Title of Invention	NOVEL RICE HUSK AND CEREAL STRAW AND/OR BAGASSE PARTICLE BOARD AND A METHOD OF MAKING THE SAME
Abstract	ABSTRACT According to this invention novel rice husk and cereal straw and/or bagasse particle boards are prepared by the following method. Rice husk from rice mills is cleaned. Cereal straw is defibred into fibrous particles. Bagasse is defibred into fibrous particles free from pith. Either one or both kinds of particles thus prepared are mixed together with rice husk in any desired proportion and then blended with cashewnut shell liquid/cardanol-phenol-formaldehyde resin. Alternatively rice husk and cereal straw and/or bagasse particles are separately blended with resin adhesive and the resin coated rice husk and particles mixed together in the desired proportion. The mix of resin coated rice husk and cereal straw and/or bagasse particles is formed into a mat or layer of uniform desired thickness and then hot pressed in the conventional manner.

Title of Invention

NOVEL RICE HUSK AND CEREAL STRAW AND/OR BAGASSE PARTICLE BOARD AND A METHOD OF MAKING THE SAME

Abstract

ABSTRACT According to this invention novel rice husk and cereal straw and/or bagasse particle boards are prepared by the following method. Rice husk from rice mills is cleaned. Cereal straw is defibred into fibrous particles. Bagasse is defibred into fibrous particles free from pith. Either one or both kinds of particles thus prepared are mixed together with rice husk in any desired proportion and then blended with cashewnut shell liquid/cardanol-phenol-formaldehyde resin. Alternatively rice husk and cereal straw and/or bagasse particles are separately blended with resin adhesive and the resin coated rice husk and particles mixed together in the desired proportion. The mix of resin coated rice husk and cereal straw and/or bagasse particles is formed into a mat or layer of uniform desired thickness and then hot pressed in the conventional manner.

Full Text	This invention relates to rice husk and cereal straw and/or bagasse particle boards and a method of making the said particle boards. Particle boards made from rice husk blended together with cashewnut shell liquid (CNSL)/cardanol-phenol-formaldehyde resins and hot pressed thereafter are known in the art. For the preparation of particle boards from cereal straw slivers and chips, isocyanate resins have been used hitherto. Bagasse particle boards bonded with urea-formaldehyde and phenol-formaldehyde resins are known in the art. The object of the invention is to prepare particle boards from a mixture of rice husk and cereal straw and/or bagasse. Rice husk and cereal straw and/or bagasse particles may be bonded together by admixing them with CNSL/cardanol-phenol-formaldehyde resins prepared by any known process. The present invention therefore relates to preparation of particle boards from an admixture of rice husk and cereal straw and/or bagasse wherein the bonding of the particles is carried out by blending them with CNSL/cardanol-phenoI-formaldehyde resin. The admixture may then be hot pressed in the conventional manner. The CNSL/cardanol-phenol-formaldehyde resin is found ideal for bonding highly siliceous materials like rice husk and cereal straw. The proportion of cereal straw and/or bagasse in the admixture of rice husk and cereal straw and/or bagasse particles may range from 1 to 99 percent. The admixture of straw fibre and/or bagasse fibre with rice husk makes ail the difference to rice husk boards. Boards containing 20 percent or more straw/bagasse fibre withstand boiling in water without even edge cracks. The straw fibre and/or bagasse fibre confer resistance to boiling on rice husk boards. This resistance indicates durability when used in adverse conditions of temperature and humidity including exterior locations. The resistance to boiling also denotes higher internal bond strength, that is, higher tensile strength perpendicular to the surface of the board. The internal bond strength of a particle board is a good indicator of the quality of the board, and the higher the internal bond strength, the better the quality of *iie board. It has therefore been found that fibre incorporated in the particle board increases the internal bond strength and quality of the board, prepared therefrom. The admixture of cereal straw fibre and/or bagasse fibre with rice husk restricts the spread of the resin coated furnish mat in the hot press thereby reducing trimming waste of the board produced, effecting economy in materials, and reducing cost of production of the board. Cereal straw may be cut into small lengths, for instance one to 5 cm length. These cut pieces may be used as such or shredded into thin slivers and/or fibres. Cereal straw may also be shredded and defibred whole, that is without first cutting it into short lengths. Bagasse may be depithed and the depithed bagasse defibred into thin fibres and/or slivers. Bagasse may also be defibred whole and the defibred material wind sifted to separate pith from bagasse fibre. Rice husk from the rice mills is wind sifted and/or sieved to remove dust and other extraneous materials therefrom. Particles thus treated are then mixed together in any desired proportion and then blended with CNSL/cardanol-phenol-formaldehyde resin. Alternatively rice husk and cereal straw and/or bagasse particles may be separately blended with resin adhesive and the resin coated rice husk and cereal straw and/or bagasse particles mixed together in the desired proportions. Resin coated particles are formed into a mat or layer of uniforitt desired thickness and then hot pressed in the conventional manner at temperatures The above mentioned furnish mat may be of any of the forms commonly employed in the particle board industry and known to persons skilled in the art of particle board manufacture. Thus, for example, the furnish mat may be of a layered construction wherein the surface layers may consist of finer particles than the core layer or may be made up of the same or smaller size particles than the core layer but with higher proportion of adhesive than the core layers. Greater surface hardness, greater surface smoothness, and economy in adhesive consumption are achieved by such known techniques. The proportion of rice husk and straw chips or straw fibre and/or bagasse fibre is not critical and may vary according to the ultimate use for which the panels are intended. For example, if a decorative finish is required straw chips, slivers or fibres or bagasse slivers or fibres may be increased or decreased accordingly. Rice husk-cereal straw/bagasse boards may be manufactured in a wide range of densities fi"om about 300 kg/m3 to over 1200 kg/m3. Panels of medium density are ideally suited for partitions, door panels, furniture, buih-in-furniture, etc. Low density boards have good thermal insulation and sound deadening characteristics and are well suited for false ceiling. Rice husk-cereal straw and/or bagasse panels containing not more than 10 to 20 percent cereal straw and/or bagasse fibre are found to be termite, decay and fire resistant. The strength characteristics, particularly the tensile strength perpendicular to the surface of the boards, increases as the proportion of cereal straw/bagasse fibre in the board increases, whereas durability characteristics improve with increase in the proportion of rice husk. Boards containing 20 percent or more strawagasse fibre withstand boiling in water for 3 hours without showing even edge cracks. By this method rice husk and cereal straw and/or bagasse are economically converted into value-added building, furniture and decorative panels. Furthermore, the panels form ideal core stock for overlaying with veneer, decorative paper, plastic films, jute fibre and fabric, coconut fibre, bamboo mats, etc. inis invention relates to rice husk and cereal straw and/or bagasse particle board which comprises a blend of rice husk and cereal straw and/or bagasse particles bonded together by CNSL/cardanol-phenol-formaldehyde resin and hot pressed to form a composite board. This invention also includes a method of making rice husk and cereal straw and/or bagasse particle board which comprises the steps of admixing cereal straw and or bagasse particles with rice husk adding CNSL/cardanol-phenol-formaldehyde resin, spreading the said blend in the desired thickness and thereafter subjecting the same to hot pressing to form a composite board. The following examples are only illustrative in nature and are not intended to restrict the scope of the invention. Example 1 16.5 kg cleaned rice husk is mixed with 5.5 kg cereal straw fibre and the mixture blended with 2.2 kg cardanol/CNSL-phenol-formaldehyde resin adhesive. The blended mixture is spread out as a uniform layer and hot pressed in the usual manner to a nominal thickness of 1.2 cm. The resulting board is cooled and trimmed to a nominal size of 1.83 m x 1.22 m. It has a jiensity of 780 kg/m3 The board withstands boiling in water for over 3 hours. Example 2 12 kg cleaned rice husk and 12 kg cereal straw fibre are mixed together and blended with 2.4 kg cardanol/CNSL-phenol-formaldehyde resin. The blended mixture is spread out as a uniform layer and hot pressed in the usual manner to a nominal thickness of 2.0 cm. The resulting rice husk-cereal straw board is cooled and trimmed to a nominal size of 1.83 m x 1.22 m. It has a density of 500 kg/m3. Example 4 38.4 kg cleaned rice busk, 6.4 kg cereal straw fibre and 6.4 kg bagasse fibre are mixed together and blended with 4.1 kg cardanol/CNSL-phenol-formaldehyde resin. The blended mixture is spread out as a uniform layer and hot pressed in the conventional manner to a nominal thickness of 1.9 cm. The resulting rice husk-cereal straw-bagasse board is cooled and trimmed to a nominal size of 2.44 m x 1.22 m. It has a density of 850 kg/m'3 and withstands 3 hour boiling. WE Claim - Rice husk and cereal straw and/or bagasse particle board comprising a blend of rice husk and cereal straw and/or bagasse bonded together by CNSL/cardanol-phenol-formaldehyde resin and hot pressed to form a composite particle board having a density range of 300 kg/m' to 1200 kg/m"3. The rice husk and cereal straw and/or bagasse particle board as claimed in Claim 1 wherein the cereal straw/bagasse is of small pieces. The rice husk and cereal straw and/or bagasse particle board as claimed in Claims 1 and 2 wherein the cut cereal straw/bagasse is of shredded slivers or fibres. The rice husk and cereal straw/bagasse particle board as claimed in Claim 1 wherein the cereal strawagasse is shredded and defibred. The rice husk and cereal straw/bagasse particle board overlaid with veneer, decorative paper, jute fibre and fabric, coconut fibre, bamboo mats or plastic films. A method of making rice husk and cereal straw and/or bagasse particle board as claimed in Claims 1-5 comprising the steps of admixing rice husk with cereal straw and/or bagasse adding-and blending cardanol/CNSL-phenol-formaldehyde resin to the said mixture, spreading the said blend in the desired thickness and thereafter subjecting the same to hot pressing to form a composite board, the bonding being carried out by hot pressing at a temperature ranging fi-om 150° to 200° C. The method as claimed in Claim 6 wherein the cereal straw/bagasse is cut to the desired size before admixing. The method as claimed in Claim 6 and 7 wherein the cereal straw/bagasse is defibred before admixing. The method as claimed in Claim 6 wherein the rice husk is cleaned before admixing. The method as claimed in Claim 6 wherein the cereal strawagasse and rice husk are first coated with CNSL/cardanol-phenol-formaldehyde resin and then admixed, and further adhesive resin added. The method as claimed in Claim 6 wherein the cereal straw/bagasse is first coated with adhesive resin and then admixed with rice husk coated with CNSL/cardanol-phenol-formaldehyde resin. The method as claimed in Claims 6 to 11 wherein the hot pressed rice husk-cereal straw/bagasse board is cooled and trimmed. A method of making rice husk cereal strawagasse particle board substantially as herein described with particular reference to the examples. Novel rice husk and cereal straw/bagasse particle board substantially as herein described with particular reference to the examples.

Full Text

This invention relates to rice husk and cereal straw and/or bagasse particle boards and a method of making the said particle boards.
Particle boards made from rice husk blended together with cashewnut shell liquid (CNSL)/cardanol-phenol-formaldehyde resins and hot pressed thereafter are known in the art. For the preparation of particle boards from cereal straw slivers and chips, isocyanate resins have been used hitherto. Bagasse particle boards bonded with urea-formaldehyde and phenol-formaldehyde resins are known in the art. The object of the invention is to prepare particle boards from a mixture of rice husk and cereal straw and/or bagasse. Rice husk and cereal straw and/or bagasse particles may be bonded together by admixing them with CNSL/cardanol-phenol-formaldehyde resins prepared by any known process. The present invention therefore relates to preparation of particle boards from an admixture of rice husk and cereal straw and/or bagasse wherein the bonding of the particles is carried out by blending them with CNSL/cardanol-phenoI-formaldehyde resin. The admixture may then be hot pressed in the conventional manner. The CNSL/cardanol-phenol-formaldehyde resin is found ideal for bonding highly siliceous materials like rice husk and cereal straw. The proportion of cereal straw and/or bagasse in the admixture of rice husk and cereal straw and/or bagasse particles may range from 1 to 99 percent.
The admixture of straw fibre and/or bagasse fibre with rice husk makes ail the difference to rice husk boards. Boards containing 20 percent or more straw/bagasse fibre withstand boiling in water without even edge cracks. The straw fibre and/or bagasse fibre confer resistance to boiling on rice husk boards. This resistance indicates durability when used in adverse conditions of temperature and humidity including exterior locations. The resistance to boiling also denotes higher internal bond strength, that is, higher tensile strength perpendicular to the surface of the board. The internal bond strength of a particle board is a good indicator of the quality of the board, and the higher the internal bond strength, the better the quality of *iie board. It has therefore been found that fibre incorporated in the particle board increases the internal bond strength and quality of the

board, prepared therefrom. The admixture of cereal straw fibre and/or bagasse fibre with rice husk restricts the spread of the resin coated furnish mat in the hot press thereby reducing trimming waste of the board produced, effecting economy in materials, and reducing cost of production of the board.
Cereal straw may be cut into small lengths, for instance one to 5 cm length. These cut pieces may be used as such or shredded into thin slivers and/or fibres. Cereal straw may also be shredded and defibred whole, that is without first cutting it into short lengths.
Bagasse may be depithed and the depithed bagasse defibred into thin fibres and/or slivers. Bagasse may also be defibred whole and the defibred material wind sifted to separate pith from bagasse fibre.
Rice husk from the rice mills is wind sifted and/or sieved to remove dust and other extraneous materials therefrom.
Particles thus treated are then mixed together in any desired proportion and then blended with CNSL/cardanol-phenol-formaldehyde resin. Alternatively rice husk and cereal straw and/or bagasse particles may be separately blended with resin adhesive and the resin coated rice husk and cereal straw and/or bagasse particles mixed together in the desired proportions. Resin coated particles are formed into a mat or layer of uniforitt desired thickness and then hot pressed in the conventional manner at temperatures

The above mentioned furnish mat may be of any of the forms commonly employed in the particle board industry and known to persons skilled in the art of particle board manufacture. Thus, for example, the furnish mat may be of a layered

construction wherein the surface layers may consist of finer particles than the core layer or may be made up of the same or smaller size particles than the core layer but with higher proportion of adhesive than the core layers. Greater surface hardness, greater surface smoothness, and economy in adhesive consumption are achieved by such known techniques.
The proportion of rice husk and straw chips or straw fibre and/or bagasse fibre is not critical and may vary according to the ultimate use for which the panels are intended. For example, if a decorative finish is required straw chips, slivers or fibres or bagasse slivers or fibres may be increased or decreased accordingly.
Rice husk-cereal straw/bagasse boards may be manufactured in a wide range of densities fi"om about 300 kg/m3 to over 1200 kg/m3. Panels of medium density are ideally suited for partitions, door panels, furniture, buih-in-furniture, etc. Low density boards have good thermal insulation and sound deadening characteristics and are well suited for false ceiling. Rice husk-cereal straw and/or bagasse panels containing not more than 10 to 20 percent cereal straw and/or bagasse fibre are found to be termite, decay and fire resistant. The strength characteristics, particularly the tensile strength perpendicular to the surface of the boards, increases as the proportion of cereal straw/bagasse fibre in the board increases, whereas durability characteristics improve with increase in the proportion of rice husk. Boards containing 20 percent or more strawagasse fibre withstand boiling in water for 3 hours without showing even edge cracks.
By this method rice husk and cereal straw and/or bagasse are economically converted into value-added building, furniture and decorative panels. Furthermore, the panels form ideal core stock for overlaying with veneer, decorative paper, plastic films, jute fibre and fabric, coconut fibre, bamboo mats, etc.

inis invention relates to rice husk and cereal straw and/or bagasse particle board which comprises a blend of rice husk and cereal straw and/or bagasse particles bonded together by CNSL/cardanol-phenol-formaldehyde resin and hot pressed to form a composite board.
This invention also includes a method of making rice husk and cereal straw and/or bagasse particle board which comprises the steps of admixing cereal straw and or bagasse particles with rice husk adding CNSL/cardanol-phenol-formaldehyde resin, spreading the said blend in the desired thickness and thereafter subjecting the same to hot pressing to form a composite board.
The following examples are only illustrative in nature and are not intended to restrict the scope of the invention.
Example 1
16.5 kg cleaned rice husk is mixed with 5.5 kg cereal straw fibre and the mixture blended with 2.2 kg cardanol/CNSL-phenol-formaldehyde resin adhesive. The blended mixture is spread out as a uniform layer and hot pressed in the usual manner to a nominal thickness of 1.2 cm. The resulting board is cooled and trimmed to a nominal size of 1.83 m x 1.22 m. It has a jiensity of 780 kg/m3 The board withstands boiling in water for over 3 hours.
Example 2
12 kg cleaned rice husk and 12 kg cereal straw fibre are mixed together and blended with 2.4 kg cardanol/CNSL-phenol-formaldehyde resin. The blended mixture is spread out as a uniform layer and hot pressed in the usual manner to a nominal thickness of 2.0 cm. The resulting rice husk-cereal straw board is cooled and trimmed to a nominal size of 1.83 m x 1.22 m. It has a density of 500 kg/m3.

Example 4
38.4 kg cleaned rice busk, 6.4 kg cereal straw fibre and 6.4 kg bagasse fibre are mixed together and blended with 4.1 kg cardanol/CNSL-phenol-formaldehyde resin. The blended mixture is spread out as a uniform layer and hot pressed in the conventional manner to a nominal thickness of 1.9 cm. The resulting rice husk-cereal straw-bagasse board is cooled and trimmed to a nominal size of 2.44 m x 1.22 m. It has a density of 850 kg/m'3 and withstands 3 hour boiling.

WE Claim -
Rice husk and cereal straw and/or bagasse particle board comprising a blend of rice husk and cereal straw and/or bagasse bonded together by CNSL/cardanol-phenol-formaldehyde resin and hot pressed to form a composite particle board having a density range of 300 kg/m' to 1200 kg/m"3.
The rice husk and cereal straw and/or bagasse particle board as claimed in Claim 1 wherein the cereal straw/bagasse is of small pieces.
The rice husk and cereal straw and/or bagasse particle board as claimed in Claims 1 and 2 wherein the cut cereal straw/bagasse is of shredded slivers or fibres.
The rice husk and cereal straw/bagasse particle board as claimed in Claim 1 wherein the cereal strawagasse is shredded and defibred.
The rice husk and cereal straw/bagasse particle board overlaid with veneer, decorative paper, jute fibre and fabric, coconut fibre, bamboo mats or plastic films.
A method of making rice husk and cereal straw and/or bagasse particle board as claimed in Claims 1-5 comprising the steps of admixing rice husk with cereal straw and/or bagasse adding-and blending cardanol/CNSL-phenol-formaldehyde resin to the said mixture, spreading the said blend in the desired thickness and thereafter subjecting the same to hot pressing to form a composite board, the bonding being carried out by hot pressing at a temperature ranging fi-om 150° to 200° C.

The method as claimed in Claim 6 wherein the cereal straw/bagasse is cut to the desired size before admixing.
The method as claimed in Claim 6 and 7 wherein the cereal straw/bagasse is defibred before admixing.
The method as claimed in Claim 6 wherein the rice husk is cleaned before admixing.
The method as claimed in Claim 6 wherein the cereal strawagasse and rice husk are first coated with CNSL/cardanol-phenol-formaldehyde resin and then admixed, and further adhesive resin added.
The method as claimed in Claim 6 wherein the cereal straw/bagasse is first coated with adhesive resin and then admixed with rice husk coated with CNSL/cardanol-phenol-formaldehyde resin.
The method as claimed in Claims 6 to 11 wherein the hot pressed rice husk-cereal straw/bagasse board is cooled and trimmed.
A method of making rice husk cereal strawagasse particle board substantially as herein described with particular reference to the examples.
Novel rice husk and cereal straw/bagasse particle board substantially as herein described with particular reference to the examples.

Documents:

0675-mas-1997 abstract.pdf

0675-mas-1997 claims.pdf

0675-mas-1997 correspondence-others.pdf

0675-mas-1997 correspondence-po.pdf

0675-mas-1997 description (complete).pdf

0675-mas-1997 form-1.pdf

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Patent Number

193404

Indian Patent Application Number

675/MAS/1997

PG Journal Number

30/2009

Publication Date

24-Jul-2009

Grant Date

Date of Filing

01-Apr-1997

Name of Patentee

DR. JOSEPH GEORGE

Applicant Address

BUILDING MATERIALS CONSULTANT 100, 5A CROSS, 3RD MAIN, HIG COLONY, RMV II STAGE, BANGALORE-560 094.

Inventors:

#	Inventor's Name	Inventor's Address
1	DR. JOSEPH GEORGE	BUILDING MATERIALS CONSULTANT 100, 5A CROSS, 3RD MAIN, HIG COLONY, RMV II STAGE, BANGALORE-560 094.

PCT International Classification Number

B27N3/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA