Title of Invention	"MANUFACTURING OF LIGHT WEIGHT FIBER CEMENT BUILDING BOARDS"
Abstract	A novel preparation of lightweight cementitious cellulose fiber reinforced building material is disclosed. The lightweight/low density is achieved by use of high amount of fibrous-reinforcing material and not by the use of Low Density Additive (LDA). The invention also discloses the preparation of lightweight cementitious cellulose fiber reinforced building material prepared by the Hatschek Process.

Title of Invention

"MANUFACTURING OF LIGHT WEIGHT FIBER CEMENT BUILDING BOARDS"

Abstract

A novel preparation of lightweight cementitious cellulose fiber reinforced building material is disclosed. The lightweight/low density is achieved by use of high amount of fibrous-reinforcing material and not by the use of Low Density Additive (LDA). The invention also discloses the preparation of lightweight cementitious cellulose fiber reinforced building material prepared by the Hatschek Process.

Full Text	FORM 2 THE PATENTS ACT 1970 (39 of 1970) AND The Patents Rules, 2003 COMPLETE SPECIFICATION (See section 10 and rulel3) 1. TITLE OF THE INVENTION: "MANUFACTURING OF LIGHT WEIGHT FIBER CEMENT BUILDING BOARDS" 2. APPLICANT: (a) NAME: EVEREST INDUSTRIES LIMITED (b)NATIONALITY: Indian Company incorporated under the Companies Act, 1956 (c) ADDRESS: Gat 152, Lakhmapur Village, Dindori Taluka, Post Bag No.5, District Nashik -422202, Maharashtra, India. 3. PREAMBLE TO THE DESCRIPTION: The following specification particularly describes the invention and the manner in which it is to be formed. FIELD OF INVENTION: The present invention relates to lightweight cementitious cellulose fiber reinforced building material without using any Low Density Additive (LDA). The invention further relates to it's preparation and standardization. BACKGROUND & PRIOR ART: Cement is binder substance that binds other materials and, if mixed with water, reacts with water and becomes as hard as stone. A fiber-reinforced cement material, commonly known as fiber cement, contains fiber reinforcement that contributes to making the fiber cement material even stronger. As on today, the fiber-reinforced cement material is largely used in the construction products, such as cladding, flooring and other applications, due to it's hardness, performance and commercial value. Fiber-reinforced cement products were invented by Ludwig Hatschek in the 19th century. Therefore, the process by which the fiber-reinforced cement products are prepared is called as Hatschek process. Initially, cement and asbestos fibers were used to produce the fiber-reinforced cement products. But as adverse effects of asbestos were came into light, safer fiber alternatives, such as cellulose fibers, were developed. US Patent 4543159 discloses a process for making a cement and non-asbestos fiber mat on a Hatschek machine. Suitable additives are extensively used in cementitious building material to obtain lightweight or make the density lower. In all cases, use of additives have been invariably reported. The use of lightweight cementitious cellulose fiber reinforced building material by using Low Density Additive (LDA) has been widely reported across the globe. US Patent No. 7727329 relates to the addition of low density additives into cementitious cellulose fiber-reinforced building materials to obtain lightweight cementitious cellulose fiber reinforced building material. US Patent No. 7727329 further discloses a fiber cement building material which comprises low density additives such as volcanic ash, hollow ceramic microspheres or combination thereof. The present inventors have resolved the problem of preparing high strength reinforced low density material without using additives. SUMMARY OF INVENTION: The present invention discloses preparation of lightweight, low density cementitious cellulose fiber reinforced building material wherein lightweight, low density is achieved by use of high amount of fibrous-reinforcing material and not by the use of Low Density Additive (LDA). The present invention further discloses lightweight cementitious cellulose fiber reinforced building material comprising a hydraulic binder, a filler and pozzolonic material, a silicious material, a fibrous-reinforcing material. The lightweight cementitious cellulose fiber reinforced building material is prepared without using any additives as have been done hereto. DETAILED DESCRIPTION: Accordingly, the present invention provides a novel formulation of lightweight cementitious cellulose fiber reinforced building material with improved workability and dimensional stability, wherein low density is achieved by use of high amount of fibrous-reinforcing material and in absence of Low Density Additive (LDA). In a preferred embodiment, the present invention provides a formulation of lightweight cementitious cellulose fiber reinforced building material wherein the fibrous-reinforcing cellulosic material consists of Virgin Wood Cellulose Pulp in an amount 10-15% by weight along with a hydraulic binder, a filler and pozzolonic material, a siliceous material, a fibrous mineral, Bauxite, Bentonite clay and Silicon water repellant additive. The hydraulic binder is selected from Portland Cement and is present in an amount 30-40% by weight. The filler and pozzolonic material is selected form pulverized fly ash and is present in an amount 20-30% by weight. The siliceous material is selected from quartz/ sand powder and is present in an amount 20-25% by weight. The fibrous mineral is Wollastonite present in an amount 4-10%. The Bauxite is present in an amount 3-6% by weight. The Bentonite clay is present in an amount 0.5-2% by weight. The Silicon water repellant additives are in amounts 0.1-0.5% by weight. Further, the virgin wood cellulose pulp acts as a fiber and helps in reinforcing powder material. The Portland cement is used for strength and holding other raw material. The pulverized fly ash bonds with Portland cement. The quartz/sand powder reacts with Portland cement at high temperature. Fibrous mineral wollastonite is used to improve the dimensional stability and moisture movement of the product. The bauxite is used for arresting expansion and shrinkage and also improves the durability of the product with the formation of 11A Al-Tobermorite in the product. The bentonite clay is used for improving interlamina bonding and the silicon water repellant additive is used for improving water resistance and reducing water absorption. The addition of silicon additive and fibrous mineral wollastonite takes care of the problem arising from use of high cellulose fiber in the formulations. The formulation for lightweight cementitious cellulose fiber reinforced building material is given below in Table 1. In another embodiment, the lightweight cementitious cellulose fiber reinforced building material is prepared by the Hatschek Process. The main advantage of the present invention is improved workability at an economical price, as well as improved dimensional stability without using low density additive. The problems of dimensional stability and moisture movement due to use of high cellulose fiber in the formulation has been overcome by using fibrous mineral wollastonite and Bauxite as part of the compositions. The problems related to high water absorption has been overcome by treating the fibrous material with silicon so that water absorption by fibrous material is minimal. Finishing method also developed by providing Tongue and Groove to the edges of the product for better jointing process of between the boards and also to have continuity in the system during laying of boards. Further details of the present invention will be apparent from the examples presented below which are purely illustrative and are not limited to the particular embodiments illustrated herein. Example 1: Table 1: Formulation for lightweight cementitious cellulose fiber reinforced building material Raw Material % By Weight Virgin Wood Cellulose Pulp 10-15 Ordinary Portland Cement 30-40 Pulverised fly ash 20-30 Wollastonite 4-10 Quartz/sand Powder 20-25 Bauxite 200 mesh 3-6 Bentonite clay 0.5-2 Silicon water repellant additive 0.1-0.5 The product formed is found to have thickness in the range of 18 mm to 20 mm. The density of the product is between 1000-1100 kg/m3. The Modulus of Rupture (bending strength under Equilibrium Moisture Content (EMC) is found to be ll.lMPa whereas saturated MOR is found to be 6.6MPa. It's cross ratio strength is found to be 59%, whereas the MOS is found to be 11.5. Both the properties are under wet conditions. The moisture movement is 0.25%. Table 2: Physical Properties PHYSICAL PROPERTIES DIMENSION Thickness (mm) 19.1 Range (19.0-19.2) Length (mm) - Width (mm) - Levelness (mm) 0.2 mm across samples Edge Straightness (mm) - Diagonal Difference (mm) - Dots Printing N/A . Density (kg/m3) Oven Dry 1050 Saturated 1040 Wet density 1520 MOR (MPa) EMC 11.1 (Avg both direction) Saturated 6.6 (Avg both direction) Cross Ratio Strength (%) Wet 59% MOS (Thoughness) Wet 11.5 AVERAGE MOISTURE MOVEMENT RANGE (EMC TO SATURATED & OVEN DRY) Moisture Movement (%) 0.25% Visual Defects Bit Lumps OK Dents OK Furriness OK Water Marks OK Other Marks OK Low density boards are also tested for following performance and durability tests. Product meets all the requirement as per Indian Standard IS 14862, International Standard ISO 8336 and also EN 12467. Tests (Performance): 1) Warm water - The boards are subjected to warm water for 56 days as per the procedure given in the above standards. 2) Freeze-Thaw - The boards are subjected to -20 deg and normal water for 50 cycles as per the procedure given in the above standards. 3) The carbonation shrinkage - The boards are exposed to Carbonation shrinkage study by exposing to CO2 and high humidity environment and study for the cracking tendency of the boards. 4) Soak-dry test - The boards are subjected to immersion in water and then exposed to temperature of 105 deg C for - 25 cycles as per the above standards. 5) Heat /Rain cycle -The boards are subjected to heat (55 deg) and rain cycle for 50 cycles as per above standards. Example 2: Process for preparation Lightweight fibre cement building boards are manufactured by using Hatscheck process. Cellulose fibre is treated using Hydropulper and then further disc refiner to open up to 28-30 degree SR with a known consistency. After refining, the pulp slurry is transferred to main mixer. Cement is prepared in a cement mixer with known consistency of water. Flyash and quartz/silica is also prepared in separate tank. After taking cellulose into main mixer, cement, quartz and flyash are also added into the main mixer along with other additives. Further material is moved to agitator and then to vats in the machine through premixing arrangement. Further sheet formation will be as described in the hatschek process. After making the sheets of desired thicknesses, the sheets are cured in autoclaves at temperature 180-190 deg C with autoclaving pressure of 150 PSI. (6-7 bar) for about 8 hours. After curing sheets are removed and finished as per the market requirement. We claim, 1. A formulation of lightweight cementitious cellulose fiber reinforced building material with improved workability and dimensional stability; wherein low density is achieved by use of high amount of fibrous-reinforcing material and in absence of Low Density Additive (LDA). 2. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 1; wherein the fibrous-reinforcing materials are Virgin Wood Cellulose Pulp & mineral fibre. 3. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 1; wherein the cellulose fiber reinforced building material comprises Virgin Wood Cellulose Pulp in an amount 10-15% by weight along with a hydraulic binder, a filler and pozzolonic material, a siliceous material, a fibrous mineral, Bauxite, Bentonite clay and Silicon water repellant additive. 4. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the hydraulic binder is Portland Cement in an amount 30-40% by weight. 5. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the filler and pozzolonic material is pulverized fly ash in an amount 20-30% by weight. 6. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the siliceous material is quartz/ sand powder in an amount 20-25% by weight. 7. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the fibrous mineral is Wollastonite in an amount 4-10%o. 8. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the Bauxite is present in an amount 3-6% by weight. 9. The formulation of lightweight, low density cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the Bentonite clay is present in an amount 0.5-2% by weight. 10. The formulation of lightweight, low density cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the Silicon water repellant additive is present in an amount 0.1-0.5% by weight.

Full Text

FORM 2
THE PATENTS ACT 1970
(39 of 1970)
AND
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rulel3)
1. TITLE OF THE INVENTION:
"MANUFACTURING OF LIGHT WEIGHT FIBER CEMENT BUILDING
BOARDS"
2. APPLICANT:
(a) NAME: EVEREST INDUSTRIES LIMITED
(b)NATIONALITY: Indian Company incorporated under the Companies Act, 1956
(c) ADDRESS: Gat 152, Lakhmapur Village, Dindori Taluka,
Post Bag No.5, District Nashik -422202, Maharashtra, India.
3. PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the invention and the manner in which it is to be formed.

FIELD OF INVENTION:
The present invention relates to lightweight cementitious cellulose fiber reinforced building material without using any Low Density Additive (LDA). The invention further relates to it's preparation and standardization.
BACKGROUND & PRIOR ART:
Cement is binder substance that binds other materials and, if mixed with water, reacts with water and becomes as hard as stone. A fiber-reinforced cement material, commonly known as fiber cement, contains fiber reinforcement that contributes to making the fiber cement material even stronger. As on today, the fiber-reinforced cement material is largely used in the construction products, such as cladding, flooring and other applications, due to it's hardness, performance and commercial value.
Fiber-reinforced cement products were invented by Ludwig Hatschek in the 19th century. Therefore, the process by which the fiber-reinforced cement products are prepared is called as Hatschek process. Initially, cement and asbestos fibers were used to produce the fiber-reinforced cement products. But as adverse effects of asbestos were came into light, safer fiber alternatives, such as cellulose fibers, were developed. US Patent 4543159 discloses a process for making a cement and non-asbestos fiber mat on a Hatschek machine.
Suitable additives are extensively used in cementitious building material to obtain lightweight or make the density lower. In all cases, use of additives have been invariably reported.
The use of lightweight cementitious cellulose fiber reinforced building material by using Low Density Additive (LDA) has been widely reported across the globe. US Patent No. 7727329 relates to the addition of low density additives into cementitious cellulose fiber-reinforced building materials to obtain lightweight cementitious cellulose fiber reinforced building material. US Patent No. 7727329 further discloses a fiber cement building

material which comprises low density additives such as volcanic ash, hollow ceramic microspheres or combination thereof.
The present inventors have resolved the problem of preparing high strength reinforced low density material without using additives.
SUMMARY OF INVENTION:
The present invention discloses preparation of lightweight, low density cementitious cellulose fiber reinforced building material wherein lightweight, low density is achieved by use of high amount of fibrous-reinforcing material and not by the use of Low Density Additive (LDA).
The present invention further discloses lightweight cementitious cellulose fiber reinforced building material comprising a hydraulic binder, a filler and pozzolonic material, a silicious material, a fibrous-reinforcing material. The lightweight cementitious cellulose fiber reinforced building material is prepared without using any additives as have been done hereto.
DETAILED DESCRIPTION:
Accordingly, the present invention provides a novel formulation of lightweight cementitious cellulose fiber reinforced building material with improved workability and dimensional stability, wherein low density is achieved by use of high amount of fibrous-reinforcing material and in absence of Low Density Additive (LDA).
In a preferred embodiment, the present invention provides a formulation of lightweight cementitious cellulose fiber reinforced building material wherein the fibrous-reinforcing cellulosic material consists of Virgin Wood Cellulose Pulp in an amount 10-15% by weight along with a hydraulic binder, a filler and pozzolonic material, a siliceous material, a fibrous mineral, Bauxite, Bentonite clay and Silicon water repellant additive.

The hydraulic binder is selected from Portland Cement and is present in an amount 30-40% by weight. The filler and pozzolonic material is selected form pulverized fly ash and is present in an amount 20-30% by weight. The siliceous material is selected from quartz/ sand powder and is present in an amount 20-25% by weight. The fibrous mineral is Wollastonite present in an amount 4-10%. The Bauxite is present in an amount 3-6% by weight. The Bentonite clay is present in an amount 0.5-2% by weight. The Silicon water repellant additives are in amounts 0.1-0.5% by weight.
Further, the virgin wood cellulose pulp acts as a fiber and helps in reinforcing powder material. The Portland cement is used for strength and holding other raw material. The pulverized fly ash bonds with Portland cement. The quartz/sand powder reacts with Portland cement at high temperature. Fibrous mineral wollastonite is used to improve the dimensional stability and moisture movement of the product. The bauxite is used for arresting expansion and shrinkage and also improves the durability of the product with the formation of 11A Al-Tobermorite in the product. The bentonite clay is used for improving interlamina bonding and the silicon water repellant additive is used for improving water resistance and reducing water absorption. The addition of silicon additive and fibrous mineral wollastonite takes care of the problem arising from use of high cellulose fiber in the formulations.
The formulation for lightweight cementitious cellulose fiber reinforced building material is given below in Table 1.
In another embodiment, the lightweight cementitious cellulose fiber reinforced building material is prepared by the Hatschek Process.
The main advantage of the present invention is improved workability at an economical price, as well as improved dimensional stability without using low density additive.
The problems of dimensional stability and moisture movement due to use of high cellulose fiber in the formulation has been overcome by using fibrous mineral wollastonite and Bauxite as part of the compositions. The problems related to high water

absorption has been overcome by treating the fibrous material with silicon so that water absorption by fibrous material is minimal.
Finishing method also developed by providing Tongue and Groove to the edges of the product for better jointing process of between the boards and also to have continuity in the system during laying of boards.
Further details of the present invention will be apparent from the examples presented below which are purely illustrative and are not limited to the particular embodiments illustrated herein.
Example 1: Table 1: Formulation for lightweight cementitious cellulose fiber reinforced building material

Raw Material % By Weight
Virgin Wood Cellulose Pulp 10-15
Ordinary Portland Cement 30-40
Pulverised fly ash 20-30
Wollastonite 4-10
Quartz/sand Powder 20-25
Bauxite 200 mesh 3-6
Bentonite clay 0.5-2
Silicon water repellant additive 0.1-0.5
The product formed is found to have thickness in the range of 18 mm to 20 mm. The density of the product is between 1000-1100 kg/m3. The Modulus of Rupture (bending strength under Equilibrium Moisture Content (EMC) is found to be ll.lMPa whereas saturated MOR is found to be 6.6MPa. It's cross ratio strength is found to be 59%, whereas the MOS is found to be 11.5. Both the properties are under wet conditions. The moisture movement is 0.25%.

Table 2: Physical Properties

PHYSICAL PROPERTIES
DIMENSION Thickness (mm) 19.1 Range (19.0-19.2)

Length (mm) -

Width (mm) -

Levelness (mm) 0.2 mm across samples

Edge Straightness (mm) -

Diagonal Difference (mm) -

Dots Printing N/A .
Density
(kg/m3) Oven Dry 1050

Saturated 1040

Wet density 1520
MOR (MPa) EMC 11.1 (Avg both direction)

Saturated 6.6 (Avg both direction)
Cross Ratio Strength (%) Wet 59%
MOS (Thoughness) Wet 11.5
AVERAGE MOISTURE MOVEMENT RANGE (EMC TO
SATURATED & OVEN DRY) Moisture Movement (%) 0.25%
Visual Defects Bit Lumps OK

Dents OK

Furriness OK

Water Marks OK

Other Marks OK

Low density boards are also tested for following performance and durability tests. Product meets all the requirement as per Indian Standard IS 14862, International Standard ISO 8336 and also EN 12467.
Tests (Performance):
1) Warm water - The boards are subjected to warm water for 56 days as per the procedure given in the above standards.
2) Freeze-Thaw - The boards are subjected to -20 deg and normal water for 50 cycles as per the procedure given in the above standards.
3) The carbonation shrinkage - The boards are exposed to Carbonation shrinkage study by exposing to CO2 and high humidity environment and study for the cracking tendency of the boards.
4) Soak-dry test - The boards are subjected to immersion in water and then exposed to temperature of 105 deg C for - 25 cycles as per the above standards.
5) Heat /Rain cycle -The boards are subjected to heat (55 deg) and rain cycle for 50 cycles as per above standards.
Example 2: Process for preparation
Lightweight fibre cement building boards are manufactured by using Hatscheck process. Cellulose fibre is treated using Hydropulper and then further disc refiner to open up to 28-30 degree SR with a known consistency. After refining, the pulp slurry is transferred to main mixer. Cement is prepared in a cement mixer with known consistency of water. Flyash and quartz/silica is also prepared in separate tank. After taking cellulose into main mixer, cement, quartz and flyash are also added into the main mixer along with other additives. Further material is moved to agitator and then to vats in the machine through premixing arrangement. Further sheet formation will be as described in the hatschek process. After making the sheets of desired thicknesses, the sheets are cured in autoclaves at temperature 180-190 deg C with autoclaving pressure of 150 PSI. (6-7 bar) for about 8 hours. After curing sheets are removed and finished as per the market requirement.

We claim,
1. A formulation of lightweight cementitious cellulose fiber reinforced building material with improved workability and dimensional stability; wherein low density is achieved by use of high amount of fibrous-reinforcing material and in absence of Low Density Additive (LDA).
2. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 1; wherein the fibrous-reinforcing materials are Virgin Wood Cellulose Pulp & mineral fibre.
3. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 1; wherein the cellulose fiber reinforced building material comprises Virgin Wood Cellulose Pulp in an amount 10-15% by weight along with a hydraulic binder, a filler and pozzolonic material, a siliceous material, a fibrous mineral, Bauxite, Bentonite clay and Silicon water repellant additive.
4. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the hydraulic binder is Portland Cement in an amount 30-40% by weight.
5. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the filler and pozzolonic material is pulverized fly ash in an amount 20-30% by weight.
6. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the siliceous material is quartz/ sand powder in an amount 20-25% by weight.
7. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the fibrous mineral is Wollastonite in an amount 4-10%o.

8. The formulation of lightweight cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the Bauxite is present in an amount 3-6% by weight.
9. The formulation of lightweight, low density cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the Bentonite clay is present in an amount 0.5-2% by weight.
10. The formulation of lightweight, low density cementitious cellulose fiber reinforced building material as claimed in claim 3, wherein the Silicon water repellant additive is present in an amount 0.1-0.5% by weight.

Documents:

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Patent Number

279236

Indian Patent Application Number

859/MUM/2012

PG Journal Number

03/2017

Publication Date

20-Jan-2017

Grant Date

16-Jan-2017

Date of Filing

27-Mar-2012

Name of Patentee

EVEREST INDUSTRIES LIMITED

Applicant Address

GAT 152, LAKHMAPUR VILLAGE, DINDORI TALUKA, POST NAG NO.5, DISTRICT NASHIK-422202, MAHARASHTRA, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	RAO YENDURI SRINIVASA	EVEREST INDUSTRIES LIMITED A-32, MOHAN CO-OP INDUSTRIAL ESTATE, MATHRA ROAD, NEW DELHI-110 044, INDIA.
2	GOSETTY, BASAVARAJAPPA	EVEREST INDUSTRIES LIMITED GAT 152, LAKHMAPUR VILLAGE, DINDORI TALUKA, POST NAG NO.5, DISTRICT NASHIK-422202, MAHARASHTRA, INDIA.
3	MALI, SHARAD SANTOSH	EVEREST INDUSTRIES LIMITED GAT 152, LAKHMAPUR VILLAGE, DINDORI TALUKA, POST NAG NO.5, DISTRICT NASHIK-422202, MAHARASHTRA, INDIA.
4	JAIN, NIKHIL ASHOK	EVEREST INDUSTRIES LIMITED GAT 152, LAKHMAPUR VILLAGE, DINDORI TALUKA, POST NAG NO.5, DISTRICT NASHIK-422202, MAHARASHTRA, INDIA.

PCT International Classification Number

C04B16/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA