Title of Invention

A PAINTING SYSTEM AND PROCESS FOR PAINTING THEREOF

Abstract

This invention relates to a novel painting system comprising of pre-treatment and autophoretic system, one or more body preparation station, final top coat powder painting station and finishing operation stations wherein said pre-treatment and autophoretic coating system comprises of degreasing station, de-rusting station, autophoretic station, reaction rinse station and curing station which are provided one after the other sequentially, after every station of degreasing station, de-rusting station and autophoretic station, there is provided a water rinse stations to rinse off the solution, and followed by a baking system, wherein said one or more body preparation stations, provided after the Pre-treatment and autophoretic coating system, comprises of sanding station, sealant station and underbody compound application station which are provided one after the other, wherein said final top coat powder painting station, provided after the body preparation stations, comprises of one or more electro-static painting guns along with powder recovery system and baking system, wherein said finishing operation stations, provided after the final top coat powder painting station, comprises of touch-up station, polishing station and cavity waxing station. This invention also includes a process of painting carried out in accordance with said system device.

Full Text

FORM 2 THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE OF THE INVENTION NOVEL PAINTING SYSTEM AND PROCESS FOR PAINTING THEREOF APPLICANTS TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India INVENTORS Mr. Ashok Gupta, Mr.Harshkumar Asthana and Mr.Veerayya S. Hiremath all Indian nationals Of TATA MOTORS LIMITED an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed. FIELD OF INVENTION This invention relates to system and process of painting used in automobile industries and more particularly this relates to system and process of painting used to coat sheet metal auto bodies. BACKGROUND OF INVENTION In automobile industry various sub assemblies including BIW shells are required to be painted in order to protect the entire vehicle from various weathering conditions and to give better aesthetic features to the vehicles. The conventional process of painting comprises of following steps: Step A - Pre-treatment and CED coating of object • Surface of the object to be painted is cleaned and made free from rust • Degreasing of said object • Activating surface of said object • Phosphating surface of said object • Passivating surface of said object • Cathodic electro deposition (CED) of said object after rinsing with DM water • Ultra filtrate rinsing of said object • Dewatering said surface of object • Curing of said object Step B -Preparation of object • Correction of imperfections of object by sanding, denting etc. • Application of sole sealant and underbody compound • Curing of said object Step C -Intermediate coating • Application of surfacer coat on said object • Air flash off on said surface • Curing of surfacer coat Step D - Final finish Coating • Wet sanding of the said object • Tac - O - rag application • Application of final finish coat on said object • Air flash off on said surface • Curing of final finish coat Step E - Finishing operation • Carrying out final touch-up • Polishing of painted surface • Cavity Waxing The drawbacks associated with the conventional painting process are: • Number of stages involved in painting are more which results in higher cycle time, which in turn requires more fuel and electricity. • This process requires large amount of DM water • This process generates lot of hazardous waste, which needs to treated before disposing off. • This is a solvent based process, which is very much prone to fire hazardous • This process is complex in nature and not economical. OBJECT OF THIS INVENTION The main object of this invention is to provide a eco-friendly painting system and process for painting thereof Yet another object of this invention is to provide a painting system and process for painting thereof which can be able to install in short period of time Yet another object of this invention is to provide a painting system and process for painting thereof with shorter cycle time. Yet another object of this invention is to provide a painting system and process for painting thereof which is able to cater with least water, electricity and fuel. Yet another object of this invention is to provide a painting system and process for painting thereof which is simple and cost effective. BRIEF DESCRIPTION OF INVENTION Painting system in accordance with this invention basically comprises of a. Pre-treatment and autophoretic coating system, b. One or more body preparation station, c. Final top coat powder painting station and d. Finishing operation stations. Wherein said Pre-treatment and autophoretic coating system comprises of degreasing station, de-rusting station, auto phoretic station, reaction rinse station and curing station which are provided one after the other as stated sequentially. After every station from degreasing station, de-rusting station and auto phoretic station, there is provided a water rinse stations to rinse off the solution on each operation. Wherein said one or more body preparation stations comprises of sanding station, sealant station and underbody compound application station which are provided one after the other as stated sequentially. Wherein said final top coat powder painting station comprises of one or more electro-static painting guns along with powder recovery system and baking system which is provided after under body application