Indian Patents. 279958:A PROCESS FOR PREPARING A CELLULOSE BASED FIBRE FOR WITHSTANDING THE HIGHLY ALKALINE CONDITIONS OF CONCRETE AND A CELLULOSE BASED FIBRE

Title of Invention	A PROCESS FOR PREPARING A CELLULOSE BASED FIBRE FOR WITHSTANDING THE HIGHLY ALKALINE CONDITIONS OF CONCRETE AND A CELLULOSE BASED FIBRE
Abstract	A cellulose based fibre known as Protekta fibre comprising 20 to 80% w/v of natural cellulose fibre,5 to 25% w/v of titanium di oxide,5 to 15% w/v of starch ether,10 to 30% w/v of silica and 5 to 30% w/v of zeolite/dolomite/china clay powder, wherein the ingredients are mixed in a rotary mixer for a period of 30 to 60 minutes to obtain a homogeneous fibre and a process thereof.

Full Text	CELLULOSE BASED FIBRE The present invention relates to the development of a new, cellulose-based fibre which can withstand the highly alkaline conditions of concrete and help in its reinforcement. Admixtures are materials other than cement, aggregate and water, which are added to concrete either before or during mixing, to alter its properties. One such material is fibre, which for ages has been used as reinforcement for mud houses and indeed, for concrete structures. In fact, in early times reinforcements like straw, rice husk and even hair have been used and today straw and different natural fibres are still added in the construction of mud houses, etc. For reinforcement, even other types of fibres like alkali-resistant glass, steel, polyethylene and polypropylene, nylon and mineral admixtures have been used. It is weil known that cellulosic materials are easily available and are cost effective. Many companies recommend the use of cellulose as fibres, but there are several disadvantages since cellulose fibres tend to degrade and decompose in the harsh alkaline environment of concrete. However, efforts have been made to use chemically treated cellulose fibres or non-cellulose fibres to avoid this shortcoming and this invention has attempted to successfully produce a cellulose based formulation with the properties most required for reinforced fibre. Background Types of fibres: Fibres can be divided into two types, viz, those with moduli lower than the cement matrix, such as cellulose, nylon and polypropylene, and those with higher moduli, such as asbestos. Organic fibres with lower modulus are generally subjected to high creep and considerable elongations or deflections may occur over a period of time. Cellulose, commonly derived from plant celt walls, has been known since 1838. It occurs in cotton fibre and in combination with other plant materials like lignin. Cellulose is a long-chain polymer made up of repeating units of glucose, a simple sugar. This has been used in several fields, mainly in the textile, pharmaceutical and food industries. Numerous projects in the construction industry, worldwide, have also been undertaken on the use of cellulose fibres as reinforcement in pressed cement and / or mortar sheets. It was, however, recognized that cellulosic materials were of limited value in many compositions because of the harsh alkaline environment of many cementitious mixtures, which caused physical degradation and instability of the cellulosic fibres in curing of the mixture. Even though this is still being used, cellulose fibre alone does not give satisfactory results and therefore the applicant decided to formulate a multipurpose admixture to reinforce concrete, using cellulose modified with different products. It should be noted that not only is the strength of the concrete important but other properties like durability and workability lead to high performance concrete and these requirements were kept in mind. PRIOR ART US 7357833 relates to a fiber-reinforced cement based or cementitious material, and process for making, where the reinforcing fiber is a chemically treated cellulose or non-cellulose fiber. The fiber reinforced cementitious material includes (t) cement, (ii) optionally, sand, aggregate, or sand and aggregate, and (iii) chemically treated fibers having a polyvalent cation content of from about 0.1 weight percent to about 5.0 weight percent based on the dry weight of the treated fibers. The present invention further provides for a fiber reinforced cementitious material having a weak acid content of from about 0.5 weight percent to about 10 weight percent based on the dry weight of the treated fibers. US 6942726 teaches a fiber-reinforced cement based or cementitious material, and process for making, where the reinforcing fiber is a chemically treated cellulose or non-cellulose fiber. The fiber reinforced cementitious material includes (i) cement, (ii) optionally, sand, aggregate, or sand and aggregate, and (iii) chemically treated libers having a polyvalent cation content of from about 0,1 weight percent to about 5.0 weight percent based on the dry weight of the treated fibers. The present invention further provides for a fiber reinforced cementitious material having a weak acid content of from about 0.5 weight percent to about 10 weight percent based on the dry weight of the treated fibers. Disadvantages of Cellulose Fibre: According to one patent (United States Patent: 6872246) "... cellulose fiber cement materials can have performance drawbacks such as tower resistance to water induced damages, higher water permeability, and higher water migration ability (also known as wicking) compared to asbestos cement composite materials. These drawbacks are largely due to the presence of water conducting channels and voids in the cellulose fiber lumens and cell walls. The pore spaces in the cellulose fibers can become filled with water when the material is submerged or exposed to rain/condensation for an extended period of time. The porosity of cellulose fibers facilitates water transportation throughout the composite materials and can affect the long-term durability and performance of the material in certain environments. As such, conventional cellulose fibers can cause the material to have a higher saturated mass, poor wet to dry dimensional stability, lower saturated strength, and decreased resistance to water damage." The invention as disclosed in this patent recommend the use of loaded fibres. Several types of cellulose fibres are available, however selection of the right one is of paramount importance. The properties, purpose and mechanism of Protekta cellulose fibre in concrete are entirely different from those of many other cellulose fibres available in the market. The quality of the fibre plays an important role. The maximum particle size too is important as it affects the fibre distribution and the quantity of fibres. Concrete should have particles not more than 10mm in size, otherwise uniform fibre distribution is difficult to achieve. The applicant, after intensive research, modified cellulose fibre and this formulation is known as Protekta Fibre. Although Protekta Fibre is known as cellulose-based fibre, this fibre contains only a moderate percentage of cellulose which in synergy with other organic additives and clays it does not decompose even in high alkaline conditions. Addition of Protekta Fibre to concrete helps in improving several properties of the material for example, toughness, fatigue resistance, impact resistance and flexural strength. These properties are better achieved if cellulose fibre incorporates different derivatives of cellulose like ethers, glycolates etc. in minor quantities. It is also very important that cellulose fibres increase the compressive strength of the concrete, shorten the type of hydration of cement and produce CSH + Calcium Hydroxide which protects the concrete from corrosion. Corrosion is the single most important factor in the deterioration of building. Therefore Protekta Fibre also incorporates natural clay like Clinoptilolite (see figure -2). This also helps the fibre to be waterproofed. It has the capacity to retain water which helps curing. The combination and the above modification make the concrete strong in compression, providing reinforcement and anti-corrosion properties. In addition to the above properties the other additives are modifiers of cellulose namely titanium salts which inhibit algae growth and microbial attack. This formulation also acts as a crack inhibitor and improves working properties. Besides the cellulose fibre is further incorporated with several other organic and inorganic additives like a siliceous and aluminous material and these siliceous materials are known to be super plasticizers, reducing water: cement ratio. So unlike ordinary cellulose which has a limited role, our formulation modifies the above and in the presence of minute amounts of other additives like chemispheres and special microspheres which consist of a polymer shell, gives thermal conductivity to the concrete. Protekta Fibre provides reinforcement to the concrete. As we have said earlier cellulose by itself is not very useful because it decomposes in the presence of the high alkaline conditions of the concrete. This product not only provides reinforcement and strength to concrete but also acts as photo