Patent Description:
<CIT> discloses a method of making drainage elements from recycled plastics. In the method, chopped waste thermoplastic plastics are supplied to an agglomerator which heats and agglomerates the plastics into noodles. The heated noodles are then conveyed from the agglomerator via conveyors into a chute of a compactor/ shaper funnel. The agglomerated plastics meld together at their contact faces when sufficiently connected and pressed together in the compactor/shaper funnel to form an integral continuous compacted ribbon of melded noodles with spaces therebetween. The ribbon exits through an outlet of the compactor/shaper funnel, where it is turned ninety degrees to be put onto a belt. The belt speed affects the rate at which the compaction occurs. The ribbon is then cooled and chopped into bats. The width and thickness of the ribbon and therefore the bats are limited by the shape and size of the compactor/shaper funnel, and the ninety degree turn when exiting the compactor/shaper funnel. The bats are disclosed to be about <NUM> wide and <NUM> thick, and this size is constant as is further described below.

Other methods of forming structures from plastic materials are shown in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

Because bats are commonly used for drainage or attenuation, it is common to require very large cross-sectional areas of the bats, for example <NUM> wide and <NUM> thick. Using the methods disclosed in <CIT> to form the bats, many bats must be formed and then stacked together to meet the size and/or shape requirements. Thus, the method to form such a drainage area from the bats disclosed in <CIT> is time consuming, and can result in stability issues if not stacked or secured together properly.

In other applications, such as soak away or water treatment applications, very small pieces or different sizes of drainage material are required, for example pieces about the size of a tennis ball. To make such a piece from <CIT>, a bat would need to be formed and then cut down to a desired size, requiring a number of extra steps to result in the desired finished product. Simply making the compactor/shaper funnel smaller may result in insufficient weight of the heated malleable noodles within the small compactor/shaper funnel to allow melding of the noodles and pushing the noodles through the compactor/shaper funnel onto the conveyor. If a larger bat were desired, the amount of heat required would likely cause the center noodles to coalesce into a solid non-porous block and lost the ability to hold open spaces between the noodles.

Additionally, some drainage structures require large open spaces and/or interconnections for connecting together. The methods disclosed in <CIT> would not be able to produce such structures.

According to a first aspect of the invention, a method of forming end-form structures from recycled plastics includes the features according to claim <NUM>.

Such a method allows for the formation of a variety of different end-form structures from recycled plastics without the need for additional inserts, such as binders, to hold the end-form together. The molten agglomerated plastics meld together at their contact faces when sufficiently connected and/or pressed together in the shaper. By controlling movement and/or position of the shaper, a large variety of end-form structures can be formed, including smaller or larger end-forms with complex shapes and complex extrusions with a curved side. The method allows for the formation of these complex structures while ensuring that the plastics weld together while maintaining voids between to keep a porous structure. In the present context, molten agglomerated plastics is intended to refer to compositions where all or part of the agglomerated plastics are in an at least partially molten state. This heat is typically imposed by friction ribbing to a melting point, without heating to a point where fully melted or liquefied.

According to an embodiment, the method further comprises cooling the entire end-form. This ensures that the end-form is set to maintain its shape and porous structure internally and externally. Optionally, this can be done with cooling liquid or gases.

According to an embodiment, the method further comprises agglomerating recycled plastics in an agglomerator to produce the molten agglomerated plastics. The agglomerated plastics can all be molten, or only a portion of the plastics can be molten depending on the composition.

According to a first embodiment, step ii) comprises delivering the molten agglomerated plastics to a mould. Such a mould could help to shape the desired end-form, and could be used to form a variety of complex shapes from the molten agglomerated noodles. In this embodiment, step iii) comprises forming a desired end-form of agglomerated plastics by moving the mould as the molten agglomerated plastics are delivered to the mould. This can ensure that the molten agglomerated plastics are delivered to every part of the mould, and at a rate such that they do not pile up with too much weight or heat in one place, which could cause too much welding, leaving few or no void spaces.