station. Wherein said finishing operation station comprises of touch-up station, polishing station and cavity waxing station which is provided after final top coat powder painting station. Body in white (BIW) is degreased wherein oil is cleaned from the body and which is further subjected for water cleaning followed by de - rusting operation wherein any flash rust or rusted components of the body of BIW gets free from rust, finally after water cleaning body is subjected for autophoreitic operation. In this stage body gets coated with the anti corrosive coating through a chemical reaction and then subjected for water rinsing then dematerialized water rinse then body dips in reaction rinse tank where the chemical reaction gets completed. Finally body is subjected for baking operation in two stages. After backing body is exposed to cooling operation at room temperature, then the body is unloaded for further top coat processing. In a top coat process the autophoreitic coated body is subjected for sanding, sealant application and underbody application. After above said step the said body is subjected to inside powder coating manually and followed by an external powder coating preferably by automatic applicators. Said body is subjected to baking operation in an oven wherein the initial baking will takes place with IR heating system and followed by conventional baking. Finally the body is inspected for the finish and then polished, waxed, and sent for final assembly BRIEF DESCRIPTION OF DRAWINGS Fig.l shows block diagram of painting system and process flow in accordance with this invention Fig. 2 shows an autophoratic process used in this invention Fig.3 shows schematic diagram indicating the principle of powder coating application used in this invention DETAILED DESCRIPTION OF INVENTION Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same Referring to figs. 1 to 3 Painting system in accordance with this invention comprises of a. Pre-treatment and autophoretic coating system, b. One or more body preparation station, c. Final top coat powder painting station and d. Finishing operation stations. Wherein said Pre-treatment and autophoretic coating system comprises of degreasing station, de-rusting station, auto phoretic station, reaction rinse station and curing station which are provided one after the other as stated sequentially. After every station from degreasing station, de-rusting station and auto phoretic station, there is provided a water rinse station to rinse off the solution on each operation. Wherein said de-greasing station comprises of one or more tanks provided with de-greasing solution with a facility to continuously circulate the de-greasing solution through heaters and filters. De-greasing solution is suitably heated to extract the oil and foreign matters from the surface of components to be dipped in said tanks by using heat exchangers preferably by using plate type heat exchanger. The temperature of de-greasing solution to be maintained is at a range of 60 to 80 deg. C and most preferably the temperature of said solution is to be maintained at 80 deg C. Dipping time of component is 2 to 5 minutes and preferably 2 to 3 minutes. Plurality of rinse stations are provided after the said de-greasing stations to rinse off the de-greasing chemicals from the surface of components. Wherein said de-rusting station comprises of one or more tanks provided with de-rust solution with a facility to continuously circulate the de-rusting solution through heaters and filters. De-rusting solution is suitably heated to extract the corrosive matter from the surface of components to be dipped in said tanks by using heat exchanger. The temperature of de-rusting solution to be maintained is at a range of 60 to 75 deg. C and most preferably the temperature of said solution is to be maintained at 75 deg C. Dipping time of component is 2 to 5 minutes and preferably 2 to 3 minutes. Plurality of rinse stations are provided after the said de-rusting station to rinse off the de-greasing chemicals from the surface of components. Pluralities of De-mineralized stations are provided after the said de-rust water rinse station to clean the surface. Wherein said autophoretic station comprises of one or more tanks provided with autophoretic solution with a facility to continuously circulate the said solution through heaters,chillers and filters. Autophoretic solution is suitably heated/chilled to react with the components which are dipped and form a uniform coating surface. Said heating/chilling is done by using heat exchanger based on requirement. The temperature of autophoretic solution is to be maintained is at a range of 18 to 24 deg. C and most preferably the temperature of said solution is to be maintained at 20 to 22 deg C. In order to achieve this temperature chilled water at 8° C shall be circulated through the auto deposition tank by means of poly propylene heat exchange coils. Dipping time of component is preferably 2 to 3 minutes . Plurality of rinse stations are provided after the said autophoretic station to rinse off the autophoretic chemicals from the surface of components. Wherein said reaction station comprises of one or more tanks provided with reaction solution with a facility to continuously circulate the said solution through heaters and filters. Reaction solution is suitably heated to react with the components which are dipped. Said heating is done by using heat exchanger based on requirement. The temperature of reaction solution is to be maintained is at a range of 60 to 75 deg. C and most preferably the temperature of said solution is to be maintained at 70 to 75 deg C. Dipping time of component is preferably 0.75 to 1 minute. The said object transfer takes place for baking , the Autophoretic coated body shell preferable get transferred on to the conveyor passing through the baking oven at the specified speed. The baking oven is designed for two stages of baking and it consists of G I closure which is self-supporting in construction, made of 200 mm thick insulated panels. The panels shall be of cassette type with Nut bolt Construction. The inside covering sheet for panels shall be GI 1.25 mm. In between inner and outer covering sheets, high-density resin bonded glass wool of 200 mm shall be filled in. The supply ducts shall be arranged at the vertical side portion of the oven and the suction ducts shall be placed at the bottom, which shall have dampers to adjust the airflow. Indirect Oil fired Heat exchanger type heating system is used for achieving the desired temperatures. The object will subjected to the baking in the above baking oven preferably at the below mentioned temperature and curing time: Oven I st stage : From ambient temp to 65° C Effective Metal Temp for preferably 10 to 12 min . Oven Ilnd Stage: From temp to 65° C to 180°C Effective Metal Temp for preferably 18 to 20 min . The baked object subjected for Natural for room temperature 20 °C. The object is transfer to body preparation station, wherein said one or more body preparation stations comprises of sanding station, sealant station and underbody compound application station which are provided one after the other as stated sequentially. The body preparation zone consisting of closed enclosure where the operator preferably uses sand papers to prepare the surface the body to adhere the powder on the autophoretic coated surface. The sealant zone consists of preferably closed enclosure with sufficient illumination. The said object is subjected to manual application of sealant in the specified locations to provide the leak proof joints to take care of rainy seasons. The under body zone consists of preferably closed enclosure with sufficient illumination and fresh air supply and exhaust system. The said object is subjected to manual application of under body PVC compound in the specified locations to provide the corrosion resistance and to provide sound proof condition. Wherein said final top coat powder painting station comprises of one or more electro-static painting guns along with powder recovery system and baking system which is provided after under body application station. The final top coat powder coating area for the said object is divided in to two zones i.e manual application zone where the internal surface of the object where auto application is not possible to reach. Other zone is auto application zone where the electrostatic auto applicators are provided to take care of external surfaces of the object. The final top powder coated body is subject for IR heating to form the uniform layer of the powder on the object surface. The IR heating zone basically consists of closed enclosure with insulated panels structure and having 80 nos of IR heating lamps to provided desired temperature preferably 80°C. After IR heating of the coated powder on the object it passes through the powder curing oven. The baking oven is designed with the G I closure which is self-supporting in construction, made of 200 mm thick insulated panels. The panels shall be of cassette type with Nut bolt Construction. The inside covering sheet for panels shall be GI 1.25 mm. In between inner and outer covering sheets, high-density resin bonded glass wool of 200 mm shall be filled in. The supply ducts shall be arranged at the vertical side portion of the oven and the suction ducts shall be placed at the bottom, which shall have dampers to adjust the airflow. Indirect Oil fired Heat exchanger type heating system is used for achieving the desired temperatures. The object will subjected to the baking in the above baking oven preferably from temp to 80° C Effective Metal Temp to 185°C at 10 -15 min curing time. Wherein said finishing operation station comprises of touch-up station, polishing station and cavity waxing station which is provided after final top coat powder painting station. Referring to Figure 1 the process for painting is carried out in following steps: 1. Surface of component to be painted made free from oil, dirt and corrosive matters by cleaning with Tag -o-Rag cloth manually. 2. Degreasing the said component by dipping in degreasing solution. De-greasing solution is suitably heated to extract the oil and foreign matters from the surface of components using heat exchangers preferably by using plate type heat exchanger. 3. Rinsing off the de-greasing chemicals from the said de-greased component with water. 4. De-rusting the said component by dipping in de-rust solution. De-rust solution is suitably heated to extract corrosive matters from the surface of components using heat exchangers. 5. Rinsing off the de-rusting chemicals from the said component with water. 6. Rinsing off the water from the said component with de-mineralized (DM) water. 7. Coating the component by dipping in autophoretic solution. Autophoretic solution is suitably heated/chilled to react with the components which are dipped and form a uniform coating surface. Said heating/chilling is done by using heat exchanger based on requirement. 8. Dipping the autophoretic coated component in reaction solution to have uniform coating. Reaction solution is suitably heated to react with the components which are dipped. Said heating is done by using heat exchanger based on requirement. 9. Baking the component by using baking oven. The baking oven is designed for two stage of baking i.e ambient to 65 deg C effective metal temperature (EMT) for 10 to 12 minutes and from 65 deg C to 180 -190 deg C effective metal temperature (EMT) for 20 minutes. 10. Natural cooling the component at room temperature for 30 minutes. 11. Preparing the autophoretic coated surface to adhere the powder to be coated on it by using sand papers of desired grades. 12. Applying sealant in the specified locations to provide the leak proof joints to take care of rainy seasons. 13. Applying the under body PVC compound in the specified locations to provide the corrosion resistance and sound proof condition. 14. Applying the final top coat powder on said component. The final top coat powder coating area for the said object is divided in to two zones i.e manual application zone where the internal surface of the object is not possible to reach by auto application. Other zone is auto application zone where the electrostatic auto applicators are provided to take care of external surfaces of the object. 15. Baking said component by IR heating system to form the uniform layer of the powder on the object surface ambient to 80 deg C effective metal temperature (EMT) for 10 to 12 minutes. 16. Curing said component with the help of baking oven from 80 deg C to 200 deg C effective metal temperatures (EMT) for 20 minutes. 17. Final finishing the component by finishing operation such as touch-up, polishing and cavity waxing. The roregoing descnption is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof. WE CLAIM 1. Novel painting system comprises of a. Pre-treatment and autophoretic coating system, b. One or more body preparation station, c. Final top coat powder painting station and d. Finishing operation stations wherein said Pre-treatment and autophoretic coating system comprises of degreasing station, de-rusting station, autophoretic station, reaction rinse station and curing station which are provided one after the other sequentially, after every station of degreasing station, de-rusting station and autophoretic station, there is provided a water rinse stations to rinse off the solution, and followed by a baking system, wherein said one or more body preparation stations, provided after the Pre-treatment and autophoretic coating system, comprises of sanding station, sealant station and underbody compound application station which are provided one after the other, wherein said final top coat powder painting station, provided after the body preparation stations, comprises of one or more electro-static painting guns along with powder recovery system and baking system, wherein said finishing operation stations, provided after the final top coat powder painting station, comprises of touch-up station, polishing station and cavity waxing station. 2. Painting system as claimed in claim 1 wherein said de-rusting station comprises of one or more tanks provided with de-rust solution with a facility to continuously circulate the de-rusting solution through poly propylene coils heaters and filters. 3. Process for painting by a painting system as claimed in claims 1 and 2 comprises of a) Surface of component to be painted made free from oil, dirt and corrosive matters; b) Degreasing the said component by dipping in degreasing solution; c) Rinsing off the de-greasing chemicals from the said de-greased component with water; d) De-rusting the said component by dipping in de-rust solution; e) Rinsing off the de-rusting chemicals from the said component with water; f) Rinsing off the water from the said component with de-mineralized (DM) water; g) Coating the component by dipping in autophoretic solution; h) Dipping the autophoretic coated component in reaction solution to have uniform coating; i) Baking the component; j) Natural cooling the component at room temperature ; k) Preparing the autophoretic coated surface to adhere the powder to be coated on it; 1) Applying sealant in the specified locations; m) Applying the under body PVC compound in the specified locations; n) Applying the final top coat powder on said component; o) Baking said component in Infrared (IR)zone of the oven; p) Curing said component with the help of baking oven; q) Final finishing the component. Process for painting as claimed in claim 3 wherein said Autophoretic solution of step 4(g)is Autophoretic 925G and is suitably heated/chilled to react with the components which are dipped and form a uniform coating surface,said heating/chilling is done by using heat exchanger based on requirement. Process for painting as claimed in claim 3 wherein said reaction solution of step 4 (h)is suitably heated to react with the components which are dipped'said heating is done by using heat exchanger based on requirement. Process for painting as claimed in claim 3 wherein said baking of step 4(i)is done in baking oven with two stage of baking from ambient to 65 deg C effective metal temperature (EMT) for 10 to 12 minutes and from 65 deg C to 180 -190 deg C effective metal temperature (EMT) for 20 minutes. Process for painting as claimed in claim 3 wherein final top coat 4(n) is done by pure polyster powder and said coating area for the said object is divided in to manual application zone and auto application zone. Process for painting as claimed in claim 3 wherein said baking of step 4(o) by IR heating system to form the uniform layer of the powder on the object surface ambient to 80 deg C effective metal temperature (EMT) for 10 to 12 minutes. Process for painting as claimed in claim 3 wherein said curing of step 4(p) is done from 80 deg C to 200 deg C effective metal temperatures (EMT) for 20 minutes. Novel painting system and process for painting thereof substantially as herein described with reference to accompanying drawings.

Documents:

704-mum-2008-abstract(31-3-2008).pdf

704-MUM-2008-ABSTRACT(7-12-2012).pdf

704-MUM-2008-CLAIMS(AMENDED)-(19-3-2014).pdf

704-MUM-2008-CLAIMS(AMENDED)-(7-12-2012).pdf

704-mum-2008-claims.doc

704-mum-2008-claims.pdf

704-mum-2008-correspondence(25-4-2008).pdf

704-mum-2008-correspondence-received.pdf

704-mum-2008-description (complete).pdf

704-mum-2008-drawings.pdf

704-MUM-2008-FORM 1(7-12-2012).pdf

704-MUM-2008-FORM 13(19-3-2014).pdf

704-mum-2008-form 18(25-4-2008).pdf

704-MUM-2008-FORM 2(TITLE PAGE)-(7-12-2012).pdf

704-mum-2008-form 8(25-4-2008).pdf

704-mum-2008-form 9(25-4-2008).pdf

704-mum-2008-form-1.pdf

704-mum-2008-form-2.doc

704-mum-2008-form-2.pdf

704-mum-2008-form-26.pdf

704-mum-2008-form-3.pdf

704-MUM-2008-GENERAL POWER OF ATTORNEY(7-12-2012).pdf

704-MUM-2008-MARKED COPY(7-12-2012).pdf

704-MUM-2008-REPLY TO EXAMINATION REPORT(7-12-2012).pdf

704-MUM-2008-REPLY TO HEARING(19-3-2014).pdf

704-MUM-2008-SPECIFICATION(AMENDED)-(19-3-2014).pdf

704-MUM-2008-SPECIFICATION(MARKED COPY)-(19-3-2014).pdf

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