1. Field of the Invention
The present invention relates to a new and improved unitary system and process for recycling contaminated material such as plastic chips which are in ground-up or shredded form obtained from plastic containers, retainers, wrappers, bags, films, and the like, so that the material may be used again. The system provides a unitary apparatus capable of operating with a wide variety of variables in terms of hot or cold liquid media with or without chemicals and different drying processes. Essentially, the present invention is directed toward a tremendous ecological problem caused by the wide usage of a wide variety of different types of plastic materials for containing and packaging foodstuffs, liquids of all types, films, wrappers, bags, and the like, employing resinous plastic material as the basic forming medium.
2. Background of the Prior Art
Present day efforts at removing contaminants from reground and/or shredded plastic materials are fraught with difficulty in that there is not available a unitary machine for handling the material after a grinding up or shredding process to provide an output that is suitable for reuse in plastic products. Moreover, material handling systems that are currently used tend to introduce air into washing mediums, thereby creating unwanted foam which is difficult to remove. Moreover, there is no acceptable system for recycling or reprocessing spent or dirty liquid media so that the liquid can be re-used in treating successive batches of plastic chips to be recycled. In addition, a substantial quantity of energy in the form of heat is lost and the overall efficiency of many processes is reduced thereby.
Oftentimes special solvents or chemicals are needed for dissolving certain substances or contaminants on the surface of reground plastic material and presently there are no efficient systems for saving these chemicals and cleansing the same for re-use in treating subsequent batches of material or for utilizing the chemicals in other areas.
In general, the fragmented approach of the industry to the monumental problem of recycling the great volume of plastic material from used containers, retainers, films, wrappers, bags, and the like, has not been dealt with in an environmentally sound and cost effective manner. Moreover, there are no systems currently available that are efficiently handling the dirt, dried milk, foodstuffs, oils, detergents, paper labeling adhesives, glues and films which are removed from the plastic materials in a recycling process.
One system that is in use involves the introduction of shredded or ground-up plastic chips into a large vat of liquid medium. The vat is provided with a plurality of propeller-type agitators to move the liquid over the surface of the chips. This system is not effective for a number of reasons which include, (1) the introduction of air into the process producing unwanted foam which later on requires an anti-foaming compound or some mechanical foam breaker means of destroying the foam that is produced. (2) The action of the propeller is sometimes effective to further grind-up or greatly reduce the size of plastic chips to be recycled and some of the chips are reduced to a consistency of fine powder which is then lost and not available for re-use. Some systems can discharge large volumes of soiled, solids-laden, liquid medium from a recycling operation into a sanitary system or sewage treatment system in a manner that is not an environmentally desirable procedure. This results in the need for further treatment and removal of the process liquid medium to eliminate and separate out the contaminants removed from the plastic chips and from the liquid medium.
U.S. Pat. No. 3,011,637 discloses a device including a rotatable drum having means for discharging and separating heavy and light fractions of materials known as float and sink particles.
U.S. Pat. No. 3,516,841 discloses a system for separating and reclaiming components from metallic-plastic laminate structures wherein wider and heavier components are separated out after shearing and grinding of the input material.
Gulzow et al. U.S. Pat. No. 3,707,858 discloses a washing machine having a drum rotatable about a horizontal axis and divided axially into a plurality of washing and rinsing compartments.
The Pearson U.S. Pat. No. 3,811,568 discloses a machine for separating plastic parts from runners used in molding the parts for collecting the runners to use again in plastic molding operations.
The Brown U.S. Pat. No. 3,852,046 discloses a method for recycling waste plastics and products by first grinding the materials into particulate form and thereafter washing the same to remove non-plastic material therefrom. The remaining materials are then heated to a temperature above the softening point of the lower melting thermoplastics but below the temperature of the softening point of the highest melting thermoplastics contained in the mixture. The resulting recycled material may then be used with asphaltic compositions or cellulosic material as a filler.
The Emil et al. U.S. Pat. No. 3,859,404 discloses a method for densifying styrene foam by heating and exposure to air pressure followed by clenching to produce a high density resin from scrap foam material.
Iseman U.S. Pat. No. 3,928,181 discloses a cottonseed and cockleburr separator where material is fed into a trough containing liquid wherein the cottonseeds sink towards the bottom and the lighter cockleburr material tends to move to the top. Screw conveyors are utilized in sloping trough enclosures.
Kolbus U.S. Pat. No. 4,000,031 discloses a method and apparatus for recovery of plastics and non-plastics from plastic coated waste material employing a helical screw flight within a perforated drum rotatable in a tank.
Bober U.S. Pat. No. 4,009,235 discloses a process for reclaiming extruded plastic resins by forming a plastic rope of resin with a rotating funnel or other device used to gather the hot molten plastic waste and twist it into the shape of a rope which is then passed through a cooling bath and pinch rolls.
U.S Pat. No. 4,033,907 discloses a system for reclaiming waste plastic material of a molecularly oriented type to facilitate subsequent washing, separating and melt processing steps. This system also discloses the use of a hot caustic solution for eliminating the growth of bacteria and mold on the recyclable plastic material.
Arendt U.S. Pat. No. 4,094,172 discloses a device for adding and/or removing fluid media from a rotating drum such as a washing machine
Saitoh et al. U.S. Pat. No. 4,119,533 discloses a method of separating hydrophobic plastics from a plastics mixture wherein the plastics having a high hydrophobicity tend to float on the aqueous liquid mixture surface.
Hobbs, Jr., et al. U.S. Pat. No. 4,162,880 discloses a scrap plastic recovery system wherein a hammer mill and separator are used for removing foreign objects and melting batches of homogeneous chips for a pelletizer used to make solid pellets.
Detsinko et al. U.S. Pat. No. 4,187,172 discloses an apparatus for separating trash from less heavy firm articles in a flow of liquid employing a rotary perforated element with helical flights on the inner and outer surface thereof.
Barnsbe U.S. Pat. No. 4,194,926 discloses an apparatus and method for selectively reclaiming parts from plastic film cartridges using a series of specific gravity separation tanks.
Dettmar U.S. Pat. No. 4,200,967 discloses a system for reclaiming plastic polymer from scrap plastic film rolls by cutting and splitting the same while on a paper core.
Cerrone U.S. Pat. No. 4,207,986 discloses apparatus for separating plastic film from paper, particularly useful in waste recycling systems and employing flighted belt conveyors with rotary reels used for picking up lighter components of a mixture of scrap.
Detwoyadesusso U.S. Pat. No. 4,234,415 discloses an apparatus for separating solids of different specific gravities out of a mixture thereof including frustoconical separation chambers rotatable about a horizontal axis.
Cerroni U.S. Pat. No. 4,314,674 discloses a process for separating paper from plastic existent in solid urban waste by partially tricurating the mixture to reduce the paper components to small particle size ground condition while the plastic film component is generally unchanged.
Fagnant et al. U.S. Pat. No. 4,342,396 discloses a separator for separating small parts from a mixture of parts of various different sizes and includes a drum rotatable about a vertical axis.
U.S. Pat. No. 4,362,276 discloses a method and apparatus for recovering and separating metal and plastic material from plastic insulated wiring.
Nowicki et al. U.S. Pat. No. 4,379,525 discloses a batch process for recycling plastic container scrap including a water process for removing labels and eventually floating plastic granules over a weir collected for deep watering.
Fish U.S. Pat. No. 4,433,925 discloses a method of separating plastic bottles and caps or portions thereof by mechanically cutting through both the bottle and the bottle cap.
U.S. Pat. No. 4,448,737 discloses a method and apparatus for producing foamed products from a mix of reclaimed plastic foam material and foamable version plastic resins. The Johnson patent discloses a feed hopper having a rotatable cyclical agitator for moving and mixing reclaimed plastic material and new virgin material prior to introduction into a twin screw compressor.
