WO1998030330A1

WO1998030330A1 - Manufacturing system

Info

Publication number: WO1998030330A1
Application number: PCT/AU1998/000004
Authority: WO
Inventors: Erwin Walter Filler
Original assignee: Phoenix Technology Corporation Limited
Priority date: 1997-01-06
Filing date: 1998-01-06
Publication date: 1998-07-16
Also published as: AUPO445697A0; TW470672B; CA2318945A1

Abstract

A processing assembly for the treatment of mixed solid waste material is disclosed which includes: mixed solid waste conveyor means (36) for conveying mixed solid waste material from an input station to a material reduction station, and material reduction means (26) at the material reduction station having a plurality of rotatable members (56, 58, 106) adapted to cooperate with a respective fixed member (61, 60, 52) to reduce solid waste material and to screen the reduced material to another reduction means and/or to other conveyor means. A method of treating mixed solid waste material is also disclosed which includes: conveying mixed solid waste material from a collecting station to a material reduction station; reducing the mixed solid waste at the material reduction station; conveying the reduced solid waste to a reduced waste separating station; and separating the reduced waste into homogeneous lots at the reduced waste separating station.

Description

"MANUFACTURING SYSTEM"

Technical field

This invention relates to a manufacturing system. The invention has particular but not exclusive application to a multi-discipline processing and manufacturing system for application-engineered building and industrial products m which the raw material feedstock includes dry mixed solid waste. The dry mixed solid waste utilised m accordance with this invention includes all mixed solid wastes from domestic, industrial and commercial sources, but includes substantially no medical, toxic, chemical, liquid, food or nuclear waste. Mixed solid waste can be regarded as waste material which, if able to be held m the hand, would not run through the fingers. References herein to "waste material" are to be understood to include a plurality of individual materials as well as a single material .

Background of Invention

It is known to process waste materials for conservation purposes. It is now common for waste material to be sorted at waste source or kerbside for subsequent recycling. The sorting is by the end-user who generates the waste material, le the householder, business or factory. Alternatively, only a few specified waste categories such as plastics, paper and glass are collected unsorted and then separated by semi-automatic or manual means. The waste material is usually sorted into paper, plastic, glass and metal lots and then distributed to product-specific locations for recycling.

Summary of Invention The present invention aims to provide an alternative to known manufacturing systems .

This invention in one aspect resides broadly m a processing assembly for the treatment of mixed solid waste material, the assembly including :- mixed solid waste conveyor means for conveying mixed solid waste material from an input station to a material reduction station, and material reduction means at the material reduction station having a plurality of rotatable members adapted to cooperate with a respective fixed member to reduce solid waste material and to screen the reduced material to another reduction means and/or to other conveyor means.

There may be a variety of other conveyors but it is preferred that the other conveyor means includes :- bulk waste conveyor means for conveying solid waste which has not been reduced from the material reduction station to a bulk waste separating station, and reduced waste conveyor means for conveying reduced solid waste from the material reduction station to at least one reduced waste separating station.

In a preferred embodiment the rotatable members are mounted for rotation about a common substantially vertical axis. It is preferred that at least one rotatable member is substantially cone-shaped and has a plurality of radially extending spoke-like members extending downwardly from a hub and adapted to pass solid waste material therebetween.

The fixed members may be located in any suitable position whereby a shearing or cutting action is applied to the mixed solid waste material, however it is preferred that each fixed member extends radially from the axis and includes a cutting edge facing the direction of rotation of its cooperating rotatable member.

In a preferred embodiment the material reduction means includes at least two rotatable members having a plurality of radially extending spoke-like members extending downwardly from a hub and adapted to pass reduced solid waste material therebetween, the two rotatable members being positioned above a lower rotatable member having a solid cone-shaped surface. It is preferred that adjacent rotatable members are adapted to rotate m opposite directions and that the uppermost rotatable member feeds the bulk waste conveyor means and the lowermost rotatable member feeds the reduced waste conveyor means.

The processing assembly may include mixed solid waste input means at the input station. The input means may be any suitable arrangement for receiving mixed solid waste material and could for example be a level dump site. However it is preferred that the mixed solid waste input means is a dumping pit, the mixed solid waste conveyor means passing through the dumping pit to remove mixed solid waste material therefrom. Suitably the mixed solid waste conveyor means includes a plurality of retention means for retaining mixed solid waste material therein. In a preferred embodiment the retention means are cup-like buckets or hoppers.

The processing assembly may also include bulk waste separation means at the bulk waste separating station for separating the bulk waste into homogeneous lots. It is preferred that the bulk waste separation means includes a plurality of cranes adapted to grab and cut individual items of bulk waste. Guide means may be associated with the reduced waste conveyor means to guide reduced waste to a plurality of reduced waste separating stations.

It is preferred that the reduced waste separating stations are adapted to separate the reduced waste into homogenous lots and include manually operable sorting means. Suitably the sorting means include a turntable and guide means for guiding material not selected by an operator from the turntable for conveying to another reduced waste separating station.

In another aspect this invention resides broadly m a method of treating mixed solid waste material, the method including :- conveying mixed solid waste material from a collecting station to a material reduction station; reducing the mixed solid waste at the material reduction station; conveying the reduced solid waste to a reduced waste separating station, and separating the reduced waste into homogeneous lots at the reduced waste separating station.

It is preferred that the mixed solid waste is treated in a processing assembly as defined in any one of the above statements.

In a further aspect this invention resides broadly in a method of manufacturing, the method including :- conveying mixed solid waste material from a collecting station to a material reduction station; reducing the mixed solid waste at the material reduction station; conveying the reduced solid waste to a reduced waste separating station; separating the reduced waste into homogeneous lots at the reduced waste separating station; providing raw material feedstock from the homogeneous lots; providing virgin material feedstock, and processing the raw material feedstock and the virgin material feedstock to produce a desired product .

It is preferred that the mixed solid waste is treated in a processing assembly as defined in any of the above statements or in accordance with the method defined above .

As used herein the expression "virgin material" means material which has not previously been used. In yet another aspect this invention resides broadly in a method of manufacturing, the method including :- providing raw material feedstock in the form of treated mixed solid waste; providing virgin material feedstock, and processing the raw material feedstock and the virgin material feedstock to produce a desired product.

In a preferred embodiment the virgin material feedstock includes virgin water and solvent binders for binding said raw material feedstock.

Alternatively the virgin material feedstock can include virgin coating materials. Preferably the coating materials are prestressed plastics. The plastics may be new polymers which have a marble-like, granite-like, timber-like or other material appearance.

It is preferred that the plastics are application engineered to be applied in a jointless form to produce the desired finished product (s). It is preferred that the virgin material feedstock is a selected polymer material, and that the desired product is a wall panel in which the raw material feedstock is sandwiched between layers of the polymer material .

In a preferred embodiment the raw material feedstock is produced by the processing assembly as defined in any of the above statements or in accordance with the method defined above.

In another aspect this invention resides broadly in a product (s) manufactured in accordance with any of the methods defined above. In a preferred embodiment the product (s) is a housing system. The housing system in accordance with the invention can include a range of raw materials and a range of panels made in accordance with the invention.

Description of Drawings

In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein: -

FIG 1 is a flow chart of the manufacturing system in accordance with the invention;

FIG 2 illustrates a processing assembly for the treatment of mixed solid waste; FIG 3 is a plan view of a mixed solid waste dumping pit;

FIG 4 is an elevation along section AA of FIG 3; FIG 5 is an elevation along section BB of FIG 3; FIG 6 is a side view of the mixed solid waste conveyor ;

FIG 7 is a plan view of a rotating waste separator;

FIG 8 is an elevation along section CC of FIG 7; FIG 9 illustrates the separating layers of the rotating waste separator;

FIG 10 illustrates the operation of the cutting edge in relation to the rotating waste separator;

FIG 11 is a plan view of a bulk waste separating station;

FIG 12 is an elevation along section DD of FIG 11;

FIG 13 is a plan view of a scrap materials separating, categorising and processing plant;

FIG 14 is a detailed plan view of a turntable of the plant illustrated in FIG 13, and

FIG 15 is a schematic diagram illustrating the production of a housing system product in accordance with the invention.

Description of Preferred Embodiment of Invention

As can be seen in FIG 1, in a manufacturing system in accordance with the invention raw material feedstock 10 and virgin material feedstock 12 are fed to a multidiscipline product manufacturing plant 14. Plant 14 includes a plurality of dedicated product-specific processing sub-plants 14a, 14b through 14n. The sub- plants are individually designed and engineered to produce dedicated products 16a, 16b through 16n.

Raw material feedstock 10 includes various individual raw materials 10a, 10b through lOn such as green wood, dry wood, paper and cardboard, rubber, metals, glass, plastics, rock and rubble etc. The raw materials are produced in a manner subsequently to be described by processing assembly 18 which treats collected mixed solid waste 20. Virgin material feedstock 12 includes various individual virgin materials 12a, 12b through 12n selected in accordance with the dedicated product being produced by the system. As is best seen in FIG 2, a processing assembly 22 for the treatment of mixed dry solid waste material (processing assembly 22 corresponds to item 18 m the flow chart of FIG 1) has a mixed waste dumping pit 24 from which dumped waste is fed to material reduction means m the form of a rotating waste separator 26, thence to a bulk waste separating station 28 and thence to a final separating, categorising and processing plant 30. Mixed dry solid waste is dumped m pit 24, reduced m size m separator 26 and bulk waste is removed and sorted at station 28. The reduced waste is sorted m plant 30.

The process for treating the waste materials can thus be summarised as one m which mixed dry solid waste

(waste from which prior to collection wet waste such as food scraps etc has been removed) is reduced m size from large to small, and then the small size waste is sorted by category. The description which follows outlines m greater detail features of preferred embodiments of pit 24, separator 26, station 28 and plant 30. However it is to be realised that details in the following description, including references to dimensions, are to be considered to be exemplary only and that the size of any given installation is merely a function of its capacity.

As is best seen in FIGS 3 to 6, a pit 32 receives mixed solid waste from bins and bulk-truck loads from waste collection sources. As seen m FIGS 3 and 5, four unloading bays 34 adjoin dumping pit 32 which has a depth of 3 meters and a length and a width of 15 meters. As can be seen m FIG 4, conveyor 36 runs from one end of the pit, along the full length of the pit and then rises gradually over 35 meters ending over the centre of bulk waste rotating separator 26. Conveyor 36 elevates 3 meters over 35 meters.

FIG 6 illustrates conveyor 36 in greater detail. The conveyor is a steel plate chain linked conveyor 3 meters wide having a plurality of rollers 42 and cups 40. The cups are 2 meters apart and approximately 2 meters high. Cups 40 extend across the 3 meter width of conveyor 36. In use, mixed bulk waste is discharged by trucks or bin- trucks by reversing into unloading bays 34. Once the truck has touched the pit border stop 38, the truck can discharge its load into pit 24. Conveyor 36 runs at a speed of 10 meters per minute. The waste mass follows the contour of the pit and conveyor cups 40 carry loads of 2 meters by 3 meters from the pit.

Conveyor 36 moves the waste on a slow rise up to a high point and down over a downwardly sloping nose portion 46 of conveyor 36 and over the bulk waste rotating separator 26.

As can be seen in FIGS 7 to 10 which illustrate rotating waste separator 26, three cone-shaped wheel assemblies 58, 56 and 106 are coaxially mounted for rotation on support post 102. Each cone-shaped assembly has a fixed upper member 60, 61, 52 respectively and a lower rotating cone-shaped member 62, 64 and 66 respectively. The two upper cone-shaped members 62 and 64 consist of a plurality of radially and downwardly extending spokes through which material can fall. The lower cone-shaped member 66 consists of a solid cone across which an array of radial ribs extend. The cone may be made of metal and may be coated by a skirt of rubber or like material.

The radial members of cone-shaped spoke wheel 62 of uppermost wheel assembly 58 are spaced 30cm apart at the axis and a maximum of 60cm apart at the circumference. The radial members of cone-shaped spoke wheel 64 of middle wheel assembly 56 are spaced apart at the circumference a maximum of 30cm and as can be seen in FIG 9 have serrated cutting edges 108. Top wheel assembly 58 is 60cm distant from the centre wheel assembly 56, which is 30cm distant from the bottom wheel assembly 106. All three wheel assemblies have a diameter of 10 meters. The top cone-shaped spoke wheel and bottom cone-shaped wheel member are powered by same motor and the centre cone- shaped spoke wheel is separately powered. The uppermost and lowermost cone-shaped wheel members 62 and 66 are driven to rotate in a clockwise direction and the middle cone-shaped spoke wheel 64 is driven to rotate in an anti-clockwise direction.

As seen in FIG 10, the two uppermost fixed upper members 60 and 61 serve the dual purpose of providing a guiding surface along a blunt trailing edge and a cutting or shearing surface along a leading sharp tungsten edge which is faced against the direction of the corresponding cone-shaped spoke wheels 62 and 64.

