Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
  • C04B26/006—Waste materials as binder
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
  • C04B2111/00612—Uses not provided for elsewhere in C04B2111/00 as one or more layers of a layered structure
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/91—Use of waste materials as fillers for mortars or concrete
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
  • Y10S264/911—Recycling consumer used articles or products
  • Y10S264/916—From porous material containing articles, e.g. sponge, foam

Definitions

• the invention relates to a method for producing a building material from a mixture of unscreened thermo ⁇ plastic waste and mineral, preferably mineral aggregate, in which method the crushed and/or screened mineral and plastic waste are washed, whereafter the mineral is heated to a predetermined temperature, and a given amount of plastic granules or plastic flakes made from the unscreened thermoplastic waste is mixed with the heated mineral, and the resulting mass is pressed into building elements.
• unscreened thermoplastic waste means all types of plastics that melt when heated and solidify when cooled, can be re- melted and thereby made usable.
• Thermoplastic waste is today recyclable if it is screened.
• this ap ⁇ plication presents a method in which unscreened thermo- plastic waste can be used as secondary raw material.
• mineral aggregate means crushed aggregate or macadam made of natural stone, gravel, sand, or gypsum waste or other mineral or ex ⁇ panded clay as well as crushed brick or crushed con- crete, which is municipal or industrial waste and which has been screened into given grain sizes.
• a method of this kind is previously known for example in connection with producing road surfacing material, which is disclosed in the publications WO 90/00161 and FR 2 563 212, for example.
• plastics are mixed with heated mineral aggreg ⁇ ate, using predetermined additives and plasticizers, with the purpose of affecting the behaviour of the above mentioned mixture of plastics and mineral aggregate.
• the plastics are of predetermined grade and type, and thus this method does not utilize plastic waste.
• the publication SE 450 572 also discloses a method for manufacturing a building material which con- sists of a mixture of mineral aggregate and cement and to which plastic granules have been added without melt ⁇ ing them. Slabs and pipes, for example, are made from this mixture by casting.
• the publication DE 3 837 430 also discloses a method in which products are manufactured from a mixture of mineral aggregate and acrylic plastic by casting or injection.
• plastic raw materials used in the above mentioned and known production methods are unused or equivalent to new materials, and they are primarily intended to increase the demand for plastics and to expand various uses of plastics.
• thermoplastic waste reclaimed for secondary use is that only certain types of thermoplastic waste are reclaimed.
• a secondary raw material made from specific clean ther ⁇ moplastic waste also replaces new thermoplastic raw ma ⁇ terial to a high extent. Secondary use of thermoplastic waste is restricted by important factors such as whether the reclaimed thermoplastic waste contains only one type of thermoplastic, whether it consists of reclaimed ther ⁇ moplastic of uniform good quality, and what kind of products can be manufactured therefrom.
• the reclaimed thermoplastic is plastic waste un ⁇ suitable for secondary use by the plastics industry, and as such it today ends up loading the capacity of dumps.
• the reclaimed raw material to be used contains such mutually incompatible types of plastics as cause problems in manufacturing processes in the plastics industry. Problems occurring in the manufactur- ing process include gassing and the relative effect of different types of plastics having different viscosities at the same temperature.
• One of the most difficult prob ⁇ lems with the secondary use of unscreened, reclaimed thermoplastic waste is to combine thermoplastics of dif- ferent grades and types and to manufacture industrially feasible end products from them.
• the very important object of the invention is to solve the problem with the use of unscreened, reclaimed thermoplastic waste by producing building ma- terials from reclaimed thermoplastic waste in an envir ⁇ onmentally friendly way.
• the method according to the invention is characterized in that the mineral and the plastic raw material are heated in a humid, water-containing environment in which the plastic raw material is plasticized and melted without adding any specific chemical solvents or plasticizers, whereafter a filler is added to the mass in order to compact the building material to be produced.
• plastic granules or plastic flakes are made from the unscreened thermoplastic waste before mixing it with minerals, whereby the process becomes controlled.
• the humid, water-containing environment is pre ⁇ ferably provided by the water remaining in the mineral or in the thermoplastic waste after it has been washed with water.
• the raw materials need not dry or be dried separately, which would slow down the process.
• Other preferred embodiments of the invention are dis ⁇ closed in claims 4 to 10.
• a significant advantage of the invention is the fact that the method can eliminate the environmental problem associated with the use of unscreened thermo ⁇ plastic waste by manufacturing, by a simple production method, a building material from plastic secondary raw materials which are at the end of their life cycle.
• the relative quality characteristics and quantities of the secondary raw materials to be used do not need to be known in advance.
• a positive environmental effect is achieved with the method according to the invention in two ways. Firstly, it reduces the load on dumps, and secondly, using products manufactured by the method of the invention makes it possible to prevent disturbing influences and harmful effects on the environment. For example, runoff from dumps into groundwater can be pre ⁇ vented by insulating them with building slabs according to this invention.
• the plastic Due to the water-containing environ ⁇ ment used in the method, the plastic can be plasticized quickly and uniformly without using solvents or plasti- cizers, which are harmful to the environment.
• the humid ⁇ ity also protects the plastic raw material from burning.
• the mineral used in the invention has two ef ⁇ fects. Firstly, it is a necessary medium which, when heated, alters the viscosity of unscreened thermoplastic and enables using in admixture certain types of plastics which otherwise cannot be used in manufacturing pro- Switchs in the plastics industry, in which impurities or incorrect materials can spoil an entire production batch.
• mineral is the basic material for the building material in which the heated mineral melts or plasticizes the thermoplastic, which serves as a binder for the mineral.
• the compactness of the building ma- terial is increased by using a filler, which is prefer ⁇ ably a fine-grained mineral aggregate, gypsum waste or other mineral, such as talc, which is added preferably in heated state to the mineral-thermoplastic mixture. Because of its poor conductivity, gypsum cannot be used as the main mineral. It is only suitable as a filler, in which case it must not account for more than approx ⁇ imately 15% of the dry weight of the mineral.
• the prop ⁇ erties, purpose of use and appearance of the building material are varied by means of different coatings, such as metal sheets, wire meshes, aluminium foils, wood, pa ⁇ per, cardboard, stone, ceramic tiles or plastics.
• the building material can also be reinforced by using vari ⁇ ous profiles or meshes. Various kinds of sandwich struc- tures may also be manufactured from it.
• the types of thermoplastics to be used may contain a certain amount of impurities, such as cardboard, paper, alumi ⁇ nium, metal or comminuted thermosetting plastic waste, as is often the case with plastic waste.
• the unscreened thermoplastic waste is washed and made into plastic granulate and/or plastic chips.
• the plastic raw material may be sorted according to specific gravity.
• the mineral used in the method is preferably mineral aggregate, from which grains smaller than 3 mm are separated in screen ⁇ ing in one fraction, and grains larger than that are screened according to the thickness of the building ma ⁇ terial to be produced so that the largest grain size is approximately one half of the thickness of the final product.
• the grain size of the mineral aggregate must not be too large, because then it is not suitable for the use according to the invention.
• Mineral with a large grain size requires a lot of energy to become heated, and in spite of that it is not certain that the entire volume of the mineral has become uniformly heated.
• the plastic raw material will not adhere to mineral heated only on the surface. On the other hand, if the surface temperature rises too much, the plastic will burn, whereby a large amount of combustion gases (and smoke) is released from the process.
• the mineral aggregate must be smaller than 20 mm.
• the most preferred grain size is 3 to 4 mm. The small grain size helps to achieve a shorter pass-through time in the manufacturing process, which is recommended.
• the screened min ⁇ eral aggregate is washed clean from dust, which improves the adherence of the thermoplastic to the mineral ag ⁇ gregate.
• the mineral aggregate which has a grain dia ⁇ meter of > 3 mm, is heated to a temperature of about 160 to 220 ⁇ C. After that, thermoplastic is added and mixed with the mineral aggregate to the extent that the grains of the mineral aggregate can receive the thermoplastic all over their surface area.
• the amount of thermoplastic to be added is 10 to 40% of the dry weight of the min ⁇ eral aggregate depending on the varying grain size of the mineral aggregate.
• the mixing process also includes a certain amount of humidity, either coming from the washed material or separately added to the process. The humidity prevents the plastic raw material from burning and facilitates its plasticizing.
• the unmixed min ⁇ eral is screened away from the thermoplastic-mineral aggregate-filler mixture, and the remaining mixture is dosed or scattered on a coating material and pressed by compression moulding or flat-pressing and/or calendering to final thickness.
• the compression is carried out by a method in which the cooling water circulating in the press plate prevents the mixture to be pressed from adhering to the press plates due to condensation and also lowers the surface temperature of the building material.
• the mixture has a temper ⁇ ature of about 160°C, and the pressure to be used is approx. 0.7 to 15 Mpa, preferably 4 to 9 Mpa, and the compression time is approx. 1 second per millimetre of thickness.
• the mineral aggregate-thermoplastic-filler mixture is scattered or dosed on the coating material, which improves the properties and usability of the building material. The last stage is the after-cooling of the building material.
• a slab element can also be manufactured so that the heated mineral aggregate is scattered on the surface of the press, and the fine-grained plastic granulate mixed with the filler is scattered on the mineral ag- gregate.
• heated water is injected through the holes in the press surfaces into the mineral aggregate-plastic granulate mixture.
• the water facilitates, due to the vaporization caused by the hot mineral aggregate, the plasticizing of the plastic granulate and thus speeds up its adher- ence to the mineral aggregate.
• the water injected into the mixture also prevents the mixture from adhering to the plate surfaces of the press.
• Various types of coat ⁇ ings can be applied to the slabs afterwards using known methods, such as glueing or plasticizing the mounting surface by means of infrared heating.
• the in ⁇ vention by means of which it is possible to manufacture an environmental slab, a so called yard slab, 500 x 500 x 50 mm in size.
• the largest grain size is approximately one half of the thickness of the final product, that is, about 25 mm.
• the grain size of the mineral aggregate is > 3 mm or the fractions > 3 to 25 mm.
• the mineral ag- gregate is heated to about 200°C.
• Thermoplastic is then added to the heated mineral aggregate, the approximate amount of thermoplastic having been determined on the basis of a product test, for example 13%, and it is mixed with the mineral aggregate. After this, a filler mineral aggregate is added to the mixture of mineral aggregate and thermoplastic.
• the filler is sand, which has a grain size of 3 mm or smaller and which has been heated to a temperature of about 150°C.
• the addition is performed uniformly and simultaneously with dosing into the slab mould.
• One layer of decorative macadam has been laid on the bottom of the mould and heated to approximately 120°C, and a coloured plastic film, which melts at approx. 100°C, is laid on top of the macadam as background colour, and the mineral ag- gregate-thermoplastic-filler mixture is applied on a plastic film.
• the thickness of the mixture in the mould is 75 to 100 mm, i.e. 1.5 to 2 times the final thick ⁇ ness.
• the mixture is pressed to a thickness of 50 mm using a pressure of approximately 1.1 Mpa for 50 seconds.
• the slab is removed from the mould when it is certain that no change of form will occur in the slab after that.
• the last stage is the after-cooling of the slab and quality classification by weighing, which enables determination of the compactness and density of the final product and thereby the strength of the slab.
• Slabs manufactured according to the invention can be installed permanently or temporarily.
• temporarily installed slabs can be mentioned slabs intended for temporary surfacing of butts and embankment fills to prevent the earth material from moving or collapsing because of weather conditions.
• noise barriers and fences it is possible to build noise barriers and fences in such a way that the slabs are piled upright on their edges between U-profile frames made of metal.
• a special property of building slabs manufac ⁇ tured by the method according to the invention is good moisture-proofness, which for example a gypsum board does not have. Typical applications of the slabs and boards are sites which require high strength and mois ⁇ ture-proofness.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Processing Of Solid Wastes (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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Publications (1)

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Cited By (9)

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Citations (3)

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• 1993
  • 1993-05-31 FI FI932482A patent/FI91249C/fi not_active IP Right Cessation
• 1994
  • 1994-05-30 US US08/553,533 patent/US5676895A/en not_active Expired - Fee Related
  • 1994-05-30 WO PCT/FI1994/000215 patent/WO1994027800A1/en active Application Filing
  • 1994-05-30 AU AU67979/94A patent/AU6797994A/en not_active Abandoned

Patent Citations (3)

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