According to the first embodiment, moving the mould may further comprise moving the mould such that the molten agglomerated plastics are delivered to the mould to build the end-form thickness throughout the mould from the bottom of the mould. This can allow for desired welding of the molten agglomerated noodles in such a way that initial noodles delivered to the mould are able to weld together and partially cool before another layer (adding more weight and heat) is placed on top. This ensures that the desired void to noodle ratio is maintained in the end-form structure.

According to the first embodiment, the method may further comprise forming connections, cavities, hollows, recesses and/or protrusions in the end-form. These can be formed in a relatively simple manner by using the mould which is shaped for the desired end form, including any desired cavities, hollows, recesses, protrusions, etc..

According to a second embodiment, step ii) comprises conveying the molten agglomerated plastics to a chute with one or more vertically oriented profile shaped conveyors. In this second embodiment, step iii) comprises forming a desired end-form extrusion of agglomerated plastics welded together by flowing the molten agglomerated plastics through a chute shaped to correspond to the desired end-form, and then through one or more vertically oriented profile shaped conveyors. Such a chute and vertically oriented profile shaped conveyors allow for forming a relatively large and/or complex extrusion shape end-form.

According to the second embodiment, step iv) may comprise cooling an outer surface of the end-form with water jets located within the shaper. Such water jets can be located, for example, between vertically orientated conveyors so that the end-form can be held and the speed of movement of the end-form be controlled. Such outer surface cooling sets an outer profile of the end-form, ensuring the desired end-form profile is maintained.

According to the second embodiment, the method may further comprise cutting the end-form to a desired length. This allows formation of the desired size of extrusion shape.

According to an embodiment, step i) comprises providing molten agglomerated plastics mixed with one or more of: charcoal, unagglomerated thermoplastics, rubber, vermiculite and fibre. Such additions can be suspended in the final end-form by the noodles, and can provide additional desired qualities to the end-form structure.

According to an embodiment, step iii) comprises controlling movement and/or position of the shaper to form an end-form of agglomerated plastics in the shaper by adjusting a speed of the shaper to affect the amounts of voids in the end-form. For example, molten agglomerated noodles can be delivered to the shaper at a faster speed to produce an end-form structure that is more dense, with less voids; or could be delivered at a slower pace to produce an end-form structure that is less dense, with more voids.

According to an embodiment, the method further comprises a step of adding a blowing agent to reduce the density of the end-form of agglomerated plastics. This would result in noodles which are fatter and less dense, producing an end-form structure that is also less dense.

According to a further aspect of the invention, a heat-bonded porous structure comprises an integrally formed end-form comprising a plurality of agglomerated plastic noodles welded together with voids therebetween and with at least one curved side according to the features of claim <NUM>. The agglomerated plastic noodles were welded together by connecting or pressing together when in a molten state. Such an integrally formed structure can be formed in a variety of complex shapes and sizes, and can therefore work well to form a variety of different stable porous structures from agglomerated plastics without the need for a binder or other addition to connect and hold the end-form together.

According to an embodiment, the drainage structure is an extrusion structure with a cross-section having at least one side which is curved.

According to an embodiment, the density of the end-form is between <NUM> kgs to <NUM> kgs per m<NUM>, though some end-forms, such as substantially spherical end-forms can have a much lower bulk density. In end-forms where openings are created, for example, a channel through the end form, the density values would change. The methods disclosed allow for controlling of the density of the end-form as desired by controlling movement and/or position of the shaper. This allows for a larger variety of end-forms to be produced according to the desired characteristics.

According to an embodiment, the voids form about <NUM>% to <NUM>% of the end-form.

According to the invention, the agglomerated plastic noodles have a size about <NUM> to <NUM> in diameter and can vary in their lengths, for example from about <NUM> - <NUM> or more. Additionally, the diameter and/or length could vary depending on desired end-form structure and requirements for that.

According to the invention, the end-form has a smallest dimension of at least <NUM>.

According to a further aspect of the invention, a heat-bonded drainage element comprises an integrally formed end-form of a plurality of agglomerated plastic noodles welded together when in a molten state, the end-form with voids therebetween, and with a channel formed through the end-form, the channel preferably having a minimum diameter of more than <NUM>.

According to a further aspect of the invention, a drainage structure comprises a plurality of drainage elements, aligned together such that the channels are continuous.

<FIG> is a schematic illustration of an apparatus <NUM> for producing an end-form structure from recycled plastics. Apparatus <NUM> includes an agglomerator <NUM>, intermediate conveyor <NUM>, delivery conveyor <NUM> and shaper <NUM>.

Agglomerator <NUM> is positioned such that molten agglomerated noodles <NUM> formed in agglomerator <NUM> fall onto intermediate conveyor <NUM>. Conveyor <NUM> then delivers molten agglomerated noodles <NUM> to delivery conveyor <NUM>, which can take a variety of different configurations depending on shaper <NUM> and the rest of apparatus <NUM>. The molten agglomerated noodles <NUM> can then be delivered to shaper <NUM> where they will be formed into a desired end-form of agglomerated plastics. The forming is done by having a shaper <NUM> which can produce a desired end-form, and controlling movement and/or position of that shaper <NUM> to produce the desired profile of the end-form while maintaining the desired structure of heat-bonded welding of noodles <NUM> with a plurality of open spaces into the profile. The final end-form is a one-piece, integral structure having sufficient strength to remain intact on subsequent handling, and with a plurality of spaces between noodles <NUM>. The open matrix of spaces in the end-forms can allow water and/or other liquids or gases to flow with relative freedom, making the end-forms ideal drainage elements for underground irrigation and drainage purposes. The specific methods of making the end-form structures will be discussed in more detail in relation to specific embodiments of apparatus <NUM> (and particularly shaper <NUM>), shown in <FIG>.

<FIG> is a side section through a dual plate type agglomerator <NUM>, which is suitable for use with apparatus <NUM>.

Agglomerator <NUM> works to form molten noodles of recycled plastics material, which may be mixed with and/or include other materials, such as charcoal, unagglomerated thermoplastics, rubber, vermiculite, fibres and/or blowing agent. Agglomerator <NUM> can include hopper <NUM> which receives the material to be agglomerated. This can be through a feed conveyor or other means of adding material on a continuous or intermittent basis. The base of the hopper <NUM> can include an extruder Archimedes screw <NUM> that transports the material along the barrel <NUM> of the agglomerator <NUM>. Flights <NUM> of the screw <NUM> can become increasingly tight so that waste material is compressed as it progresses along the barrel <NUM>. Barrel <NUM> is connected to an agglomerator chamber housing <NUM> which mounts a fixed circular, dished, agglomeration plate <NUM>. Plate <NUM> is fixed in the housing <NUM>, and has a central circular inlet opening <NUM>, through which the compressed waste material passes.

A main housing <NUM> of agglomerator <NUM> mounts an axially adjustable shaft carriage <NUM> that is threaded in internal threads <NUM> of the housing <NUM>. A motor <NUM> operates to rotate a worm drive <NUM> (through drive linkages not shown or further described). Worm drive <NUM> is engaged with a ring gear <NUM> formed on the shaft carriage <NUM>. Thus, rotation of worm drive <NUM> rotates carriage <NUM> about its longitudinal axis, screwing it into or out of housing <NUM>, and thereby adjusting its axial position therein. Shaft carriage <NUM> rotatably mounts a drive shaft <NUM> though bearings <NUM>, <NUM>, and extends into agglomeration chamber <NUM> and terminates with a round, domed agglomeration plate <NUM>. Plate <NUM> is formed in two parts 70a, 70b to define a water-cooling chamber <NUM>. Water is fed from the other end of shaft <NUM> though central bore <NUM> and evacuated through parallel bore <NUM>. At the distal end of shaft <NUM>, a rotary coupling <NUM> permits attachment of a cooling water supply <NUM>. Also on the distal end of shaft <NUM> is mounted a drive pulley <NUM> to drive shaft <NUM> by a motor (not shown).

Plates <NUM>, <NUM> are nested against one another. In the face of plate <NUM>, a number of radiating grooves are disposed somewhat inclined to the radius of plate <NUM>. Also on the face <NUM> are disposed a number of radially inclined ridges <NUM>. By virtue of their inclination to the radius, they tend to transport material caught between plates <NUM>, <NUM> radially outwards.