FIG 8 illustrates the configuration of the three wheel assemblies which constitute separator 26. The top wheel assembly receives waste from conveyor 36 and the centre wheel assembly receives smaller waste which has fallen through the 60cm wide spokes of top spoke wheel . It also receives larger waste, such as tree branches, large timber pieces etc, which is cut by the shearing action between the tungsten cutting blade on fixed member 60 as the centre and top spoke wheels rotate in opposite directions. The tungsten bladed cutting edges closely abut the rotating spoke wheels. Smaller waste items will also fall through the centre wheel spokes on to the bottom wheel which has a solid surface or they will be cut in similar manner to that described above due to the opposite directions of rotation of the centre and bottom wheels. Every fourth spoke on the top cone-shaped spoke wheel 62 has a rounded upper edge whereas the remainder have square edges which provide a "cutting" edge when rotated under the fixed cutting edge 60. All spokes on the middle cone-shaped spoke wheel 64 have serrated cutting edges 108. All spokes on both cone-shaped spoke wheels are inclined at a 20° angle and fall from the central support to the circumference. The bottom cone- shaped wheel 106 has a solid hard rubber surface, with 5cm wide steel spokes 110 extending radially across the surface. Spokes 110 are 4cm high and 5 meters long. There are the same number of spokes on each wheel assembly. The stack of rotating wheel assemblies is housed m a steel or concrete walled silo or cylinder 112 the inner surface of which closely adjoins the circumference of the wheels Silo 112 has a vertically extending opening 114 adjacent the leading edge of the fixed direction beams for the exit of waste. Bulk waste exits from the top wheel through opening 114 onto bulk waste conveyor 54 and reduced waste exits from the centre and lower wheels onto reduced waste conveyor 80.

As described above three of the four spokes on the top wheel have a tungsten bladed square cutting edge and each spoke on the centre wheel has serrated tungsten bladed edging. Consequently, as the wheels turn m opposite direction, all large items located between the top wheel and the centre wheel are cut to size when the spokes meet the sharpened cutting edge of the fixed direction beam.

In use the downward guiding nose 46 of conveyor 36 directs the inflow of bulk waste materials which are guided by guiding beam 44 and fall and separate at the same time. The bulk waste guiding beam 44 guides all waste such that it is discharged over the point of the bulk waste separation wheel furthest from the sharpened cutting edge. The waste is thus forced to travel the longest possible way on the surface of the top wheel . As the mixed waste falls on to the top wheel through the 20° angle, larger items automatically fall towards the outside of the top wheel where the spokes are 60cm wide. If the items which fall through protrude above the top wheel between the spokes of the wheel they are cut off as the spoke meets the sharpened cutting edge of the direction beam.

Larger items such as refrigerators, furniture, washing machines, car bodies and other large items made of timber, metal and plastics will not fall through the spokes as they do not have a minimum dimension less than 60cm. These larger items are thus not cut but are pushed on by rotation of the wheel and by the action of the direction beam and are discharged onto bulk waste conveyor 54 which conveys the bulk waste material to bulk waste separating station 28.

The centre wheel cuts and discharges its material onto reduced waste conveyor 80 which runs parallel to and 110cm beneath bulk waste conveyor 54. The bottom wheel also discharges its material onto conveyor 80. Conveyors 54 and 80 are of the same width.

A large crane 48 is mounted on circular rail 50 to move 180° from the incoming point of conveyor 36 to the exit point of bulk waste conveyor 54. Crane 48 can reach the centre of wheel assembly 58 to retrieve oversized items unable to be processed through the system. The crane functions to both grab and cut oversize items. As is best seen in FIGS 11 and 12, bulk waste and oversize waste material is conveyed on top bulk waste conveyor 54 to bulk waste separating station 28 where a plurality of grab and cutting cranes 68 lift oversize items from conveyor 54 and transfer them onto cross conveyors 70, 72 and 74 for bulk metal, bulk timber and other bulk material respectively. Cross conveyors 70, 72 and 74 run underneath conveyors 54 and 80. Grab/cutter cranes 68 are fixed in position and can swivel through 360°. A vertically hinged pivot guide plate 76 is supported over bottom conveyor 80. Guide plate 76 can be adjusted to guide and direct the reduced waste stream on conveyor 80. In a central position the flow is distributed evenly to conveyors 118 and 120. Alternatively guide plate 76 can pivoted to either side of conveyor 80 to direct waste solely to one or the other conveyor 118 or 120.

