some examples, such as certain blind components, the cap may have a thickness of about 8 to about 10 thousandths of an inch. For some examples, for example, certain deck board components, the cap may have a thickness of from about 20 to about 30 thousandths of an inch. 
     The composite member may include hollow microspheres comprising a blowing agent component, for example, coated hollow microspheres as disclosed in Campese et al U.S. Patent Publication No. 2003/0198780. In one example, the composite member is substantially free of hollow microspheres. 
     In one example, the composite member may further comprise one or more other polymeric components, for example, a second polymeric component, in addition to the HDPE component. For example, the second polymeric component may be present in the composite member in an amount less than the amount of the HDPE component present in the composite member. Examples of other polymeric components include one or more other polyolefins and the like. In one example, polypropylene (PP) may be included as a second polymeric component. 
     Examples of other polymeric components that may be used in some examples, with the HDPE thermopolymer component include polymers made, at least in part, from other ethylenically unsaturated olefinic monomers including without limitation: monoolefinic hydrocarbons, i.e. monomers containing substantially only carbon and hydrogen, including such materials as ethylcellulose, 3-methylbutene-1, 4-methylpentene-1, pentene-1,3,3-dimethylbutene-1,4,4-dimethylbutene-1, octene-1, decene-1 and the like, and mixtures thereof. 
     The thermopolymeric component or components preferably have a modulus of elasticity of at least about 200,000. The present composite members may include one or more filler components (other than fiberglass). In one example, the composite member may include a wood component, such as, for example, wood powder (flour), small wood chips, wood shavings and the like. Other fillers may include talc or other inorganic fillers. The wood component, if present at all, may be present in an amount less than the HDPE component. 
     As noted above, the present composite members include chopped fiberglass strand and/or mat. Chopped fiberglass strand and chopped fiberglass mat are well-known and readily available materials. By “chopped fiberglass mat” is meant fragments of a mat comprised of glass fibers treated with a silane coupling agent and said treated glass fibers laid randomly across one another and held together with a binder to form a planar glass fiber sheet having multidimensional strength within the plane. In one example, the chopped fiberglass strand and/or mat (CFM) included in the present composite members may be provided in suitably sized particles so as to provide substantially the same strength benefit to the entire composite member. In one example, the CFM&#39;s provide substantially homogeneously throughout the present composite members. Such CFM may be chopped to about ¼″ to about ⅛″ in length. The CFM may be mixed, or otherwise combined, with the other filler components of the composite member precursor mixture so that the precursor mixture is substantially homogeneous. The sum of the weight percentages of CFM and other filler components (if present) preferably does not exceed about 40% of the composition. 
     The amount of chopped fiberglass strand and/or mat in the composites of the present invention is about 20% by weight or less of the composite member. The amount of chopped fiberglass may be about 10% by weight or less or about 5% by weight or less or about 2% by weight or less of the composite member. 
     The CFM in these concentration ranges has been advantageously shown to increase the strength of the composite member, for example, relative to the composite member without the CFM. 
     In addition, the relatively small amounts of CFM required to provide such increases in strength in the compositions set forth herein has been found to be substantially not harmful to processing machinery producing the composite members, unlike higher percentages thereof. 
     Furthermore, the relatively small amounts of CFM required to provide such increases in strength, as set forth herein, surprisingly now make the use of a fiberglass component in accordance with the present invention a cost-effective way to provide added strength to the HDPE-containing compositions set forth herein. 
     CFM will be understood to contain an intrinsic coupling agent, so that the composition may require no added coupling agent. 
     In one example, a composite member in accordance with the present invention comprises about 50% to about 98%, by weight, preferably about 70% to about 95%, of high density polyethylene (HDPE). The HDPE component may have a density of at least about 0.94 to about 0.97 gm/cc, or about 0.95 gm/cc. The HDPE component may have a melt flow index of at least about 0.3 to about 20 mfi, or about 10 mfi. 
     A foaming component may be included in the precursor composition of the composite member to provide the desired degree of foaming of the composite member. In some examples, the foaming agent may comprise a gas at least partly dissolved or sequestered in the compositions of the present invention. Often chemical foaming agents (CFAs) are used, either alone or in conjunction with a physical blowing agent, such as an inert gas. CFAs may be in powered form, in liquid form, or provided in pelletized form. 
     In some examples, an endothermic CFA capable of liberating a gas during extrusion may be used. Endothermic chemical foaming agents are chemicals that utilize energy from the extrusion process and consume heat in the chemical reaction. Typically an endothermic CFA may liberate CO 2  during the manufacturing process. This produces foams with a much smaller cell structure, resulting in improved appearance and better physical properties. HDPE-compatible endothermic chemical foaming agents (CFAs) are well-known and include endothermic CFAs made by, for example, Endex International, Dow Chemical Co., Clarient (which utilizes a CFA comprising sodium bicarbonate and citric acid). 
     In some examples, exothermic CFAs may be used. Exothermic CFAs generate heat during the decomposition process. They liberate more gas (generally N 2 ) per gram of foaming agent than endothermic agents and generate a higher gas pressure. Examples of HDPE-compatible exothermic CFAs include, without limitation, Acrulyte 416 (KibbeChem, Inc.). HDPE-compatible exothermic chemical foaming agents (CFAs) are well-known and may also include exothermic CFAs made by, for example, Endex International, Dow Chemical Co. and Clarient. Some exothermic CFAs may comprise hydrazines and azo compounds. In some examples a combination of an endothermic and an exothermic foaming agent may be used. 
     CFAs may be combined with the other ingredients of the compositions to be formed as profiles in accordance with some aspects of the present invention, and thereafter made into a form useful for the manufacturing process to be selected; for example, the compositions may be pelletized for use in a thermoplastic extrusion process. 
     In some examples, a physical blowing agent gas, such as CO 2  gas, pentane, or nitrogen gas may be injected into the plastic melt during the extrusion process, either alone, or in conjunction with a chemical foaming agent added, for example, as a nucleation aid. 
     In some examples, an encapsulated foaming component may be used. In one example, the encapsulated foaming component comprises small particles, for example, foaming component microparticles, such as foaming component microspheres and the like. In one example, the encapsulated foaming component may comprise an encapsulating component and a blowing agent. See Wycech, U.S. Pat. No. 4,769,391 and see Melber et al, U.S. Pat. No. 4,843,104. The disclosure of each of these two patents is incorporated in its entirety herein by reference. Other encapsulated CFAs which may be used in the present composites, such as those made by Akzo-NobelExpancel, are well known in the art. 
     The encapsulating component of an encapsulated CFA may comprise a polymer component, which may include one or a variety of polymers. These polymers may include, for example, ethylene/vinyl acetate, polyvinylidene chloride, polyacrylonitrile, poly-alkyl methacrylates, and mixtures thereof. In one embodiment, the encapsulating component comprises a copolymer. In one embodiment, the encapsulating component comprises a copolymer of ethylene/vinyl acetate. 
     A wide variety of blowing agents may be employed in an encapsulated foaming component. In one embodiment, the blowing agent comprises at least one hydrocarbon. For example, blowing agents useful in this invention include at least one saturated aliphatic hydrocarbon having about 3 carbon atoms to about 8 carbon atoms per molecule. For example, lower alkanes including propane, butane, pentane (e.g., isopentane) and the like, and mixtures thereof are very useful. See Melber et al, and Wycech, cited above. 
     In unexpanded form, the encapsulated foaming component may be made in a variety of sizes, those readily available in commerce being most often on the order of about 2 microns to about 20 microns, for example, about 3 microns to about 10 microns. It is possible to make encapsulated foaming component in a wider range of sizes. It has been demonstrated, for example, that encapsulated foaming components can be made from as small as about 0.1 micron, up to as large as about 1 millimeter, in diameter, before expansion. 
     An example of an encapsulated foaming component useful for this invention is sold by Expancel of Sundsvall, Sweden under the trade name Expancel 092 MB 120. This encapsulated foaming component comprises an ethylene/vinyl acetate encapsulating component and isopentane blowing agent. 
     In some examples, the encapsulated foaming component may be uniformly distributed in the composite member precursor composition to allow for a uniform distribution of density in the article formed from the composition. In other examples, the concentration of the encapsulated foaming component is not uniformly distributed to allow for some regions of the article formed by the composition to be more or less dense than other regions. 
     In some preferred examples an encapsulated foaming component is not used. 
     The composite member may further comprise a wood component. The wood component may be present, if at all, in the present compositions in an amount in a range of about 0.5% to about 40% by weight, for example, about 1% to about 15% by weight, based on the total weight of the composite member. The wood component may be present in any suitable form. For example, the wood may be present as wood particles, such as wood chips, wood flakes, sawdust, wood flour, and the like and mixtures thereof. Such particles may have a size in the range of about 40 U.S. mesh to about 150 U.S. mesh, for example, about 40 U.S. mesh to about 100 U.S. mesh. The sum of the weight percentages of CFM and all other fillers in the composite member is preferably less than about 50%, or less than about 45%, or less than abut 40%, or less than about 30%, or less than about 20%. 
     The wood component may be selected from any suitable wood, including pine wood, woods softer than pine wood, such as fir wood and the like and mixtures thereof. The wood component may include a wood which is harder than pine wood, such as oak wood, walnut wood, hickory wood, maple wood and the like and mixtures thereof. One embodiment of the present invention includes a wood component that includes a first wood at least as soft as pine wood and a second wood harder than pine wood. In this embodiment, the first wood preferably is present as a major amount, that is at least about 50% of the total wood present, while the relatively hard wood is present in a minor amount, that is, less than about 50% of the total wood present. The wood component may act to reinforce the present compositions. 
     Further ingredients may include fillers other than wood, or in addition to wood. Additional fillers may include inorganic fillers such as talc, carbon fibers, mica, kaolin, calcium carbonate and the like. Organic fillers may include polymeric fibre and cellulose based fillers (such as coir, hemp, husks and the like) other than wood. 
     The compositions of the present invention may contain a lubricant, for example, as an extrusion aid. Various types of lubricant can be used, such as silicone oil, wax, fatty acids, etc. Light mineral oil is commonly used as a lubricant; additional lubricants may include a hydrocarbon based oil or wax such as a multilub. 
     The compositions of the present invention may comprise one or more additional ingredients, such as (without limitation) antioxidants, light stabilizers, heat stabilizers, nucleating agents, and/or colorants. 
     In one example of the present invention, compositions are provided which comprise substantially uniform blends, including powders and pellets, comprising a HDPE component, a chemical foaming agent, and a chopped fiberglass component (CFM), such as a chopped fiberglass mat component. In other examples, compositions are provided which comprise substantially uniform blends, including powders and pellets, comprising a HDPE component and a chemical foaming agent, wherein a chopped fiberglass component (CFM) is added to the melt prior to the final extrusion of the profile through the extrusion die. 
     The following non-limiting examples illustrate some of the aspects and advantages of the present invention. 
     EXAMPLES 1 TO 3 
     The following formulations are prepared by combining the listed ingredients: 
     
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
                 Example 1  
                 Example 2  
                 Example 3  
               
               
                   
                   
                 wt % 
                 wt % 
                 wt % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 HDPE (10 mfi) 
                 56.2 
                 58.1 
                 63.1 
               
               
                   
                 LLDPE 
                 4.0 
                 4.0 
                 4.0 
               
               
                   
                 Mineral oil, heavy 
                 0.4 
                 0.4 
                 0.4 
               
               
                   
                 Talc (10 micron) 
                 5.0 
                 5.0 
                 5.0 
               
               
                   
                 MultiLub 
                 1.0 
                 1.0 
                 1.0 
               
               
                   
                 Wood Flour  
                 30.0 
                 24.0 
                 20.0 
               
               
                   
                 (60-100 mesh) 
                   
                   
                   
               
               
                   
                 Chopped fiberglass  
                 3.00 
                 7.0 
                 10.0 
               
               
                   
                 (CFM); ⅛″ 
                   
                   
                   
               
               
                   
                 Foaming agent (CFA) 
                 0.4 
                 0.5 
                 0.6 
               
               
                   
                   
               
               
                   
                 HDPE (High density polyethylene, having a modulus of elasticity of at least about 200,000, or preferably at least about 240,000. 
               
               
                   
                 LLDPE (linear low density polyethylene) . 
               
             
          
         
       
     
     Each of these formulations of Examples 1 to 3 is thoroughly mixed, and preferably formulated in pellet form. If the chopped fiberglass is formulated with the other ingredients, it may be important that the mixture is formulated as a pellet (preferably a “compacted” pellet made at low temperature due to the high concentration of HDPE, rather than a fused pellet made at higher temperature) to form a substantially uniform, extrudable composition. If not formulated as a pellet after mixture, the glass will tend to separate from the polymeric components of the mixture. 
     EXAMPLES 4 TO 6 
     Each of the samples that is produced in Examples 1 to 3 is successfully formed into pellets using a 3000 Series pellet mill (California Pellet Mill), with continuous mixing of the ingredients to prevent the chopped glass from becoming separated. The pellet mill presses and compacts the ingredients together with no applied heat, and a minimum of resulting heat from friction. The resulting pellets are useful for shipment, storage, or for immediately use in an extrusion process. 
     EXAMPLES 7 TO 9 
     A sample of the pellets produced in each of Examples 4-6 is placed in a Cincinnati Milacron Model CM-80 conical twin screw extruder. 
     The foamable composition is permitted to react to become a foamed composition, in the form of a composite in the shape of a rail baluster element  12 , shown in  FIG. 1 . Additionally, another portion of a coextruded composition lacking the foaming component, is present on the rail baluster element as a cap  14  on the outer surface of the rail baluster element. The capped rail baluster element is a rail baluster  16  and is useful as such. See, for example, U.S. Pat. Nos. 6,054,207; 5,518,677; 4,769,391; and 4,722,943. 
     The rail baluster  16  is subjected to a stiffness test for use as a rail element and found to pass such tests. The rail baluster has sufficient strength and weatherability to be used out-of-doors on a long term basis. 
     EXAMPLES 10-12 
     Similar processing to that set forth in Examples 7-9 may be used to produce decking element  22  and capped decking element  20 , which includes a coextruded weatherable cap  24 , and is a decking slat  26  and is useful as such. 
     The decking slat  26  is found to have a sufficient strength and weatherability to be used out-of-doors on a long term basis. 
     EXAMPLES 13-15 
     Additionally, similar processing to that set forth in Examples 7-9 may be used to produce window covering element  32  and a capped window covering  30 , which includes a cap  34  and is a window covering element  36  and is useful as such. 
     The window covering element  36  is found to have sufficient strength and weatherability to be used out-of-doors or on windows exposed to direct sunlight on a long term basis. 
     EXAMPLE 16 
     A composition is made using the formulation of Example 2, but without the added fiberglass component. This composition is pelleted as set forth in Examples 4-6, and then used as the thermoplastic component in the extrusion process set forth in Examples 7-9. The same amount of the fiberglass component is added to the plastic melt before the foaming step, and the resulting composition is then formed into a foamed profile. This profile is found to have substantially substantially similar strength characteristics as an identical profile made using the formulation of Example 2, in which the glass is added before pelleting. 
     EXAMPLE 17 
     A composition is made using the formulation of Example 2, but without the added foaming component. This composition is pelleted as set forth in Examples 4-6, and then used as the thermoplastic component in the extrusion process set forth in Examples 7-9. The same amount of the foaming component is added to the plastic melt before the foaming step, and the resulting composition is then formed into a foamed profile. This profile is found to have substantially similar strength characteristics as identical profiles made using the formulation of Example 2 or made using the method of Example 16. 
     A number of patents have been cited herein. The disclosure of each of these patents is incorporated in its entirety herein by reference. 
     While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.