The face of plate <NUM> corresponds substantially with the face <NUM> of plate <NUM>, and has similar ridges <NUM> on its face. Depending on the axial position of the shaft carriage <NUM>, the ridges <NUM>, <NUM> have a friction rubbing and shearing action on material between them when the shaft <NUM> is rotated. As shaft <NUM> rotates, the continuous friction rubbing caused by the ridges <NUM>, <NUM> generates heat in the plastics material. Consequently, the thermoplastics substantially begin to soften at least to some extent. This softening is typically to around its melting point without becoming fully melted or liquefied.

The face of plate <NUM> is more dished than the face of plate <NUM> is domed. This means that the plastics material is squeezed into a progressively tighter space as it extrudes radially outwardly. In this event, the only outlet for the material worked is through the space between the plates <NUM>, <NUM>. By the time the thermoplastics materials have reached this point, at least a portion of them have softened considerably, and have become at least partially molten. So they are extruded from the grooves as spaghetti-like noodles that break and fall through an open bottom <NUM> of the agglomeration chamber <NUM>.

Underneath opening <NUM>, intermediate conveyor <NUM> is disposed. By adjusting the worm screw <NUM>, and adjusting the separation between the plates <NUM>, <NUM>, the degree of friction rubbing and shearing of the plastics material between the two plates can be controlled.

Screw <NUM> is shown abutting shaft <NUM> but is not driven by it. Shaft <NUM> rotates at a different speed than screw <NUM>, and so the latter is provided with its own independent drive (not shown).

Prior to molten agglomerated noodles <NUM> falling onto intermediate conveyor <NUM>, conveyor <NUM> can be sprayed with water or another liquid or gas to cool and/or wet the conveyor <NUM>. This can prevent molten agglomerated noodles <NUM> from immediately sticking to the conveyor and can help to cool the molten agglomerated noodles <NUM> so that their surfaces become petrified so that they do not adhere to the conveyor but still remain molten internally, preventing the molten agglomerated noodles <NUM> from coalescing and forming a solid mass.

Conveyor <NUM> delivers molten agglomerated noodles <NUM> to delivery conveyor <NUM>. Delivery conveyor <NUM> can then deliver molten agglomerated noodles <NUM> as desired to shaper <NUM>. This can be a steady stream of noodles or delivery in batches, whichever form is required by apparatus <NUM> and shaper <NUM> to produce a desired end-form structure.

<FIG> shows a first embodiment of apparatus <NUM>, not falling under the scope of the claims, which produces an end-form of small loose clusters <NUM> of heat bonded plastic noodles <NUM> with a porous structure. <FIG> shows an end-form cluster <NUM> produced by apparatus <NUM>.

Apparatus <NUM> includes agglomerator <NUM>, intermediate conveyor <NUM>, delivery conveyor <NUM>, shaper <NUM> and cooling tank <NUM>. Agglomerator <NUM> can be the type shown and described in <FIG> or another dual disc agglomerator. Delivery conveyor <NUM> is a bucket type or deep flighted elevator conveyor with a plurality of buckets <NUM> for carrying clusters <NUM> of molten agglomerated noodles <NUM>. Shaper <NUM> is a rotating cylindrical tube <NUM>, such as a drum, that is sloped.

Cooling tank <NUM> can be a vessel of cooling water or another liquid to fix the shape and structures of the end-forms exiting shaper <NUM>. In other embodiments, the cooling can be done in another way, for example, with a conveyor that is sprayed with a cooling liquid.

In operation of apparatus <NUM>, chopped plastics are provided to agglomerator <NUM>, which heats the plastics to a homogeneous condition so that malleable molten agglomerated noodles <NUM> of softened plastics exit agglomerator <NUM>. Agglomerator <NUM> is located such that noodles <NUM> exit agglomerator <NUM> onto intermediate conveyor <NUM>. Intermediate conveyor <NUM> must be able to withstand temperatures of molten agglomerated noodles <NUM> and be non-stick such that molten agglomerated noodles <NUM> do not stick to conveyor <NUM>. This can be done, for example, by spraying conveyor <NUM> with water and/or using various coatings to make the surface non-stick.