Top bulk waste conveyor 54 terminates some 7 meters from a wedge shaped island 78 and therefore any items left on this conveyor are discharged onto the bottom reduced waste conveyor 80 which discharges its waste onto a vibrating screening grid 82 which vibrates waste along a 15° incline down to conveyors 118 and 120 via apron feeders 84 and 86 respectively.

Vibrating grid 82 separates very fine materials from larger items which now constitute the total waste stream passing this point of separation. At the same time the waste stream is evened out, and the waste items are positioned in side by side relationship on conveyors 118 and 120 so as not to overly each other.

Vibrating screen grid 82 is 3 meters wide at the narrowest point and 4.6 meters at the widest point and 2 meters long. The screening grid passes materials sized 25mm and less which as seen in FIG 13, drop to cross conveyor 116 for further processing at a gravel processing section. Elevated conveyors 118 and 120 carry the reduced waste material for further processing at separating plant 30.

Thus in summary, mixed waste is discharged from bulk waste rotating separator 26 via three separating wheel assemblies onto bulk waste conveyor 54 and reduced waste conveyor 80. Conveyor 54 is 7 meters shorter than the conveyor 80 and discharges onto conveyor 80 all waste not picked by the crab/cutter cranes 68.

Pivot guide 76 and fixed island 78 are suspended 10mm over and at the end of conveyor 80 so as to guide waste (mostly evened out waste) between conveyors 118 and 120 by either shutting off waste flow to either one of the conveyors or staying in a central position to even out flow.

Reduced waste conveyor 80 is 3 meters in width and 35 meters in length and discharges its materials onto the vibrating screen grid 82 which is 30cm lower than discharging conveyor 80. Vibrating screen grid 82 has a 15° incline and discharges its materials onto steel plate apron feeders 84 and 86 for feeding onto conveyors 118 and 120 respectively. Bulk waste separating station 28 thus functions to separate large items before further separation occurs.

As is best seen in FIGS 13 and 14, final separating plant 30 processes waste materials into raw material feedstock by pick separation sorting into nine different categories thereby transforming mixed waste into a number of categories of valuable basic raw materials. The nine categories of raw materials are: 1. Wood (green wood) ;

2. Wood (dry wood) ;

3. Paper and cardboard:

4. Rubber;

5. Metals (ferrous and non-ferrous/blends); 6. Glass (all types of glass);

7. Plastics (all soft and hard plastic mixes);

8. rock and rubble (concrete, brick, plaster etc) ; and

9. Mixed non-separable items. All waste is discharged by the vibrating screen grid 82 onto conveyors 118 and 120 via apron feeders 84 and 86 respectively and then taken by conveyors 118 and 120 to respective banks of eight rotating turntables 88. Conveyors 118 and 120 run parallel to each other and are simply a duplication of each other. A third parallel conveyor can be introduced to increase capacity.

Conveyors 118 and 120 comprise an array of short conveyors discharging waste from a higher level conveyor 98 onto each turntable 88, and after the specific category of material is picked off each turntable, the remaining amount of mixed waste is pushed by rotating table 90 (as seen in FIG 14) via a deflector system 94,96 to a lower level on to the next continuing conveyor 100.

This process continues along both conveyor lines and at each wheel a specific product category is picked off by an operator. At the last turntable station only rock and small rock items remain and this continues onto conveyors 122 and 124. The array of eight turntable stations and the exit material from the last turntable thus constitute, for each conveyor line 118 and 120, separating stations for the nine selected categories of material . Each turntable 88 is a solid base table with raised rubber strips 92 and is cone-shaped at an angle of 20°. The turntables 88 rotate either clockwise or anticlockwise depending on feeding or discharging position of conveyors, and have a guide 94 to guide waste materials along the wheel and a deflector guide 96 to push and guide the material onto the next conveyor.

Each turntable 88 thus constitutes a sorting and pick station characterised as follows :-

(a) Each sorting/pick station has work space for 6 operators or pickers to pick a product category from the wheel or belt and the picked product is then placed by the picker into a chute 104. Each time waste material is discharged from a conveyor belt onto a separation wheel the waste material is turned over.

(b) A chute is located next to each picker. Chutes in the heavy section (which incorporates wood, tyres, green wood) are manufactured from 12mm steel, whereas chutes in the lighter section of the plant are manufactured from 2mm steel. At the pickers level chutes are lm x 1.5 meters, and are substantially of cylindrical shape.

