FORM 2
THE PATENT ACT 1970
(39 OF 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
1 TITLE OF THE INVENTION :
PERMANENT AND TAMPER RESISTANT BRANDING/LETTERING/LOGO IMPRINTED COLD ROLLED SHEETS AND A PROCESS FOR PRODUCING THE SAME.
2 APPLICANT (S)
Name : JSW STEEL LIMITED.
Nationality : An Indian Company.
Address : Jindal Mansion, 5-A, Dr. G. Deshmukh Marg, Mumbai - 400 026,
State of Maharastra, India.
3 PREAMBLE TO THE DESCRIPTION
COMPLETE
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 permanent and tamper resistant branding/lettering/logo imprinted cold rolled sheets and also to a process for branding/lettering/logo imprinting on the cold rolled sheets during rolling in cold rolling mills. More particularly, the present invention is directed to providing a process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets following a simple and cost-effective process by selectively generating desired impression involving difference of amplitude/waviness of roughness between the logo/letter/brand name and rest of the sheet such as to create a difference in appearance in normal light on the surface. Importantly, the impression is created on the on the surface of cold rolled close annealed(CRCA) sheet itself and which can be easily recognized and distinguished from others in the trade market and does not affect subsequent utitlity/processing operations such as painting etc at the customer's end.
BACKGROUND OF THE INVENTION
Cold rolled steel sheets are one of the key products in steel industry, as it offers a variety of properties including easy formability and a smooth and clean surface. It finds wider applications in automobiles, white goods, furniture, and many other day to day items. Cold rolling process involves cold reduction of hot-rolled and pickled coils to thinner thickness. This is followed by annealing to make it soft and formable. Annealed coils are lightly rolled in the skin pass mill to prevent a defect called stretcher strain, improve strip shape, and adjust mechanical properties. After skin pass rolling, coils are processed at the recoiling line, where they are cut to produce product coils of the specified weight, or at the shearing line, where they are cut into sheets of the specified dimensions. Product thickness, width, shape, and surface quality are inspected and mechanical properties are tested using specimens taken at the finishing line. These cold rolled compact annealed (CRCA) sheets are distributed in the market through retail outlets. CRCA steel sheets of various companies do not have any distinguished appearance and is difficult to identify its source. Hence, it becomes very important to brand the CRCA sheets by imprinting company logo or a specific product name before its distribution into the market to maintain a good market identity or origin and value.

Steel companies use various methods to distinguish its product from others by marking its logo or product brand name on the sheets or on the packaging using ink marking, painting, stamping or stickering etc. However, these methods have their own limitations and are not suitable for retail market distribution. The performance of the existing methods employed by companies to distinguish its product by marking its logo or product brand name on the sheets or on the packaging using ink marking, painting, stamping or stickering etc has been un-satisfactory. These methods are vulnerable to atmospheric conditions and also get removed/damaged during handling and transportation.
There has been thus a need in the related art to developing an effective method of making a permanent impression (company logo or brand name) on the CRCA sheets. An attempt has been made by way of the present invention to avoid the limitations of product identification in case of cold rolled sheets by providing a permanent method of logo or brand impression creation on such sheets has been devised which will remain intact so that the CRCA sheet reaches to the final customer with desired identity of origin and retain its brand value and distinctive difference from competitors' products.
OBJECTS OF THE INVENTION
The basic object of the present invention is thus directed to a process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets involving a simply and cost effective process without the need for additional equipments or gadgets.
A further object of the present invention is directed to said process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets which would enable the impression to remain which could be easily recognized and distinguished from others and does not affect subsequent processing operations such as painting etc at the customer's end.
A still further object of the present invention is directed to said process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets which cannot be rubbed or tampered as being obtained as an integral part of the formation of cold rolled sheets.

A still further object of the present invention is directed to said process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets whereby the CRCA sheets produced would have a permanent impression of company logo or brand name on the CRCA sheets to maintain distinct identity in traders' market.
A still further object of the present invention is directed to said process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets whereby desired impression could be transferred to the coils involving work roll all along the sheet.
A still further object of the present invention is directed to said process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets involving variety in visual impression of the said branding/lettering/logo and related different distinguishable appearances selected from bright, shiny, dull and the like distinguishing appearance on the surface.
A still further object of the present invention is directed to said process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets whereby the impressions would selectively create a difference in appearance under normal light on the surface.
SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention the same is directed to a process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets comprising:
skin pass rolling by subjecting coils to light rolling in the skin pass mill wherein said skin pass rolling is carried out involving rollers having desired texture with selective roughness on surface with a clearly distinguishable therefrom altered amplitude /waviness of surface finish/roughness identifying said brand/lettering/logo.
A further aspect of the present invention is directed to a process that comprises cold reduction of hot-rolled and pickled coils to thinner thickness, followed by annealing to make it soft and formable and thereafter subjecting the annealed coils to said light rolling in the skin pass mill.

A still further aspect of the present invention is directed to said process wherein the said distinguishable altered amplitude /waviness of roughness on surface provides for desired impression which is transferred to the coils during rolling all along the sheet.
A still further aspect of the present invention is directed to said process comprising generating said desired impression involving said difference of amplitude/waviness of roughness between the logo/letter/brand name and rest of the sheet such as to create a difference in appearance under normal light on the surface.
A still further aspect of the present invention is directed to said process wherein said rollers in skin pass are selectively involved of varying roughness to create different textures and different distinguishable appearances selected from bright, shiny, dull and the like distinguishing appearance on the surface.
A still further aspect of the present invention is directed to said process wherein said skin pass rollers used have desired texture with selective roughness on surface with a clearly distinguishable therefrom altered amplitude /waviness of surface finish/roughness identifying said brand/lettering/logo which said altered amplitude /waviness of surface finish/roughness of the roll is achieved involving strong acid and etching and the selection of the acid and the time of etching is selectively involved in the process of obtaining said roller to ensure that there is no undesired surface abnormalities during subsequent processing operations such as painting etc due to longer etching time or stronger acid or not result in shallow impression which may not be properly transferred to the coil and may also not be present till the end of the expected life of the roll due to shorter etching time or weak acid.
Yet another aspect of the present invention is directed to a work roll adapted for creating tamper resistant branding or marking of coil surface of cold rolled coils at the skin pass line of cold rolling mills comprising having desired texture with selective roughness on surface with a clearly distinguishable therefrom altered amplitude /waviness of surface finish/roughness adapted for identifying any brand/lettering/logo.
A further aspect of the present invention is directed to said work roll wherein said clearly distinguishable therefrom amplitude/waviness of surface finish/roughness adapted for

identifying any brand/lettering/logo is selectively provided on the said rest of the uniformly roughened surface of the roll.
A still further aspect of the present invention I directed to said work roll comprising selectively varying roughness adapted to create different textures and different distinguishable appearances selected from bright, shiny, dull and the like distinguishing appearance.
According to a further aspect of the present invention is directed to a process for the
manufacture of work roll as described above comprising the steps of:
i) Grinding the work roll ;
ii) Texture the entire work roll at a particular roughness; iii) Cleaning the portion to be selectively imprinted portion of the roll with said
altered amplitude /waviness of surface finish/roughness of the roll ; iv) Stickering the desired altered amplitude /waviness of surface finish/roughness
of the roll with cut-out sticker on the roll; v) Applying/brushing for strong acid treating of the cut portion of the sticker; vi) Cleaning the thus acid treated surface and removing the sticker; vii) Cleaning the thus marked portion to thereby provide said roll with adapted for
creating effective branding or marking of coil surface of cold rolled coils at the
skin pass line.
A still further aspect of the present invention directed to said process for the manufacture of work roll wherein said altered amplitude /waviness of surface finish/roughness of the roll is achieved involving strong acid and etching and the selection of the acid and the time of etching is selectively involved in the process of obtaining said roller to ensure that there is no undesired surface abnormalities during subsequent processing operations such as painting etc due to longer etching time or stronger acid or not result in shallow impression which may not be properly transferred to the coil and may also not be present till the end of the expected life of the roll due to shorter etching time or weak acid.
A still further aspect of the present invention is directed to said process for the manufacture of work roll wherein said cleaning is done preferably by Acetone and said acid treatment is done by a strong acid solution preferably aquaregia; HCI : HN03 = 3:1.

A still further aspect of the present invention is directed to cold rolled sheet steel comprising permanent and tamper resistant branding/lettering/logo imprinting wherein said branding/lettering/logo imprinting comprises of desired texture with selective roughness on steel sheet surface with a clearly distinguishable altered amplitude /waviness of surface finish/roughness with respect to the rest of the sheet steel surface roughness.
The advancement is described hereunder in greater detail in relation to the following non-limiting examples and accompanying figures.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURE
Figure 1: is the flow illustrating the steps involved in the process for preparation and logo imprinting on the used roll or the new roll involving skin pass rolling in accordance with the present advancement.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a process for permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets at the skin pass mill of cold rolling mill, a work roll to generate such impression during skin pass rolling and the CRCA sheets with such impressions produced by the process.
The objective of the skin pass rolling in CRCA sheets is not only to reduce the stretcher strains but also to imprint a particular texture on the surface of the sheet. Process of texturing involves creating or making a desired roughness on the surface. The work rolls used in skin pass operation are grinded and textured to desired roughness using an electro discharge texturing machine. Texture or roughness is transferred on the sheet from the skin pass rolls during rolling. Different roughness will create different textures and will have different distinguishable appearances (bright, shiny, dull etc) on the surface. In the present work, skin pass rolls are specially prepared with logo/letter/brand impression of a particular size and shape which is clearly distinguishable. The distinguishability is achieved by altering the amplitude/waviness of roughness on the logo/letter/brand image (selected area) by chemical etching. The stencil/sticker with the desired cut-out showing logo/letter/brand

image is placed on the textured roll and is chemically etched using a strong acid capable of partially rubbing away the metal to few microns. The amplitude/waviness of roughness on the exposed surface or opening area inside the stencil or the sticker is altered or flattened due to reaction with chemical reagent. The imprint must be visible on the roll but will not have significant difference in roughness. This impression or the difference in amplitude/waviness of roughness is transferred to the coils during rolling all along the sheet. In this method, the difference of amplitude/waviness of roughness between the logo/letter/brand name and rest of the sheet will create a difference in appearance in normal light on the surface.
EXAMPLE:
The following exemplary manner of providing the permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets at the skin pass mill of cold rolling mill as per the stages shown in accompanying Figure 1 is discussed hereunder :
(1) Grinding the work roll for removing the 100-120micron lop layer,
(ii) Placing the grinded work roll on electro discharge texturing machine with an aim to achieve 3.5 Ra roughness maintaining the desired process parameters including
OUT TIME: 28 microsec,
OFFTIME: 38 microsec,
AMPS(CURRENT): 20, GAIN: 10,
THREAHOLD: 8.6, R.P.M (ROLL RPM):14, CARRIAGE SPEED: 60 mm/min, POLARITY: POSITIVE,
(iii) Placing the roll on the stand and cleaning at the logo imprint location using acetone;
(iv) Placing the JSW logo cut out sticker on the roll at the cleaned portion;
(v) Applying aquaregia; HCI : HN03 = 3:1, using a cotton brush on the cut out region. Time : 1 min;
(vi) Removing the sticker and cleaning the surface after 1-2 mins ;
(vii) If found accepatable subject the same to skin pass rolling and if not repeat the stages (i) to (vi) above.

It would be clearly apparent that the present advancement makes the advantageous and selective use of the skin pass rolling usually employed in combination with the strong acid treatment and time of etching to achieve desired impression or the difference in amplitude/waviness of roughness is transferred to the coils during rolling for creation of the intended permanent and tamper resistant branding/lettering/logo imprinting on the cold rolled sheets following a very simple , user friendly and cost-effective procedure. This is clearly distinct and technically more advantageous vis-a-vis the difference in the amplitude /waviness of roughness achieved in some of the previous arts by using aerosol and two step texturing or marking the logo on the roll using a laser machine. These prior arts are slower and add to the cost of processing. Present advancement is faster and no cost addition solution to have permanent impression on the coil.
In the present invention the difference in amplitude/waviness of roughness is the key to the impression. The difference created by the aforesaid method depends on the optimum combination of acid strength and time of etching. For the preferred concentration if aquaregia; HCI : HN03 = 3:1 the application time is 1 min. For diluted acid the treatment time will be more than 1 min and for further stronger acids the treatment time has to be less than 1 min. The selection of the acid and the time of etching is selectively involved in the process to ensure that there is no undesired surface abnormalities during subsequent processing operations such as painting etc due to longer etching time or stronger acid or not result in shallow impression which may not be properly transferred to the coil and may also not be present till the end of the expected life of the roll due to shorter etching time or weak acid.
The present invention thus relates to a method of creating effective branding or marking of coil surface of cold rolled coils at the skin pass line of CRM, comprising the following steps:
a) Grinding the work roll;
b) Texture the entire work roll at a particular roughness;
c) Cleaning the to be imprinted portion of the roll by acetone to make it oil free
d) Stickering the desired cut-out sticker on the roll;
e) Applying/brushing strong acid solution such as aquaregia, HCI : HN03 = 3 : 1 to the cut portion of the sticker;
f) Cleaning the acid applied surface after 1 min and removing the sticker;
g) Cleaning the marked portion by acetone and inspection for acceptance;

h) Sending the roll to skin pass mill for imprinting on the coils;
It is thus possible by way of the present invention to for the first time provide permanent and tamper resistant branding/iettering/logo imprinted cold rolled sheets and also provide for the required method for a process for permanent and tamper resistant imprinting of the company logo/letters/brand name on the surface CRCA sheet which could be carried out selectively during the skin pass operation. The logo imprinted by the process helps in clearly differentiating the company product from others in the trade market. Importantly, such impression made by the aforesaid method is advantageously such that cannot be rubbed, removed and tampered . The process can be implemented easily as the roll preparation requires very less time and no addition of new technology or machine is required. Advantageously also, the impression can be created by the skin pass roll and thus no requirement of using the texturing machine twice. The size, shape and dimensions of the imprint can be changed from roll to roll. The imprint made does not affect subsequent processing such as forming and painting.
The process according to the present invention thus enable a simple and cost effective yet reliable means for imprinting the company logo/letters/brand name on the surface CRCA sheet itself during the skin pass operation simply by the use of sticker and chemical etching for creating the imprint without any addition to the existing cost of manufacturing, favouring wide application in rolling mills/sheet metal manufacturers,

We Claim:
1. A process for permanent and tamper resistant branding/lettering/logo imprinting on
the cold rolled sheets comprising:
skin pass rolling by subjecting coils to light rolling In the skin pass mill wherein said skin pass rolling is carried out involving rollers having desired texture with selective roughness on surface with a clearly distinguishable therefrom altered amplitude /waviness of surface finish/roughness identifying said brand/lettering/logo.
2. A process as claimed in claim 1 comprising cold reduction of hot-rolled and pickled coils to thinner thickness, followed by annealing to make it soft and formable and thereafter subjecting the annealed coils to said light rolling in the skin pass mill.
3. A process as claimed in anyone of claims 1 or 2 wherein the said distinguishable altered amplitude /waviness of roughness on surface provides for desired impression which is transferred to the coils during rolling all along the sheet.
4. A process as claimed in anyone of claims 1 to 3 comprising generating said desired impression involving said difference of amplitude/waviness of roughness between the logo/letter/brand name and rest of the sheet such as to create a difference in appearance in normal light on the surface.
5. A process as claimed in anyone of claims 1 to 4 wherein said rollers in skin pass are selectively involved of varying roughness to create different textures and different distinguishable appearances selected from bright, shiny, dull and the like distinguishing appearance on the surface.
6. A process as claimed in anyone of claims 1 to 5 wherein said skin pass rollers used have desired texture with selective roughness on surface with a clearly distinguishable therefrom altered amplitude /waviness of surface finish/roughness identifying said brand/lettering/logo which said altered amplitude /waviness of surface finish/roughness of the roll is achieved involving strong acid and etching and the selection of the acid and the time of etching is selectively involved in the process of obtaining said roller to ensure that there is no undesired surface abnormalities during subsequent processing operations such as painting etc due to longer etching time or stronger acid or not result in shallow impression which may not be properly

transferred to the coil and may also not be present till the end of the expected life of the roll due to shorter etching time or weak acid.
7. A work roll adapted for creating tamper resistant branding or marking of coil surface of cold rolled coils at the skin pass line of cold rolling mills comprising having desired texture with selective roughness on surface with a clearly distinguishable therefrom altered amplitude/waviness of surface finish/roughness adapted for identifying any brand/lettering/logo.
8. A work roll as claimed in claim 7 wherein said clearly distinguishable therefrom amplitude /waviness of surface finish/roughness adapted for identifying any brand/lettering/logo is selectively provided on the said rest of the uniformly roughened surface of the roll.
9. A work roll as claimed in anyone of claims 7 or 8 comprising selectively varying
roughness adapted to create different textures and different distinguishable appearances
selected from bright, shiny, dull and the like distinguishing appearance.
10. A process for the manufacture of work roll as claimed in anyone of claims 5 to 9
comprising:
i) Grinding the work roll ;
viii) Texture the entire work roll at a particular roughness; ix) Cleaning the portion to be selectively imprinted portion of the roll with said
altered amplitude /waviness of surface finish/roughness of the roll ; x) Stickering the desired altered amplitude /waviness of surface finish/roughness
of the roll with cut-out sticker on the roll; XI) Applying/brushing, for stroag acid treating of the cut portion, of the sticker; xii) Cleaning the thus acid treated surface and removing the sticker; xiii) Cleaning the thus marked portion to thereby provide said roll with adapted for
creating effective branding or marking of coil surface of cold rolled coils at the
skin pass line.
11. A process for the manufacture of work roll as claimed in claim 10 wherein said said
altered amplitude /waviness of surface finish/roughness of the roll is achieved involving
strong acid and,etching and the selection of the acid and the time of etching is selectively
involved in the process of obtaining said roller to ensure that there is no undesired surface

abnormalities during subsequent processing operations such as painting etc due to longer etching time or stronger acid or not result in shallow impression which may not be properly transferred to the coil and may also not be present till the end of the expected life of the roll due to shorter etching time or weak acid.
12. A process as claimed in anyone of claims 10 or 11 wherein said cleaning is done
preferably by Acetone and said acid treatment is done by a strong acid solution preferably
aquaregia; HCI : HN03 = 3:1.
13. Cold rolled sheet steel comprising permanent and tamper resistant
branding/lettering/logo imprinting wherein said branding/iettering/logo imprinting
comprises of desired texture with selective roughness on steel sheet surface with a clearly
distinguishable altered amplitude/waviness of surface finish/roughness with respect to the
rest of the sheet steel surface roughness.