The disclosure generally relates to an extruder. More particularly the disclosure relates to an extruder system for manufacture of reinforced thermoplastics. The disclosure also relates to a method for manufacture of reinforced thermoplastics. BACKGROUND
Polymeric materials may be enhanced by the incorporation of fillers as reinforcement at the nano, micro or macro scales.
Biomass such as wood and wood waste, agricultural waste such as wheat straw, peanut shell, rice husk, olive residue etc natural fibers such as jute, hemp, kenaf, sisal, flax, coir etc, and organic fibers such as cellulose fiber can be used for reinforcing polymeric materials. In order to make reinforced polymeric materials, biomass is added to the molten polymers in a desired ratio.
Raw biomass is usually not available in the particle size or fiber length that is needed for compounding with polymers. Moreover raw biomass in its natural form often has high moisture content. These aspects generally result in expensive material preparation steps such drying and grinding of biomass before it may be added to the melted polymer.
Various forms of equipment, including extrusion equipment, and methods of adding biomass to polymers for the manufacture of reinforced polymer have proven to be impractical because of the inconsistent characteristics of biomass such as wood fibers and the polymer being processed. The variety and moisture content of the source materials also often cause poor quality control for the end product.
US patent application number 2003/0214067 discloses an extruder for the addition of organic filler to a polymeric material. However, as the polymer melt is introduced into the extruder processing the biomass, it is not possible to determine the precise size and moisture content present in the reinforcement material. It has also been difficult to obtain precise size control of the filer material using the system disclosed in US2003/0214067.

Therefore there is a need for an extruder system and a method that would allow for the manufacture of reinforced thermoplastic in a simple and efficient manner. Moreover, the extruder system should be such that it would allow for precise control of the size and the moisture content of the filler that is used for the reinforcement of the thermoplastic. BREF DESCRIPTION OF ACCOMPANYING FIGURES
The accompanying drawing illustrates the preferred embodiments of the invention and together with the following detailed description serves to explain the principle of the invention.
Figure 1, illustrates the plan view of the extruder system in accordance with an embodiment.
Figure 2 illustrates the elevation view of the extruder system in accordance with an embodiment.
Figure 3, illustrates the side view of the extruder system in accordance with an embodiment.
Figure 4, illustrates radial plane of a biomass processing twin screw extruder in accordance with an embodiment. SUMMARY
An extruder system for manufacturing reinforced thermoplastic is disclosed. The extruder system comprising a polymer compounding extruder configured for forming a thermoplastic melt and compounding the thermoplastic melt with processed biomass and at least one biomass processing extruder. The biomass processing extruder is a co-rotating twin screw extruder configured for removing moisture and achieving particle size reduction of the biomass for reinforcement of thermoplastic. The output of the biomass processing extruder directly connected to an inlet in the thermoplastic compounding extruder.

In accordance with an embodiment, the polymer compounding extruder comprises a polymer processing zone configured for receiving polymer components and forming polymer melt. The polymer compounding extruder further comprises of at least one biomass receiving zone configured for receiving biomass from an inlet and at least one reinforcement zone configured for compounding the polymer melt with the biomass.
In accordance with an embodiment, the biomass processing extruder comprises a receiving zone configured for receiving biomass to be processed. The biomass processing extruder further comprises a processing zone configured for crushing biomass received from the receiving zone. The biomass processing extruder further comprises a conveying zone configured for conveying the crushed biomass from the biomass processing extruder into the inlet of the polymer compounding extruder.
In accordance with an aspect, a polymer melt is prepared by melting and mixing the polymer components in a polymer compounding extruder. Further, biomass is processed for reinforcement in a biomass processing extruder. The processed biomass obtained from the biomass processing extruder is feeded into the polymer compounding extruder and mixed with the polymer melt to obtain reinforced thermoplastics. DETAILED DESCRIPTION OF THE INVENTION
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated method and system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof Throughout the patent specification, a convention employed is that in the appended drawings, like numerals denote like components.
An extruder system (10) for the production of reinforced thermoplastic is disclosed.
Referring to figure 1 and 2, the extruder system (10) in accordance with an embodiment is illustrated. The extruder system (10) comprises of a polymer compounding extruder (12) and a biomass processing extruder (14) that are linked together. The polymer compounding extruder (12) is configured for receiving and processing the polymeric material and for the manufacture of reinforced thermoplastic. The biomass processing extruder (14) is configured for receiving and processing biomass. As illustrated in the figures, the output from the biomass processing extruder (14) is directly coupled to a side inlet (16) of the polymer compounding extruder (12) such that the biomass processed by the biomass processing extruder (14) is fed directly into the polymer compounding extruder (12).
The polymer compounding extruder (12) is configured for receiving and processing polymer material. The polymer compounding extruder (12) is also configured for receiving the biomass from the biomass processing extruder (14) for manufacture of the reinforced thermoplastics. As illustrated in the figure 1 and 2 the polymer compounding extruder (12) comprises of three zones, a polymer processing zone (18) configured for forming a polymer melt by melting and mixing the components of the polymer received from an inlet hopper (20), a biomass receiving zone (22) configured for receiving the processed biomass from the biomass processing extruder (14) and reinforcement zone (24) configured for mixing the biomass into the polymer mix.
The polymer compounding extruder (12) may be a twin screw extruder. The polymer compounding extruder (12) may be co-rotating or a counter rotating extruder. Alternatively,

the polymer compounding extruder (12) may be a single screw extruder. The choice of the polymer compounding extruder (12) depends upon the type of polymer that is being used for the manufacture of reinforced thermoplastics.
The extrusion elements provided in each zone are configured for that zone. By way of a specific example, suitable available extruder elements may be provisioned in each zone.
Referring to figure 3, the biomass processing extruder (14) of the extruder system (10) is illustrated in accordance with an embodiment. The biomass processing extruder (14) is a co-rotating twin screw extruder that is configured for receiving and processing the biomass. The biomass processing extruder (14) comprises of a receiving zone (26) configured for receiving the biomass fed from an biomass inlet hopper (28), a processing zone (30) configured for processing the biomass received from the receiving zone (26) and a conveying zone (32) configured for conveying the crushed filler fi*om the processing zone (30) to the polymer compounding extruder (12). The various zones of the biomass processing extruder (14) comprises of conventional screw elements suited for the particular zones of the extruder.
In accordance with an aspect, the receiving zone (26) is provided with screw elements configured for receiving the biomass to be processed from the biomass inlet hopper (28) and for conveying the biomass to be processed to the processing zone. By way of an example, the screw elements provided in the receiving zone (26) are extruder conveying elements.
The extruder elements that may be provided in the receiving zone (26) include but are not limited to a Schubkanten Elements or Shovel elements or their combination.
In accordance with an aspect, the processing zone (30) comprises of at least one extruder element that is suited for reducing the size of the biomass. In accordance with an aspect, the processing zone (30) is provided with screw elements configured for crushing the biomass. By way of an example, the screw elements provided in the processing zone (30) are extruder kneading elements.

The processing zone (30) comprises of at least one extruder kneading element. Various known extruder kneading elements may be used in the processing zone. The extruder kneading element that may be provided in the processing zone (30) include but is not limited to right handed kneading blocks, neutral kneading blocks, left handed kneaded blocks, eccentric kneading blocks, fractional lobed kneading blocks or their combination.
In accordance with an aspect, the processing zone (30) may comprise of a plurality of kneading blocks positioned such that kneading blocks are placed in alternation with other screw elements.
The particle size of the biomass being processed may be adjusted by adjusting the configuration of the processing zone (30). By use of different screw configuration the particle size of the crushed biomass achieved may be varied. By way of a specific example, smaller particles of the biomass are obtained by increasing the number of extruder kneading elements in the processing zone (30).
The conveying zone (32) is provided with screw elements configured for conveying the crushed biomass from the processing zone (30) to the biomass receiving zone (22) of the polymer compounding extruder. By way of specific example the screw elements provided in the conveying zone (32) are extruder dispersive elements. The conveying zone (32) elements may also serve to separate the processed biomass and to limit agglomeration of processed biomass. The conveying zone (32) elements are also configured to separate the larger biomass particles received from the processing zone (30) and to crush the larger biomass particles before conveying them to the biomass receiving zone (22) of the polymer compounding extruder (12).
In accordance with an aspect, the screw elements that may be provided in the conveying zone (32) include but are not limited to the normal bi-lobed right handed screw element, screw mixing element or their combination.

In accordance with an aspect, the screw elements in at least one zone of the biomass processing extruder (14) have substantially uniform screw-screw clearance in the radial plane throughout the length of the screw element. Figure 4 illustrates the radial plane of the biomass processing extruder (14) with the extruder elements at a 30 degree position and at a 45 degree position. As illustrated in figure 4 by way of a specific example the screw-screw clearance at both 30 degree and 45 degree position is 0.50mm. In accordance with an aspect, the screw-screw clearance in the radial direction may be as small as 0.12 mm, for extruder elements in at least one zone of the biomass processing extruder (14). In accordance with an aspect, all the screw elements in the biomass processing extruder (14) have substantially uniform screw-screw clearance in the radial plane throughout the length of the screw element.
In accordance with an embodiment, the biomass processing extruder (14) may be provided with a vacuum pump configured for removing the volatiles and moisture from the biomass. In accordance with an embodiment, supercritical carbon dioxide may be injected into the biomass processing extruder (14) to control the moisture content of the biomass processed.
In accordance with an aspect, the extruder system (10) comprises of at least two biomass processing extruders (14) linked to the polymer compounding extruder (12). In accordance with an embodiment both the biomass processing extruders (14) may be configured have the same configuration, such that the processed biomass obtained from both the biomass processing extrudes is the same. Alternatively, configuration of the biomass processing extruders (14) may be different, such that the processed biomass obtained from the biomass processing extruders (14) has substantially different particle size or substantially different moisture content. By way of a specific example in an extruder system (10) comprising of two biomass processing extruders (14) connected to the polymer compounding extruder (12), the first biomass processing extruder (14) is configured such that the particle

size of the processed biomass obtained from it is in the range of 1 to 5 mm, and the second biomass processing extruder (14) is configured such that the particle size of the processed biomass obtained from the second biomass processing extruder (14) is in the range of 2 to 3 mm.
In accordance with an aspect the biomass processing extruders (14) of the extruder system (10) may also be configured for processing different types of biomass such that the polymer reinforced thermoplastic obtained comprises of two different types of biomass reinforcement material. In the extruder system (10) comprising of two of more biomass processing extruders (14), the polymer compounding extruder (12) comprises of two biomass receiving zones (22) in alternation with two reinforcement zones (24).
A method for the manufacture of reinforced thermoplastic is disclosed. The method comprises of preparing a polymer melt by melting and mixing components of the polymer in a polymer compounding extruder, processing biomass for reinforcement in a biomass processing extruder, feeding the processed biomass obtained from the biomass processing extruder into the polymer compounding extruder through a side inlet and mixing the processed biomass with the polymer melt to obtain reinforced thermoplastics.
In accordance with an aspect, the processing of the biomass comprises of reducing the particle size of the biomass by passing the biomass through the biomass processing extruder.
The moisture content of the biomass is also reduced during the processing stage. The moisture of the biomass may be reduced by heating the biomass during processing in the biomass processing extruder. Alternatively supercritical carbon dioxide may be injected into the biomass processing extruder to control the moisture content of the biomass. In accordance with an aspect, processing of the biomass may further comprise of reducing the volatile content of the biomass.

The processed biomass obtained from the biomass processing extruder is directly fed into the polymer compounding extruder and mixed with the polymer melt to obtain a reinforced thermoplastic material.
In accordance with an aspect, the process further comprises of passing the reinforced thermoplastic material through a pelletizing system to obtain pellets of reinforced thermoplastic.
In accordance with an aspect the reinforced thermoplastic material may also be used directly for forming other structures including tubes and sheets using suitable moulds and dies.
In accordance with an aspect, the reinforced thermoplastic material may be pushed into a single screw extruder arranged in a cascaded or a series arrangement. This reinforced thermoplastic material obtained from the single screw extruder may be extruded into a profile by using suitable dies and moulds.
The biomass that may be used for the manufacture of reinforced thermoplastic includes but is not limited to wood and wood waste, agricultural waste such as wheat sfraw, peanut shell, rice husk, olive residue etc natural fibers such as jute, hemp, kenaf, sisal, flax, coir etc, and organic fibers such as cellulose fiber The thermoplastic composite may include but is not limited to poljropylene, polyethylene, polyamides, polyamines, polycarbonate, polystyrene, styrene-acrylonitrile copolymers, acrylonitrile-butandiene-styrene , polysulphones, polyesters, polyurethanes, polyphenylene sulfides, polyphenylene ethers or their combinations. SPECIFIC EMBODIMENT ARE DESCRIBED BELOW
An extruder system for manufacturing reinforced thermoplastic comprising a polymer compounding extruder configured for forming a thermoplastic melt and compounding the thermoplastic melt with processed biomass and at least one biomass processing extruder, the

biomass processing extruder is a co-rotating twin screw extruder configured for removing moisture and achieving particle size reduction of the biomass for reinforcement of thermoplastic, the output of the biomass processing extruder directly connected to an inlet in the thermoplastic compounding extruder.
Such extruder system(s), wherein the polymer compounding extruder comprises a polymer processing zone configured for receiving polymer components and forming polymer melt, at least one biomass receiving zone configured for receiving biomass from an inlet and at least one reinforcement zone configured for compounding the polymer melt with the biomass.
Such extruder system(s), wherein the biomass processing extruder comprises a receiving zone configured for receiving biomass to be processed, a processing zone configured for crushing biomass received from the receiving zone and a conveying zone configured for conveying the crushed biomass from the biomass processing extruder into the inlet of the polymer compounding extruder.
Such extruder system(s), wherein the elements in at least one zone of the biomass processing extruder have substantially uniform screw-screw clearance in radial plane throughout the length of the screw elements.
Such extruder system(s), wherein at the screw-screw clearance in the radial direction is in the range of 0.5 mm to 0.12 mm.
Such extruder system(s), wherein the extruder screw elements in the receiving zone of the biomass processing extruder are any of Schubkanten Elements or Shovel elements or their combination.
Such extruder system(s), wherein at least one extruder screw element in the processing zone of the biomass processing extruder is an extruder kneading element to do work on the material other than the purpose of moving or conveying the biomass.

Such extruder system(s), wherein the extruder kneading element provided in the processing zone of the biomass processing extruder is any of right handed kneading blocks, neutral kneading blocks, left handed kneaded blocks, eccentric kneading blocks, fractional lobed kneading blocks or their combination.
Such extruder system(s), wherein at least one extruder screw element in the conveying zone of the biomass processing extruder is any one of normal bi-lobed right handed screw element, screw mixing element or their combination.
Such extruder system(s), wherein the biomass processing extruder further comprising a vacuum pump configured for removing volatiles and moisture from the biomass.
Such extruder system(s), wherein the biomass processing extruder fiirther comprising an inlet for injecting supercritical carbon dioxide into the biomass processing extruder. FURTHER SPECIFIC EMBODIMENTS ARE DESCRIBED BELOW
A method for the manufacture of reinforced thermoplastic comprising; preparing a polymer melt by melting and mixing the polymer components in a polymer compounding extruder, processing biomass for reinforcement in a biomass processing extruder, feeding the processed biomass obtained from the biomass processing extruder into the polymer compounding extruder and mixing the processed biomass with the polymer melt in the polymer compounding extruder to obtain reinforced thermoplastics.
Such method(s), comprising preparing a polymer melt by melting and mixing the polymer components in a polymer compounding extruder, processing the biomass for reinforcement in at least two biomass processing extruders, feeding the processed biomass from the biomass processing extruders onto the polymer compounding extruder; and mixing the processed biomass with the polymer melt in the polymer compounding extruder to obtain reinforced thermoplastics.

Such method(s), further comprising of drying the biomass during processing of the biomass in the biomass processing extruder.
Such method(s), further comprising of removing volatiles from the biomass during processing of the biomass in the biomass processing extruder.
Such method(s), further comprising of injecting into the biomass processing extruder supercritical carbon dioxide. INDUSTRIAL APPLICABILITY
The system as disclosed allows for the incorporation of biomass into thermoplastic composite for manufacturing reinforced thermoplastics in a simple and efficient manner. As the system disclosed can be separated during operation, it allows for checking of particle size and moisture content of the biomass during actual operation of the system. This allows for a greater control of the particle size and the moisture content of the biomass used for reinforcement of thermoplastic.
In the system as disclosed the screw elements provided in at least one zone of the biomass processing extruder have equal screw-screw clearance in the radial plane along the entire length of the extruder element. Moreover, the screw-screw clearance between the screw elements in the biomass processing extruder is reduced. It is believed that due to the fact that there is not sufficient pressure to force material through these gaps, the meta-radial shearing forces in the intermeshing zone that causes shear stress peaks does not operate. Moreover, adhesive wear due to the metal radial shearing forces that push the screw apart to the 3 o'clock and 9 o'clock position is vastly reduced. It is believed it is these features of the biomass processing extruder that allows the biomass processing extruder process biomass only.
The system as disclosed also allows for the addition of biomass in a phased manner. For example, 20 pre-cent of the biomass may be added first followed by a phase of mixing of

the biomass with the polymer melt after which the remaining 80 per-cent of the biomass may be added to the polymer melt. The system also allows for the formation of a reinforced thermoplastic, having two or more reinforcement materials.
It is believed that mixing dry biomass into wet polymer melt achieves better mixing of the components.

WE CLAIM:
1. An extruder system for manufacturing reinforced thermoplastic comprising:
a polymer compounding extruder configured for forming a thermoplastic melt and compounding the thermoplastic melt with processed biomass; and
at least one biomass processing extruder, the biomass processing extruder is a co-rotating twin screw extruder configured for removing moisture and achieving particle size reduction of the biomass for reinforcement of thermoplastic, the output of the biomass processing extruder directly connected to an inlet in the thermoplastic compounding extruder.
2. An extruder system as claimed in claim 1, wherein the polymer compounding
extruder comprises:
a polymer processing zone configured for receiving polymer components and forming polymer melt;
at least one biomass receiving zone configured for receiving biomass from an inlet; and
at least one reinforcement zone configured for compounding the polymer melt with the biomass.
3. An extruder system as claimed in claim 1, wherein the biomass processing extruder
comprises:
a receiving zone configured for receiving biomass to be processed; a processing zone configured for crushing biomass received from the receiving zone; and

a conveying zone configured for conveying the crushed biomass from the biomass processing extruder into the inlet of the polymer compounding extruder.
4. An extruder system as claimed in claim 1 or 3, wherein the elements in at least one zone of the biomass processing extruder have substantially uniform screw-screw clearance in radial plane throughout the length of the screw elements.
5. An extruder system as claimed in claim 4, wherein at the screw-screw clearance in the radial direction is in the range of 0.5 mm to 0.12 mm.
6. An extruder system as claimed in claim 3, wherein the extruder screw elements in the receiving zone of the biomass processing extruder are any of Schubkanten Elements or Shovel elements or their combination.
7. An extruder system as claimed in claim 3, wherein at least one extruder screw element in the processing zone of the biomass processing extruder is an extruder kneading element to do work on the material other than the purpose of moving or conveying the biomass.
8. An extruder system as claimed in claim 7, wherein the extruder kneading element provided in the processing zone of the biomass processing extruder is any of right handed kneading blocks, neutral kneading blocks, left handed kneaded blocks, eccentric kneading blocks, fractional lobed kneading blocks or their combination.

9. An extruder system as claimed in claim 3, wherein at least one extruder screw element in the conveying zone of the biomass processing extruder is any one of normal bi-lobed right handed screw element, screw mixing element or their combination.
10. An extruder system as claimed in claim 1 or 3 wherein the biomass processing extruder fiirther comprising a vacuum pump configured for removing volatiles and moisture from the biomass.
11. An extruder system as claimed in claim 1 or 3 wherein the biomass processing extruder further comprising an inlet for injecting supercritical carbon dioxide into the biomass processing extruder.
12. A method for the manufacture of reinforced thermoplastic comprising
preparing a polymer melt by melting and mixing the polymer components in a polymer compounding extruder;
processing biomass for reinforcement in a biomass processing extruder;
feeding the processed biomass obtained from the biomass processing extruder into the polymer compounding extruder; and
mixing the processed biomass with the polymer melt in the polymer compounding extruder to obtain reinforced thermoplastics.
13. A method as claimed in claim 12, comprising
preparing a polymer melt by melting and mixing the polymer components in a polymer compounding extruder;

processing the biomass for reinforcement in at least two biomass processing extruders;
feeding the processed biomass from the biomass processing extruders onto the polymer compounding extruder; and
mixing the processed biomass with the polymer melt in the polymer compounding extruder to obtain reinforced thermoplastics.
14. A method as claimed in claim 12 or 13 further comprising of drying the biomass
during processing of the biomass in the biomass processing extruder.
15. A method as claimed in claim 12 or 13 further comprising of removing volatiles from
the biomass during processing of the biomass in the biomass processing extruder.
16. A method as claimed in claim 12 or 13 further comprising of injecting into the
biomass processing extruder supercritical carbon dioxide.