(c) The picking conveyors are 1.5m or 1.2m wide flat conveyors with a speed of 10 meters per minute. Foot pedal controls are located at each picking wheel so that the operator/picker can stop the conveyor if necessary. Impact idlers are located at the beginning of each conveyor and at 1.5 meter spacings. Floor areas at different levels and stair treads are covered with WA 255 S and galvanised grid mesh.

The cross conveyors are of different width and length and carry individual sorted categories of processed waste or raw material feedstock. The conveyors are generally troughed conveyors running on fully supported steel plate. The conveyors are fitted with scrapers on the underside and head pulleys where required. All conveyors are suitably troughed to obviate the need for skirt plates.

Magnetic head pulleys are incorporated at the end of the conveyors which deliver the dry wood and green wood from each plant to the processing areas. In the case of the dry wood, an additional overhead magnet is also used at the delivery point.

Additional processing equipment adjoins the cross conveyors for processing categorised waste, in accordance with the category of raw material, into fine shredded or pulverised or powdered fine material for further processing .

Thus in summary, downsized and partially separated large, small and fine materials are discharged from vibrating screen grid 82 onto conveyors 118 and 120 via steel plate apron feeders 84 and 86 which elevate the mixed waste materials on to picking conveyors. The picking conveyors discharge onto the separation/picking wheel at each wheel picking station. Two pickers per chute pick designated categories of material at each station/wheel. The picked items are then placed in the chute next to the picker, fall down the chute and then picked up at the bottom of the chute by the cross conveyor designated for that material category. The items are then transported by conveyors for further automatic fine processing into chip, particle form or fine dust form. For example, dry timber is processed into fine particle form and stored for transport to a Wood Panel Plant .

As will be subsequently described in greater detail, the separation machine plants may also include additional processing and manufacturing plant for processing the treated material into finished products.

By way of non-limiting example, wall panels may be manufactured m accordance with the method of the present invention. In this embodiment the raw material feedstock produced from the treated solid waste is combined with virgin material feedstock m the form of a selected polymer material. The wall panel has the raw material feedstock sandwiched between layers of the polymer material .

Thus as is illustrated schematically FIG 15, a stream of domestic, industrial and commercial waste contains waste plastic, waste paper, waste rubble, waste rubber, waste glass, waste metals, waste timber and intermingled waste materials, is processed into a number of categories of raw material .

These categories are timber, paper, glass, metals, plastics, rubber, rubble and these materials intermingled.

In a mixing and blending operation, virgin water and solvent based binders are added to and mixed with the raw materials. The raw materials can be further processed to produce core material for wall panels or the like.

The core material is coated with virgin coating material m the form of prestressed plastics such as polymers which have the appearance of marble, granite, timber etc. The polymers are application engineered for application to the core material m jomtless form to produce the desired finish product.

The panel cores may be either concrete based or resin based. Alternatively the panel cores may be mixed plastic . The blend of fillers to be incorporated into concrete based panels is predetermined to provide the optimum mix of recycled materials needed to meet the particular requirements of the panel, eg whether the panel is to be used for flooring or roofing. The mam steps of the concrete based panel production process are filler pretreatment , concrete foaming, filler incorporation, prestressor incorporation, concrete setting/stressing and finally, panel lamination. The predetermined blend of recycled materials is chemically treated to ensure good bonding with the foamed cement. The concrete is "blown" or foamed inside a purpose built extrusion system using oxygen to aerate a hydraulic cement. This process reduces the quantity of cement required and therefore its density to approximately half that of normal concrete. The pretreated and blended recycled materials are then introduced into the extrusion process and a woven wire incorporated into the mix as a strengthening element. The extruded mix is formed over a flat conveyor belt where the woven wire is pretensioned and the concrete is set . As the set slab moves along the conveyor it is cut to length and stored for curing. The cured, pre-stressed concrete cores are then sealed by a lamination process.

Alternatively, polymers recovered by the process can be used for reinforcing or space filling in resin based panel cores. The recovered polymers are first shredded and then bonded together. A thermosetting resin is used to bind the polymer particles together and to provide a better surface. The cores are prepared using epoxy and acrylic thermosetting resins to bond mixed recycled plastics together. Cores can were also be prepared using shredded timber, in place of mixed recycled plastics. The formed cores are laminated to provide a functional and decorative finish.

The process involves casting of homogeneous layer of an acrylic resin which contains various colouring and special effect additives, eg marble chips. The curing agent needed to solidify the mix of resin and additives is injected into the mix just before the mix enters the mould. When solid, the panels may be stress relieved by a process which utilises the known heat history of the particular batch of product. This can reduce the potential for stress fracture of the panel during its manufacture into the finished product.

A less expensive alternative is for the production of mixed plastic panel cores wherein the binding of the mixed recovered plastics is achieved through a partial fusion of the polymers themselves. The fusion process acts to bind the various polymers together, rather than using a thermosetting resin as a binding agent. The laminating process utilises virgin epoxy and acrylic thermosetting resins to provide a durable surface over the panel core depending on its end use. Laminate thickness can be reproducibly controlled from approximately 5mm down to 0.5mm. To reduce cost, the thickness of the laminate layer required to effectively cover the panel core is minimised by controlling the filler particle size. Grinding and/or filling can also be used to prepare the surface of the panel core before the core is laminated. It will be realised that the manufacturing system in accordance with the present invention, by providing raw material feedstock which includes mixed solid waste treated in accordance with the invention, solves many current problems of solid waste recycling at a cost substantially less than existing methods by utilising a holistic approach which avoids transferring the problem of waste disposal from a general problem to a product- specific problem.

The manufacturing system in accordance with the present invention has numerous practical commercial and environmental advantages. These include the following:

* The system will remain economically viable even if an acceptance fee paid to accept the waste is as little as one third the cost currently paid to waste disposal operators or collectors to bury the waste at a landfill site or tip. Much of the current cost of waste disposal is hidden in the sense that it is an indirect cost, paid by a local authority but borne eventually by ratepayers. Furthermore, the costs in many cities will escalate as it becomes necessary to transport the waste increasing distances and handle it by increasingly sophisticated methods. Many of these hidden costs are avoided by the present invention which will also significantly dimmish the impact of the anticipated escalation m costs

* It will be unnecessary to establish new landfill sites and thereby incur the increasing problems such as toxic leaching associated therewith, because the life expectancy of existing landfill sites will be significantly increased.

* Because the manufacturing system m accordance with the invention does not incinerate or accept toxins, environmental protection is enhanced.

* The present invention provides a single coordinated waste collection system and improves the performance and efficiency of existing waste collection which is usually performed by a variety of contractors some of whom collect household "garbage" on a weekly basis, others of whom collect household "recycling" waste often sorted into plastic, glass and paper on a less frequent often fortnightly basis, and others who collect unsorted bulk waste at longer perhaps quarterly intervals.

* In existing waste disposal systems, and even so-called "recycling" systems (which still generate waste with comparatively little of the material collected finding its way back into production) , usually between 60% and 80% of mixed solid waste is "dumped" in landfill or off-shore sites. On the other hand, up to 95% of solid mixed waste m the present system is utilised as raw material feedstock in the manufacturing system and thus as little as 5% of mixed solid waste requires disposal.

* Utilisation of up to 95% of solid mixed waste as raw material feedstock in the manufacturing system results in a lower demand on virgin raw material for manufacture and a corresponding reduced demand on the earth's natural resources. The manufacturing system accordance with the present invention is particularly flexible and can be modified to take account of differing compositions of mixed solid waste which occur in differing locations. The system can also be modified to take account of different requirements for manufactured products arising in different locations. The system of the present invention is thus adaptable to process the differing inputs imposed and provide the differing outputs required in accordance with the local conditions as they vary within a country or in accordance with the varying conditions in different countries.

It will of course be realised that whilst the above has been given by way of an illustrative example of this invention, all such and other modifications and variations hereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of this invention as is herein set forth.

Claims

1. A processing assembly for the treatment of mixed solid waste material, said assembly including :- mixed solid waste conveyor means for conveying mixed solid waste material from an input station to a material reduction station, and material reduction means at said material reduction station having a plurality of rotatable members adapted to cooperate with a respective fixed member to reduce solid waste material and to screen said reduced material to another reduction means and/or to other conveyor means .

2. A processing assembly as claimed in claim 1, wherein said other conveyor means includes :- bulk waste conveyor means for conveying solid waste which has not been reduced from said material reduction station to a bulk waste separating station, and reduced waste conveyor means for conveying reduced solid waste from said material reduction station to at least one reduced waste separating station.

3. A processing assembly as claimed in claim 1, wherein said rotatable members are mounted for rotation about a common substantially vertical axis.

4. A processing assembly as claimed in claim 1, wherein at least one rotatable member is substantially cone- shaped and has a plurality of radially extending spokelike members extending downwardly from a hub and adapted to pass solid waste material therebetween.

5. A processing assembly as claimed in claim 1, wherein each said fixed member extends radially from said axis and includes a cutting edge facing the direction of rotation of its cooperating rotatable member.

6 A processing assembly as claimed claim 1, wherein said material reduction means includes at least two rotatable members having a plurality of radially extending spoke-like members extending downwardly from a hub and adapted to pass reduced solid waste material therebetween, said at least two rotatable members being positioned above a lower rotatable member having a solid cone-shaped surface.

7. A processing assembly as claimed claim 1, wherein adjacent rotatable members are adapted to rotate m opposite directions.

8. A processing assembly as claimed m claim 6, wherein the uppermost rotatable member feeds said bulk waste conveyor means and the lowermost rotatable member feeds said reduced waste conveyor means.

9. A processing assembly as claimed claim 1, and including mixed solid waste input means at said input station.

10. A processing assembly as claimed in claim 9, wherein said mixed solid waste input means is a dumping pit, said mixed solid waste conveyor means passing through said dumping pit to remove mixed solid waste material therefrom.

11. A processing assembly as claimed m claim 10, wherein said mixed solid waste conveyor means includes a plurality of retention means for retaining mixed solid waste material therein.

12. A processing assembly as claimed m claim 11, wherein said retention means are cup-like buckets or hoppers .

13. A processing assembly as claimed m claim 1, and including bulk waste separation means at said bulk waste separating station for separating said bulk waste into homogeneous lots.

14 A processing assembly as claimed m claim 13, wherein said bulk waste separation means includes a plurality of cranes adapted to grab and cut individual items of bulk waste.

15. A processing assembly as claimed claim 2, and including guide means associated with said reduced waste conveyor means and adapted to guide reduced waste to a plurality of reduced waste separating stations.

16. A processing assembly as claimed m claim 15, wherein said reduced waste separating stations are adapted to separate said reduced waste into homogenous lots and include manually operable sorting means.

17. A processing assembly as claimed m claim 16, wherein said sorting means include a turntable and guide means for guiding material not selected by an operator from the turntable for conveying to another reduced waste separating station.

18. A method of treating mixed solid waste material, said method including :- conveying mixed solid waste material from a collecting station to a material reduction station; reducing said mixed solid waste at said material reduction station; conveying said reduced solid waste to a reduced waste separating station, and separating said reduced waste into homogeneous lots at said reduced waste separating station.

19. A method of treating mixed solid waste material as claimed in claim 18, wherein said mixed solid waste is treated in a processing assembly as claimed in claim 1.

20. A method of manufacturing, said method including :- conveying mixed solid waste material from a collecting station to a material reduction station; reducing said mixed solid waste at said material reduction station; conveying said reduced solid waste to a reduced waste separating station; separating said reduced waste into homogeneous lots at said reduced waste separating station; providing raw material feedstock from said homogeneous lots; providing virgin material feedstock, and processing said raw material feedstock and said virgin material feedstock to produce a desired product.

21. A method of manufacturing as claimed in claim 20, wherein said mixed solid waste is treated in a processing assembly as defined in claim 1.

22. A method of manufacturing as claimed in claim 20, wherein said mixed solid waste is treated in accordance with the method claimed in claim 18.

23. A method of manufacturing, said method including :- providing raw material feedstock in the form of treated mixed solid waste; providing virgin material feedstock, and processing said raw material feedstock and said virgin material feedstock to produce a desired product.

24. A method of manufacturing as claimed in claim 23, wherein said virgin material feedstock includes virgin water and solvent binders for binding said raw material feedstock.

25. A method of manufacturing as claimed in claim 23, wherein said virgin material feedstock includes virgin plastic coating materials.

26. A method of manufacturing as claimed in claim 25, wherein said virgin plastic coating material is applied in a jointless form to produce the finished product (s) .

27. A method of manufacturing as claimed in claim 26, wherein said virgin material feedstock is a selected polymer material, and said desired product is a wall panel in which said raw material feedstock is sandwiched between layers of said polymer material .

28. A method of manufacturing as claimed in claim 23, wherein said raw material feedstock is produced by the processing assembly as claimed in claim 1.

29. A method of manufacturing as claimed in claim 23, wherein said raw material feedstock is produced in accordance with the method claimed in claim 18.

30. A product manufactured in accordance with the method claimed in claim 18.

31. A product as claimed in claim 30, wherein said product is a housing system including a range of raw materials and a range of panels.

32. A product manufactured in accordance with the method claimed in claim 20.

33. A product manufactured in accordance with the method claimed in claim 23.