United States Patent Application: 0020040084
First, to get it out of the way, since official United States Patent and Trademark Office links to files in their electronic database often prove unreliable and not durable, here's an independent site record of the United States Patent Application we make report of herein:
Fly ash filler and polyvinyl chloride compositions and conduits therefrom - Boral Material Technologies, Inc..
You'll note the name "Boral Material Technologies" in the above link, and, they are a Coal Fly Ash recycling enterprise about whom we've made previous report.
As seen in:
West Virginia Coal Association | Texas Converts Coal Ash to Cash | Research & Development;
"Boral Material Technologies Incorporated", "BMTI", of San Antonio, Texas, are a subsidiary of Sydney, Australia's "Boral Limited", which was established all the way back in 1946, and, which, according to their web site, "focuses its operations in building and construction materials with annual sales over $2 billion (US) and employs over 11,000 personnel in 500 operating sites worldwide". BMTI declare themselves to be "a leading marketer of fly ash and all coal combustion products", and, to have "more than four decades of experience marketing fly ash to the concrete industry".
And, as further documented in that report, BMTI have already established an impressive body of Coal Fly Ash utilization technology, represented, in part, by:
"United States Patent: 6916863 - Filler Comprising Fly Ash for Use in Polymer Composites; 2005";
"United States Patent: 7241818 - Filler Comprising Fly Ash for Use in Composites; 2007"; and,
"United States Patent: 7879144 - Filler Comprising Fly Ash for Use in Polymer Composites. 2011".
We once again, regrettably, note that links to USPTO patent application and patent records are proving unreliable. Should those above not survive with their functionality intact, we'll leave it to anyone who actually might give a hoot to track them down on independent sites via a patent number search.
Herein, we submit yet another Coal Ash utilization technology established by Boral Material Technologies, one which, apparently, has languished in the bowels of the United States Patent and Trademark Office as a published US Patent Application, without being rejected or having a patent issue from it, for more than one full decade.
We've no idea what that might mean or imply. It could be that Boral has simply declined to respond to written inquiry from the USPTO about certain details of the disclosure, since, as we will discuss, the potential market size identified herein might not be perceived as being large enough to warrant the effort.
Actually, relative to the immense potentials which exist for more fully utilizing Coal Ash in the manufacture of Portland Cement and Portland Cement Concrete, it represents a very, very minor outlet for Coal Ash.
We are, in fact, only making the effort to document it for you herein to emphasize the fact that multiple productive uses for our Coal Utilization Byproducts do exist; and, that, if we applied ourselves to exploiting all of those options, we wouldn't have any concerns, at all, with Coal Ash disposal.
In any case, as seen in excerpts from the two initial links in this dispatch, with comment inserted and appended, Boral scientists tell us how to productively utilize our Coal Ash in the manufacture of yet another type of plastic product:
"US Patent Application 20020040084 - Fly Ash Filler and Polyvinyl Chloride Compositions and Conduits
Date: April, 2002
Inventors: Joel Colmar and Aron McBay, AZ
Assignee: Boral Material Technologies, Inc., (Boral® Fly Ash Product Home Page)
Abstract: A composition comprising fly ash particles with an average particle diameter of not greater than 100 micrometers and a moisture content of not greater than 0.25 percent by weight. The compositions are useful as both a filler and a colorant in polymer containing compositions, particularly polyvinyl chloride compositions for extruding pipes and conduits. Desirably, the composition is used at a filler loading level of from about 1 to about 80 parts by weight of the fly ash per hundred parts of the polymer. Fly ash-filled polyvinyl chloride compositions containing the fly ash as described meet commercial requirements and are economically and environmentally beneficial.
(Basically, they're talking about PVC pipe. And, in fact, even though they say the "filler loading level" can be "from about 1 to about 80 parts by weight of the fly ash per hundred parts of the polymer", various codes and government specifications, such as those promulgated by the Iowa Department of Transportation, in:
http://www.iowadot.gov/erl/current/GS/content/4149.pdf; "Section 4149. Sanitary and Storm Sewer Pipe and Structures Materials", typically limit mineral filler loading in PVC pipe to "10 parts by weight per 100".
And, further, our understanding, correctly or incorrectly, is that mineral-filled PVC pipe would, in fact, be limited to use in non-potable water applications, such as the above "Sanitary and Storm Sewer Pipe "; and, in things like protective electrical cable conduits, where non-abrasive, non-conducting shielding is in places needed, or specified, to provide physical protection for the primary insulation.
For the most part, PVC is considered a "low-value" piping and conduit material, and, general discussions about PVC pipe and the materials used in it, as in:
Essential Compounding Chemicals used with PVC Resin, Primary, Secondary Plasticiser, Heat, Light Stabilisers;
suggest that, given the properties of PVC and the uses to which it's put, reinforcing additives and fillers, such as glass fiber, aren't worth the effort or expense; and, of the non-reinforcing fillers, "the most important is Calcium Carbonate"; that is, ground limestone, although in some applications very fine Calcium Carbonate that has been chemically precipitated can be employed.
A good background can be had, almost of course, in:
Polyvinyl chloride - Wikipedia, the free encyclopedia; "Roughly half of the world's polyvinyl chloride resin manufactured annually is used for producing pipes for municipal and industrial applications. In the water distribution market it accounts for 66% of the market in the US, and in sanitary sewer pipe applications, it accounts for 75%. In the United States and Canada, PVC pipes account for the largest majority of pipe materials used in buried municipal applications for drinking water distribution and wastewater mains.
And, again, to make certain it's clear, the PVC and Fly Ash compositions being disclosed herein would not be suitable, for multiple reasons, for "drinking water distribution".)
Claims: A polyvinyl chloride composition comprising polyvinyl chloride and fly ash particles, wherein the fly ash particles have a diameter greater than about 25 micrometers and are characterized by a moisture content of not greater than about 0.25 percent by weight water and an average particle size of not greater than about 100 micrometers
The polyvinyl chloride composition ... wherein the fly ash particles have an effective top size (ranges as specified, and) wherein the polyvinyl chloride composition comprises from about 1 to 80 parts by weight of the fly ash per hundred parts by weight of the polyvinyl chloride.
(We do note that there are other types of "conduits", such as, for instance, channels molded in place, by the inclusion of flexible pipe pre-placed in the forms, in poured concrete structures, for the routing of utility cables, aside from water and sewer pipes, where higher loadings of filler might be acceptable.
However, a major maker and marketer of PVC pipes and conduits, Rinker Materials, see:
Rinker Pipe Home Page, which was acquired by the Mexican multi-national cement company, Cemex (Cemex - Wikipedia, the free encyclopedia), in 2007, recommended, via:
http://www.rinkerpipe.com/TechnicalInformation/InfoBriefs_Series/IB%202002%20Fillers%20Used%20in%20Ply%20_Vinyl%20Chloride_%20;
that, any fillers in PVC pipe of any sort "be limited to 10 parts by weight to 100 parts of resin".
So, the total market for Fly Ash in such PVC applications might be relatively limited, even though, as can be learned via:
Polyvinyl chloride - Wikipedia, the free encyclopedia; "Roughly half of the world's polyvinyl chloride resin manufactured annually is used for producing pipes for municipal and industrial applications. (And) in sanitary sewer pipe applications (to which we think such filled PVC pipe, aside from utility conduits, would be limited, PVC pipe) accounts for 75% (of the North American market)";
the market for PVC pipe itself is pretty huge.)
A conduit comprising the polyvinyl chloride composition ... and meeting UL specification 1285 for flattening and impact.
(Scope for UL 1285; "Pipe and Couplings, Polyvinyl Chloride (PVC), and Oriented Polyvinyl Chloride (PVCO) for Underground Fire Service", the "Underground Fire Service" meaning the distribution of water only for the purpose of fighting fires, not for drinking.)
Background and Field: The present invention is directed to particulate coal fly ash compositions that are useful as fillers and, optionally, colorants in polymer-based compositions. In one desirable embodiment, the present invention is directed to fly ash compositions that are useful as fillers in polyvinyl chloride based compositions and fly ash filled polyvinyl chloride compositions therefrom. These fly ash-filled polyvinyl chloride compositions are useful for manufacturing pipes, conduits and other profiles of various shapes and sizes, particularly electrical conduits.
(Again in molded "electrical conduits", "80 parts by weight of the fly ash per hundred parts by weight of the polyvinyl chloride" might be perfectly acceptable.)
Fillers are frequently added to plastic compositions to reduce the costs of and to improve the properties of products produced from the plastic compositions. Fillers are usually inorganic, inert materials that can be added to plastic resins and can reduce cost, reduce shrinkage, improve surface appearance and improve moldability. Fillers typically cost much less than the plastic resins into which they are incorporated and therefore, increasing the amount of filler that can be admixed into the resin generally decreases the overall material cost. Although fillers are used in combination with resins primarily to reduce cost, they may also improve ultraviolet resistance, heat deflection temperature, electrical properties, blocking resistance, and control opacity and gloss. Pigments are used in resins to provide color and may increase opacity and weathering characteristics.
Fillers are typically admixed into a molten plastic material prior to or during forming of an article of the filled plastic material. The admixing of the filler can be done by a plastic resin supplier, a special compounder whose expertise is the selection and addition of various additives or by a manufacturer of the plastic article. Extrusion is one common method of incorporating fillers into plastic compositions.
Polyvinyl chloride (hereinafter "PVC") resins are readily available, low cost plastic resins that are used to form pipes, conduits and other assorted profiles.
The PVC compositions that are used to form these articles typically contain some type of filler to increase the stiffness and the thermal stability to articles manufactured from the filled PVC compositions. Calcium carbonate, CaCO3, is a common filler incorporated in PVC compositions. Other types of fillers are primarily limited to specialty applications, e.g., calcined clays for electrical applications. Calcium carbonate is, predominantly, a mined material that requires crushing and grinding of mined limestone to be used as a filler material. Mining and subsequent crushing and grinding of calcium carbonate add to the cost of the calcium carbonate as filler. Further, because calcium carbonate is mined from naturally occurring deposits, calcium carbonate has limited regional availability and may require extensive shipping. Shipping also adds to the cost of calcium carbonate as a filler.
In contrast, fly ash is a byproduct that is produced by coal burning facilities, such as power generating plants, and is more readily available.
Because fly ash is produced in abundance, it is readily available at lesser cost than most fillers. Although fly ash is currently incorporated into concrete and brick compositions, there is a need to develop additional uses for fly ash.
The use of fly ash as a filler offers various advantages over the use of various other mineral fillers. Fly ash is more readily available and has lower cost than other widely used mineral fillers. Fly ash also has a lower specific gravity.
For example, the specific gravity of fly as is about 2.1-2.4 compared to calcium carbonate, which has a specific gravity of about 2.7. Thus, fly ash and fly ash-filled compositions are lighter in weight and may be substituted for conventional fillers to reduce shipping costs. Further, the intrinsic color of the fly ash varies from gray to black and may be used to reduce the amount of black colorant required in the filled plastic compositions such as electrical conduits.
Summary: The polymer compositions can contain from about 1 to 80 parts by weight fly ash per hundred by weight resin. Fly ash filler loading levels for PVC of about 5 to 40 parts per hundred of fly ash are desired and filler loading levels of about 10 to 20 parts per hundred are more desired. The polymer compositions describe herein comprise polyvinyl chloride as the base resin. Fly ash-filled polyvinyl chloride compositions containing the fly ash particles as described herein can be provided to extrude conduits that meet commercial and industry standards.
Loading levels of the fly ash in PVC may vary from about 1 to 80 parts by weight fly ash per one hundred parts by weight PVC. Loading level is defined as the ratio of the weight of the filler or additive to the weight of the base resin and can be expressed in parts of additive per hundred parts base resin ... .
A desired fly ash filler level is about 5 to 40 parts by weight fly ash per one hundred parts by weight PVC. A more desired fly ash filler level is about 10 to 20 parts by weight fly ash per one hundred parts by weight PVC. Higher filler loading levels are desired to reduce costs but lower filler levels may be needed in order to maintain certain mechanical properties."
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As you might surmise, and as we indicated in our introductory comments, the above represents, relative to the potentials for a fuller use of Coal Ash in the manufacture of Cement and Concrete, a pretty small opportunity for the productive consumption of more Coal Ash. But, it is an opportunity, nonetheless.
And, as can be extrapolated from data provided in:
Marketing In the Pipeline; "U.S. sales of PVC pipe in 1996 were in excess of 5.36 billion pounds";
hard as that might be to believe. But, those are the published numbers, and close to 3 million tons of PVC pipe, alone, are purchased annually in the United States.
And, if half that pipe was destined for non-drinking water purposes, and was filled, as seems practical according to our subject herein, to a level of at least 10 percent by weight with Coal Ash, even though our subject does indicate that the "polymer compositions can contain (up) to 80 parts by weight fly ash per hundred by weight resin", that would be about 150,000 tons of Coal Ash which could be productively utilized in PVC pipe applications.
That might sound like a lot; but, since, as can be learned from the United States Geologic Survey, via:
http://minerals.usgs.gov/ds/2005/140/coalcombustionproducts.pdf;
we produce, on very rough average, about 60 million tons of Coal Ash per year in the United States, it is only a very minor percentage of the total; pretty small potatoes.
The point is, though, that this is still a productive use of Coal Ash which might be of special interest to the operators of a Coal-fired power plant in the vicinity of a factory that extrudes PVC pipe or other molded PVC products.
As we understand the details of the full Disclosure of "US Patent Application 20020040084 - Fly Ash Filler and Polyvinyl Chloride Compositions and Conduits", Coal Ash can be utilized in PVC extrusions with only minimal processing, which would mostly be concerned with particle size. Even residual Carbon in the Ash is pretty much okay, since it doesn't affect the finished PVC product's physical properties, and might even, since PVC piping products are color-coded according to intended end-use, with black and dark gray indicating some industrial, waste water and electrical conduit applications, reduce, as "US Patent Application 20020040084" does suggest, the need to purchase pigments to add to the PVC resin.
So, at a much reduced cost, the Coal-fired power plant operator could dispose of at least some of their Coal Ash, while the PVC product extruder saves a few bucks as well.
All in all, it's a small part of the total solution; but, it is, or could be, nonetheless, a part of that solution.
