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EP-3870417-B1 - PRECONDITIONED RESIN AGGREGATE

EP3870417B1EP 3870417 B1EP3870417 B1EP 3870417B1EP-3870417-B1

Inventors

  • THOMSON, DONALD WILLIAM

Dates

Publication Date
20260506
Application Date
20191022

Claims (15)

  1. A method of making a preconditioned resin aggregate, the method comprising: Obtaining (100) a preconditioned feedstock consisting of a supply of granulated mixed plastic waste treated with a preconditioning agent that comprises at least one of calcium oxide and calcium hydroxide to improve sanitation of the granulated mixed plastic waste in a dry cleaning manner; Mixing (104) the preconditioned feedstock with one or more additives to form a plastic waste mixture, the one or more additives comprising pozzolans; hot extruding (106) the plastic waste mixture to form an extruded product comprising waste plastic material; and processing (110) the extruded product to form an aggregate in which the waste plastic material is exposed at exterior surfaces thereof.
  2. The method of claim 1 wherein the supply of granulated mixed plastic waste includes a variety of plastic materials including at least one of high density polyethylene, polypropylene, PVC, ABS, polyurethane, polyamide, and PET.
  3. The method of one of the preceding clams wherein the supply of granulated mixed plastic waste comprises non-plastic material in the form of food residue, cellulosic material and/or metallic foil material.
  4. The method of one of the preceding claims wherein the supply of granulated mixed plastic waste has a bulk density that is at least five times greater than a bulk density of mixed plastic waste products from which the granulated mixed plastic waste is derived.
  5. The method of one of the preceding claims wherein the preconditioned feedstock includes about 4% to about 22% calcium compounds by weight.
  6. The method of one of the preceding claims wherein the plastic waste mixture to be hot extruded includes about 2% to about 14% of pozzolans by weight.
  7. The method of one of the preceding claims wherein the plastic waste mixture to be hot extruded includes about 6% to about 18% of calcium compounds by weight.
  8. The method of one of the preceding claims wherein the plastic waste mixture to be hot extruded includes at least 50% plastic material by weight.
  9. The method of one of the preceding claims wherein the one or more additives of the plastic waste mixture further comprises at least of an essence, a fire retardant, and an anti-bacterial agent.
  10. The method of one of the preceding claims wherein the plastic waste mixture is hot extruded (106) at a processing temperature between about 165°C and about 230°C.
  11. The method of one of the preceding claims wherein the plastic waste mixture has a moisture content sufficient to assist in forming cavities within the extruded product during the hot extruding of the plastic waste mixture.
  12. The method of one of the preceding claims wherein the plastic waste mixture to be hot extruded consists essentially of the granulated mixed plastic waste treated with the preconditioning agent and the pozzolans.
  13. The method of one of the preceding claims wherein processing (110) the extruded product to form the aggregate includes crushing and screening the extruded product to meet industry standard sizing requirements for aggregate.
  14. The method of one of the preceding claims wherein hot extruding (106) is performed in a subsequent step from mixing (104) the preconditioned feedstock with one or more additives.
  15. The method of one of the preceding claims wherein obtaining (100) the supply of granulated mixed plastic waste and forming the preconditioned mixture is a separate and distinct step from mixing (104) the preconditioned mixture to form the plastic waste mixture.

Description

BACKGROUND Technical Field This disclosure generally relates to aggregate particles, and is particularly, but not exclusively, applicable to cementitious compositions for use in the building industry or related industries. Description of the Related Art Cementitious building and paving products are well known and are commonly made up of aggregate material and a cementitious or similar type binder and may include such articles as bricks, concrete, paving stones, roofing tiles, blocks, decorative articles, and the like. An undesirable feature which may be associated with such cementitious products is their high density. Lightweight aggregates are important engineering materials. Together with cement and water, they are used to prepare lightweight aggregate concrete. Lightweight aggregate concrete is a relatively low density material that is finding increasing use in building construction. Lightweight aggregates confer significant engineering benefits. Lightweight aggregates currently available include manufactured materials such as sintered fly-ash, expanded clay, expanded shale, and foamed slag, as well as naturally occurring geological materials such as scoria and pumice. Such known lightweight aggregates and methods of making and utilizing the same may suffer from a variety of deficiencies or drawbacks. Accordingly, applicant believes improved aggregates and methods of making and utilizing the same are desirable. Furthermore, only a small percentage of the plastics materials that are set aside for recycling are in fact recycled due to the time and cost of sorting the plastics into their differing types and washing the plastic before each type of plastic can be processed further. As a result, a large percentage of such plastic materials may be placed in landfills or leaked into the environment. Plastics are one of the fastest growing municipal solid waste components, and there is increasing public demand for recycling. However, plastics are exceedingly difficult to recycle efficiently with available technology. For example, much of the plastic material in municipal wastes is multi-layered, heavily pigmented, contaminated and difficult to sort. The need to separate the various plastic types makes recycling of plastics technically difficult and expensive. Traditional recycling is therefore capable of dealing with just a small portion of the total volume of waste plastic generated by society. Accordingly, applicant believes improved methods and processes of repurposing mixed plastic waste are desirable. WO2016084007-A1 relates to a method of making a plastic aggregate, and its use to make concrete products. The aggregate is formed by providing a granulated waste plastic material, introducing the granulated waste plastic material into an extruder having a die, the die having a ratio of die nozzle open area to die land area of about 1:10 to about 1:40, and extruding the granulated waste plastic material through the extruder to generate an extruded plastic aggregate. The method can include the presence of controlled cooling, the addition of additives and treatment of the surface of the aggregate to produce a desired aggregate that may be used to make a concrete product with desired properties, such as compressive strength and weight. US2003041782-A1 is directed at a synthetic lightweight aggregate composition comprising fly ash and a mixture of two or more polymer components. More specifically, it is also directed at a lightweight concrete which cures to a hardened cementious composite comprising Portland cement, water in a weight ratio of between about 0.2 and 0.7 of the water to the Portland cement, synthetic lightweight aggregate in a weight ratio of between about 0.1 and 0.5 of the synthetic lightweight aggregate to the cement, wherein the synthetic lightweight aggregate comprises fly ash and two or more polymer components. US2012077890-A1 discloses a composite building material includes carpet waste having carpet fibers and adhesive, and an inorganic filler that includes fly ash. The composite building material may be produced by providing the carpet waste, mixing the carpet waste with the inorganic filler to produce a homogeneous blend, and forming the homogeneous blend into the composite building material. The composite building material may optionally include a base polymer, slack wax, and/or calcium carbonate. EP0591895-A2 discloses a building, stowing or filling material intended for use in underground mining and contains a proportion of plastic. US2013102727-A1 discloses synthetic aggregates and methods of producing them. The aggregates utilize styrene polymer particles coated with additional materials such as fly ash, silica fume, and/or "liquid glass" in order to provide a means for manufacturing lightweight concrete. BRIEF SUMMARY The present application provides a method in accordance with the claims which follow. The method described herein provides a lightweight aggregate made in part of mixed pl