catalyst. Description The novel cellulose based fibre is a formulation produced by using chemicals like natural cellulose fibre, titanium dioxide and other titanium salts, starch ether, cellulose ether, methyl cellulose, sodium starch glycolate, clinoptilolite, with fume silica and sodium bentonate along with several organic additives like spray dried polymers, ceramic chemispheres and micro spheres consisting of a polymer shell encapsulating a gas (commercially available as Expancel). The combination of these products gives the claimed fibre, which has the following uses and properties: As a synergistic composition it is excellent for reinforcing concrete Increases compressive strength by 10-15% Shortens hydration reaction time As crack inhibitor - reduces thermal cracks, prevents crack formation, gives a crack-free surface Is stable in the harsh alkaline conditions of concrete Increases workability Prevents shrinkage Reduces water permeability Increases flexibility Is anti-corrosive Is environmentally friendly and non-hazardous The most salient feature of this product is that it increases the compressive strength of the concrete and shortens the rate of hydration reaction, producing CSH + calcium hydroxide which forms a passive layer around reinforcement to give protection to the concrete from corrosion, which is the single most important factor in the deterioration of building. Therefore Protekta Fibre also imbibes natural clay like Clinoptilolite, spray dried redispersible polymers and GL5(M) (waterproofing and super plasticizer). This also helps the fibre to be waterproofed. It has the capacity to retain water, which helps curing. The combination and the above modification make the concrete strong in compression, providing reinforcement and anti-corrosion properties. In addition to the above properties there are other additives that modify the cellulose, namely titanium salts, that inhibit algae growth and microbial attack. Titanium salts in the presence of UV light produces photo catalyst, which helps in the disintegration of nitrogen dioxide, etc. The titanium salt is used in nanotechnology-size particles and these get activated by the energy in sunlight. Titanium dioxide thus creates a charged separation of electrons which disperse on the surface of the photo catalyst and react with external substances, like toxic gases, e.g. nitrogen dioxide, etc. causing their chemical reduction and oxidation and the decomposition of these toxic organic compounds purifies the environment. This concept of photo catalyst is well known in nature. (Ref. article in Concrete Decor Magazine Online, "Photocatalysts, Self-Cleaning Concrete" by Michael Chusid, FCSI). This Novel Fibre formulation also acts as a crack inhibitor, giving a crack-free surface and improving the working properties of cement. Besides, this cellulose fibre is further incorporated with several other organic and inorganic additives like siliceous and aluminous materials. These siliceous materials are known to be super plasticizers, reducing the water: cement ratio. So unlike ordinary cellulose fibre, which has a limited role, the present novel formulation modifies the fibre in the presence of minute amounts of other additives. It is known in the literature that natural clays like zeolites and metakaloins increase the compressive strength of the concrete and shorten the time of concrete setting. It is also enriched by ceramic admixtures and the Applicant's proprietary anti-shrinkage compound called Protekta AC1. The present novel Fibre is thus not just a cellulose fibre, but is a novel multi-functionalproduct. Cellulose Based Fibre Appearance White PH 7.5-8 Density 280 g/l Residue on Ignition (850°) I 25% Cellulose fibre by itself has limited and mild properties while Protekta Fibre, which is this fibre modified and formulated with other admixtures, as above, offers exceptional properties leading to high performance concrete. Briefly said, these are anti-cracking, anti-shrinkage, durability and strength, workability; anti-alkali aggregate expansion and corrosion inhibiting admixture and reduces the water: cement ratio, leading to high performance concrete. It also plays a role in air-entraining admixture. This makes it a safe and excellent product, giving compressive strength and durability to the reinforced concrete. PROPERTIES Prevents shrinkage Reduces water permeability Increases flexibility Is environmental friendly and non-hazardous Increases compressive strength Excellent thermal crack resistance and reduction APPLICATION Plain concrete and wall plastering Footings, foundations, walls and tanks Pipes, burial vaults, pre-stressed beams, etc. Manhole covers, tiles etc. Roads and pavements Bridges and dams TECHNICAL DATA Appearance White Powder Density 280 g/l pH : 7.5 + 1 Residue on Ignition (850°): 25% Statement of the invention: According to the invention a process for preparing cellulose based fibre known as Protekta Fibre comprising the following steps: a) Taking 20 to 80% w/v of natural cellulose fibre in a rotary mixer, b) Adding 5 to 25% w/v of titanium di oxide, c) Adding 5 to 15% w/v of starch ether, d) Adding 10 to 30% w/v of silica, e) Adding 5 to 30% of zeolite/dolomite/china clay powder, f) Mixing the ingredients by stirring in a rotary mixer for 30 to 60 minutes to get a homogeneous fibre. According to an embodiment of the inventions cellulose based fibre known as Protekta fibre comprising 20 to 80% w/v of natural cellulose fibre, 5 to 25% w/v of titanium di oxide.5 to 15% w/v of starch ether,10 to 30% w/v of silica and 5 to 30% w/v of zeolite/dolomite/china clay powder; wherein the ingredients are mixed in a rotary mixer for a period of 30 to 60 minutes to obtain a homogeneous fibre. According to another embodiment of the invention ,a cellulose based fibre known as Protekta Fibre, wherein the cellulose fibre is obtained from wood pulp. According to another embodiment of the invention ,a cellulose based fibre known as Protekta fibre, wherein the starch ether is starch glycate. According to another embodiment of the invention, a cellulose based fibre known as Protekta Fibre, wherein the silica is fumed silica. The invention is described with reference to the examples, which are provided by way of illustration only,and these examples should not be construed to limit the scope of the present invention. PROCESS : (FIBRE) EXAMPLE -1 Take an open 100 Itr vessel fitted with a rotary mixer made by SS 316. 20 to 50 % of natural cellulose fibre was taken and to this was added 5 to 25 % of titanium di-oxide, 5 to 15 % starch glycate, (starch ether), 10 to 30 % of fumed silica, and 5 to 30 % of zeolite / dolomite / china clay and mixed for 30 minutes. The final product is a homogeneous fibre known as Protekta Fibre, hereinafter called product "A". EXAMPLE - 2 Take an open 100 Itr vessel fitted with a rotary mixer. Add 30 to 80 % of natural cellulose fibre from wood pulp, add 5 to 15 % of titanium di-oxide, add 5 to 10 % starch glycate, add 25 to 30 % of fumed silica and 5 to 30% of dolomite / china clay powder. Mix for one hour. A homogeneous fibre will be obtained known as Protekta Fibre, hereinafter called product "A". CONCLUSION: Cellulose fibre itself has limited and mild properties while Protekta Fibre which is modified / formulated with other admixtures as above offers exceptional properties which briefly said, are Anti-Cracking, Anti-Shrinkage, Durability and Strength, Workability, Anti-Alkali Aggregate Expansion and Corrosion Inhibiting Admixture, reduction of Water-Cement Ratio, Super Plasticizer, Anti-Corrosion - all leading to high performance concrete. It also plays a role of Air-Entraining Admixture. We claim: 1. A process for preparing cellulose based fibre known as Protekta Fibre comprising the following steps: a) Taking 20 to 80% w/v of natural cellulose fibre in a rotary mixer, b) Adding 5 to 25% w/v of titanium di oxide, c) Adding 5 to 15% w/v of starch ether, d) Adding 10 to 30% w/v of silica, e) Adding 5 to 30% of zeolite/dolomite /china clay powder, f) Mixing the ingredients by stirring in a rotary mixer for 30 to 60 minutes to get a homogeneous fibre. 2. A cellulose based fibre known as Protekta fibre comprising 20 to 80% w/v of natural cellulose fibre,5 to 25% w/v of titanium di oxide,5 to 15% w/v of starch ether,10 to 30% w/v of silica and 5 to 30% w/v of zeolite/dolomite/china clay powder, wherein the ingredients are mixed in a rotary mixer for a period of 30 to 60 minutes to obtain a homogeneous fibre. 3. A cellulose based fibre known as Protekta Fibre, wherein the cellulose fibre is obtained from wood pulp. 4. A cellulose based fibre known as Protekta fibre, wherein the starch ether is starch glycate. 5. A cellulose based fibre known as Protekta Fibre, wherein the silica is fumed silica. 6. A process for preparing cellulose based fibre known as Protekta Fibre substantially as hereinbefore described with reference to the accompanying drawings. 7. A cellulose based fibre known as Protekta fibre substantially as hereinbefore described with reference to the accompanying drawings.

Full Text

CELLULOSE BASED FIBRE

The present invention relates to the development of a new, cellulose-based fibre which can withstand the highly alkaline conditions of concrete and help in its reinforcement.

Admixtures are materials other than cement, aggregate and water, which are added to concrete either before or during mixing, to alter its properties. One such material is fibre, which for ages has been used as reinforcement for mud houses and indeed, for concrete structures. In fact, in early times reinforcements like straw, rice husk and even hair have been used and today straw and different natural fibres are still added in the construction of mud houses, etc.

For reinforcement, even other types of fibres like alkali-resistant glass, steel, polyethylene and polypropylene, nylon and mineral admixtures have been used.

It is weil known that cellulosic materials are easily available and are cost effective. Many companies recommend the use of cellulose as fibres, but there are several disadvantages since cellulose fibres tend to degrade and decompose in the harsh alkaline environment of concrete. However, efforts have been made to use chemically treated cellulose fibres or non-cellulose fibres to avoid this shortcoming and this invention has attempted to successfully produce a cellulose based formulation with the properties most required for reinforced fibre.

Background

Types of fibres: Fibres can be divided into two types, viz, those with moduli lower than the cement matrix, such as cellulose, nylon and polypropylene, and those with higher moduli, such as asbestos. Organic fibres with lower modulus are generally subjected to high creep and considerable elongations or deflections may occur over a period of time.

Cellulose, commonly derived from plant celt walls, has been known since 1838. It occurs in cotton fibre and in combination with other plant materials like lignin. Cellulose is a long-chain polymer made up of repeating units of glucose, a simple sugar. This has been used in several fields, mainly in the textile, pharmaceutical and food industries. Numerous projects in the construction industry, worldwide, have also been undertaken on the use of cellulose fibres as reinforcement in pressed cement and / or mortar sheets. It was, however, recognized that cellulosic materials were of limited value in many compositions because of the harsh alkaline environment of many cementitious mixtures, which caused physical degradation and instability of the cellulosic fibres in curing of the mixture.

Even though this is still being used, cellulose fibre alone does not give satisfactory results and therefore the applicant decided to formulate a multipurpose admixture to reinforce concrete, using cellulose modified with different products. It should be noted that not only is the strength of the concrete important but other properties like durability and workability lead to high performance concrete and these requirements were kept in mind.

PRIOR ART

US 7357833 relates to a fiber-reinforced cement based or cementitious material, and process for making, where the reinforcing fiber is a chemically treated cellulose or non-cellulose fiber. The fiber reinforced cementitious material includes (t) cement, (ii) optionally, sand, aggregate, or sand and aggregate, and (iii) chemically treated fibers having a polyvalent cation content of from about 0.1 weight percent to about 5.0 weight percent based on the dry weight of the treated fibers. The present invention further provides for a fiber reinforced cementitious material having a weak acid content of from about 0.5 weight percent to about 10 weight percent based on the dry weight of the treated fibers.

US 6942726 teaches a fiber-reinforced cement based or cementitious material, and process for making, where the reinforcing fiber is a chemically treated cellulose or non-cellulose fiber. The fiber reinforced cementitious material includes (i) cement, (ii) optionally, sand, aggregate, or sand and aggregate, and (iii) chemically treated libers having a polyvalent cation content of from about 0,1 weight percent to about 5.0 weight percent based on the dry weight of the treated fibers. The present invention further provides for a fiber reinforced cementitious material having a weak acid content of from about 0.5 weight percent to about 10 weight percent based on the dry weight of the treated fibers.

Disadvantages of Cellulose Fibre: According to one patent (United States Patent: 6872246) "... cellulose fiber cement materials can have performance drawbacks such as tower resistance to water induced damages, higher water permeability, and higher water migration ability (also known as wicking) compared to asbestos cement composite materials. These drawbacks are largely due to the presence of water conducting channels and voids in the cellulose fiber lumens and cell walls. The pore spaces in the cellulose fibers can become filled with water when the material is submerged or exposed to rain/condensation for an extended period of time. The porosity of cellulose fibers facilitates water transportation throughout the composite materials and can affect the long-term durability and performance of the material in certain environments. As such, conventional cellulose fibers can cause the material to have a higher saturated mass, poor wet to dry dimensional stability, lower saturated strength, and decreased resistance to water damage."
The invention as disclosed in this patent recommend the use of loaded fibres.

Several types of cellulose fibres are available, however selection of the right one is of paramount importance. The properties, purpose and mechanism of Protekta cellulose fibre in concrete are entirely different from those of many other cellulose fibres available in the market. The quality of the fibre plays an important role. The maximum particle size too is important as it affects the fibre distribution and the quantity of fibres. Concrete should have particles not more than 10mm in size, otherwise uniform fibre distribution is difficult to achieve. The applicant, after intensive research, modified cellulose fibre and this formulation is known as Protekta Fibre.
Although Protekta Fibre is known as cellulose-based fibre, this fibre contains only a moderate percentage of cellulose which in synergy with other organic additives and clays it does not decompose even in high alkaline conditions.
Addition of Protekta Fibre to concrete helps in improving several properties of the material for example, toughness, fatigue resistance, impact resistance and flexural strength. These properties are better achieved if cellulose fibre incorporates different derivatives of cellulose like ethers, glycolates etc. in minor quantities.

It is also very important that cellulose fibres increase the compressive strength of the concrete, shorten the type of hydration of cement and produce CSH + Calcium Hydroxide which protects the concrete from corrosion.

Corrosion is the single most important factor in the deterioration of building. Therefore Protekta Fibre also incorporates natural clay like Clinoptilolite (see figure -2).

This also helps the fibre to be waterproofed. It has the capacity to retain water which helps curing. The combination and the above modification make the concrete strong in compression, providing reinforcement and anti-corrosion properties.

In addition to the above properties the other additives are modifiers of cellulose namely titanium salts which inhibit algae growth and microbial attack. This formulation also acts as a crack inhibitor and improves working properties. Besides the cellulose fibre is further incorporated with several other organic and inorganic additives like a siliceous and aluminous material and these siliceous materials are known to be super plasticizers, reducing water: cement ratio.

So unlike ordinary cellulose which has a limited role, our formulation modifies the above and in the presence of minute amounts of other additives like chemispheres and special microspheres which consist of a polymer shell, gives thermal conductivity to the concrete.

Protekta Fibre provides reinforcement to the concrete. As we have said earlier cellulose by itself is not very useful because it decomposes in the presence of the high alkaline conditions of the concrete. This product not only provides reinforcement and strength to concrete but also acts as photo catalyst.

Description

The novel cellulose based fibre is a formulation produced by using chemicals like natural cellulose fibre, titanium dioxide and other titanium salts, starch ether, cellulose ether, methyl cellulose, sodium starch glycolate, clinoptilolite, with fume silica and sodium bentonate along with several organic additives like spray dried polymers, ceramic chemispheres and micro spheres consisting of a polymer shell encapsulating a gas (commercially available as Expancel). The combination of these products gives the claimed fibre, which has the following uses and properties:

As a synergistic composition it is excellent for reinforcing concrete
Increases compressive strength by 10-15%
Shortens hydration reaction time
As crack inhibitor - reduces thermal cracks, prevents crack formation, gives a
crack-free surface
Is stable in the harsh alkaline conditions of concrete
Increases workability
Prevents shrinkage
Reduces water permeability
Increases flexibility
Is anti-corrosive
Is environmentally friendly and non-hazardous
The most salient feature of this product is that it increases the compressive strength of the concrete and shortens the rate of hydration reaction, producing CSH + calcium hydroxide which forms a passive layer around reinforcement to give protection to the concrete from corrosion, which is the single most important factor in the deterioration of building. Therefore Protekta Fibre also imbibes natural clay like Clinoptilolite, spray dried redispersible polymers and GL5(M) (waterproofing and super plasticizer). This also helps the fibre to be waterproofed. It has the capacity to retain water, which helps curing. The combination and the above modification make the concrete strong in compression, providing reinforcement and anti-corrosion properties.
In addition to the above properties there are other additives that modify the cellulose, namely titanium salts, that inhibit algae growth and microbial attack. Titanium salts in the presence of UV light produces photo catalyst, which helps in the disintegration of nitrogen dioxide, etc. The titanium salt is used in nanotechnology-size particles and these get activated by the energy in sunlight. Titanium dioxide thus creates a charged separation of electrons which disperse on the surface of the photo catalyst and react with external substances, like toxic gases, e.g. nitrogen dioxide, etc. causing their chemical reduction and oxidation and the decomposition of these toxic organic compounds purifies the environment. This concept of photo catalyst is well known in nature. (Ref. article in Concrete Decor Magazine Online, "Photocatalysts, Self-Cleaning Concrete" by Michael Chusid, FCSI).

This Novel Fibre formulation also acts as a crack inhibitor, giving a crack-free surface and improving the working properties of cement. Besides, this cellulose fibre is further incorporated with several other organic and inorganic additives like siliceous and aluminous materials. These siliceous materials are known to be super plasticizers, reducing the water:
cement ratio.

So unlike ordinary cellulose fibre, which has a limited role, the present novel formulation modifies the fibre in the presence of minute amounts of other additives. It is known in the literature that natural clays like zeolites and metakaloins increase the compressive strength of the concrete and shorten the time of concrete setting. It is also enriched by ceramic admixtures and the Applicant's proprietary anti-shrinkage compound called Protekta AC1.
The present novel Fibre is thus not just a cellulose fibre, but is a novel multi-functionalproduct.

Cellulose Based Fibre
Appearance White
PH 7.5-8
Density 280 g/l
Residue on Ignition (850°) I 25%
Cellulose fibre by itself has limited and mild properties while Protekta Fibre, which is this fibre modified and formulated with other admixtures, as above, offers exceptional properties leading to high performance concrete. Briefly said, these are anti-cracking, anti-shrinkage, durability and strength, workability; anti-alkali aggregate expansion and corrosion inhibiting admixture and reduces the water: cement ratio, leading to high performance concrete. It also plays a role in air-entraining admixture. This makes it a safe and excellent product, giving compressive strength and durability to the reinforced concrete.

PROPERTIES

Prevents shrinkage
Reduces water permeability
Increases flexibility
Is environmental friendly and non-hazardous
Increases compressive strength
Excellent thermal crack resistance and reduction

APPLICATION

Plain concrete and wall plastering Footings, foundations, walls and tanks Pipes, burial vaults, pre-stressed beams, etc. Manhole covers, tiles etc. Roads and pavements Bridges and dams

TECHNICAL DATA

Appearance White Powder
Density 280 g/l
pH : 7.5 + 1
Residue on Ignition (850°): 25%
Statement of the invention: According to the invention a process for preparing cellulose based fibre known as Protekta Fibre comprising the following steps:

a) Taking 20 to 80% w/v of natural cellulose fibre in a rotary mixer,
b) Adding 5 to 25% w/v of titanium di oxide,
c) Adding 5 to 15% w/v of starch ether,
d) Adding 10 to 30% w/v of silica,
e) Adding 5 to 30% of zeolite/dolomite/china clay powder,
f) Mixing the ingredients by stirring in a rotary mixer for 30 to 60 minutes to get a homogeneous fibre.

According to an embodiment of the inventions cellulose based fibre known as Protekta fibre comprising 20 to 80% w/v of natural cellulose fibre, 5 to 25% w/v of titanium di oxide.5 to 15% w/v of starch ether,10 to 30% w/v of silica and 5 to 30% w/v of zeolite/dolomite/china clay powder; wherein the ingredients are mixed in a rotary mixer for a period of 30 to 60 minutes to obtain a homogeneous fibre. According to another embodiment of the invention ,a cellulose based fibre known as Protekta Fibre, wherein the cellulose fibre is obtained from wood pulp.
According to another embodiment of the invention ,a cellulose based fibre known as Protekta fibre, wherein the starch ether is starch glycate.

According to another embodiment of the invention, a cellulose based fibre known as Protekta Fibre, wherein the silica is fumed silica.

The invention is described with reference to the examples, which are provided by way of illustration only,and these examples should not be construed to limit the scope of the present invention. PROCESS : (FIBRE)

EXAMPLE -1

Take an open 100 Itr vessel fitted with a rotary mixer made by SS 316. 20 to 50 % of natural cellulose fibre was taken and to this was added 5 to 25 % of titanium di-oxide, 5 to 15 % starch glycate, (starch ether), 10 to 30 % of fumed silica, and 5 to 30 % of zeolite / dolomite / china clay and mixed for 30 minutes. The final product is a homogeneous fibre known as Protekta Fibre, hereinafter called product "A".

EXAMPLE - 2

Take an open 100 Itr vessel fitted with a rotary mixer. Add 30 to 80 % of natural cellulose fibre from wood pulp, add 5 to 15 % of titanium di-oxide, add 5 to 10 % starch glycate, add 25 to 30 % of fumed silica and 5 to 30% of dolomite / china clay powder. Mix for one hour. A homogeneous fibre will be obtained known as Protekta Fibre, hereinafter called product "A".

CONCLUSION: Cellulose fibre itself has limited and mild properties while Protekta Fibre which is modified / formulated with other admixtures as above offers exceptional properties which briefly said, are Anti-Cracking, Anti-Shrinkage, Durability and Strength, Workability, Anti-Alkali Aggregate Expansion and Corrosion Inhibiting Admixture, reduction of Water-Cement Ratio, Super Plasticizer, Anti-Corrosion - all leading to high performance concrete. It also plays a role of Air-Entraining Admixture.

We claim:

1. A process for preparing cellulose based fibre known as Protekta Fibre

comprising the following steps:

a) Taking 20 to 80% w/v of natural cellulose fibre in a rotary mixer,

b) Adding 5 to 25% w/v of titanium di oxide,

c) Adding 5 to 15% w/v of starch ether,

d) Adding 10 to 30% w/v of silica,

e) Adding 5 to 30% of zeolite/dolomite /china clay powder,

f) Mixing the ingredients by stirring in a rotary mixer for 30 to 60 minutes to get a homogeneous fibre.

2. A cellulose based fibre known as Protekta fibre comprising 20 to 80% w/v of natural cellulose fibre,5 to 25% w/v of titanium di oxide,5 to 15% w/v of starch ether,10 to 30% w/v of silica and 5 to 30% w/v of zeolite/dolomite/china clay powder, wherein the ingredients are mixed in a rotary mixer for a period of 30 to 60 minutes to obtain a homogeneous fibre.

3. A cellulose based fibre known as Protekta Fibre, wherein the cellulose fibre is obtained from wood pulp.

4. A cellulose based fibre known as Protekta fibre, wherein the starch ether is starch glycate.

5. A cellulose based fibre known as Protekta Fibre, wherein the silica is fumed silica.

6. A process for preparing cellulose based fibre known as Protekta Fibre substantially as hereinbefore described with reference to the accompanying drawings.

7. A cellulose based fibre known as Protekta fibre substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

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Patent Number

279958

Indian Patent Application Number

480/CHE/2009

PG Journal Number

06/2017

Publication Date

10-Feb-2017

Grant Date

06-Feb-2017

Date of Filing

04-Mar-2009

Name of Patentee

TECH-DRY (INDIA) PVT. LTD

Applicant Address

769, GROUND FLOOR, 1ST STAGE, 1ST CROSS, INDRA NAGAR, BANGALORE - 560 038

Inventors:

#	Inventor's Name	Inventor's Address
1	SURENDRA P. BHATNAGAR	205,2ND FLOOR, KRISHNA JEE, 3RD MAIN DEFENCE COLONY, INDRA NAGAR, BANGALORE - 560 038

PCT International Classification Number

C08L

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA