F O R M 2

THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)

1. Title of the invention: AN IMPROVED DEVICE AND METHOD OF DE MASKING COMPONENT AFTER ITS PLATING PROCESS

2. Applicant(s):

(a) NAME : LARSEN & TOUBRO LIMITED
(b) NATIONALITY : An Indian Company
(c) ADDRESS : L & T House, Ballard Estate, Mumbai 400 001,
State of Maharashtra, India

3. PREAMBLE TO THE DESCRIPTION

The following specification particularly describes the invention and the manner in which it is to be performed:


FIELD OF THE INVENTION

The present invention relates to the process of removal of masking compound after the plating process. More particularly, the invention relates to an improved device and a process of de-masking components after its plating process.

BACKGROUND OF THE INVENTION

Rising prices of silver calls for plating the component only at functional surfaces. Therefore, the component is masked by using a PVC based compound before plating. After the plating process this masked compound needs to be removed. This is presently done by peeling it off by hand which is a time consuming process.

Secondly, during de masking if the compound is not properly removed then during the second stage of plating, the plating cannot be done and also any leftover masking compound affects the product quality, since it does not conduct heat and electricity. This also provides scope for greater productivity with less cycle time.

The disadvantage of the prior art is that the existing method removes the compound by peeling it off by hand which is time consuming and cumbersome.

Thus there is need for an improved method and device of removal of masking compound after the plating process which provide improved method of demasking as compared to the conventional method, efficient method of de masking, the process can take care of any complex geometry of the component, good quality of demasking and 100% elimination of any masked compound on the component.
OBJECTS OF THE INVENTION

One object of the present invention is to overcome the drawbacks/disadvantages of the prior art.

The basic object of the present invention is to provide a where the existing method to remove the compound by peeling it off by hand.

Another object of the present invention is to provide an improved method that ensures 100% elimination of any masked compound on the component.

Yet another object of the present invention is to provide an improved device where the existing method to remove the compound by peeling it off by hand.

These and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided an improved device for de-masking of masked components after its plating process, said device comprising
a first means comprising :
a first rinsing means substantially placed inside said first means containing de-laminating solution adapted to dissolve said compound in the solution and

an first ultrasonic means substantially placed inside said first means adapted to ensure that the surface of the component is cleaned of any masked component ;

a second means substantially connected with said first means by way of a valve means and said second means is substantially located at a higher level than said first means for cascade flow, said second means comprising :
a second rinsing means substantially placed inside said second means containing de-laminating solution adapted to dissolve said compound in the solution containing de-laminating solution and
an second ultrasonic means substantially placed inside said second means adapted to ensure that the surface of the component is cleaned of any masked component and

a third means containing de mineralized water ,said third means comprising an outlet means to supply compressed air throughout and keep the said water in continuous agitated state adapted ensures that the component is cleaned of the de laminating solution layer that forms on the component and is made suitable for further plating/ assembly after drying.

According to another aspect of the present invention there is provided an improved method for de-masking of masked components after its plating process, said method comprising steps of
(i) rinsing of said masked component in de laminating solution in a first rinsing means ,said first rinsing means is substantially placed inside a first means ,adapted to dissolve the component with said de laminating solution for a predetermined time and perform the first stage cleaning of said masked component in said first means;

(ii) de-masking of said masked component in a first ultrasonic means, said first ultrasonic means substantially placed inside a first means adapted to ensure that the surface of the component is cleaned of any masked component for a predetermined time and perform the first stage cleaning of said rinsed component in said first means;

such that said steps (i) and step (ii) are performed simultaneously;

(iii) rinsing of said masked component from step (ii) in de laminating solution in a second rinsing means , said second rinsing means is substantially placed inside a second means adapted to dissolve the component with said de laminating solution for a predetermined time ensuring the left over masking compound from said first means is dissolved in fresh de laminating solution and perform the second stage cleaning of said de-laminated masked component in said second means;

(iv) de-masking of said masked component from step (iii) in a second ultrasonic means, said second ultrasonic means substantially placed inside a second means adapted to ensure that the surface of the component is cleaned of any masked component and perform the second stage cleaning of said de-laminated masked component in said second means;

such that steps (iii) and (iv) are performed simultaneously and
(v) cleaning of said de-laminated component in a third means containing de mineralized water, said third means comprising a outlet means adapted to provide compressed air supply to ensures that the component is cleaned of the de laminating solution layer that forms on the component and is made suitable for further plating/ assembly after drying.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an improved device and method of removal of masking compound after the plating process.

