Title of Invention	"AN IMPROVED PROCESS OF MAKING JUTE-GLASS FIBRE HYBRID SHEET MOULDING COMPOUND (SMS) USEFUL FOR MAKING LOW COST COMPOSITE COMPONENTS"
Abstract	An improved process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components The present invention provides a hydrid jute-glasss fibre sheet moulding compound which is cheaper and has increase strength. The novel outcome is achieved by using the polymer solution impregnated jute fibre in the form of felt or stiched mat which is used to form a sandwich with the glass fibre, which in turn impregnated with a polymer slurry comprising resin, filler component, thickening agent, fire retardant additive and shrinkage controlling additive.

Title of Invention

"AN IMPROVED PROCESS OF MAKING JUTE-GLASS FIBRE HYBRID SHEET MOULDING COMPOUND (SMS) USEFUL FOR MAKING LOW COST COMPOSITE COMPONENTS"

Abstract

An improved process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components The present invention provides a hydrid jute-glasss fibre sheet moulding compound which is cheaper and has increase strength. The novel outcome is achieved by using the polymer solution impregnated jute fibre in the form of felt or stiched mat which is used to form a sandwich with the glass fibre, which in turn impregnated with a polymer slurry comprising resin, filler component, thickening agent, fire retardant additive and shrinkage controlling additive.

Full Text	The present invention relates to an improved process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components. Jute - glass fibre hybrid sheet moulding compound (SMC) may be used to produce composites of various shapes and sizes required for applications in railways, furniture industry, electrical industry and domestic appliances. This type of composite can replace an assembly of many pieces of sheet metals and fibre board with a product offering simpler installation, better performance with low noise and smoother interior and exterior surfaces with better aesthetic appeal without the necessity for painting. It also has additional advantages of being lighter in weight and lower in cost. In the previous method of producing jute-glass fibre hybrid composite jute cloth, and glass fibre were mixed with polyester resin, catalyst and accelerator by using hand lay up method or by press moulding method without forming sheet moulding compound (SMC), Reference for which may be made to (1) Composite Materials Technology, Manser Publishers, N.Y. p 62, 1990, by P.K. Mallick/S.Newman, (2) Fibre Sci. & Techn., 15, 41, 1981 by A.M. Shah and S.L. Lakkad, (3) J. Mater. Sci. Letters, 2, 99, 1983 , by R. Mohan, K. Kishore, M.K. Sridhar and R.M.V.G.K. Rao, (4) Proc. of 3rd International Conference on Mech. Behaviour of Materials, Cambridge, Aug., 1979, Pergamon Press, 1979 by K.K.Chawla and A.C. Bastos, (5) Proc. of the Second International conference on Mech. Behaviour of Materials, Boston, Aug., 1977, ASM, p 1920, by K.K.Chawla, (6) Rev. Bras. Tech., Vol. 9, 1978, p 79-99 by K. K. Chawla, R.R.Avilez, R.R.Rodrigues, A.C.M. SA and L.G.P.L. , Cavadas and (7) proc. of 3rd International Conference on Composite Materials in Paris, France, Vol. 1, 1980, by K.K. Chawla, E.E.A. Aragao, R.R.C. Monteoro, F. G. Fernandez and M. M. Moraes; wherein the strength of the composite is not at all comparable to conventional glass based SMC composite because of poor wettability of jute fibre in polyester resin. The main drawbacks of the above noted hitherto known processes are : 1. Jute fibre in general, require high percentage of polymeric matrices to wet the surfaces due to weak interfacial bonding between the fibre and the polymeric matrices and due to hygroscopic nature of the jute fibres. The alpha cellulose content of jute fibre possesses three hydroxyl groups for each glucose residue and the hemicellulose content of jute fibre possesses two hydroxyl groups for each pentose residence. These hydroxyl groups are the active centres to attract water molecules. Hydrogen bonds are formed between the hydroxyl groups and water molecules. First the direct attachment of water molecules through the active sites (i.e. hydroxyl group) occur and then the indirect attachment through directly attached water molecules take place, Reference for which may be made to "Proc. of the International Symposium on Biocomposites and Blends based on jute and allied fibres", Nov. 30 - Dec. 2, 1994, by Dr. B.C.Mitra. Hence similar to the application of coupling agent in the form of sizing solution to the glass fibre, attempts have been made by several investigators to block the hydroxyl groups of cellulose and hemicellulose of jute fibre by the application of different chemicals but the surface functionality was not much improved and as such the wettability of jute fibre in polymer matrices was poor. References for which may be made to (a) Ind. J. Text. Res. 7:87, 1982, by M.K.Sridhar et.al, (b) J. Appl. Phys. Sci., 26:4069,1981 by R.M.V.G.K. Rao et.al (c) Reinforced Plastics, 8, 306, June, 1964, by A.R.Philip, (d) Eng. Mater. Des., 8, 475 1965. In spite of these efforts, however, there has not been any extensive commercial utilisation of jute fiber composites. One of the several reasons for this failure lies in the poor adhesion between resin matrix and jute fiber leading to debonding of the composite on aging. 2. Jute fibre is less efficient than glass fibre in its resin distribution properties. It has a greater flow resistance and tend to be less buoyant in dry state and compressed more readily thereby entrapping small air bubbles in the laminates. Because of these characteristics it is not easily amenable to the common moulding processes like hand lay up moulding. It is also very difficult to impregnate raw jute fibre with polymeric resin as like glass fibre in common sheet moulding manufacturing system until and unless it is properly treated by using polymer solution. The main object of the present invention is to provide a process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components which obviates the drawbacks as detailed above. Another object of the present invention is to provide a composition for making jute-glass fibre hybrid sheet moulding compound (SMC). Accordingly, the present invention provides an improved process fof making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components which comprises (i) impregnating jute fibre with a polymer solution by known methods such as wetting, followed by passing through squeeze rollers, drying the polymer coated jute fibre in an oven at a temperature in the range of 50° - 70°C for a time period in the range of 1 - 1.5 hrs., (ii) preparing a slurry by mixing 27 - 35 wt.% polyester resin, such as herein described 1.5-2 gms. Tertiary utyl perbenzoate per 100 gms. of polyester resin, 8-10 wt.% filler and 2-3 wt% thickening agent as defined herein, 8-15 wt% fire retardant additive, selective from chlorinated paraffin wax, antimony trioxide, alumina trihydrate, magnesium carbonate or mixture thereof, 2 - 3.34 wt% shrinkage controlling additive selected from polyvinyl acetate, low density polyethylene, polyvinyl chloride, polystyrene or mixture thereof 3 -4 wt.% zinc stearate (iii) impregnating unde roller pressure 15-20 wt% of the dried polymer coated jute fibre as obtained at step (i) in between 20 - 25 wt.% glass fibre layers, into the slurry as obtained at step (ii) and squeezing out in between two cellophane papers to obtain a hybrid sheet moulding compound (SMC), rolling the SMC over a mandrel and maturing at a temperature in the range of 10° - 15°C 7 days to get the desired jute - glass fibre hybrid sheet moulding compound. In an embodiment of the present invention the jute fibre used may be in the form of felt or stiched mat. In another embodiment of the present invention the polymer solution used may be such as 4 - 7 gms melamine formaldehyde resin in 93 - 96 ml. butanol, 4-7 gms. phenol formaldehyde resin in 93 - 96 ml., mixture of methanol, 4 gms. phenol formaldehyde resin and 2 gms. polyvinyl butyral resin in 94 ml., mixture of methanol, butanol and toluene, 4-7 gms. polystyrene resin and 1 - 2 ml. v -Methacryloxypropyltrimethoxysilane in 91 - 95 ml. toluene. In yet another ebdoiment of the present invention the glass fibres used may be such as surface mat, chopped strand mat, woven roving, fabric or mixture thereof. In another embodiment of the present invention the polyester resin used may be such as general purpose, isophthalic, bisphenolic, vinyl ester or mixture thereof. In yet another embodiment of the present invention the filler used may be such as calcium carbonate, talcum powder, silica powder or mixture thereof. In another embodiment of the present invention the thickening agent used may