Intermediate conveyor <NUM> delivers molten agglomerated noodles <NUM> to delivery conveyor <NUM>. The speed of conveyor <NUM> and conveyor <NUM> are set such that a desired amount of molten agglomerated noodles <NUM> are delivered to each bucket <NUM> to form a cluster <NUM> within that bucket. The molten agglomerated noodles heat bond weld together at their contact faces to form clusters <NUM>. The set speeds of conveyors <NUM>, <NUM> result in each end-form cluster <NUM> being a generally regularized size. Clusters <NUM> of molten agglomerated noodles <NUM> within buckets <NUM> do not generally fully coalesce due to the temperature and weight of each cluster <NUM>, but will typically become heat bond welded at multiple contact points at their contact faces where pressed together. The temperature will also generally make clusters <NUM> stay soft and malleable.

Delivery conveyor <NUM> then deposits each cluster <NUM> into rotating cylindrical tube <NUM> of shaper <NUM>. Clusters <NUM> move in a rolling and tumbling action from an entrance of cylindrical tube to an exit. The rolling and tumbling action of the clusters <NUM> of melded noodles forms the end-form cluster <NUM> into a generally spherical shape and further increases the number of welded connections within each separate end-form cluster <NUM> but maintains multiple open spaces between heat bonded noodles <NUM> within each end-form cluster <NUM>. The speed of rotation and amount of slope of tube <NUM> can be adjusted to control the melding of the end-form clusters <NUM> of the noodles <NUM>, and the density of the end-form produced. The speed of rotation affects the melding of clusters <NUM> into end-form clusters <NUM>, with a faster speed resulting in more welded connections and a slower speed resulting in less welded connections and more open spaces or voids within end-form clusters <NUM>. The slope of cylindrical tube <NUM> provides movement along the tube <NUM> to subject clusters to more or less rolling and tumbling actions when moving from the entrance of the tube to the exit.

At the exit of the tube <NUM>, end-form clusters <NUM> are delivered for cooling. Cooling in this embodiment is done by dropping end-form clusters <NUM> into cooling tank <NUM>, which can be a vessel of cooling water or another liquid to fix the shape and structures of the end-forms (clusters <NUM>) exiting shaper <NUM>. In other embodiments, cooling can be done in another way, for example, with a conveyor that is sprayed with a cooling liquid or gas. After cooling, end-form clusters <NUM> can be gathered and stored.

As shown in <FIG>, end-form clusters <NUM> produced by apparatus <NUM> of <FIG> are generally spherical in shape and contain open spaces. By using a delivery conveyor <NUM> with buckets <NUM> and a rotating sloping drum <NUM> as a shaper <NUM>, apparatus <NUM> is able to produce end-form structures that are relatively small from heat-bond welded agglomerated plastic noodles <NUM>. These are desirable for a variety of applications, for example, in water treatment media, as soakaway infill media and loose lightweight infill media to fill void spaces. End-form clusters <NUM> can be, for example, the size of a tennis ball with a diameter of about <NUM>-<NUM>, or another size depending on system components (bucket size <NUM>, cylinder size <NUM>, etc.) and/or desired end-form size and shape. An end-form could have voids forming about <NUM>% to <NUM>% of the end-form, but these percentages can change depending on end-form desired qualities and usage.

<FIG> is a second embodiment of apparatus <NUM>, which uses a movable mould <NUM> as shaper <NUM>. <FIG> shows the mould <NUM>, and <FIG> shows an end-form <NUM> shape produced by apparatus <NUM>.

Apparatus <NUM> shown in <FIG> includes agglomerator <NUM>, intermediate conveyor <NUM>, delivery conveyor <NUM> and mould <NUM> as shaper <NUM>. Mould <NUM> includes a centre portion <NUM> to form a void <NUM> in end-form <NUM>.

As in apparatus of <FIG>, agglomerator <NUM> heats chopped plastics to form agglomerated noodles <NUM> of softened or molten plastics. The heat is such that a significant portion can become heat-bond welded together at their contact faces when sufficiently connected and pressed together, but still maintain void spaces between noodles <NUM>.

Molten agglomerated noodles <NUM> are then delivered to conveyor <NUM>, which can withstand the temperature and ensure that noodles <NUM> do not stick to conveyor <NUM>. From conveyor <NUM>, noodles <NUM> are delivered to delivery conveyor <NUM>. Delivery conveyor <NUM> then delivers molten agglomerated noodles <NUM> into mould <NUM>.

Mould <NUM> is shaped corresponding to a desired end-form <NUM>, and can include inserts, projections, etc. to form different cavities, shapes, connecting parts, etc. Mould is able to move in all directions to ensure that molten agglomerated noodles <NUM> accumulate evenly in mould <NUM> without leaving unfilled spaces, building up from a bottom <NUM> to a top <NUM> of mould <NUM>. This movement can be automated to ensure a very even build-up of noodles <NUM> in end-form <NUM>. Movement also ensures that a sufficient quantity of molten agglomerated noodles <NUM> are accumulated evenly and welding between heated noodles <NUM> occurs, but that the total quantity of molten agglomerated noodles <NUM> at any point is limited to ensure that the weight and temperature do not build up to levels which would result in the noodles <NUM> becoming overly compressed and/or overheated, and possibly coalescing into a solid block. Predetermined movements of mould <NUM> in synchronization with the stream of molten agglomerated noodles <NUM> from conveyor <NUM> allows a depth of heat bonded porous structure to be gradually increased within the mould <NUM> without leaving unfilled spaces.

Once the desired amount of noodles <NUM> have been delivered to mould <NUM>, cooling can be done while end-form <NUM> is still in mould <NUM>, and can be passive cooling (simply letting the end-form and mould cool), or can be active cooling, for example using a liquid or gas to quicken the cooling process. Then, end-form <NUM> can be removed from mould <NUM>, and will maintain open spaces <NUM>, as shown in <FIG>.

Using a moveable mould <NUM> allows for a variety of shapes of end-form <NUM>, including very thick shapes, shapes with hollows, recesses or protrusions, and other shapes of end-forms which were not possible in prior art methods which formed products from recycled plastic noodles. By using a movable mould <NUM>, end-form <NUM> can be built up gradually from bottom <NUM> to top <NUM>, allowing for proper heat bond welding between molten agglomerated noodles <NUM> but ensuring that a proper distribution is made and that no area has too many noodles <NUM> or too much heat at a certain time to prevent over compression and overheating. Additionally, once one mould <NUM> has been filled with noodles <NUM>, another different mould can be placed into apparatus, allowing for efficiently producing a variety of different shaped end-forms by having a variety of different moulds <NUM>. This method can allow for a wide variety of three-dimensional end-forms <NUM>, and can be especially useful in end-forms that require large open spaces, for example, if the end-form is being used as a soak-away, water storage, infiltration or attenuation system for stormwater or for increased flow rates or irrigation applications.

<FIG> is a third embodiment of apparatus <NUM> with a profile shaped conveyor <NUM> as shaper <NUM>. Apparatus <NUM> shown in <FIG> includes agglomerator <NUM>, intermediate conveyor <NUM>, delivery conveyor <NUM>, shaper <NUM> and cooling jets <NUM>. <FIG> shows a portion of the shaper <NUM>, and <FIG> shows the end-form <NUM> which apparatus <NUM> produces.

Profile shaped conveyor <NUM> includes chute <NUM> and one or more conveyors <NUM>, <NUM> which form a desired end-form profile shape. In this embodiment, three vertically oriented, generally flat conveyors <NUM> are shown, and one conveyor <NUM> has a semi-circular shape to form an end-form profile <NUM> which is flat on one side and rounded on the other side. Conveyor <NUM> is formed from segmented sections that make the shape of the intended end form. In some embodiments, conveyor <NUM> could be a flexible conveyor belt shaped to produce the intended end-form.

In operation, apparatus <NUM> of <FIG> starts in much the same manner as apparatus <NUM> of <FIG>. Agglomerator <NUM> agglomerates plastics to form molten agglomerated noodles <NUM>. Conveyors <NUM>, <NUM>, deliver these molten agglomerated noodles <NUM> to shaper <NUM> without noodles <NUM> sticking to conveyors <NUM>, <NUM>.

Chute <NUM> of shaper <NUM> receives molten agglomerated noodles <NUM>, and is shaped to correspond to a desired end-form extrusion profile. Chute <NUM> aligns closely with conveyors <NUM>, <NUM>; which are arranged to give continuous moving surfaces to a final extrusion shape that is being formed. Conveyors <NUM>, <NUM> work to move and shape welded end-form extrusion coming out of chute <NUM>. Cooling jets <NUM> are arranged to spray an outside of the end-form <NUM> for fixing a profile shape of the end-form <NUM> being made. Speed of conveyors <NUM>, <NUM> are controlled according to the desired buildup of noodles <NUM> in chute <NUM> and the desired compression and heat bonding of molten agglomerated noodles <NUM>, therefore controlling the desired ratio of noodles <NUM> to void spaces in end profile formed. All conveyors <NUM>, <NUM> are typically moving at the same speed. By controlling the head of molten agglomerated noodles <NUM> in chute <NUM>, the speed of shaper <NUM> conveyors <NUM>, <NUM> and including cooling jets <NUM>; sufficient melding can be achieved without allowing excessive build-up of weight of molten agglomerated noodles and/or build up of temperature within end-form <NUM> prior to cooling. This results in an end-form <NUM> which is sufficiently melded into a porous structure without allowing molten agglomerated noodles <NUM> to coalesce into a solid block.

After exiting shaper <NUM>, end-form <NUM> can be cut to any required length. By having a moving, profile shaped conveyor <NUM> as a shaper <NUM>, and with outer cooling jets <NUM>; an end-form <NUM> with a variety of desired profiles can be formed. The vertical orientation of conveyors <NUM>, <NUM> allows for an increase in cross-sectional thickness as well compared to prior art methods, as the extruded end-form <NUM> is not turned ninety degrees as in the prior art methods (which caused stretching and compression). For example, a typical thickness could be between about <NUM> and <NUM>. Thus, end-form <NUM> is able to be formed substantially larger and in more complex shapes, allowing formation of more varieties of draining structures than prior art methods.

In summary, apparatus <NUM> and particularly shaper <NUM> of the embodiments shown allow for a variety of complex and differently sized and shaped drainage structures with different characteristics (i.e., porosity, density) to be formed of recycled plastic materials agglomeratored into noodles <NUM> without the need for additional binders or other material to hold end-forms together. In the prior art methods, the forming of drainage material and dimensions was limited by the compactor/funnel used. If larger or smaller sizes were needed they would have to be formed by extra manufacturing steps (cutting or stacking together) which resulted in less efficient production and less stable end products.

By forming shaper <NUM> with controlled movements, shaper <NUM> allows for the formation of end structures with molten agglomerated noodles <NUM> that are stable and securely bonded together, while maintaining open spaces at a desired ratio within the structure without a lot of finishing steps. Agglomerator <NUM> can agglomerate plastics into noodles <NUM>, and heat the noodles using mechanical energy to a generally homogenous condition such that a substantial number of them are molten. Adjustments can be made in agglomerator <NUM> to affect the size, physical character and/or temperature of molten agglomerated noodles <NUM> produced to maintain a desired and substantially regularized output. This allows for using recycled waste plastics that may be of different types and/or sources (and that melt at different temperatures and/or have different properties when melted or re-melted), and may include residual fractions of other material. The process allows for these to be captured and bound in the resulting end-form structure, helping to preserve the porous nature of the structure by aiding interstitial space. Additionally, other additives and/or inclusions, such as a blowing agent and/or chips of fibre, rubber, vermiculite, solid thermoplastics and/or charcoal could be added to the agglomerator <NUM>. This can result in different qualities in the end-form, such as retention of water, which is desirable during dry periods in end-forms used for irrigation purposes. The addition of a blowing agent would result in fatter, less dense noodles <NUM>, preferably having an open cell structure. That would make the resulting end-form less heavy, and may give it greater water retention through penetration of the noodles themselves and retention thereby.