Young U.S. Pat. No. 4,454,030 discloses a separating machine for separating acceptable molded parts from the material output from a molding machine so that the sprues and other runners and defective parts can be recycled.
Grimm et al. U S. Patent No. 4,617,111 discloses a method for the separation of a mixture of polyvinylchloride and polyethylene teraphalate utilizing a chemical solution which is absorbed in the polyvinylchloride.
Morrass et al. U.S. Pat. No. 4,619,121 discloses a sealing system for tunnel washing machines for removal of gas or liquid media from a rotating drum.
The West et al. U.S. Pat. No. 4,635,862 discloses a rotary granulator for communuting waste plastics material for recycling.
Fagnant U.S. Pat. No. 4,723,717 discloses a rotary shearing/cutting machine for cutting, shearing and shredding or otherwise communuting objects and articles for disposal purposes such as thermoplastic materials from molding operations, sprues, runners and defective molded articles.
Tomaszek U.S. Pat. Nos. 4,728,045 and 4,809,854 disclose a method and apparatus for reclaiming bonded together tube resin articles for reclaiming the reusable resin materials from bottles and other scrap items.
Grimm U.S. Pat. No. 4,746,422 discloses a method for the separation of a mixture of plastic material and contaminants utilizing a two phase solution composed of a halogenated hydrocarbon and water.
U.S. Pat. No. 4,830,188 discloses a system for plastic separation and recycling methods wherein light and heavy plastic fractions are separated from one another and contaminants are removed therefrom.
The Hunter et al. U.S. Pat. No. 4,844,106 discloses a method and apparatus for cleaning shards such as clay pigeons for fragments of debris and contaminant articles ready for recycling.
Holloway U.S. Pat. No. 4,844,351 discloses a method for separation recovery and recycling of plastics from municipal solid waste wherein a rotating drum mounted on a sloping axis includes a plurality of generally helically extending flights for mechanical agitation of the municipal solid waste material.
Lee U.S. Pat. No. 4,940,187 discloses a systematic equipment system for recycling raw materials from waste wires so that metallic wire material is separated from plastic insulating materials on the wire.
Jay, Sr., et al. U.S. Pat. No. 4,944,868 discloses a process and apparatus for separating plastics from contaminants employing a separation tank, a wash tank, a rinse tank a lift conveyor and a material dryer.
Ingram et al. U.S. Pat. No. 4,964,512 discloses a recyclable film package for photographic film so that the material therein may be reused.
Placzek U.S. Pat. No. 4,974,781 discloses a method and apparatus for preparing paper containing and plastic containing waste materials for component fraction separation and utilizes an elongated rotary drum mounted on a sloping axis and employing a plurality of radially inwardly extending flights around the surface of a first portion and a plurality of helical flights around a second portion of the drum.
Volker U.S. Pat. No. 4,979,682 discloses a system for reclaiming synthetic material and metal from a synthetic metal scrap combination but first communuting the scrap and pulverizing the particles to obtain a fluidized bed of synthetic fibers and metal and utilizing air flow to separate the fibers from the metal.
Rimmer U.S. Pat. No. 4,981,876 discloses a process for separating vinyl skin from foam backing material and recovering the separated components by mixing the small chips of composite plastics with a quantity of water to swell and break the cell structure of the foam at the foam vinyl interface.
Richardson et al. U.S. Pat. No. 5,011,087 discloses a method of az apparatus for continuously treating communuted synthetic plastic containers and products having contaminants bonded thereto for recycling purposes. The system includes an elongated horizontal drum or vessel employing one or more elongated helical screws therein for agitation of a liquid medium in which the material is contained.
Bridge et al. U.S. Pat. No. 5,644,000 discloses a bent inlet deflector for use with a granulator wherein scrap plastic is to be fed into a granulating device.
Nugent U.S. Pat. No. 5,022,985 discloses a process for the separation and recovery of mixtures containing plastics and other materials using flotation and aqueous dispersion. The process is said to be useful for separating polyethylene and polyvinyl chloride from communuted wire and cable scrap.