be such as magnesium hydroxide, magnesium oxide or mixture thereof. In still another embodiment of the present invention the fire retardant additive used may be such as chlorinated paraffin wax, antimony trioxide, alumina trihydrate, magnesium carbonate or mixture thereof. In yet another embodiment of the present invention the shrinkage controlling dditive used may be such as polyvinyl acetate, low density polyethylene, polyvinyl chloride, polystyrene or mixture thereof. The details of the present invention are given below : a) The polymer solution is first prepared by mixing 4-7 gms. melamine formaldehyde resin in 93-96 ml. butanol, or by mixing 4-7 gms. phenol formaldehyde resin in 93-96 ml. methanol, or by mixing 4 gms. phenol formaldehyde resin and 2 gms. polyvinyl butyral resin in 94ml. mixture of methanol, butanol and toluene or by mixing 4-7 gms. polystyrene and 1-2 ml. y-Methacryloxypropyltrimethoxysilane in 91-95 ml. toluene. Jute fibre in the form of felt or stiched mat is impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. b) Polymer coated jute fibre is dried at a temperature in the range of 50-70°C for a time in the range of 1- 1.5 hrs in an oven. c) 15-20 wt. % of the dried polymer coated jute fibre is placed in between 20-25 wt. % glass fibre layers. d) A thick slurry is prepared by mixing 27-35 wt. % polyester resin such as general purpose, isophthalic, bisphenolic, vinyl ester or mixture thereof, 1.5-2 gm. tertiarybutyl perbenzoate per 100 gms. of polyester resin , 8-10 wt. % filler such as calcium carbonate, talcum powder, silica powder or mixture thereof, 2-3 wt. % thickening agent such as magnesium hydroxide, magnesium oxide or mixture thereof, 8-15 wt. % fire retardant additive such as chlorinated paraffin wax, antimony trioxide, alumina trihydrate, magnesium carbonate or mixture thereof, 2 - 3.34 wt.% shrinkage controlling additive such as polyvinyl acetate, low density polyethylene or polyvinyl chloride and 3-4wt. % zinc stearate in a high shear mixer for 10-15 mins. e) Using the slurry prepared in step (d) polymer coated jute fibre and glass fibre sandwich is impregnated under roller pressure and squeezed out in between two cellophane papers. f) The sheet moulding compound (SMC) thus formed is then rolled over a mandrel and stored in a cool place for maturing at 10-15°C for 7 days. g) The Jute-glass fibre hybrid sheet moulding compound (SMC) so obtained may be press moulded in a hot hydraulic press and can be prepared into a sheet or a moulded component. The -novelty-re-that^he jute-glass fibre hybrid sheet moulding compound (SMC) prepared by the process of the present invention is cheaper and has increased strength. The novel outcome is achieved by the inventive steps which resides in the polymer solution impregnated jute fibre in the form of felt or stiched mat used to form a sandwich with the glass fibre which in turn impregnated with a polymer slurry such as herein described. The following examples are given by way of illustration of the process and should not therefore be construed to limit the scope of the present invention. Example -1 The polymer solution was first prepared by mixing 4 gms. general purpose polystyrene resin, 1ml. Y-Methacryloxypropyltrimethoxysilane and 95 ml. toluene. Jute fibre in the form of felt was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated jute felt was then dried at 58°C for 1.25 hours in an oven and stored in an airtight container. A thick slurry was prepared by mixing 27 gms. polyester resin, 0.4 gm. tertiary butyl perbenzoate, 8 gms. calcium carbonate, 2 gms magnesium hydroxide, 5 gms. chlorinated paraffin wax, 5 gjms. antimony trioxide, 5 gms. alumina trihydrate, 2.5 gms. polyvinyl acetate and 3.1 gms. zinc stearate in a high shear mixture for 10 mins. 15 gms. polymer coated jute felt placed in sandwich form between 25 gms. glass fibre layers were impregnated with the above slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 10° C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated. The properties evaluated for jute-glass fibre hybrid composite are given below. (Table Removed) Example - 2 The polymer solution was first prepared by mixing 5 gms. melamine formaldehyde resin with 95 ml. butanol. Jute fibre in the form of stiched mat was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated stiched mat was then dried at 60°C for 1 hour in an oven and stored in an airtight container. A thick slurry is prepared by mixing 29 gms. vinyl ester resin, 0.58 gm. tertiary butyl perbenzoate, 10 gms. talcum powder, 2 gms. magnesium hydroxide, 1 gm. magnesium oxide, 4 gms. chlorinated paraffin wax, 4 gms. antimony trioxide, 4 gms. magnesium carbonate, 2 gms. low density polyethylene and 3.42 gms. zinc stearate in a high shear mixture for 15 mins. 16 gms. polymer coated stiched mat placed in sandwich form between 24 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 12°C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated. The properties evaluated for jute-glass fibre hybrid composite are given below: (Table Removed)10 The polymer solution was first prepared by mixing 6 gms. phenol formaldehyde resin with 94 ml. of toluene. Jute fibre in the form of felt was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated jute felt was then dried at 62°C for 1 hour in an oven and stored in an airtight container. A thick slurry was prepared by mixing 32 gms. bisphenolic polyester resin, 0.64 gm. tertiary butyl perbenzoate, 9 gms. silica powder, 2 gms. magnesium hydroxide, 4 gms. chlorinated paraffin wax, 5 gms.. antimony trioxide, 4 gms. alumina trihydrate, 3 gms. polyvinyl chloride and 3.36 gms. zinc stearate in a high shear mixture for 12 mins. 17 gms. polymer coated jute felt placed in sandwich form between 20 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 12°C or 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated. The properties evaluated for jute-glass fibre hybrid composite are given below: (Table Removed) Example - 4 The polymer solution was first prepared by mixing 4 gms. phenol formaldehyde resin, 2 gms. polyvinyl butyral resin and 2 ml. y-Methacryloxypropyltrimethoxysilane in 92 ml. mixture of methanol, butanol and toluene. Jute fibre in the form of stiched mat was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated stiched mat was then dried at 65°C for 1 hour in an oven and stored in an airtight container. A thick slurry was prepared by mixing 33 gms. bisphenolic polyester resin, 0.66 gm. tertiary butyl perbenzoate, 10 gms. calcium carbonate, 2 gms. magnesium hydroxide, 1 gm. magnesium oxide, 4 gms..antimony trioxide, 4 gms. alumina trihydrate, 3.34 gms. polyvinyl chloride and 4 gms. zinc stearate in a high shear mixture for 10 mins. 18 gms. polymer coated stiched mat placed in sandwich form between 20 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 15°C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated. The properties evaluated for jute-glass fibre hybrid composite are given below: (Table Removed) Example -5 The polymer solution was first prepared by mixing 7 gms. polystyrene resin, 1ml. y-Methacryloxypropyltrimethoxysilane in 92 ml. toluene. Jute fibre in the form of stiched mat was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated stiched mat was then dried at 65°C for 1 hour in an oven and stored in