The system consists of 3 tanks of which first 2 tanks have ultrasonic chambers. The first two tanks are filled with a delaminating solution and are connected together with one way flow control valve. The delaminating solution is a combination of medium boiling aromatic solvents of exceptional purity and solvency. These two tanks are provided with ultrasonic systems. The third tank is filled with de mineralized water in an agitated state by providing compressed air outlet at the bottom of the tank.

The components to be de masked are kept inside a rinsing bucket. It is then put inside the first tank containing the delaminating solution. The ultrasonic equipment inside the tank is turned on for some time. Then the components are put in the second tank with fresh de laminating solution.

One of the embodiments of the present invention is to provide an improved device for de-masking of masked components after its plating process. The device comprising a first means , a second means substantially connected with said first means by way of a valve means and said second means is substantially located at a higher level than said first means for cascade flow and a third means containing de mineralized water ,said third means comprising an outlet means to supply compressed air throughout and keep the said water in continuous agitated state adapted ensures that the component is cleaned of the de laminating solution layer that forms on the component and is made suitable for further plating/ assembly after drying.
The first means comprising a first rinsing means substantially placed inside said first means containing de-laminating solution adapted to dissolve said compound in the solution and an first ultrasonic means substantially placed inside said first means adapted to ensure that the surface of the component is cleaned of any masked component .
The second means comprising a second rinsing means substantially placed inside said second means containing de-laminating solution adapted to dissolve said compound in the solution containing de-laminating solution and an second ultrasonic means substantially placed inside said second means adapted to ensure that the surface of the component is cleaned of any masked component .
The first and second ultrasonic means comprises an ultrasonic chamber. The valve means comprises a control valve and is adapted to allow unidirectional flow of de-laminating solution. The first and second rinsing means comprises a rinsing container.

The unidirectional flow is from second means to first means of said de-laminating solution.

The third means further comprising a third valve means adapted to drain out left over water during maintenance and the first means further comprising a first valve means adapted to drain out left over solution during maintenance.

Another embodiment of the present invention is to provide an improved method for de-masking of masked components after its plating process. The method steps comprising steps of
(i) Rinsing of the masked component in de laminating solution in a first rinsing means where the first rinsing means is substantially placed inside a first means . the first rinsing means is adapted to dissolve the component with said de laminating solution for a predetermined time and perform the first stage cleaning of said masked component in said first means.

(ii) De-masking of the masked component in a first ultrasonic means, said first ultrasonic means substantially placed inside a first means . the first ultrasonic means is adapted to ensure that the surface of the component is cleaned of any masked component for a predetermined time and perform the first stage cleaning of said rinsed component in said first means.

The steps (i) and step (ii) are performed simultaneously.
(iii) Rinsing of the masked component from step (ii) in de laminating solution in a second rinsing means , said second rinsing means is substantially placed inside a second means
(iv) The second rinsing means is adapted to dissolve the component with said de laminating solution for a predetermined time ensuring the left over masking compound from said first means is dissolved in fresh de laminating solution and perform the second stage cleaning of said de-laminated masked component in said second means.

(v) De-masking of said masked component from step (iii) in a second ultrasonic means, said second ultrasonic means substantially placed inside a second means . the second ultrasonic means is adapted to ensure that the surface of the component is cleaned of any masked component and perform the second stage cleaning of said de-laminated masked component in said second means.

The steps (iii) and (iv) are performed simultaneously and
(vi) Cleaning of said de-laminated component in a third means containing mineralized water, said third means comprising a outlet means adapted to provide compressed air supply to ensures that the component is cleaned of the de laminating solution.

The method by which, de masking of partially plated components can be done- efficiently and easily. This method of de masking provides high degree of cleaning of the components and makes it suitable for second stage plating.
The solution is a delaminating solution. It’s a combination of medium boiling aromatic solvents of high solvency in order to soften PVC and dissolve it.

The solution and its amount used in first tank (tank 1 and second tank (tank 2) are the same. Also, the second tank is kept at a higher level for cascade flow.(flow of solution from second tank to first tank, and fresh solution poured to second tank).

The purpose of the first tank is to dissolve as much masking compound as possible, thereby making the solution in tank 1 less powerful and effective. Almost 85-90 % of cleaning is done in this tank. So, more solution is provided from tank 2.

Tank 2 is meant for a second stage cleaning, which uses the solution to give a final cleaning to the component. The solution in this tank gets ineffective very slowly since its just providing a final cleaning. This tank ensures that the masking compound that is left over on the component (mostly in the holes and rounds) is removed. Complete cleaning of the component is required since the masking compound is electrically non conductive and hence affects the product quality.

Complete cleaning cannot be achieved in tank 1 by keeping it for more time because the effectiveness of the solution keeps on reducing, so more solution would be required w.r.t time. Also, the cleaning won’t be effective since the solution gets contaminated with the masking compound, and the solution will form a layer on the component making it difficult to remove at later stage.

The components should be kept inside tank 1 and tank 2 ultrasonic chambers for about 10-15 minutes.

The main idea to use a second tank for cleaning is because the solution in this tank gets ineffective very slowly since its just providing a final cleaning. This tank ensures that the masking compound that is left over on the component (mostly in the holes and rounds) is removed. Complete cleaning of the component is required since the masking compound is electrically non conductive and hence affects the product quality.

Again, the ultrasonic equipments in the second tank are turned on and components kept for some time. Then the components are transferred to the third tank containing de mineralized water for active rinsing.

This process of de masking provides high degree of cleaning of the components and makes it suitable for second stage plating. The surface finish of the component is enhanced through this process.

Features of the invention:
• Improved method of demasking as compared to the conventional method.
• Efficient method of de masking.
• The process can take care of any complex geometry of the component.
• Good quality of demasking.
• 100% elimination of any masked compound on the component.
Advantages:
• Efficient de masking process.
• Better aesthetic appeal.
• Better surface finish.
• No damage to the silver layer.
• Suitable for partial/differential plating in large numbers.
• De masking by hand can’t be possible when the component geometry is intricate. This invention ensures that all components with delicate geometry can be de masked with this process.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

Other features as well as the advantages of the invention will be clear from the following description.
In the appended drawing:

Figure 1 illustrates the device of de masking component after its plating process

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWING

In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and illustrate the best mode presently contemplated for carrying out the invention. Further functioning of the mechanism has been discussed below to describe the way the mechanism operates. However, such description should not be considered as any limitation of scope of the present unit. The structure thus conceived is susceptible of numerous modifications and variations, all the details may furthermore be replaced with elements having technical equivalence. In practice the materials and dimensions may be any according to the requirements, which will still be comprised within its true spirit.
Tank 1: It consists of de laminating solution in an ultrasonic chamber (10). The components are put in a rinsing bucket and kept in the chamber (10) for some time. This ensures that the masking compound is dissolved in the solution while the ultrasonic ensures that the surface of the component is cleaned of any masked material. Inflow of de laminating solution to this tank is from tank 2 through a one way flow control valve (30). Left over solution can be drained out with the drainage valve (70) during maintenance.

Tank 2: Consists of fresh de laminating solution in an ultrasonic chamber. The tank is supplied with fresh solution as and when the level of solution decreases beyond a certain level.

The fresh solution is supplied to tank 2 manually by pouring the solution into it. This is done in regular intervals as and when the level of the solution in tank 1 goes down and the solution in tank 2 is drained to tank 1 through the one way flow control valve (30).The components are put in a rinsing bucket and kept inside the ultrasonic chamber (20) for some time. This ensures that the left over masking compound from tank one is dissolved in the fresh solution while the ultrasonic ensures that the surface of the component is cleaned of any masked material.

Tank 3: Consists of de mineralized water (40). The water in the tank is kept in a continuously agitated state by providing compressed air supply outlet (50) in the bottom of the tank. This ensures that the component is cleaned of the de laminating solution layer that forms on the component and is made suitable for further plating/ assembly after drying. Left over water can be drained out with the drainage valve (60) during maintenance.

WE CLAIM

1. An improved device for de-masking of masked components after its plating process, said device comprising
a first means comprising :
a first rinsing means substantially placed inside said first means containing de-laminating solution adapted to dissolve said compound in the solution and

an first ultrasonic means substantially placed inside said first means adapted to ensure that the surface of the component is cleaned of any masked component ;

a second means substantially connected with said first means by way of a valve means and said second means is substantially located at a higher level than said first means for cascade flow, said second means comprising :
a second rinsing means substantially placed inside said second means containing de-laminating solution adapted to dissolve said compound in the solution containing de-laminating solution and
an second ultrasonic means substantially placed inside said second means adapted to ensure that the surface of the component is cleaned of any masked component and

a third means containing de mineralized water ,said third means comprising an outlet means to supply compressed air throughout and keep the said water in continuous agitated state adapted ensures that the component is cleaned of the de laminating solution layer that forms on the component and is made suitable for further plating/ assembly after drying.

2. Device as claimed in claim 1 wherein said first ultrasonic means comprises an ultrasonic chamber.

3. Device as claimed in claim 1 wherein said second ultrasonic means comprises an ultrasonic chamber.

4. Device as claimed in claim 1 wherein said valve means comprises a control valve .
5. Device as claimed in claim 4 wherein said control valve is adapted to allow unidirectional flow of de-laminating solution.

6. Device as claimed in claim 5 wherein said unidirectional flow is from second means to first means of said de-laminating solution.

7. Device as claimed in claim 1 wherein said first rinsing means comprises a rinsing container.

8. Device as claimed in claim 1 wherein said second rinsing means comprises a rinsing container.

9. Device as claimed in any of the preceding claims wherein said de-laminating solution comprising combination of medium boiling aromatic solvents of exceptional purity and solvency.

10. Device as claimed in claim 1 wherein said third means further comprising a third valve means adapted to drain out left over water during maintenance.

11. Device as claimed in claim 1 wherein said first means further comprising a first valve means adapted to drain out left over solution during maintenance.

12. An improved method for de-masking of masked components after its plating process, said method comprising steps of
(i) rinsing of said masked component in de laminating solution in a first rinsing means ,said first rinsing means is substantially placed inside a first means ,adapted to dissolve the component with said de laminating solution for a predetermined time and perform the first stage cleaning of said masked component in said first means;

(ii) de-masking of said masked component in a first ultrasonic means, said first ultrasonic means substantially placed inside a first means adapted to ensure that the surface of the component is cleaned of any masked component for a predetermined time and perform the first stage cleaning of said rinsed component in said first means;

such that said steps (i) and step (ii) are performed simultaneously;

(iii) rinsing of said masked component from step (ii) in de laminating solution in a second rinsing means , said second rinsing means is substantially placed inside a second means adapted to dissolve the component with said de laminating solution for a predetermined time ensuring the left over masking compound from said first means is dissolved in fresh de laminating solution and perform the second stage cleaning of said de-laminated masked component in said second means;

(iv) de-masking of said masked component from step (iii) in a second ultrasonic means, said second ultrasonic means substantially placed inside a second means adapted to ensure that the surface of the component is cleaned of any masked component and perform the second stage cleaning of said de-laminated masked component in said second means;

such that steps (iii) and (iv) are performed simultaneously and
(v) cleaning of said de-laminated component in a third means containing de mineralized water, said third means comprising a outlet means adapted to provide compressed air supply to ensures that the component is cleaned of the de laminating solution layer that forms on the component and is made suitable for further plating/ assembly after drying.

13. Method as claimed in claim 12 wherein said de laminating solution comprising combination of medium boiling aromatic solvents of exceptional purity and solvency.

14. Method as claimed in claim 12 wherein said first and second means is connected through a control valve.

15. Method as claimed in claim 14 wherein said control valve is unidirectional.

16. Method as claimed in claim 15 wherein said unidirectional flow is from second means to first means de-laminating solution.

17. Method as claimed in claim 12 wherein said second means is substantially located at a higher level than said first means adapted level for cascade flow.

18. Method as claimed in claim 12 wherein said third means further comprising a valve means adapted to drain out left over water during maintenance.

19. Method as claimed in claim 12 wherein said first means further comprising a valve means adapted to drain out left over solution during maintenance.

20. Method as claimed in claim 12 wherein said first stage cleaning in first means perform about 85% to 90 % of cleaning of said masked components.

21. Method as claimed in claim 12 wherein said second stage cleaning in second means is to provide final cleaning to the component.

22. Method as claimed in claim 12 wherein said predetermined time of said first and second means is for about 10 to 15 minutes.

23. An improved device of de-masking of masked components after its plating process device as herein substantially described and illustrated with the accompanying drawings.

24. An improved method of de-masking of masked components after its plating process as herein substantially described and illustrated with the accompanying drawings.