AU2001271429A1 - Thermokinetic mixer, compositions and structural products - Google Patents

Description

Title: Thermokinetic Mixer, Compositions and Structural Products

Inventor: David Little, Elmer Good, Chris Brough, John Taylor, David Rice

BACKGROUND OF THE INVENTION

This invention relates to solids for use as bricks, building blocks, landscaping blocks, walkway stones, railroad ties, building blocks, steps, retaining wall blocks and other structural components. In particular, this invention provides for the use of a substantial proportion of a thermokinetically molten polymeric binder and optionally other components in a feed mixture material to be compressed in a molten state and solidified to form solids, including building blocks, landscaping blocks and the like.

The relatively high cost of re-ground or recycled polymers has barred their use in the substantial quantities required for large, low cost members such as bricks, building blocks, landscaping blocks, walkway stones, railroad ties, building blocks, steps, retaining wall blocks and other structural components. Where cement or mineral based mixtures are used as binders for competing products, the non- competitive cost of using polymer binders in structural members has been, in the prior art, an effective hurdle heretofore not traversed. The invention process uses a novel method and composition to overcome this hurdle.

US Patent 5,895,790 discloses thermokinetic mixers used for melt blending, a novel application for that device. The invention therein economically recovered polymer blends and waste thermoset material into useful products by first forming a predictable quality thermoset material from disparate polymers and then melt blending the thermoset material with a thermoplastic material into the useful products.

US Patent 4808665 discloses shaped articles are made from blends of rubber and plastic in which the rubber is in the form of discrete vulcanized particles dispersed in the plastic. After shaping the articles, they are exposed to free-radical crosslinking which converts the blends from thermoplastics to thermosets. The blends were formed in a low rotation speed device operating at around 100 rpm. US Patent 4,789,597 discloses an very important teaching in the prior art with regard to thermokinetic mixers, or "high flux" mixers as disclosed in that patent. It is critical to the effective operation of the device to prevent melting of the chamber processed particles. In this patent, chemically reactive agents are locked to particles of suitable synthetic resins without "wholly fluxing" or melting the resins. Thus a high quality intermediate product is obtained having no premature reaction taking place, suitable for further techniques. The process comprises the steps of intensively mixing and thermokinetically heating a batch of finely divided resin particles, with a chemically reactive agent, in an enclosed mixing chamber with a plurality of blades attached to arms rotating about a central axis within the chamber, and having a blade tip speed of at least about 18 meters per second, mixing the batch until the chemically reactive agent is locked to the resin particles, ensuring that temperature of the batch stays well below decomposition temperature of the reactive agent and below fluxing temperature of the resin particles, discharging the batch from the mixing chamber and cooling the discharged batch to avoid agglomeration of the resin particles. It is clear from the Table I disclosure in that patent that operating with tip speeds in excess of an allowable level for a specific polymer will result in unwanted "occasional agglomerates" which must be separated from and disposed

SUMMARY OF THE INVENTION An alternate embodiment of the novel thermokinetic mixer and compositions to form products from its operation, the present improvement is for compositions and methods to make structural products, referred to herein as the structural products embodiment. Some of the desired structural products are bricks, building blocks, landscaping blocks, walkway stones, railroad ties, building blocks, steps, retaining wall blocks, shingles and other structural components. The structural products embodiments are described below after the description of the novel thermokinetic mixing device and compositions resulting fron its operation.

The present invention comprises a novel thermokinetic mixer. In one form of the invention, the mixing chamber shaft projections are removable at least in part and replaceable without cutting the projections from the shaft. In another form of the invention, only a tip portion of such projections are removable and replaceable without such cutting. In yet another form of the invention, shaft projections into the mixing chamber comprise a tooth having a substantially reticulated face forming a deflecting surface such that substantially all mixing chamber particles encountering the tooth strike and are deflected at an incident substantially lateral angle from the deflecting surface.

The invention having deflecting surfaces comprises a novel method of melt blending many grades and processing products of single polymers for primary formation into a useful product or recycling into useful products as well as forming products from a wide variety of post-user or post-consumer polymers, especially those previously unknown to be reformable into useful products such as for PVC and styrene in high relative weight percent relative to all polymers in such a product.

The invention also comprises a two piece tooth effectively attached to the rotating shaft. At least one of the pieces comprises the entire deflecting surface which is easily replaceable after substantial wear from high speed and/or high temperature use in melt blending or physical compounding polymers within the mixing chamber. It has been unknown that the high temperature and/or high speed use of a thermokinetic mixer to melt blend polymers as in the Good patent (US Patent 5895790) would cause dramatically accelerated wear on the prior art thermokinetic mixer shaft extensions. The prior art use outside of the Good patent repeatedly confine operation of such mixers to strict limits on upper temperatures and rotation speeds. Outside of the Good patent, the prior art used thermokinetic mixers only for compounding short of melt blending or chemical reaction between particles, i.e., the product does not emerge from the mixing chamber in a molten state. The present inventors found to their surprise that exceeding the recommended mixture temperatures and rotation speeds as disclosed in the Good patent resulted in short effective life for the shaft extensions which drive the mix chamber particles into the side walls of the mix chamber to achieve the melt blending effect. In yet another aspect of the present invention, the disclosed patterns of deflecting surfaces as developed in the side by side arrangement of shaft-axis rows of teeth have especially advantageous effects in achieving melt blending of a wider range of polymers than contemplated in the Good patent. BRIEF DESCRIPTION OF THE DRAWINGS Figures 1 and 2 are perspective views of the invention mixer assembly, respectively assembled and exploded views.

Figure 3 is an exploded view of the shaft assembly of Figure 2. Figure 4 is a side view of the shaft components and a sample set of teeth faces.

Figures 5-9 are respectively cross sections AA and BB and sections C, D, and E of Figure 4.

Figure 10 are teeth face orientations of sets according to the invention of Figure 2.

Figures 11-13 are perspective, side and end views of a tooth base according to the invention. Figures 14-17 are perspective, top, side and end views of a tooth according to the invention.

Figures 18 and 19 are perspective and broken line side views of the feed screw.

Respectively for the feed screw end plate and the shaft end plate are Figures 20-21 and 22-24, the series of three figures being respectively side, edge and top views.

Respectively for the bottom housing and top housing are Figures 26-28 and 29- 31 , the series of three figures being respectively top, end and Section AA views. Figures 32 to 34 are perspective, side and top views of the dropout opening door.

Figure 1A are views of prior art unitary plastic pallets. Figure 2A is perspective view of the invention unitary plastic pallet. Figures 3A, 4A, 5A and 6A are respectively bottom, top, forklift side, and pallet jack side views of the invention pallet.

DETAILED DESCRIPTION OF THE INVENTION The invention is now discussed with reference to the Figures. The invention is especially described with reference to the art of thermokinetic mixers and the uses described for such mixers and as disclosed herein. It is well known in the art of thermokinetic mixers that tip speed of the shaft extensions is a critical a measure of the capability of the mixer to heat polymer particles by causing mixing chamber impinging collision induced the high speed rotation of the shaft. It is a repeated and a required teaching in the art that the shaft extensions comprise substantially smooth and rounded shaft extensions, albeit comprising substantially sinuous and rounded shafts and sometimes having at the shaft-distal end a rounded and small paddle with a face normal to the tangent of the circular rotation of the shaft extension. This construction is consistent with the uses to which such prior art devices have been primarily used, i.e., except for the Good patent, for non-melting mixing and compounding of polymers. The Good patent disclosed that thermoset material, normally without value for recycling or any use except for commingling at lower than 35 weight percent with thermoplastics, could be combined with as little as 25% thermoplastics for forming a useful article. The device suggested in the Good patent was the Draiswerke Gelimat® machine, as well known in this art. Such a device comprises no paddle shaped sections on its shaft extensions, consisting of a relatively amorphous smooth and substantially round shaft with some broad and rounded side to side bends. The smooth and rounded shape is formed such that the shaft extension does not cause polymer collision that would cause agglomeration by melting.

Figures 1 and 2 show respectively assembled and exploded perspective views of the invention mixer assembly. The reference numbers of Figures 1 and 2 are used only for those figures, although the referenced component names refer to substantially identical components among all the figures. For Figures 1 and 2, a frame 1 supports associated components such that a shaft assembly 2 is inserted in an axis of a shaft hole through end plate 3 and a feed screw hole through end plate 4, the two end plates defining enclosing ends of a mixing chamber cylinder, the bottom portion of the cylinder defined by the inside surface of the lower housing 5. Lower housing 5 comprises a dropout opening closed off during operation with discharge door 6. The upper housing 7 comprises an upper part of the cylinder of the inside surface of the mixing chamber of the invention. The feed housing 8 is adapted to permit feeding of material to the feed screw of the shaft assembly so that such material is, in combination with the feed screw rotation, compressingly forced into mixing chamber from an external feed. Door 6 rotatably closes about discharge door pivot pin 9. End plate 3 has attached to it a rack & pinion cylinder 18 with spacer 10 interposed. At the top of housing 7 is mounted a bracket 11 with which to support an IR temperature sensor 20 for the mixing chamber. Door guard 12 protects the sometimes high temperature door 5 from accidental human contact with dropout material. Rotary guard 13 and drive coupling guard 14 guard human operators from contact with rotating components during operation. Drive motor 15 is preferably an electric motor with sufficient power to accomplish the invention operation, but in a specific example below is about 150 HP. The pillow blocks 16 and 17 support the shaft assembly 2.

Figure 3 shows an exploded view of the shaft assembly 2 of Figure 2. The reference numbers of Figure 3 are used only for that figure and in Figure 4, although the referenced component names refer to substantially identical components among all the figures. A series of connected shafts comprise shaft components 1 supported at one end on the bearing 6. The feed screw 2 engages at the visible end of its hollow shaft the noticeable spline of the shaft components 1 such that appropriate rotation of the shaft causes the feed screw also to rotate. One preferred form of the invention comprises the tooth bases 3 being connected to either of a left edge tooth 4 or a right edge tooth 5 by slots and keys and tooth base screws 8 to teeth 4 or 5, whereafter the bases 3 are connected by slots and keys and tooth base to shaft screws 7 to the shaft, thereby forming removable base 3 and teeth 4 or 5 assemblies. This removable assembly concept for thermokinetic mixers is unknown in the prior art. The breadth of the concept of this aspect of the invention includes providing equivalent removable shaft extensions for all thermokinetic mixers. The disclosure herein enables the skilled person to adapt the removable extension concept to such prior art devices as disclosed above. The concept of the abutting slot and key attachments with securing screws has heretofore been unknown. More specifically, the base 3 may be attached by welding wherein only a portion of the shaft extension is removably attached as described herein. Or in the alternate, the teeth 4 or 5 or equivalent end portion of a shaft extension are a single piece with a base 3 or its equivalent in the prior art, the entire shaft extension thereafter being removable as disclosed herein for base 3 from the shaft comprising slots therefore. First row slots teeth sets 101', second row slots teeth sets 102', third row slots teeth sets 103', and fourth row slots teeth sets 104' correspond respectively with the first row slots 101 , second row slots 102, third row slots 103, and fourth row slots 104 as shown and described in and for Figure 4. The pattern of teeth 4 and 5 in Figure 3 are a preferred embodiment of the invention. In one embodiment, a row slots teeth set comprises all teeth 4 or 5. In another embodiment, all row slots teeth sets comprise all teeth 4 or 5 or each rotationally successive row slots teeth set comprises all teeth 4 followed by one of all teeth 5. In the embodiment of Figure 3, each row slots teeth set comprises two teeth 4 or 5 whereby the rotationally adjacent row slots teeth sets to each such set comprises two teeth 5 or 4 respectively. A most specific embodiment of Figure 3 shows first row slots teeth sets 101' with left to right teeth 5 / 4 / 4, second row slots teeth sets 102' with left to right teeth 5 / 4 / 5, third row slots teeth sets 103' with left to right teeth 4 / 5 / 4, and fourth row slots teeth sets 104' with left to right teeth 5 / 4 / 4. As shown in Figure 4, this pattern produces a set to set staggering of the teeth faces as they rotate into a plane passing through the shaft 100 axis. This sets pattern of teeth faces

With reference to rest of the Figures, shaft components 1 are further shown to comprise an attachment shaft section 100 whereupon are located some of the attachment means for attaching bases 3 to the shaft components 1. In this side view, first row slots 101 , second row slots 102 and third row slots 103 are visible, a fourth row slots 104 existing on the opposite side of the section 100 and further disclosed in Figure 6.

The slots and keys referenced herein comprise a preferred embodiment of abuttable slots having an open and closed end, the mateable key on another piece insertable into the open end and the first inserted end of the key then being moved from the open to the closed end of the slot to thereby abut the closed end of the slot. It is intended that rotation of the shaft 100 in the direction from the closed to open ends of the slots 101-104 will thereby cause the engaged first inserted end of the keys of the teeth bases to be pressed more securely into the slots 101-104 of shaft 100. Thus, each slot 101-104 has a slot length 105 in a preferred embodiment of about 1.75 inches divided exactly in two by one of two shaft axial planes normal to each other, whereby an open end of the slot is extended further along the shaft 100 such that the bases keys may be inserted, the further extension being about 0.625 inches, the combined slot lengths equaling about 2.375 inches.

Each slot 101-104 further comprises a base to shaft screw 7 hole 106 threaded to receive screws 7. The holes 106 are oriented to encourage retention of the tooth base key in the slots 101-104. The slots 101-104 are about 1.25 inches wide and 0.75 inches deep with internal cross section notches extending into the slot rectangle about 0.25 inches. The slot floor to floor width 107 is about 3.5 inches. Hole 106 angle 108 is about 20 degrees. For slots 101-104, the slot centeriine to centeriine distance 110 is about 1.75, whereby it will be appreciated that each row slots teeth set is axially lengthwise staggered from its rotationally adjacent row slots teeth set. Preferably, the staggering is such that teeth of two rotationally adjacent row slots teeth sets passing through an axial plane in operation rotation are equally spaced. As a definition of a specific example herein, Figure 10 shows teeth faces of the sets 101'-104' in solid lines as they would appear rotationally passing the plane view as shown by the teeth faces 103' TEETH FACES in Figure 9. In broken lines in Figure 10 are shown the rotationally following set of teeth faces, as would be encountered by a particle in the mixing chamber striking a tooth face of one set if passing through the teeth of that set to encounter the teeth faces of the next set. For example, all the sets 101 '-104' comprise, as easily seen in Figure 10, left to right adjacent teeth faces 5 and 4 (as in Figure 3), such that the inclination of those adjacent tooth faces tends drives all particles encountered from just below the top inclined face in between the gap formed by such adjacent tooth faces. The major tooth faces of such adjacent teeth form a rough "V" shape with a gap in between. The effect of such combination of adjacent teeth causes the particles thus funneled to the gap to encounter the gap-filling tooth in the rotationally following set. Notwithstanding this more limited, albeit preferred embodiment, of adjacency of teeth faces, it is preferred that the staggering of teeth in rotationally adjacent sets result in a substantially gap-filling action as shown in Figure 10 so that particles encountering a first set of teeth may strike them and/or be funneled to a gap between adjacent teeth in a set such that a rotationally following set tooth face is oriented to fill such a gap when it rotates to the position of the leading set. As further described below, the tips of the teeth of sets 101'-104' when installed define a width 325 and a height 326 within an inside chamber circumference 327.

Shaft components 1 further comprises spline attachment means 109 is constructed and oriented to securingly engage the appropriate end of a mating extension for shaft 100 and spline attachment means 109A constructed and oriented to securingly engage the appropriate end of a the feed screw 2 of Figure 3, thereby causing the feed screw to rotate with shaft components 1.

Figures 11-17 are discussed now for a detailed discussion of the teeth bases and teeth. The specific example described is an optimized device. This disclosure more broadly includes replaceable shaft extensions or at least upper portions of shaft extensions for thermokinetic mixers. Tooth base 200 has a base height 201 of about 3.5 inches, a width 202 of about 2.375 inches, a support width 203 of about 1.75 inches. A top end of the base 200 comprises a slot 204 for receiving a key from a tooth and at the bottom a shaft key 205 for insertion into the shaft 100 slots 101-104. The key height 206 is just less than 0.25 inches, the slot depth 207 is about 0.19 inches, the key width 208 is just less than 1.25 inches, the key attachment width 209 is just less than 0.75 inches. The base 200 comprises a tooth base to shaft screw hole 210 for receiving a screw for securing the tooth 300 to base 200 after insertion of the tooth key into the slot 204. The base 200 comprises tooth to tooth base screw hole 211 for receiving a screw for securing the base 200 to shaft 100 after insertion of the base key 205 into a slot of slots 101-104. The slot base width 212 is about 0.875 inches and the slot top width 213 is about 0.05 inches.

Right leading edge tooth 300 (as shown in Figure 3 as teeth 5) comprises attachment means for attaching to the tooth base 200. When the tooth base is engaged with a slot of slots 101-104, the appropriately attached tooth 300 presents a tooth face to a shaft 100 axial plane when the tooth 300 rotates about shaft 100. The tooth face comprises a reticulated major face 300 having an acute angle with respect to said plane, the vertex of that acute angle being the leading edge 304 of the major face. The presentation of the leading edge 304 is preferably linear and parallel to the said plane, although such leading edge may be slightly angled into or away from said plane and still accomplish objects of the invention. The shape of the leading edge 304 may comprise smooth transitions or notches and still accomplish the object of the invention.

A forming of such an angled major face 304 on a tooth face is heretofore unknown in the art of thermokinetic mixers. The effect of the angled major face in operation of the mixer assembly is to drive a majority of mixing chamber particles encountering the angled major face to one side or another of the supported tooth. Prior art thermokinetic mixers are intended as devices for throwing particles at the inside surfaces of a mixing chamber. The present invention tends to retain particles within a rotational cylindrical space between the shaft 100 surface and the tips of the teeth until such particles melt and/or agglomerate or are captured by melted polymers at the extra-cylindrical space clearance between the tooth tips and the inside surface of the mixing chamber. The major angled faces of the teeth make the invention device specifically adapted to melt blending polymers and/or non-melting filler polymers or other material. The above disclosure as to the teeth face presentations in Figure 10 clearly show that mixing chamber particles will be driven not only against the teeth and inside surface of the mixing chamber, but also inevitably with great force against each other. The invention device permits an unexpectedly large number of non-recyclable or limited value recyclable materials to be made into very useful compositions after melt blending therein.

The tooth 300 comprises in one preferred from a leading edge width 301 of about 3.2 inches, a following edge width 302 about 2.4 inches. A key 305 is formed in the upper convex portion of the L-shaped tooth 300, which key is insertable into the slot 204. The insertion can only be accomplished in one manner for the key 305 and slot 204 shown. Thus, the tooth 300 forms a protective cap or shield to the tooth base 200 as to encountering mixing chamber particles. A tooth to tooth base screw hole 306 receives the screw 8 as in Figure 3 for securing the tooth 300 to the tooth base 200. The tooth 200 further comprises a leading edge side 307, a following edge side 308, and a lower bevel face 309. Lower bevel face 309 comprises a portion of the tooth face below angled major face 304 in shaft 100 axis elevation. This face is preferred for avoiding agglomeration of melted particles at the shaft 100 to tooth base 200 transition, although such a face may be minimized or eliminated with substantially the function of the invention device preserved.

Tooth height 310 is about 4.5 inches, making total tooth sets 101/102 or 103/104 height 326 about 12.95 to 12.98 inches and total tooth sets 101/102 or 103/104 width 325 is about 8.25 inches. Leading edge height 311 is about 3.325 inches. Tooth 300 further comprises a lower face bottom edge 312 which rises to a lower face height 313 of about 0.75 inches. Tooth length 314 is about 3.2 inches and tooth less leading edge length 315 is about 1.75 inches. Top face 316 comprises a third portion of the tooth face. Faces 303 and 309 generally deflect particles in the mixing chamber toward the gap in teeth in a set. Top face 316 tends to drive particles into collision with the inside surface of the mixing chamber. Bottom slot width 319 is about 0.875 inches, top slot width 320 is about 0.50 inches, slot depth 321 is about 0.19 inches, and tooth width 322 is about 1.25 inches. Following edge 323 is the edge of major face 303 opposite leading edge 304.

It has been observed that in operation tooth top leading edge comer 324 becomes substantially worn after melt blending polymers and in fact the entire top transition edge between major face 303 and top face 316 becomes quite smooth and is abraded more than any other portion of the tooth in the preferred operation of melt blending.

The mixing chamber inside surface outline 327 as in Figure 4 has a circular diameter of about 13 inches and a width of about 10 inches, for a mixing chamber volume of about 1325 cubic inches. The clearance between the tooth tips and the inside of the mixing chamber walls is about 0.05 inches, thereby providing very little of the mixing chamber volume outside of the reach of the teeth.

Figures 18 and 20 show the feed screw 400 having shaft 404 with a length 401 of about 14 inches and two complementary screw blades 403, each having a pitch or crest to crest distance 402 of about 4 inches. A single screw blade on the feed screw is adequate to achieve the invention objects. Figures 20 to 25 show views of the mixing chamber end plates. Feed screw end plate 500 comprises an end plate 501 , an end plate base 502, end plate to housing bolt holes 503 in plate 501 , a feed screw hole 504 sufficiently large to accommodate rotation of the feed screw 400, housing inside surface circumference 505 approximately defining the mixing chamber inside circumference of the circular section, and a mixing chamber surface 506. Shaft end plate 600 comprises an end plate 601 , an end plate base 602, an end plate to housing bolt holes 603 in plate 601 , feed screw hole 604 sufficiently large to permit rotation of shaft 100 without escape of particles or molten polymer, a housing inside surface circumference 605 approximately defining the mixing chamber inside circumference of the circular section and a mixing chamber surface 606.

Figures 26 to 31 show views of the mixing chamber housings. Bottom housing 700 comprises an inside surface 701 , flange section 702 for joining with top housing 800, an inside diameter 703, a width 704 of about 10 inches, a dropout opening 705 about 7.25 inches square for allowing molten material to drop from the mixing chamber after shaft 100 rotation has optionally stopped or an appropriate process temperature has been reached within the mixing chamber. End plate bolt holes 706 permit attachment to the end plates.

Top housing 800 comprises an inside surface 801 , flange section 802, inside diameter 803, sensor opening 804 for insertion of an IR sensor for mixing chamber temperature, a width 805 of about 10 inches, and end plate bolt holes 806 to permit attachment to the end plates. Figures 31 to 33 disclose views of the dropout opening door 900 comprising a handle portion 901 and a door 902, which door is rotatable about a hinge for securingly closing the mixing chamber during operation.

The invention device includes the concept of melt blending polymers and other meldable material into a composition capable of being made into a useful object. The shaft 100 is intended to rotate such that the teeth faces will collide with particles of substantial size (about the feed screw blades separation width) to powders. When in operation, the housing 8 of Figures 1 and 2 accommodate insertion of such particles. The feed screw forces the particles into the mixing chamber to comminuted and melt blended. The rotational speed of the shaft can vary from below about 1800 rpm (to about 1500 rpm) to above about 3600 rpm. The choice of shaft speed will depend on the polymers and other materials being processed and the processing temperature desired to be reached. For example, a mixture with a very high weight percentage of PVC (normally not recyclable or only in very low relative amounts with other polymers) may be melt blended at 1800 rpm to its processing temperature, say around 120-200 C as measured by the IR sensor for the mixing chamber.

When a desired processing temperature is sensed by the temperature sensor for the charged amount of one or several materials within the mixing chamber and contrary to the methods of the prior art for melt blending for thermokinetic mixers, rotation of the shaft is preferably continued at the set rotation speed. It has been an unexpected result that an opening of the dropout door will substantially empty the mixing chamber of a substantially uniform composition of molten and moldable material without having to stop the shaft rotation. It is preferred that a control means cause the opening of the dropout door to occur at the sensing of an upper limit temperature by the temperature sensor. The dropout door preferably instantly closes after the release of the melt blended charge, thereby initiating feed of another amount of charge material to housing 8, feed screw transfer to the mixing chamber, heating by thermokinetic effect and release from the mixing chamber through the dropout door once again without substantial adhesion to the shaft or teeth or shaft extensions.. The mixing chamber sensed temperature falls upon introduction of a new feed charge to the mixing chamber. The average cycle time for melt blending a charge for the device of the specific example is about 5-8 seconds. Some materials in the charge to the mixing chamber with low melting temperatures, such as PVC, have a lower cycle time (by a few seconds) while other materials take longer. At around 3600 rpm, the invention device heats and melts a mixing chamber mixture of polyolefins to about 230 C in about 5 seconds. A more preferred operating speed is about 2800 rpm so that a desired ultimate batch temperature may be more easily controlled and obtained.

It is a less preferable method of operation to stop the shaft rotation for emptying of the mixing chamber, although the objects of the thermokinetic heating and melt blending of a very broad range of incompatible materials may be so processed. The top and bottom housings are double walled so that water can be flowed through them to cool the housing during operation. It is preferred that the clearance between the tips of the teeth and the mixing chamber wall be small, although some of the objects of the invention device could be achieved with substantial clearance therefore.

The number of teeth in each rotationally successive set should be equal and staggered as described above although using from 2 to 10 teeth in each seat will accomplish the ends of the invention device. It will be clear from this disclosure that increasing the number of teeth or extending their tip to tip height requires an expansion of the mixing chamber and therefore an increase in the drive motor for the shaft 100 and feed screw. Those adaptations will permit an increase in the batch size processed. The volume of the material to be processed in the invention device should be limited to about less than the volume of the mixing chamber less the volume of the shaft 100 and sets 101'-104'. An invention device using only two sets 101' and 103' or 102' and 104' may be used to accomplish some of the objects of the invention, although use of all four sets are preferred. The acute angle of the major face with respect to a plane including the shaft axis is as shown in Figure 15 is about 45 degrees, although the invention may be practiced with such angles equaling from 5 to 85 degrees, more preferably 20 to 70 degrees, and most preferably from 30 to 60 degrees.

The invention thermokinetic mixer also comprises a replaceable wear surface case or body hardened on an inner surface to a high Rockwell number where the wear surface substantially comprises the entire inside surface of the mixing chamber. In the specific example, this would mean an inside surface of inner jackets would substantially comprise surfaces 701 and 801 such that the underlying structural support would maintain the position of the jackets in the positions of the surfaces 701 and 801 as shown in the Figures. The replaceability of the jackets reduces the cost of repairing inevitable wear on the jackets from melt blend processing, especially where substantial processing of unsorted trash is performed comprising metal and silica glass pieces.

The invention assembly also comprises means for removeably mounting the feed screw to the rotation shaft for replacement for wear.

Thermokinetic Mixer Compositions The mixing assembly of the present invention has dramatically expanded the potential for melt blended compositions made therefrom. The Good patent discloses the well known prior art device, an ultra-high speed thermokinetic mixing device, such as the one produced by Draiswerke, Inc. and described in their brochure entitled "High Speed Thermokinetic Mixing, Compounding, Fluxing" (thermokinetic mixer, as described herein). The Draiswerke, Inc. device called the Gelimat® heats thermokinetically through particle impingement against the interior surface of the mixing chamber. Although melt blending of a very finely divided (35-100 mesh) thermoset material and a shredded or chopped thermoplastic polyolefin resin may be accomplished by external heating in heated extrusion means to produce an extrudable material, such melt blending is limited by inadequate mixing within the barrel of the heated extruder.

The Good patent further discloses that using a device like the Gelimat® or a similar thermokinetic mixer as a device for practicing melt blending, wherein as about 0.25-0.5 inch flakes are added to the Gelimat® with shredded or chopped thermoplastic polyolefin resin. Extremely rapid heating and sheer grinding of relatively large particles (0.25-0.5 inches in diameter) of thermoset material occurs and enhances melt blending and homogeneity. The melt blend is created in seconds in the devices like the Gelimat® as opposed to requiring substantially longer in a conventional extruder. The prior art thermokinetic mixers have proven limits, as disclosed in the Good patent, in melt blending compositions. For instance, only a relatively low percentage of PVC or polystyrene were capable of being melt blended into a moldable material. It is clear from the shaft extension configurations of the Gelimat® and other prior art thermokinetic mixers that their designs originated in the art of non-melt blending compounding. Those shaft extensions in a front view comprise substantial "paddle" portions at their free ends provided to drive the mixing chamber particles into the inside surface of the mixing chamber.

In contrast, the invention means for thermokinetic melt blending comprise an very important departure from the thermokinetic mixer art. As appreciated by the above description of the invention means, polymer or polymer containing particles within the mixing chamber obtain their thermokinetic heating primarily by their impact and deflection with the shaft extensions while a relatively lesser degree of heating is obtained by the particle impact with the inside surface of the mixing chamber. The introduction of means for maintaining substantially all the mixing chamber particles in the rotational field of the shaft extensions where the shaft extensions have a substantial defined and articulated leading edge means that those mixing chamber particles are subjected not only to repetitive thermokinetic heating deflection from the shaft extensions but also repetitive and significant chopping action from the sharply defined leading edge of the teeth. Prior art shaft extensions are smoothed and arcuately angular as to the rotating face surfaces encountering mixing chamber particles. The invention device permits thermokinetic melt blending of materials, shapes and textures heretofore impossible to so process. The invention processes of the invention mixing assembly include not only novel combinations of polymers and non-polymer materials, but also of prior art combinations of such materials in shapes and textures as have made recycling or reprocessing impossible.

The following examples are novel compositions thermokinetically melt blended by processing in the thermokinetic mixer of the present invention. The polymers processed thereby are preferably from post-user disposal of the polymers, i.e., substantially processed and containing additives and/or dirt or small pieces of undesirable waste such as paper, fiber, metal scraps that are non-economic to remove that otherwise make recycling difficult or impossible. However, the invention melt blending function is also highly effective in processing virgin polymer materials as well. The percentages described in the examples are weight percents unless otherwise stated. The examples refer to a polymer portion and non-polymer portion where the polymer portion is that portion that consists substantially of polymers, although some part may include the non-economically removable waste as described above since actual operation that processed the example requires weighing bulk materials being fed to the invention mixer.

Example 1 consists of flexible or rigid PVC as 30-100 percent of the polymer portion feed to the invention thermokinetic mixer. The pieces are preferably chipped to about 3/8 inches and less. In a more specific example, the polymer portion consists of 50% flexible and 50% rigid PVC. A preferred balance of the polymer portion is LLDPE, although polyolefin polymers, copolymers and the like are also very effective in producing a moldable material. A charge of the Example 1 material is melt blended in the invention mixer for about 5 seconds at a shaft speed of about 1800 rpm. At a sensed temperature of about 350-400 degrees F, the dropout door is opened and a molten mass of material is dropped to a receiving surface. The molten mass is transferred to a compression mold and pressed into the mold to form objects such as wheels. Example 2 consists of thermoset polymers as over 75 percent of the polymer portion feed to the invention thermokinetic mixer. As used herein, thermoset or crosslinked means polymers whose melting temperature is effectively greater than its decomposition temperature. It is well known that materials such as Formica® is such a thermoset that will not melt but merely become soft and leathery on heating to a certain range and thereafter merely char instead of burning. The thermoset pieces are preferably chipped to about 3/8 inches and less. In a more specific example, the polymer portion consists of 100% thermoset polyolefins. A preferred balance of the polymer portion is LLDPE, although polyolefin polymers, copolymers and the like are also very effective in producing a moldable material. A charge of the Example 2 material is melt blended in the invention mixer for about 5 seconds at a shaft speed of about 3600 rpm. At a sensed temperature of about 350-400 degrees F, the dropout door is opened and a molten mass of material is dropped to a receiving surface. The molten mass is transferred to a compression mold and pressed into the mold to form objects such as wheels. Example 3 consists of up to 50 percent of thermoset polymers and a balance amount of a polyolefin as the polymer portion feed to the invention thermokinetic mixer and processed as in Example 2, except that the material is not molded but is cooled and ground to a particle size appropriate for processing in a heated extruder. In a more specific example of the material of this Example 3, the feed to the invention mixer is 40 percent of thermoset polymers and a balance amount of LLDPE as the polymer portion feed is easily fed to a heated extruder and easily injection molded to form objects substantially as easily as LLDPE without the thermoset material. This Example 3 is a dramatic improvement in the art of recovery of thermoset material into injection molded components where the physical characteristics are substantially identical with pure LLDPE without the necessity of fine grinding to 100 mesh or smaller particles to accomplish this effect, as disclosed in the Good patent. Example 4 consists of up to 30 percent of ground tire fragments including the fibers incorporated into the tire, up to 30 percent thermoset polymers and and a balance amount of a polyolefin as the polymer portion feed to the invention thermokinetic mixer and processed as in Example 2. It is unknown to the art to thermokinetically melt blend unprocessed tire fragments with any materials to form a useful product. The invention mixer provides a chopping action impossible with prior art devices such that the texture and form of the tire fragments are completely disassociated for melt blending with the other polymer components of the polymer portion. Example 5 consists of up to 100 percent of shredded synthetic (such as the nylons and other such polymers) carpet with or without a natural fiber backing and a balance amount of a polyolefin as the polymer portion feed to the invention thermokinetic mixer and processed as in Example 2. It is unknown to the art to thermokinetically melt blend shredded synthetic carpet with any materials to form a useful product. The invention mixer provides a chopping action impossible with prior art devices such that the texture and form of the shredded carpet are completely disassociated for melt blending with the other polymer components of the polymer portion.

Example 6 consists of up to 100 percent of polystyrene percent and a balance amount of a polyolefin as the polymer portion feed to the invention thermokinetic mixer and processed as in Example 2. It is especially difficult to recycle polystyrene foam in the prior art methods and mechanisms. The Good patent discloses the limits to prior art thermokinetic mixers in melt blending such materials as about 11 weight percent of the polymer portion. Example 7 comprises separate use of from a minimal amount to 100 percent of one or a mixture of the following group: nylons, urethane, polycarbonate, ABS, HIPS, acryilics, and PEX; and a balance amount of a polyolefin as the polymer portion feed to the invention thermokinetic mixer and processed as in Example 2. Example 8 consists of defining for the above examples a non-polymer portion. It is well known in the art that any of a large number non-polymer materials may be added to molten polymer to obtain a range of performance or physical properties different than a product made with the polymer alone. The present invention mixer now allows melt blending of a wider range of such materials into a wider range of single or multiple polymers than possible in the prior art. The non- polymer portion may comprise materials such as shredded natural fibers, wood based products (wood chips, sawdust, paper, cardboard, chemical containing papers such as photographic paper with about 4 weight percent silver compounds), metals (ground aluminum, copper, iron, tin, and others found in post user waste or included to obtain physical or electrical properties of the melt blended material), non-plastic organic material (food materials, paints, oils and other such materials quickly vaporize a volatile portion and leave a small residue behind), glass and silica based particles, and other such materials as are apparent to the skilled person with this disclosure. The non-polymer portion may be up to 90 percent as compared to the polymer portion, although desired physical properties of the molded composition will control the specific addition of individual non-polymers to the polymer portion. Some non-polymer portion may be part of an integrated product containing polymers, such as polymer carpet fibers woven into a natural fiber backing or natural fiber cord or metal strands made with tires or coated wires, whereby separation of the polymer and non- polymer portions are unnecessary for feeding to the mixing chamber. The non- polymer portion includes materials in the prior art that have been incapable of being melt blended thermokinetically for lack of a chopping action from the mixer shaft extensions as in the invention mixer. Such materials include materials that would be waste unless further processed with prior art methods (not including thermokinetic melt blending) such as one- or two-direction stretchable T-shirt cotton material, and the otherwise described carpet and cord-strengthened tires, thermoset-covered copper and aluminum wires and cables, aluminum foil, computer floppy disks with slidable metal covers, computer compact disks with integral magnetic particles, fiber reinforced or glass filled polymers, cardboard juice containers with polymer caps and bases, pens or markers having an ink and/or fiber core, circuit boards having solder, metal and/or semiconductor pieces integrated thereon, particleboard or wood panels having polymer sheeting adhered thereto, carboard core ring binders with a plastic sheet or woven fiber cover and many other such products having been manufactured with a polymer and non-polymer portion. The non-polymer portion materials are included to improve strength and other desired physical characteristics as generally disclosed in prior art compositions, however the present expanded capability of the invention mixer compositions also reduces the complexity and cost of recycling plastics and post user waste. One of the most expensive and time consuming operations in plastics recycling is separation of recoverable polymers from non-recoverable polymers and other waste. The above Example 8 enables a composition with a non-polymer portion with almost no sorting on post user waste, whether industrial or consumer, since the invention mixing compositions can be supplied with a relatively small amount polyolefins as the polymer portion from which a moldable composition may be formed.

For instance, as Example 9, the a polymer portion may comprise about 50 percent PET as the polymer portion and 50 percent Kodak® paper as the non- polymer portion. No special extraction or solvent preparation is needed to separate the photographic chemicals from the paper.

Many films (such as PE and PET or PE and PE) that are co-extruded with interlayer adhesive cannot be recycled conventionally without extraction of the adhesive. Such films are easily melt blended using the invention process to become products described herein with those polymers. The polymers PET and PETG are used extensively in the making of movie film and contain so substantial amounts of chemicals that they must normally be substantially removed before recycling, although the invention process can easily process them as feed polymers to the melt blend.

It is another embodiment of the invention method for forming products from the melt blended composition to use a ram extruder to form products therefrom. It is another embodiment of the invention method to provide feed to a thermokinetic mixer for thermokinetic melt blending such that a cross linking agent, such as dicumyl peroxide or others known in the art, is added to the feed to the thermokinetic mixer so that a substantially thermoset composition is obtained thereby. A substantial portion of polymers in the feed, say at least about 20% by weight, are capable becoming thermoset through processing in the thermokinetic mixer temperatures as described above. It is known in the art that several types of polymers are capable of becoming thermoset upon melt blending or melting in the presence of a cross linking agent.

In another range of embodiments of the invention compositions, it is unknown in the art to include for any composition melt-blended within a thermokinetic mixer to comprise a foaming, expansion or cell forming agent which is activated upon thermokinetic heating. Compositions described in the Good patent as appropriate for melt blending in a thermokinetic mixer as well as those described herein may comprise a small portion of an agent resulting in foaming, expansion or cell formation of the melt blended composition expelled or dropped from the thermokinetic mix chamber and thereafter forming a foamed, substantially expanded or multi-celled product upon cooling. A useful feed polymer composition to a thermokinetic mixer comprises up to 60 percent by weight of a thermoset polyethylene and an effective amount of a foaming, expansion or cell forming agent. As a specific example, wood chips or sawdust may be included in the feed composition to a thermokinetic mixer and heated therein with the feed polymer to cause smoke formation which is captured within the melt blended polymers as bubbles approximating the effect of a more conventional liquid or meltable hydrocarbon foaming agent. The use of foaming agents has in a specific example reduced the weight of a non-expanded highway bumper formed of melt blended materials from an invention thermokinetic mixer from 18 pounds to 10 to 12 pounds using an expansion or foaming agent such that a product with substantially similar strength and wear qualities is obtained. It has been found that the use of a foaming, expansion or cell forming agent in melt blending in thermokinetic mixers results is a desirable bubble size distribution for the final molded product whereby larger bubbles form in the center of the product and smaller bubbles are formed near the surface of the product.

STRUCTURAL PRODUCTS EMBODIMENTS The structural products embodiments include bricks, building blocks, landscaping blocks, walkway stones, railroad ties, building blocks, steps, retaining wall blocks, shingles and other structural components. Generally exemplary of the structural components is described below compositions and methods for making stepping stones, as the particular range of structural stresses, abrasive top surface wear, wide temperature ranges, and corrosive / abrasive soil conditions make success for this product a particularly effect test of success for other structural components. This embodiment comprises using large amounts of currently relatively low cost and/or low quality polymers with or without low cost filler materials to form structural products. In one embodiment, relatively large amounts of the polymer portion of the feed stream is post-use polyvinyl chloride. It well known in the art that post-use polymers such as PVC are not equivalent in any sense to the unprocessed original resin. The product properties of recycled polymers processed through the invention kinetic mixer are surprising and mostly useful over the predictable results based on expectations in the prior art. The present state of the art in re-use of PVC is expressed in US Patent 6,000,892 where polyvinyl chloride wastes are melted or pulverized, and wood chips are mixed into the molten or pulverized plastic waste. The mixture thus made is molded and used as plate members such as backings of building interior members and balcony steps. However, these plate members, made from a mixture of thermoplastics and wood chips, are soft. Thus, when a wood screw is driven into such a plate member, its surface tends to bulge around the screw. The present embodiment processes PVC in a heretofore unknown manner by thermokinetic melt blending in a novel device. The desirability of a high PVC structural product embodiment is described in

US Patent 6,210,792. In that patent, PVC and wood fiber are intimately mixed by high shear mixing in a heated extruder to form a polymer wood composite. The polymer mixture has a continuous organic phase and the wood fiber with the recycled materials forms a discontinuous phase suspended or dispersed throughout the polymer phase. The manufacture of the dispersed fiber phase within a continuous polymer phase requires substantial mechanical input. Such input can be achieved in US Patent 6,210,792 only by using a heated extruder where the materials are mixed under conditions of high shear until the appropriate degree of wetting and intimate contact is achieved. In US Patent 6,210,792, the heated composite is exposed to atmospheric pressure or reduced pressure at elevated temperature for a sufficient period of time to remove moisture resulting in a final moisture content of about 8 weight percent or less. Such moisture reduction is required where pressurized melt blending as in a heated extruder, as in US Patent 6,210,792. The mechanical properties of the structural products made according to the process of US Patent 6,210,792 appear to be quite good with the exception of being limited to high pressure mechanical heated blending as in a heated extruder. The present invention contemplates that the same feed compositions as disclosed in US Patent 6,210,792 are processed far more efficiently and more intimately mixed by high speed thermokinetic mixing and melt blending in the invention thermokinetic mixer disclosed below. The particle size of the polymer portion of the feed stream is relatively inconsequential as the construction of the invention thermokinetic mixer is effective in processing even large pieces of post-use polymers.

The structural products embodiment of the present invention contemplates that a range of one to over fifty weight percent, or more preferably from about 25-50 weight percent, PVC in the feed stream (with the balance made up of other post- use polymers (preferably polyolefins) or fillers) results in a unique surface texture of the resulting compression molded stepping stone. The surface of the invention structural product having a polymer portion with greater than 25 weight percent PVC has a distinct elastomeric quality forming against other objects a friction interface substantially similar as that of rubber or similar elastomers. Although this structural product has great structural strength and moisture and corrosion resistance through the range of ambient temperatures throughout the world, the surface texture makes it very valuable in structural products where rigidity and a rubber-like surface required, such as in non-skid stepping stones and industrial environment mats where footing is important.

The structural products also include a combination of particulated crumb rubber and recycled or re-ground polyethylene, especially where the crumb rubber is reduce to about 40 mesh or finer.

The structural products also include a novel method of forming shingles. As described above, a melt blend may be ejected or dropped by gravity from the mixing chamber of the invention thermokinetic mixer. In a shingle making operation, a floor or lowest portion of the compression mold comprises loose mineral particulates like sand or fine stone particles. The molten material drops on to the particulates and is compressed into a substantially planar shape as for a shingle. Upon cooling and removal from the shingle mold, a broad surface of the shingle has impressed into it the particulates that perform the dual role of solar reflection and forming a surface with a pleasing appearance and color when installed on a roof of a building.

The structural products also include forming stepping stones in a similar manner as that of the shingles, although the loose particulates may be replaced with larger stone or porcelain pieces and the height of the mold cavity is increased to the thickness of an aesthetically pleasing and effective stepping stone, i.e., about 1-2 inches in one embodiment. The outer shape of the mold cavity is made to create a stepping stone outline as desired, such as the interesting foot shape of US Patent D393726, although the shape may be round, rectangular, or another geometric or quickly recognizable shape.

MIXED RECYCLED POLYMER PALLET

Exemplary figures from the above patents are shown in Figure 1A. There appears to be a need for a unitary plastic pallet, preferably one using large amounts of low cost recycled plastic, sorted or unsorted, having an adaptation for use with pallet jacks.

The invention pallet is made of recycled plastic waste. The method and devices required for providing molten polymer mixtures for compression molding into the invention pallet are described above. It is well described that the invention processes and devices of those applications are capable of producing a semi- continuous series of molten batches of recycled and virgin polymers in combination with non-polymeric fillers, chemical agents and waste which with the invention processes and devices is not required to be removed from the feed to the invention devices to form a molten melt blended material.

The invention pallet has an upper load-bearing deck which may comprise a solid, slotted or perforated sheet deck board so that the pallet top deck construction can be varied to suit the intended use and product need. For example, a greater number of slots in the deck board can provide an almost solid top deck to support heavy loads or bulk commodities in bags. Or, a lesser number of slots in the deckboard allows space for ventilation through the pallet and ventilation through and around goods stacked thereon. Such ventilation means can also be used to advantage when products which are chilled or deep-frozen or, conversely, to be heated, are transported on the pallets so that cooling air or heated air can circulate through the loaded space and alongside the product. Moreover, the ability to regulate the flow of air by specific pallet construction, through a stack of pallets and loaded product, can be used to advantage in the introduction of controlled atmospheres during the transport and/or storage of many agricultural and other perishable products. For instance, products such as apples or bananas may be kept under controlled atmospheric conditions while in sea transport or for fumigation to control the unwanted introduction of pests or product spoilage. Other practical considerations for a pallet top deck board with slots or holes include the presence of additional attachment means and to provide openings for visual inspection of pallet loads, thus be formed of relatively heavy components but at a relatively low cost.

The effective footboard support of the invention pallet comprises just the bottom edges of the bottom view box structure, where the box structure is adapted to have slots and cutouts to accommodate insertion of lifting means of devices such as forklifts. A single rib in the bottom view box structure is all that is required for even the heaviest of loads for an invention pallet up to about 6 feet by 6 feet square. The bottom edge cutouts are adapted to accommodate hand drawn or motorized pallet jacks. Accordingly, it is an object of the present invention to provide a plastic pallet, for use with a fork lift or pallet jack, which has excellent bending strength characteristics and advantages in handling and maintenance. The pallet of the invention and its method of manufacture and assembly allows it to be of differing dimensions to conform with all known present standard pallet dimensions, as well as special dimensions as may be required by industry in the future, and to be compatible with existing pallet storage rack systems. A further object of this invention is to provide a pallet for which the smallest possible quantities of material are employed and which can nevertheless support very heavy loads. An additional object of this invention is to provide a pallet which withstands long periods of heavy use in extreme conditions of temperature, pressure and chemical (liquid, gas or solid) exposure. Still further objects are to provide a pallet made without the necessity of metallic fasteners or other incompatible materials to eliminate the requirement of repair while making possible inexpensive reprocessing and remanufacture of the pallet expeditiously; to provide a pallet wherein the seamless construction of structurally resilient and long lasting polymers eliminates loosening of pieces as seen with multi-piece prior art pallets. Still a further object of the invention is to provide a new and improved molded plastic pallet, for use with a forklift, having high bending strength characteristics which are remarkably superior to those of conventional plastic pallets and comparable to those of wooden pallets, and a method of producing the same. These and other objects of the invention, as will hereinafter become clear to one skilled in the art from the ensuing discussion, are attained by providing a pallet and method according to the present invention.

Alternately, the composition of the invention pallet may comprise those disclosed in the US Patent 5,895,790 to Good that discloses thermokinetic mixers used for melt blending, a novel application for that device. The Good patent described economically recovering waste thermoset material into useful products by first forming a predictable quality thermoset material from disparate polymers and then melt blending the thermoset material with a thermoplastic material into the useful products. The devices and processes of the above incorporated patent applications provides a novel improvement to the process of the Good patent such that immediately successive melt blend batches are ejected from the door at the bottom of the thermokinetic mixer when the melt blend in the mixer reaches a desired temperature while feed polymers are continuously fed to a hopper access to a screw feeder delivering fresh feed to the continuously rotating blades of the thermokinetic mixer. The process of the Good patent did not allow for formation of flat sections due to the length of time required for processing of each relatively small batch. The process of the Good patent required feed of a single batch amount into a hopper directly to the thermokinetic mixer chamber, rotating the mixer blades at high speed until the batch reached a desired temperature, stopping the mixer blade rotation, dropping the molten material out of the thermokinetic mixer from the bottom door, closing the bottom door and starting again. By the time a second batch in the Good process was ready for delivery to a mold, the first batch had cooled so much that it was meltable into a mold in the same product as the second batch. Where the product contains more than about 20% by weight waste thermoset materials, remelting the first batch is not an appropriate alternative.

However, the devices and process of the above incorporated applications delivers successive molten batches within seconds of each other that can be transferred to a single mold cavity for compression molding into the structural members of the invention, unlike the Good process. Therefore, the invention pallet disclosed herein obtain their superior strength and resistance to abrasion and moisture or biologic or corrosive materials from the compositions capable of being produced by the invention devices and processes. The invention pallet preferably comprises above 50% to about 80% by weight polymeric material which has been thermoset before processing in the process of forming a melt blend for the structural elements, i.e., the feed polymers to the thermokinetic mixer are about 50% to about 80% by weight thermoset polymers. It is well known that thermoset polyolefin materials have superior resistance to weathering and are very tough, although obtaining a plank, board or plate as in the present invention with high amounts of thermoset materials has not previously been contemplated. The a balance of the polymers in the polymer structural elements are preferably a polyolefin, more preferably a mixture of linear polyethylene, and most preferably the balance polymers consisting of a mixture of linear polyethylene and low and high density polyethylene in the ratio of about 3:1 by weight.

The present invention can make use of polymer residue from the automotive manufacturing industry. Such industries produce such large volumes of polymer waste not practicably usable in large quantities by prior art processes. The present invention provides the opportunity to produce a product having a substantial amount of polymer weight supplied in large part or entirely by such residue. The invention is now discussed with reference to the Figures. The invention pallet is generally a box shaped case having a single dividing rev from one side of the box shaped to the other side. The sides of the box shaped and the support rev have either cut outs or openings to accommodate the fork pieces of a fork lift or the prongs of a pallet jack. Figure 2A shows the invention pallet 100 having an underside 101 of the support deck further having extended from it pallet jack sides 102, fork lift sides 104, and support rib 103 extending from about the mid point of one fork left side 104 to the other fork lift side 104. The pallet Jack sides 102 have cut outs 106 aligned with cut outs 106 on support rib 103, the cut outs 106 being adapted to permit lifting of the invention pallet 100 with either the forks of a fork lift or the prongs of a pallet jack. Fork lift sides 104 have openings 105 adapted and aligned such that the forks of a fork lift may be inserted into them to lift the invention pallet.

The following description of a specific example of the invention pallet is intended as an example only although disclosing a particularly preferred embodiment of the invention. As described above, the invention pallet is a unitary piece comprising mostly polymers. It may be appreciated from examination of the figures that the invention pallet may be formed in a single compression mold. The top side 109 of the support deck may be formed with openings or slots as needed for a specific use of the invention pallet, although superior structural strength is achieved by a solid support deck as shown in figure 4A. In one embodiment the support deck is square with a side length of from about 2 feet to 7 feet, more preferably from about 3 feet to about 6 feet. The thickness of the sides 102 and 104 and support rib 103 are about from ³λ of an inch to about 2 inches, although more preferably in the range of about 1 inch to 1 A inches. The support deck thickness is preferably about 1/4 inches to 2 inches, although more preferably from about 1/2 inches to about 1 inch. The height of sides 102 and 104 and support rib 103 is greater than about 3 inches to the bottom side 101 of the support deck, but the height is preferably from about 3 inches to about 6 inches. The relationship of length 107 to width 108 is variable so that the invention pallet is rectangular but other than square, although the relationship is preferably in the range of 4:1 to 1 :1 to maintain an optimum structural strength for the invention pallet.

The process of forming the invention pallet comprises taking successive molten batches of melt blended polymers and placing them on a bottom half of a compression mold surface until sufficient material is (as determined by approximate weight and/or volume) is available on the mold surface. The top half of the mold is impressed to the bottom half, the molten polymers thereby flowing to the mold walls and thereafter cooling and/or reacting to form a solid, unitary pallet. It will be appreciated from examination of the prior art unitary plastic pallets that adaptation for pallet jacks was eliminated or that the adaptation made the pallet too weak to hold the heaviest loads. The present invention, however, allows the user to subject the pallet to twisting and crushing forces far beyond its structural strength to failure of the basic structure, although the remaining materials and structure will be at least partly usably as a pallet. In addition, the invention devices and processes in the above incorporated applications permit the worn invention pallets to be recycled and reprocesses endlessly to new pallets.

The above design disclosures present the skilled person with considerable and wide ranges from which to choose appropriate obvious modifications for the above examples. However, the objects of the present invention will still be obtained by the skilled person applying such design disclosures in an appropriate manner.

Claims (32)

We claim:

1. A thermokinetic mixer comprising:

(a) a substantially cylindrical mixing chamber with an inside enclosing a- shaft rotatable at relatively high speed substantially about the axis of the cylindrical mixing chamber, the mixing chamber adapted to receive particles of polymers and other material therein; and

(b) shaft extensions removable from the shaft, the shaft extensions adapted to encounter the particles and drive them at least in part to the inside surface such that substantial energy is imparted to them.

2. The mixer of claim 1 wherein the shaft extensions comprise a base and an end portion, the end portion being removable from the base portion and the base portion being removable from the shaft.

3. The mixer of claim 2 wherein the end portion comprises a tooth face comprising a major face, the major face being substantially flat and oriented such that when passing through a plane including the shaft axis the major face first encounters the plane with a leading edge of the major face and the major face extends along an acute angle therefrom away from the plane.

4. The mixer of claim 3 wherein the leading edge comprises most of a height of the shaft extension.

5. The mixer of claim 3 wherein the shaft extension rises from the shaft to very close to the inside surface.

6. The mixer of claim 3 wherein the base portion is secured to the shaft by slot and key means.

7. The mixer of claim 6 wherein the end portion comprises a substantially complete shield for the base portion from the particles during rotational operation of the mixer.

8. The mixer of claim 7 wherein the tooth face further comprises a lower bevel face extending away from the plane from a lower edge of the major face at a greater angle to the plane than the major face.

9. The mixer of claim 8 wherein the tooth face further comprises a top face extending away from a top edge of the major face and adapted to drive the particles into the inside surface.

10. A thermokinetic mixer comprising: (a) a substantially cylindrical mixing chamber with an inside enclosing a shaft rotatable at relatively high speed substantially about the axis of the cylindrical mixing chamber, the mixing chamber adapted to receive particles of polymers and other material therein; (b) shaft extensions comprising a tooth face, each shaft extension adapted to encounter the particles and drive them at least in part to the inside surface such that substantial energy is imparted to them; and (c) the tooth face comprising a major face, the major face being substantially flat and oriented such that when passing through a plane including the shaft axis the major face first encounters the plane with a leading edge of the major face and the major face extends along an acute angle therefrom away from the plane.

11. The mixer of claim 10 wherein the shaft supports at least two rows 180 degrees apart of shaft extensions along the length of the shaft.

12. The mixer of claim 10 wherein the shaft supports at least four rows 90 degrees apart of shaft extensions along the length of the shaft.

13. The mixer of claim 10 wherein the leading edge comprises most of a height of the shaft extension.

14. The mixer of claim 13 wherein the shaft extension rises from the shaft to very close to the inside surface.

15. The mixer of claim 13 wherein the tooth face further comprises a lower bevel face extending away from the plane from a lower edge of the major face at a greater angle to the plane than the major face.

16. The mixer of claim 15 wherein the tooth face further comprises a top face extending away from a top edge of the major face and adapted to drive the particles into the inside surface.

17. A method of melt blending using thermokinetic mixer comprising:

(a) a substantially cylindrical mixing chamber with an inside enclosing a shaft rotatable at relatively high speed substantially about the axis of the cylindrical mixing chamber, the mixing chamber adapted to receive particles of polymers and other material therein; (b) shaft extensions comprising a tooth face, each shaft extension adapted to encounter the particles and drive them at least in part to the inside surface such that substantial energy is imparted to them;

(c) the tooth face comprising a major face, the major face being substantially flat and oriented such that when passing through a plane including the shaft axis the major face first encounters the plane with a leading edge of the major face and the major face extends along an acute angle therefrom away from the plane; and operating the mixer at above about 1500 rpm with a mixture comprising sufficient polymer particles having meltable by thermokinetic mixing for and for sufficient time that a melt blended mixture is obtained thereby.

18. A thermokinetically melt blended composition having been melt blended in a thermokinetic mixer that may be ground and thereafter extrudable from a heated extruder to form an injection molded product where a feed composition to the thermokinetic mixer comprises:

(c) 0.5 to 40 weight percent of a polymer portion consisting of one or more thermoset polymers; and

(d) the balance of the polymer portion consisting of one or more polyolefin polymers.

19. The composition of claim 18 wherein polyolefin polymers consist of one or more polyethylene polymers.

20. A thermokinetically melt blended composition having been melt blended in a thermokinetic mixer where a feed composition to the thermokinetic mixer comprises: (a) 0.5 to 100 weight percent of a first part of a polymer portion consisting of one or more polymers from the following group: nylons, polystyrenes, polyvinyl chlorides, polyvinyl acetates, thermoset polymers, ABS, acrylic polymers, polycarbonates, polyesters, polyurethanes, and thermoset polymers; and (b) a second part of the polymer portion is the balance of the polymer portion consisting of one or more polyolefin polymers.

21. The composition of claim 20 wherein polyolefin polymers consist of one or more polyethylenes.

22. The composition of claim 20 wherein a third part of the polymer portion comprises 0.5 to 90 weight percent elastomer.

23. The composition of claim 22 wherein the elastomer comprises a substantial amount bf ground tires.

24. The composition of claim 22 wherein a non-polymer portion comprises a portion of the feed composition, where the feed composition is greater than about 10 weight percent of the polymer portion.

25. The composition of claim 24 wherein the non-polymer portion comprises shredded natural fibers, wood based products, metals, non-plastic organic material, or silica based particles.

26. The composition of claim 22 wherein the first part of the polymer portion consists of only thermoset polymers and the first part of the polymer portion is greater than about 56 weight percent of the polymer portion.

27. The composition of claim 22 wherein the first part of the polymer portion consists of only nylons.

28. The composition of claim 22 wherein the first part of the polymer portion consists of only polystyrenes and the first part of the polymer portion is greater than about 11 weight percent of the polymer portion.

29. The composition of claim 22 wherein the first part of the polymer portion consists of only polyvinyl chlorides and the first part of the polymer portion is greater than about 7 weight percent of the polymer portion.

30. The composition of claim 22 wherein a third part of the polymer portion comprises 0.5 to 50 weight percent PET.

31. The composition of claim 22 wherein the polymers of shredded carpet with a natural or synthetic fiber backing comprises at least a substantial amount of polymers the first part of the polymer portion.

32. A thermokinetically melt blended composition having been melt blended in a thermokinetic mixer where a feed composition to the thermokinetic mixer comprises: (a) a polymer portion comprising at least 20% by weight of one or more polymers from the following group: nylons, polystyrenes, polyvinyl chlorides, polyvinyl acetates, thermoset polymers, ABS, acrylic polymers, polycarbonates, polyesters, polyurethanes, and polyolefin polymers; and (b) sufficient cross linking agent such that the thermokinetically melt blended composition becomes substantially thermoset by thermokinetic melt blending.