an airtight container. A thick slurry was prepared by mixing 35 gms. general purpose polyester resin, 0.7 gm tertiary butyl perbenzoate, 8 gms. calcium carbonate, 2 gms. magnesium hydroxide, 4 gms. .antimony trioxide, 5 gms. alumina trihydrate, 2 gms. low density polyethylene and 3.3 gms. zinc stearate in a high shear mixture for 12 mins. 19 gms. polymer coated stiched mat placed in sandwich form between 21 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 12°C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated. The properties evaluated for jute-glass fibre hybrid composite are given below: (TableRemoved) (Table Removed) Example-6 The polymer solution was first prepared by mixing 6 gms. polystyrene resin, 2 ml. y-Methacryloxypropyltrimethoxysilane and 92 ml. toluene. Jute fibre in the form of stiched mat was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated stiched mat was then dried at 60°C for 1.5 hour in an oven and stored in an airtight container. A thick slurry was prepared by mixing 35 gms. isophthalic polyester resin, 0.7 gm tertiary butyl perbenzoate, 8 gms. calcium carbonate, 2 gms. magnesium hydroxide, 3 gms. .antimony trioxide, 5 gms. alumina trihydrate, 3.3 gms. polyvinyl acetate and 3 gms. zinc stearate in a high shear mixture for 12 mins. 20 gms. polymer coated stiched mat placed in sandwich form between 20 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 15 C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated. The properties evaluated for jute-glass fibre hybrid composite are given below: (Table Removed) The summary of the properties evaluated for jute-glass fibre hybrid composites is given below: (Table Removed) The novelties and inventive steps of the present invention are : (1) Improvement of the wettability property of jute fibre in polyester resin by using polymer coated jute fibre and thereby increasing the strength of the composite. (2) Partial reduction of high cost glass fibre in SMC by incorporating polymer coated jute fibre and thereby reducing the cost of the composite. (3) Improvement of the strength of the SMC composite by partial reduction of filler in SMC by incorporating polymer coated jute fibre. Analysis for the achievement of the strength properties of the composite components based on jute-glass fibre hybrid SMC. Jute is a naturally occuring fibre having a great potential for use in composite materials. Their specific strength and stiffness are quite high, however, hygroscopic nature of jute creates problem in the long term durability of composites made only out of them. Hybridisation with glass fibre provides a viable alternative to overcome this problem. In the conventional SMC preparation calcium carbonate is basically used as a cheap paniculate filler and these particles are extremely inefficient as reinforcing agent because of their low aspect ratio. In the jute-glass fibre hybrid composite a part of this filler is replaced by jute fibre which can also act as a cheap substitute of filler provides the extra advantage of improving the strength because jute fibre is also act as a reinforcing agent for its high aspect ratio. Jute fibre is thus considered as a filler fibre for the preparation of composite components. This in rum allow the reduction of glass fibre percentage in the conventional SMC and thereby reducing the cost and density of the composite components.. The main advantages of the present invention are: 1. Wettability property of jute fibre in polyester resin is made easy for preparing jute- glass fibre hybrid sheet moulding compound ( SMC). 2. The inclusion of jute fibre as partial replacement of glass fibre in the preparation of compound reducing (i) the cost of the composite components and (ii) the weight of the composite components. 3. The strength properties of jute-glass fibre hybrid SMC based composite components can be comparable with the present day high cost only glass fibre based sheet moulding compound (SMC) based composite components. 4. Jute fibre can be considered as an extremely effective and economic type filler fibre_because of its high aspect ratio for the preparation of jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components. 5. Conventional roller mill machine may be used for the preparation of jute- glass fibre hybrid SMC. 6. By using this jute-glass fibre hybrid SMC various composite components of different shapes and sizes can be manufactured for applications in railways, furniture industry, electrical industry and domestic appliances. We Claim: 1. An improved process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components which comprises (i) impregnating jute fibre with a polymer solution by conventional manner preferably by wetting followed by passing through squeeze rollers, drying the polymer coated jute fibre in an oven at a temperature in the range of 50° - 70°C for a time period in the range of 1-1.5 hrs., (ii) preparing a slurry by mixing 27 - 35 wt.% polyester resin such as herein described 1.5-2 gms., of tertiary butyl perbenzoate per 100 gms. of polyester resin, 8-10 wt.% filler and 2 -3 wt% thickening agent as defined herein, 8-15 wt% fire retardant additive selected from chlorinated paraffin wax, antimony trioxide, alumina trihydrate, magnesium carbonate or mixture thereof, 2 - 3.34 wt% shrinkage controlling additive selected from polyvinyl acetate, low density polyethylene, polyvinyl chloride, polystyrene or mixture thereof 3-4 wt.% zinc stearate (iii) impregnating under roller pressure 15 -20 wt% of the dried polymer coated jute fibre as obtained at step (i) in between 20 - 25 wt.% glass fibre layers, into the slurry as obtained at step (ii) and squeezing out in between two cellophane papers to obtain a hybrid sheet moulding compound (SMC), rolling the obtained SMC over a mandrel and maturing at a temperature in the range of 10° - 15°C for a period of 7 days to get the desired jute - glass fibre hybrid sheet moulding compound. 2. An improved process as claimed in claim 1 wherein the jute fibre used is selected from felt or stiched mat. 3. An improved process as claimed in claims 1 - 2 wherein the polymer solution used in step (i) is selected from 4-7 gms melamine formaldehyde resin in 93 - 96 ml. butanol, 4-7 gms. phenol formaldehyde resin in 93 - 96 ml. methanol, 4 gms. phenol formaldehyde resin and 2 gms. polyvinyl butyral resin in 94 ml., mixture of methanol, butanol and toluene, 4-7 gms. polystyrene resin and 1 - 2 ml. Y -Methacryloxypyropultrimethoxysilane in 91 - 95 ml. toluene. 4. An improved process as claimed in claims 1-3 wherein the glass fibres used is selected from mat, chopped strand mat, woven roving, fabric or mixture thereof. 5. An improved process as claimed in claims 1-4 wherein the polyester resin used in step (ii) is selected from isophthalic, bisphenolic, vinyl ester or mixture thereof. 6. An improved process as claimed in claims 1 - 5 wherein the filler used is in step (ii) is selected from calcium carbonate, talcum powder, silica powder or mixture thereof. 7. An improved process as claimed in claim 1-6 wherein the thickening agent used in step (ii) is selected from magnesium hydroxide, magnesium oxide or mixture thereof. 8. An improved process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components substantially as herein described with reference to the examples.

Full Text

The present invention relates to an improved process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components.
Jute - glass fibre hybrid sheet moulding compound (SMC) may be used to produce composites of various shapes and sizes required for applications in railways, furniture industry, electrical industry and domestic appliances. This type of composite can replace an assembly of many pieces of sheet metals and fibre board with a product offering simpler installation, better performance with low noise and smoother interior and exterior surfaces with better aesthetic appeal without the necessity for painting. It also has additional advantages of being lighter in weight and lower in cost.
In the previous method of producing jute-glass fibre hybrid composite jute cloth, and glass fibre were mixed with polyester resin, catalyst and accelerator by using hand lay up method or by press moulding method without forming sheet moulding compound (SMC), Reference for which may be made to (1) Composite Materials Technology, Manser Publishers, N.Y. p 62, 1990, by P.K. Mallick/S.Newman, (2) Fibre Sci. & Techn., 15, 41, 1981 by A.M. Shah and S.L. Lakkad, (3) J. Mater. Sci. Letters, 2, 99, 1983 , by R. Mohan, K. Kishore, M.K. Sridhar and R.M.V.G.K. Rao,
(4) Proc. of 3rd International Conference on Mech. Behaviour of Materials,
Cambridge, Aug., 1979, Pergamon Press, 1979 by K.K.Chawla and A.C. Bastos,
(5) Proc. of the Second International conference on Mech. Behaviour of Materials,
Boston, Aug., 1977, ASM, p 1920, by K.K.Chawla, (6) Rev. Bras. Tech., Vol. 9,
1978, p 79-99 by K. K. Chawla, R.R.Avilez, R.R.Rodrigues, A.C.M. SA and
L.G.P.L. , Cavadas and (7) proc. of 3rd International Conference on Composite
Materials in Paris, France, Vol. 1, 1980, by K.K. Chawla, E.E.A. Aragao, R.R.C.
Monteoro, F. G. Fernandez and M. M. Moraes; wherein the strength of the

composite is not at all comparable to conventional glass based SMC composite because
of poor wettability of jute fibre in polyester resin.
The main drawbacks of the above noted hitherto known processes are :
1. Jute fibre in general, require high percentage of polymeric matrices to wet the surfaces due to weak interfacial bonding between the fibre and the polymeric matrices and due to hygroscopic nature of the jute fibres. The alpha cellulose content of jute fibre possesses three hydroxyl groups for each glucose residue and the hemicellulose content of jute fibre possesses two hydroxyl groups for each pentose residence. These hydroxyl groups are the active centres to attract water molecules. Hydrogen bonds are formed between the hydroxyl groups and water molecules. First the direct attachment of water molecules through the active sites (i.e. hydroxyl group) occur and then the indirect attachment through directly attached water molecules take place, Reference for which may be made to "Proc. of the International Symposium on Biocomposites and Blends based on jute and allied fibres", Nov. 30 - Dec. 2, 1994, by Dr. B.C.Mitra.
Hence similar to the application of coupling agent in the form of sizing solution to the glass fibre, attempts have been made by several investigators to block the hydroxyl groups of cellulose and hemicellulose of jute fibre by the application of different chemicals but the surface functionality was not much improved and as such the wettability of jute fibre in polymer matrices was poor. References for which may be made to (a) Ind. J. Text. Res. 7:87, 1982, by M.K.Sridhar et.al, (b) J. Appl. Phys. Sci.,
26:4069,1981 by R.M.V.G.K. Rao et.al (c) Reinforced Plastics, 8, 306, June, 1964, by
A.R.Philip, (d) Eng. Mater. Des., 8, 475 1965. In spite of these efforts, however, there has not been any extensive commercial utilisation of jute fiber composites. One of the

several reasons for this failure lies in the poor adhesion between resin matrix and jute fiber leading to debonding of the composite on aging.
2. Jute fibre is less efficient than glass fibre in its resin distribution properties. It has a greater flow resistance and tend to be less buoyant in dry state and compressed more readily thereby entrapping small air bubbles in the laminates. Because of these characteristics it is not easily amenable to the common moulding processes like hand lay up moulding. It is also very difficult to impregnate raw jute fibre with polymeric resin as like glass fibre in common sheet moulding manufacturing system until and unless it is properly treated by using polymer solution.
The main object of the present invention is to provide a process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components which obviates the drawbacks as detailed above.
Another object of the present invention is to provide a composition for making jute-glass fibre hybrid sheet moulding compound (SMC).
Accordingly, the present invention provides an improved process fof making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components which comprises (i) impregnating jute fibre with a polymer solution by known methods such as wetting, followed by passing through squeeze rollers, drying the polymer coated jute fibre in an oven at a temperature in the range of 50° - 70°C for a time period in the range of 1 - 1.5 hrs., (ii) preparing a slurry by mixing 27 - 35 wt.% polyester resin, such as herein described 1.5-2 gms. Tertiary utyl perbenzoate per 100 gms. of polyester resin, 8-10 wt.% filler and 2-3 wt% thickening agent as defined herein, 8-15 wt% fire retardant additive, selective from chlorinated paraffin wax, antimony trioxide, alumina trihydrate, magnesium carbonate or mixture thereof, 2 - 3.34 wt% shrinkage controlling additive selected from polyvinyl acetate, low density polyethylene, polyvinyl chloride, polystyrene or mixture thereof 3 -4 wt.% zinc stearate (iii) impregnating unde roller pressure 15-20 wt% of the dried

polymer coated jute fibre as obtained at step (i) in between 20 - 25 wt.% glass fibre layers, into the slurry as obtained at step (ii) and squeezing out in between two cellophane papers to obtain a hybrid sheet moulding compound (SMC), rolling the SMC over a mandrel and maturing at a temperature in the range of 10° - 15°C 7 days to get the desired jute - glass fibre hybrid sheet moulding compound.
In an embodiment of the present invention the jute fibre used may be in the form of felt or stiched mat.
In another embodiment of the present invention the polymer solution used may be such as 4 - 7 gms melamine formaldehyde resin in 93 - 96 ml. butanol, 4-7 gms. phenol formaldehyde resin in 93 - 96 ml., mixture of methanol, 4 gms. phenol formaldehyde resin and 2 gms. polyvinyl butyral resin in 94 ml., mixture of methanol, butanol and toluene, 4-7 gms. polystyrene resin and 1 - 2 ml. v -Methacryloxypropyltrimethoxysilane in 91 - 95 ml. toluene.
In yet another ebdoiment of the present invention the glass fibres used may be such as surface mat, chopped strand mat, woven roving, fabric or mixture thereof.
In another embodiment of the present invention the polyester resin used may be such as general purpose, isophthalic, bisphenolic, vinyl ester or mixture thereof.
In yet another embodiment of the present invention the filler used may be such as calcium carbonate, talcum powder, silica powder or mixture thereof.
In another embodiment of the present invention the thickening agent used may be such as magnesium hydroxide, magnesium oxide or mixture thereof.
In still another embodiment of the present invention the fire retardant additive used may be such as chlorinated paraffin wax, antimony trioxide, alumina trihydrate, magnesium carbonate or mixture thereof.
In yet another embodiment of the present invention the shrinkage controlling dditive used may be such as polyvinyl acetate, low density polyethylene, polyvinyl chloride, polystyrene or mixture thereof. The details of the present invention are given below :
a) The polymer solution is first prepared by mixing 4-7 gms. melamine
formaldehyde resin in 93-96 ml. butanol, or by mixing 4-7 gms. phenol formaldehyde
resin in 93-96 ml. methanol, or by mixing 4 gms. phenol formaldehyde resin and 2
gms. polyvinyl butyral resin in 94ml. mixture of methanol, butanol and toluene or by
mixing 4-7 gms. polystyrene and 1-2 ml. y-Methacryloxypropyltrimethoxysilane in
91-95 ml. toluene. Jute fibre in the form of felt or stiched mat is impregnated with this
polymer solution by known methods such as wetting, followed by passing through
squeeze rollers.
b) Polymer coated jute fibre is dried at a temperature in the range of 50-70°C for
a time in the range of 1- 1.5 hrs in an oven.
c) 15-20 wt. % of the dried polymer coated jute fibre is placed in between 20-25
wt. % glass fibre layers.
d) A thick slurry is prepared by mixing 27-35 wt. % polyester resin such as
general purpose, isophthalic, bisphenolic, vinyl ester or mixture thereof, 1.5-2 gm.
tertiarybutyl perbenzoate per 100 gms. of polyester resin , 8-10 wt. % filler such as
calcium carbonate, talcum powder, silica powder or mixture thereof, 2-3 wt. %
thickening agent such as magnesium hydroxide, magnesium oxide or mixture
thereof, 8-15 wt. % fire retardant additive such as chlorinated paraffin wax, antimony
trioxide, alumina trihydrate, magnesium carbonate or mixture thereof, 2 - 3.34 wt.%
shrinkage controlling additive such as polyvinyl acetate, low density polyethylene or polyvinyl chloride and 3-4wt. % zinc stearate in a high shear mixer for 10-15 mins.
e) Using the slurry prepared in step (d) polymer coated jute fibre and glass fibre
sandwich is impregnated under roller pressure and squeezed out in between two
cellophane papers.
f) The sheet moulding compound (SMC) thus formed is then rolled over a
mandrel and stored in a cool place for maturing at 10-15°C for 7 days.
g) The Jute-glass fibre hybrid sheet moulding compound (SMC) so obtained may
be press moulded in a hot hydraulic press and can be prepared into a sheet or a moulded
component.
The -novelty-re-that^he jute-glass fibre hybrid sheet moulding compound (SMC) prepared by the process of the present invention is cheaper and has increased strength. The novel outcome is achieved by the inventive steps which resides in the polymer solution impregnated jute fibre in the form of felt or stiched mat used to form a sandwich with the glass fibre which in turn impregnated with a polymer slurry such as herein described.
The following examples are given by way of illustration of the process and should not therefore be construed to limit the scope of the present invention.
Example -1
The polymer solution was first prepared by mixing 4 gms. general purpose polystyrene resin, 1ml. Y-Methacryloxypropyltrimethoxysilane and 95 ml. toluene. Jute fibre in the form of felt was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated jute felt was then dried at 58°C for 1.25 hours in an oven and stored in an airtight container.
A thick slurry was prepared by mixing 27 gms. polyester resin, 0.4 gm. tertiary butyl perbenzoate, 8 gms. calcium carbonate, 2 gms magnesium hydroxide, 5 gms. chlorinated paraffin wax, 5 gjms. antimony trioxide, 5 gms. alumina trihydrate, 2.5 gms. polyvinyl acetate and 3.1 gms. zinc stearate in a high shear mixture for 10 mins.
15 gms. polymer coated jute felt placed in sandwich form between 25 gms. glass fibre layers were impregnated with the above slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 10° C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated.
The properties evaluated for jute-glass fibre hybrid composite are given below.
(Table Removed)
Example - 2
The polymer solution was first prepared by mixing 5 gms. melamine formaldehyde resin with 95 ml. butanol. Jute fibre in the form of stiched mat was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated stiched mat was then dried at 60°C for 1 hour in an oven and stored in an airtight container.
A thick slurry is prepared by mixing 29 gms. vinyl ester resin, 0.58 gm. tertiary butyl perbenzoate, 10 gms. talcum powder, 2 gms. magnesium hydroxide, 1 gm. magnesium oxide, 4 gms. chlorinated paraffin wax, 4 gms. antimony trioxide, 4 gms.

magnesium carbonate, 2 gms. low density polyethylene and 3.42 gms. zinc stearate in a high shear mixture for 15 mins.
16 gms. polymer coated stiched mat placed in sandwich form between 24 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 12°C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated. The properties evaluated for jute-glass fibre hybrid composite are given below:
(Table Removed)10

The polymer solution was first prepared by mixing 6 gms. phenol formaldehyde resin with 94 ml. of toluene. Jute fibre in the form of felt was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated jute felt was then dried at 62°C for 1 hour in an oven and stored in an airtight container.
A thick slurry was prepared by mixing 32 gms. bisphenolic polyester resin, 0.64 gm. tertiary butyl perbenzoate, 9 gms. silica powder, 2 gms. magnesium hydroxide, 4 gms. chlorinated paraffin wax, 5 gms.. antimony trioxide, 4 gms. alumina trihydrate, 3 gms. polyvinyl chloride and 3.36 gms. zinc stearate in a high shear mixture for 12 mins.
17 gms. polymer coated jute felt placed in sandwich form between 20 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 12°C or 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated.
The properties evaluated for jute-glass fibre hybrid composite are given below:
(Table Removed)
Example - 4
The polymer solution was first prepared by mixing 4 gms. phenol formaldehyde resin, 2 gms. polyvinyl butyral resin and 2 ml. y-Methacryloxypropyltrimethoxysilane in 92 ml. mixture of methanol, butanol and toluene. Jute fibre in the form of stiched mat was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated stiched mat was then dried at 65°C for 1 hour in an oven and stored in an airtight container.
A thick slurry was prepared by mixing 33 gms. bisphenolic polyester resin, 0.66 gm. tertiary butyl perbenzoate, 10 gms. calcium carbonate, 2 gms. magnesium hydroxide, 1 gm. magnesium oxide, 4 gms..antimony trioxide, 4 gms. alumina trihydrate, 3.34 gms. polyvinyl chloride and 4 gms. zinc stearate in a high shear mixture for 10 mins.
18 gms. polymer coated stiched mat placed in sandwich form between 20 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 15°C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated. The properties evaluated for jute-glass fibre hybrid composite are given below: (Table Removed)
Example -5
The polymer solution was first prepared by mixing 7 gms. polystyrene resin, 1ml. y-Methacryloxypropyltrimethoxysilane in 92 ml. toluene. Jute fibre in the form of
stiched mat was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated stiched mat was then dried at 65°C for 1 hour in an oven and stored in an airtight container.
A thick slurry was prepared by mixing 35 gms. general purpose polyester resin, 0.7 gm tertiary butyl perbenzoate, 8 gms. calcium carbonate, 2 gms. magnesium hydroxide, 4 gms. .antimony trioxide, 5 gms. alumina trihydrate, 2 gms. low density polyethylene and 3.3 gms. zinc stearate in a high shear mixture for 12 mins.
19 gms. polymer coated stiched mat placed in sandwich form between 21 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 12°C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet were then evaluated.
The properties evaluated for jute-glass fibre hybrid composite are given below:
(TableRemoved)
(Table Removed)
Example-6
The polymer solution was first prepared by mixing 6 gms. polystyrene resin, 2 ml. y-Methacryloxypropyltrimethoxysilane and 92 ml. toluene. Jute fibre in the form of stiched mat was impregnated with this polymer solution by known methods such as wetting, followed by passing through squeeze rollers. Polymer coated stiched mat was then dried at 60°C for 1.5 hour in an oven and stored in an airtight container.
A thick slurry was prepared by mixing 35 gms. isophthalic polyester resin, 0.7 gm tertiary butyl perbenzoate, 8 gms. calcium carbonate, 2 gms. magnesium hydroxide, 3 gms. .antimony trioxide, 5 gms. alumina trihydrate, 3.3 gms. polyvinyl acetate and 3 gms. zinc stearate in a high shear mixture for 12 mins.
20 gms. polymer coated stiched mat placed in sandwich form between 20 gms. glass fibre layers were impregnated with the slurry under roller pressure and squeezed out in between two cellophane papers. The sheet moulding compound (SMC) thus formed was then rolled over a mandrel and stored in a cool place for maturing at 15 C for 7 days. Jute-glass fibre hybrid sheet moulding compound (SMC) was press
moulded in a hot hydraulic press and prepared into a sheet. The properties of the sheet
were then evaluated.
The properties evaluated for jute-glass fibre hybrid composite are given below: (Table Removed)
The summary of the properties evaluated for jute-glass fibre hybrid composites is given below:
(Table Removed)
The novelties and inventive steps of the present invention are :
(1) Improvement of the wettability property of jute fibre in polyester resin by
using polymer coated jute fibre and thereby increasing the strength of the composite.
(2) Partial reduction of high cost glass fibre in SMC by incorporating polymer
coated jute fibre and thereby reducing the cost of the composite.
(3) Improvement of the strength of the SMC composite by partial reduction of
filler in SMC by incorporating polymer coated jute fibre.
Analysis for the achievement of the strength properties of the composite components based on jute-glass fibre hybrid SMC.
Jute is a naturally occuring fibre having a great potential for use in composite materials. Their specific strength and stiffness are quite high, however, hygroscopic nature of jute creates problem in the long term durability of composites made only out of them. Hybridisation with glass fibre provides a viable alternative to overcome this problem.
In the conventional SMC preparation calcium carbonate is basically used as a cheap paniculate filler and these particles are extremely inefficient as reinforcing agent because of their low aspect ratio. In the jute-glass fibre hybrid composite a part of this filler is replaced by jute fibre which can also act as a cheap substitute of filler provides the extra advantage of improving the strength because jute fibre is also act as a reinforcing agent for its high aspect ratio. Jute fibre is thus considered as a filler fibre for the preparation of composite components. This in rum allow the reduction of glass fibre percentage in the conventional SMC and thereby reducing the cost and density of the composite components..
The main advantages of the present invention are:
1. Wettability property of jute fibre in polyester resin is made easy for
preparing jute- glass fibre hybrid sheet moulding compound ( SMC).
2. The inclusion of jute fibre as partial replacement of glass fibre in the
preparation of compound reducing (i) the cost of the composite components and (ii)
the weight of the composite components.
3. The strength properties of jute-glass fibre hybrid SMC based composite
components can be comparable with the present day high cost only glass
fibre based sheet moulding compound (SMC) based composite components.
4. Jute fibre can be considered as an extremely effective and economic type filler
fibre_because of its high aspect ratio for the preparation of jute-glass fibre hybrid
sheet moulding compound (SMC) useful for making low cost composite
components.
5. Conventional roller mill machine may be used for the preparation of jute-
glass fibre hybrid SMC.
6. By using this jute-glass fibre hybrid SMC various composite components of
different shapes and sizes can be manufactured for applications in railways,
furniture industry, electrical industry and domestic appliances.

We Claim:
1. An improved process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components which comprises (i) impregnating jute fibre with a polymer solution by conventional manner preferably by wetting followed by passing through squeeze rollers, drying the polymer coated jute fibre in an oven at a temperature in the range of 50° - 70°C for a time period in the range of 1-1.5 hrs., (ii) preparing a slurry by mixing 27 - 35 wt.% polyester resin such as herein described 1.5-2 gms., of tertiary butyl perbenzoate per 100 gms. of polyester resin, 8-10 wt.% filler and 2 -3 wt% thickening agent as defined herein, 8-15 wt% fire retardant additive selected from chlorinated paraffin wax, antimony trioxide, alumina trihydrate, magnesium carbonate or mixture thereof, 2 - 3.34 wt% shrinkage controlling additive selected from polyvinyl acetate, low density polyethylene, polyvinyl chloride, polystyrene or mixture thereof 3-4 wt.% zinc stearate (iii) impregnating under roller pressure 15 -20 wt% of the dried polymer coated jute fibre as obtained at step (i) in between 20 - 25 wt.% glass fibre layers, into the slurry as obtained at step (ii) and squeezing out in between two cellophane papers to obtain a hybrid sheet moulding compound (SMC), rolling the obtained SMC over a mandrel and maturing at a temperature in the range of 10° -
15°C for a period of 7 days to get the desired jute - glass fibre hybrid sheet moulding compound.
2. An improved process as claimed in claim 1 wherein the jute fibre used
is selected from felt or stiched mat.
3. An improved process as claimed in claims 1 - 2 wherein the polymer
solution used in step (i) is selected from 4-7 gms melamine
formaldehyde resin in 93 - 96 ml. butanol, 4-7 gms. phenol
formaldehyde resin in 93 - 96 ml. methanol, 4 gms. phenol
formaldehyde resin and 2 gms. polyvinyl butyral resin in 94 ml., mixture
of methanol, butanol and toluene, 4-7 gms. polystyrene resin and 1 -
2 ml. Y -Methacryloxypyropultrimethoxysilane in 91 - 95 ml. toluene.
4. An improved process as claimed in claims 1-3 wherein the glass
fibres used is selected from mat, chopped strand mat, woven roving,
fabric or mixture thereof.
5. An improved process as claimed in claims 1-4 wherein the polyester
resin used in step (ii) is selected from isophthalic, bisphenolic, vinyl
ester or mixture thereof.
6. An improved process as claimed in claims 1 - 5 wherein the filler used
is in step (ii) is selected from calcium carbonate, talcum powder, silica
powder or mixture thereof.
7. An improved process as claimed in claim 1-6 wherein the thickening
agent used in step (ii) is selected from magnesium hydroxide,
magnesium oxide or mixture thereof.
8. An improved process of making jute-glass fibre hybrid sheet moulding compound (SMC) useful for making low cost composite components substantially as herein described with reference to the examples.

Documents:

612-del-2000-abstract.pdf

612-del-2000-claims.pdf

612-del-2000-complete specification (granted).pdf

612-del-2000-correspondence-others.pdf

612-del-2000-correspondence-po.pdf

612-del-2000-description (complete).pdf

612-del-2000-form-1.pdf

612-del-2000-form-19.pdf

612-del-2000-form-2.pdf

612-del-2000-form-3.pdf

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Patent Number

226273

Indian Patent Application Number

612/DEL/2000

PG Journal Number

04/2009

Publication Date

23-Jan-2009

Grant Date

16-Dec-2008

Date of Filing

23-Jun-2000

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI- 110 001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	KALYAN KUMAR PHANI	CENTRAL GLASS & CERAMIC RESEARCH INSTITUTE, CALCUTTA 700 032
2	SRIKANTA DALUI	CENTRAL GLASS & CERAMIC RESEARCH INSTITUTE, CALCUTTA 700 032
3	NRIPATI RANJAN BOSE	CENTRAL GLASS & CERAMIC RESEARCH INSTITUTE, CALCUTTA 700 032

PCT International Classification Number

DO1C 1/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA