DESC:Composition and Process for Manufacturing Designer Corrugated Roofing Sheets with Color Using Stains

Field of the invention:

The present invention generally relates to roofing sheets and more particularly, to a composition and a process for manufacturing designer corrugated roofing sheets with color using stains.

Background of the invention:

Since many years together the roof of any industrial unit, godown, railway stations and like is of plain corrugated sheets and the roofing industry has been manufacturing and supplying the plain corrugated sheets to the consumers. Normal AC sheets are used for the roofing in the houses, factory sheds, cladding and other purpose. These sheets are having top surface smooth and bottom surface rough. These sheets come in the natural grey color and after some years algae are formed on the top surface thereof thereby making their appearance dull. If the normal AC sheets are painted, the paint life is only five years and there are chances to peel off the paint. Also due to the algae / fungus formation it looks dirty.

There has always been a demand by the consumers for many more changes as the consumers look for more value from their investment in the roofing sheets. Currently, the corrugated sheets are available in different colors however they do not add any beauty to the roofs as they fade/have cracks due to expansion and contraction of sheet. Further, the corrugated roofing sheets design is not available that provides safety and durability to the roofs along with the aesthetic look.

Accordingly, there exists need to provide a composition and a process for manufacturing designer corrugated roofing sheets with color using stains that overcomes the above mentioned drawbacks in the prior art.

Objects of the invention:

An object of the present invention is to provide corrugated roofing sheets that add beauty, durability and heat reduction to the roofs without compromising with the safety and durability of the roofs.

Another object of the present invention is to provide corrugated roofing sheets that withstands extreme weather conditions, reduce drumming sounds during rains and do not get affected by acid rains.

Summary of the invention

Accordingly, the present invention provides composition 1 and 2 for manufacturing designer corrugated roofing sheets with color using stains. More particularly, the present invention provides the composition 1 for manufacturing the designer corrugated asbestos roofing sheets and the composition 2 is provided for manufacturing designer corrugated non-asbestos roofing sheets.

In accordance with the present invention, the composition 1 comprises asbestos fibre in a range of 9.0 % to 11.0 %. Specifically, 48% of chrysotile fibre of 5th grade and 52% of chrysotile fibre of 6th grade is used. Further, the composition 1 comprises cement in a range of 52.0 % to 58.0 %. Furthermore, the composition 1 comprises fly ash in a range of 30.0 % to 34.0 %. Moreover, the composition 1 comprises pulp in a range of 2.0 % to 3.0 %. Further, the composition 1 comprises wollastonite in a range of 0.3 % to 0.8 %. Furthermore, the composition 1 comprises synthetic fibre in a range of 0.3 % to 1.0 %. Specifically, the synthetic fibre is selected from anyone of polyester fibre and polyvinyl alcohol fibre. Moreover, the composition 1 comprises hard ground waste in a range of 1.0 % to 3.0 %.

In accordance with the present invention, the composition 2 comprises cement in a range of 55.0 % to 60.0 %. Further, the composition 2 comprises fly ash in a range of 28.0 % to 34.0 %. Furthermore, the composition 2 comprises pulp in a range of 3.0 % to 5.0 %. Moreover, the composition 2 comprises wollastonite in a range of 3.0 % to 5.0 %. Further, the composition 2 comprises synthetic fibre in a range of 1.0 % to 2.0 %. Specifically, the synthetic fibre is selected from anyone of polyester fibre and polyvinyl alcohol fibre. Furthermore, the composition 2 comprises hard ground waste in a range of 2.0 % to 4.0 %.

In another aspect, the present invention provides a process for manufacturing designer corrugated roofing sheets with color using stains from the composition 1 and 2 of the present invention.

Brief description of the drawings:

The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1 shows a flowchart of a process for manufacturing designer corrugated asbestos roofing sheets with color using stains, in accordance with the present invention;

Figure 2 shows an actual image of the designer corrugated roofing sheet manufactured by the process of the present invention.

Detailed description of the invention:

The foregoing objects of the invention are accomplished, and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiments.

The present invention provides a composition and a process for manufacturing designer corrugated roofing sheets with color using stains. The composition and the process of the present invention provide corrugated roofing sheets that add beauty to the roofs without compromising with the safety and durability of the roofs without compromising with the safety and durability of the roofs.

The present invention is now illustrated with reference to the accompanying drawings.

In one aspect, the present invention provides composition 1 and 2 for manufacturing designer corrugated roofing sheets with color using stains. More particularly, the present invention provides the composition 1 for manufacturing the designer corrugated asbestos roofing sheets.

In the context of the present invention, the composition 1 includes a predefined amount of fly ash, pulp, wollastonite, synthetic fibre and HGW (Hard Ground Waste) added in a predefined proportion of the total composition. More specifically, the composition 1 comprises asbestos fibre in a range of 9.0 % to 11.0 %. Specifically, 48% of chrysotile fibre of 5th grade and 52% of chrysotile fibre of 6th grade is used. Further, the composition 1 comprises cement in a range of 52.0 % to 58.0 %. Specifically, 43 grade ordinary portland cement (OPC cement) 53 % in RM mix is used. Furthermore, the composition 1 comprises fly ash in a range of 30.0 % to 34.0 %. Moreover, the composition 1 comprises pulp in a range of 2.0 % to 3.0 %. Further, the composition 1 comprises wollastonite in a range of 0.3 % to 0.8 %. Furthermore, the composition 1 comprises synthetic fibre in a range of 0.3 % to 1.0 %. Specifically, the synthetic fibre is selected from anyone of polyester fibre and polyvinyl alcohol fibre. Moreover, the composition 1 comprises hard ground waste in a range of 1.0 % to 3.0 %.
However, it is understood here that the quantity of each raw material may vary in other alternative embodiments of the present invention and % rang provided herein above are to be interpreted merely as an illustration and they are in no way to be construed as a limitation.

In the context of the present invention, the composition 2 is provided for manufacturing designer corrugated non-asbestos roofing sheets. In this one embodiment, the composition includes a predefined amount of Portland cement, fly ash, pulp, Wollastonite, synthetic fibre and HGW (Hard Ground Waste) added in a predefined proportion of the total composition.

More specifically, the composition 2 comprises cement in a range of 55.0 % to 60.0 %. Further, the composition 2 comprises fly ash in a range of 28.0 % to 34.0 %. Furthermore, the composition 2 comprises pulp in a range of 3.0 % to 5.0 %. Moreover, the composition 2 comprises wollastonite in a range of 3.0 % to 5.0 %. Further, the composition 2 comprises synthetic fibre in a range of 1.0 % to 2.0 %. Specifically, the synthetic fibre is selected from anyone of polyester fibre and polyvinyl alcohol fibre. Furthermore, the composition 2 comprises hard ground waste (HGW) in a range of 2.0 % to 4.0 %.

However, it is understood here that the quantity of each raw material may vary in other alternative embodiments of the present invention and % rang provided herein above are to be interpreted merely as an illustration and they are in no way to be construed as a limitation.

In accordance with the present invention, the designer corrugated roofing sheets manufactured using the composition 1 and 2 have thickness of 6 mm, width of 1050 mm and can have lengths of 1.50 meters, 2.00 meters, 2.50 meters, 3.00 meters. However, it is understood here that the designer corrugated roofing sheets can be customized to have other dimensions in other alternative embodiments of the present invention as per the intended use.
In another aspect, the present invention provides a process for manufacturing the designer corrugated roofing sheets with color using stains from the composition 1 and 2. Specifically, the process broadly involves three stages namely: a raw material preparation stage, a processing stage on Hatcheck machine and a piling and curing stage. The process of the present invention does not require any external heating.

Referring to figure 1, a flowchart of a process for manufacturing the designer corrugated asbestos roofing sheets from the composition 1 is shown in accordance with the present invention. In the raw material preparation stage, all the raw materials are taken in pre-weighed quantities and then the individual raw material is prepared in a slurry form. Specifically, all the raw material preparation is performed through a programmable logistic controller (PLC) and weighing is done using load cells.

In the context of the present invention, the raw material mixing consists of adding pre-weighed quantities of cement, fly ash, fibres and HGW in different mixers in water to form slurry. Particularly, the fixed quantity of pulp after weighing is fed into a pulper, prepared in the slurry form and the slurry is then stored in a chest. The stored slurry in the chest is continuously stirred. The fixed volume of pulp is then transferred into a main mixer. The asbestos fiber is taken as batch in BOD and transferred to an asbestos fiber mill and water is mixed in the mill to prevent the fibre from becoming air borne. In the fiber mixer, fiber is mixed homogeneously to open fiber and the synthetic fibre is added in the fibre mixer and stirred to mix homogenously. In the context of the present invention, 0.5% more asbestos fibre is used than the normal AC corrugated sheets. This extra fibre helps for high strength in the product and better reinforcement and better life span as compared to the normal AC sheets. Further, in the process of the present invention 0.3% synthetic fibre is used, which is replacing 1.2% asbestos in the mix. Use of the synthetic fibre makes the process more ecofriendly. The cement is fed to the mixer in pre-weighed quantities through a screw conveyor and water is already taken in the mixer for making slurry of cement. Fly ash is also fed in the same mixer in pre-weighed quantities. The cement-fly ash slurry is then stirred for predetermined period and transferred into the main mixer. The slurry of all the raw materials is stirred for given period in individual mixer and then feed to the main mixer as per the sequence. Wet waste slurry and high ground waste (HGW) slurry in pre-weighed quantities is also fed into the main mixer. The slurry is sampled and tested for the desired characteristics at different stages. Before entering to the main mixer the slurry gets filtered through a wet sieve for the filtration of the foreign particles like bag particles and others. Thereafter, the slurry of all the raw materials is mixed in the main mixer to prepare a final slurry. From the main mixer, the final slurry is fed into a premix mixer in a batch quantity. In this mixer, the slurry is further diluted by water and this controlled slurry is then fed to seven vats of Hatcheck sheet forming machine.

In Hatschek machine, a wet sheet is formed with the help of a wet sieve and a felt by the filtration process and the drained out water is pumped out by a sieve pocket to a cone for re-circulation. The thin layer formed on the wet sieve is transferred to the felt (at 1 to 1.2 mm thick) and water particles in that layer are sucked with the help of vacuum trays. Then this layer of slurry is transferred to a cylindrical bole having pre-installed designer sleeve. Specifically, a metallic circular bole picks the formed layer. For the designer corrugated roofing sheets of the present invention, the metallic bole is drilled from both the sides to mount a designer sleeve thereon. The designer sleeve made from FRP with wood design engraved thereon is mounted on the pre-drilled bole with the help of the stainless steel nuts and bolts. The buildup on bole is having the wood design on the top surface. For getting the correct design transfer on the sheet, sheet moisture and bole pressure are controlled in such a way to pick layer easily and also to not disturb the design. The slurry concentrations get controlled through a computerized control system. The additional length and width formed in the machine is cut to required size with allowances for cutting without disturbing the design thereon. After achieving the required thickness the wet sheet is cut and laid down on a first belt conveyor.

On the first belt conveyor, the sheet is cut to a required width size and transferred on a second conveyor. On the second conveyor, the sheet is cut to a required length. While cutting batch no., brand name, ISI marks are stamped on the sheet. At both the cutting remaining waste is transferred to a wet waste slurry mixer and then this slurry is fed to the main mixer. After cutting, a corrugated pad of a piling machine lifts the cut sheets with the help of a vacuum. After lifting, the corrugated pad corrugates the sheet and pile on an intermediate pad and thereafter, the corrugated sheets are lifted and piled on a mixed bogie. In the mixed bogie, the corrugated sheets are piled with steel templates between them.

After stacking in the mixed bogie, the mixed bogie is transferred to a tunnel for a pre-curing. After the pre-curing, the mixed bogie is transferred to a de-stacker. At the de-stacker steel templates are removed from the mixed bogie and corrugated sheets are kept on each other in a stack of 65. While de-stacking, 100 % visual inspection is done for the visual checks like TC, VC, fissures, corner fold, corner damage, bad cutting, waste patch, etc. and defected sheets are removed and stacked together for segregation. The stack of approved sheets is then sent for curing. The curing is done naturally wherein the stack is kept in an atmosphere with cover thereon for 21 days.

In accordance with the present invention, after the curing the sheets are colored with the special stains. To look aesthetically more appealing, instead of normal paint, the corrugated roofing sheets are painted with the stains. As time passes stain becomes brighter. Figure 2 shows an actual image of the designer corrugated roofing sheet manufactured by the process of the present invention. The advantages of the stain are protection of corrugated roofing sheets from UV rays, fungus / algae, fading and from peeling of the paint. Further, these stains protects the corrugated roofing sheets by giving 50% more life compared to normal paints i.e. making the corrugated roofing sheets more durable. These stains are absorbed in the material surface, so there is no chance of peeling off. Apart from longer life, stains give option of two-tone shades.

Finally, the stain painted designer corrugated roofing sheets are tested and checked for visual and dimensional parameters as per IS 459: 1992, IS 14871 and for technical parameters as per IS 5913: 1989 and released as per the criteria.

In another embodiment, the present invention provides a process for manufacturing designer corrugated non-asbestos roofing sheets. In this one embodiment, the raw material mixing consists of adding pre-weighed quantities of cement, fly ash, cellulose fibre and synthetic fibre in different mixers in water to form slurry. The cellulose fibre helps for strength in the product and better reinforcement and better life span compared to normal AC sheets. In this one embodiment, 0.5% synthetic fibre is used. However, it is understood here that the synthetic fibre may be used in different proportions in other alternative embodiments of the present invention. In non-asbestos sheet, asbestos is replaced by cellulose fibre and synthetic fibre thereby making the roofing sheets more ecofriendly. All the steps after the formation of slurry from the raw material preparation to the final inspection are same for the manufacture of the designed corrugated non-asbestos roofing sheets as that explained above for the manufacture of the designer corrugated asbestos roofing sheets and are not described herein again for the sake of the brevity of the invention.

In accordance with the present invention, the designer corrugated roofing sheets with color using stains manufactured by the process of the present invention are useful for roofing of houses, farm houses and like thereby adding benefit in beautifying the exterior look of the roof of the house. These corrugated roofing sheets are also useful for side cladding of industrial sheds, godowns, poultry sheds and houses. In the context of the present invention, the corrugated roofing sheets have wooden texture which gives the roof aesthetic look. Further, the corrugated roofing sheets can be manufactured in different colors, for example stain colors like walnut, terracotta and coffee Brown stain color. Moreover, these sheets can be easily re-stained whenever required to maintain its pleasantness look. However, it is understood here that the corrugated roofing sheets may be colored with attractive designs in different sheds in other alternative embodiments of the present invention.

The designer corrugated roofing sheets with color using stains manufactured by the process of the present invention includes a top surface with wood design structure instead of normal smooth surface and looks like a natural wood and mixes with the surroundings. With the different engraved designs on sleeve, more numbers of designs and pattern can be offered. The top surface of the corrugated roofing sheets is breathable but does not penetrate water from the same due to this the bottom surface will not have any dampness like normal AC sheet and eliminates smell generated due to this dampness and UV stains added reduce the temperature.

Advantages of the invention:

1. The designer corrugated roofing sheets with color using stains manufactured from the composition and by the process of the present invention are non corrosive, fire retardant and have longer life.
2. The designer corrugated roofing sheets with color using stains manufactured from the composition and by the process of the present invention are having wood design top surface with stains, instead of normal smooth surface of AC sheets of natural grey color.
3. The designer corrugated roofing sheets with color using stains are manufactured as per IS-459-1992 and IS 14871.
4. The designer corrugated roofing sheets with color using stains manufactured by the process of the present invention withstand extreme weather conditions, reduce drumming sounds during rains and do not get affected by acid rains.
5. The designer corrugated roofing sheets with color using stains manufactured by the process of the present invention are ideal for use in windy areas as wind up-liftment is minimum.
6. The designer corrugated roofing sheets with color using stains are placed / fixed on a steel structure and no additional cost is required on the steel structure for adding to look.
7. The designer corrugated roofing sheets with color using stains manufactured by the process of the present invention improve the aesthetics of the home and other structures where it is used and also solves the leakage problem.
8. The designer corrugated roofing sheets with color using stains have a pleasant look of teak wood finish and naturally add beauty to existing roofs anywhere and anytime.
9. The designer corrugated roofing sheets with color using stains manufactured by the process of the present invention become stronger over a period of time. Theses sheets are cooler during summers and retain the heat inside during winter.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the present invention. ,CLAIMS:We claim:

1. A composition for manufacturing designer corrugated roofing sheets with color using stains, the composition comprising:
asbestos fibre in a range of 9.0 % to 11.0 %;
cement in a range of 52.0 % to 58.0 %;
fly ash in a range of 30.0 % to 34.0 %;
pulp in a range of 2.0 % to 3.0 %;
wollastonite in a range of 0.3 % to 0.8 %;
synthetic fibre in a range of 0.3 % to 1.0 %; and
hard ground waste in a range of 1.0 % to 3.0 %.

2. The composition as claimed in claim 1, wherein 48% of chrysotile fibre of 5th grade and 52% of chrysotile fibre of 6th grade is used.

3. The composition as claimed in claim 1, wherein the synthetic fibre is selected from anyone of polyester fibre and polyvinyl alcohol fibre.

4. A composition for manufacturing designer corrugated roofing sheets with color using stains, the composition comprising:
cement in a range of 55.0 % to 60.0 %
fly ash in a range of 28.0 % to 34.0 %
pulp in a range of 3.0 % to 5.0 %
wollastonite in a range of 3.0 % to 5.0 %
synthetic fibre in a range of 1.0 % to 2.0 %
hard ground waste in a range of 2.0 % to 4.0 %

5. The composition as claimed in claim 3, wherein the synthetic fibre is selected from anyone of polyester fibre and polyvinyl alcohol fibre.

6. A process for manufacturing designer corrugated roofing sheets with color using stains from the composition as claimed in claim 1 and claim 4, the process comprising the steps of:
adding pre-weighed quantities of cement, fly ash, pulp, fibres and hard ground waste in water and stirred for given period in an individual mixer to form a slurry;
filtering the slurry of all the materials through a wet sieve for the filtration of the foreign particles;
mixing the slurry of all the materials in a main mixer to prepare a final slurry;
feeding the final slurry into a premix mixer in a batch quantity and diluting the slurry by water to form a controlled slurry;
feeding the controlled slurry to seven vats of Hatcheck sheet forming machine for forming a wet sheet with the help of a wet sieve and a felt by a filtration process, wherein thin layer of slurry is transferred to a cylindrical bole having pre-installed designer sleeve to form the wet sheet and the formed wet sheet is cut to a required width size on a first belt conveyor and cut to a required length a second conveyor;
piling the cut sheets by using a piling machine lifts with the help of a vacuum, wherein the corrugated sheets are piled with steel templates between them in a mixed bogie;
pre-curing the corrugated sheets stacked in the mixed bogie and de-stacking to remove the steel templates from the mixed bogie, wherein the visual inspection is performed while de-stacking;
curing stack of approved sheets in an atmosphere for 21 days;
painting the corrugated roofing sheets with the stains; and
testing and checking the stain painted designer corrugated roofing sheets for visual and dimensional parameters.

7. The process as claimed in claim 6, wherein the designer corrugated roofing sheets manufactured using the compositions have thickness of 6 mm, width of 1050 mm and have lengths of 1.50 meters, 2.00 meters, 2.50 meters and 3.00 meters.