Noodles <NUM> can be about <NUM> - <NUM> in diameter and can vary in their lengths, for example from about <NUM> - <NUM> or more. Noodles <NUM> can also vary in diameter if desired for a specific application. Typically, when describing the noodles as "molten", it means that they are at a temperature where at least a portion of them are soft and malleable and able to weld to another noodle at contact faces when pressed or connected together. Temperatures at which noodles <NUM> will become molten will vary based on the composition of the agglomerated plastics (and possibly other additions) which form noodles <NUM>. Some plastics will become molten at higher temperatures than others. Additionally, apparatus <NUM> could add or remove heat from system at points other than agglomerator <NUM>, for example, at conveyors <NUM>, <NUM> and/or shaper <NUM>, to maintain the desired temperature to achieve the desired molten state of noodles <NUM>. While the terms "molten agglomerated noodles" or "molten agglomerated plastics" are used, these encompass compositions where only a portion of the noodles/plastics are in at least a partially molten state.

Because the malleable noodles <NUM> exiting agglomerator <NUM> are heated to a generally homogenous condition and hold sufficient temperature, noodles <NUM> can be made to become heat-bond welded together at their contact faces when sufficiently connected and/or pressed together (without the need for binders), but still maintain multiple open spaces between each noodle <NUM>.

Shaper <NUM> can take a variety of forms, as shown in the embodiments disclosed, and helps to form the desired end-form from noodles <NUM>. A rotating sloping cylinder <NUM> (along with a particular delivery conveyor <NUM>) can be used to make end-form clusters <NUM>. A moveable mould <NUM> can be used to form a variety of shapes according to the shape of the mould <NUM>, including very thick end-forms and/or end-forms with large open spaces, hollows, recesses, cavities, connection points and/or protrusions. A shaped chute <NUM> with one or more vertically oriented, shaped conveyors <NUM>, <NUM> and outer cooling jets <NUM> can be used to form extrusion end-forms with a variety of profiles, and particularly thicker or profiles with more complex shapes, for example with at least one side which is curved. By using a shaper <NUM> which has controllable movements and/or positions, apparatus <NUM> can form stable desired end-form shapes of drainage material with desired properties (density, etc.) without requiring a lot of extra finishing steps. This results in a more flexible apparatus <NUM> and methods for making draining products into the shapes and sizes desired for specific applications.

While end-forms can have different shapes, sizes and properties, a density of about 250kgs to 750kgs per m<NUM> is typically present in end-form to ensure sufficient stability and porosity. The percentage of end-form which is comprised of the voids can vary, but can be in the range of about <NUM>%-<NUM>%, for example.

While different cooling methods are shown, including cooling jets and a cooling vessel, cooling could also be performed in other ways, for example, by simply leaving the end-form out at room temperature or in a cooler area to cool naturally, or introducing a cooling gas to the area and/or to be directed toward the end-form. Conveyors <NUM>, <NUM> can also take many different forms depending on the desired delivery of noodles <NUM> to shaper <NUM>. For example, if it is desired to have noodles <NUM> build up in shaper <NUM> gradually or if it is desired to deliver a number at a time, conveyors <NUM> and/or <NUM> can take different configurations to help facilitate this.

Claim 1:
A method of forming end-form structures (<NUM>) having complex shapes, from recycled waste plastics of different types, the method comprising:
i) providing partially molten agglomerated plastics in noodle form, the noodles (<NUM>) having varying lengths of from <NUM> to <NUM> and diameters of from <NUM> to <NUM>;
ii) delivering the partially molten agglomerated plastic noodles to a shaper(<NUM>);
iii) forming an end-form of agglomerated plastics in the shaper by controlling movement and/or position of the shaper , the end-form comprising the agglomerated plastic noodles welded together with voids therebetween; and
iv) cooling at least an outer profile of the end-form to form the structure;
wherein either:
a) step ii) comprises delivering the molten agglomerated plastic noodles to a mould (<NUM>) having at least one curved side and step iii) comprises forming a desired end-form of agglomerated plastic noodles by moving the mould as the molten agglomerated plastic noodles are delivered to the mould
or
b) step ii) comprises conveying the molten agglomerated plastics to a chute (<NUM>) with one or more vertically oriented curved profile shaped conveyors (<NUM>) and step iii) comprises forming a desired end-form extrusion of agglomerated plastics welded together by flowing the molten agglomerated plastics through the chute shaped to correspond to the desired end-form, and then through the one or more vertically oriented curved profile shaped conveyors.