US3268378A

US3268378A - Method of preparing mated embossing rolls

Info

Publication number: US3268378A
Application number: US418732A
Authority: US
Inventors: Frank W Broderick
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-12-16
Filing date: 1964-12-16
Publication date: 1966-08-23
Anticipated expiration: 1983-08-23

Description

g- 1966 F. w. BRODERICK METHOD OF PREPARING MATED EMBOSSING ROLLS 2 Sheets-Sheet 1 Filed Dec. 16, 1964 g- 1966 F. w. BRODERICK METHOD OF PREPARING MATED EMBOSSING ROLLS 2 Sheets-Sheet 2 Filed Dec.

United States Patent 3,268,378 METHOD OF PREPARING MATED EMBOSSING ROLLS Frank W. Broderick, P.O. Box 2, Stirling, NJ. Filed Dec. 16, 1964, Ser. No. 418,732 4 Claims. (Cl. 1S614) This invention relates to a method of preparing mated embossing rolls and more particularly to a method and apparatus of cold finishing with cold embossing of a strip of dull finish aluminum sheet to produce depressed glossy cold finished surfaces adjacent to elevated nonglossy wearing or pitted surfaces.

This invention is a continuation-in-p-art of patent application Ser. No. 145,956, filed October 18, 1961, now abandoned.

In the preparation of treads now commonly used in automobiles, the embossed glossy surfaces 'elevated above the original horizontal plane are easily scratched and otherwise disfigured by conventional shoe traffic going in and out of the automobile, thereby presenting treads having unsightly scratched embossed designs thereon.

Moreover, the present practice of purchasing highly polished aluminum sheet for preparing treads for automobiles is unsatisfactory in that such polished aluminum sheet is relatively expensive and is easily marred in transportation and normal handling so as to produce scratches thereon rendering the sheet a piece of scrap.

It is an object of this invention to prepare a mated pair of embossing rolls adapted to produce an embossed metal sheet or foil having a design the top wearing surfaces of which are provided with a roughened design pattern or texture.

It is also an object of this invention to provide a method of producing metal sheet or foil having embossed designs having raised non-glossy surfaces, such as for example pebble grain, satin finish, and the like type of surfaces.

It is another object to provide a method of converting commercial aluminum sheet having a conventional nonglossy mill finish to a sheet of glossy finish by contacting the dull surface of the sheet with a suitably highly polished female roll.

In the preparation of aluminum treads for automobile use, the dull aluminum sheet surface is converted into a glossy surface simultaneously as the sheet is being embossed into the design cavities of the female embossing roll, the bottom surfaces of said cavities being provided with the desired pebble grain or satin finish.

The method of this invention is illustrated in the accompanying drawing in which;

FIG. 1 is a perspective view of a portion of a photoerigraved female roll having a repeated arrow and repeated annulus design,

FIG. 2 is an enlar ed sectio of FIG- 1, g n view taken on line 2 2 FIG. 3 is a section view similar to FIG. 2, showin the conventional preparation of a male roll having pro tuberances of a height equal to the depth of the female cavities,

FIG. 4 is a section view of the male roll of FIG. 3 coated with a resist soluble only in methyl ethyl ketone FIG. 5 is a section view of FIG. 4 after a doctor blade has removed the excess resist so as to have the blade contact the top surfaces of the male protuberances,

FIG. 6 is a view similar to FIG. 5 showing the spray droplets of an asphaltum resist soluble in turpentine,

FIG. 7 is a view similar to FIG. 6 with all the resist removed and showing the etched pebble grain top surfaces on the male protuberances,

FIG. 8 is a view similar to FIG. 7 showing the ap- "ice plication of an acid resist to only the top surfaces of the male protuberances,

FIG. 9 is a section view of the female roll coated with resist and the prepared male roll about to be mated so as to force out excess resist with metal contact or engagement between the top of the male protuberances and the bottom of the female cavities,

FIG. 10 is a section view of the female roll coated with resist and ready for acid etching,

FIG. 11 is a section view of a fully prepared female roll having the bottom walls of its cavities acid etched and receiving the design of the pebble grain finish of the top surfaces of the male protuberances,

FIG. 12 is a section view of a portion of a mated pair of a fully prepared female roll and a fully prepared rnale roll, shown in exaggeration the .001 to .002 clearance between the smooth surfaces of the female and male rolls and showing also the simultaneous contact of the rough or pebble grain surfaces of the female and male rolls, and

FIG. 13 is a section view of a metal sheet passed through the rolls of FIG. 12.

In this invention the bottom of the femalecavities of the female embossing roll are provided with roughened or pitted, i.e. satin finish or pebble grain surfaces, which surfaces appearing on the embossed aluminum sheet do not show foot tralfic or other scratches.

Turning now to the drawing, a female steel roll 10 is provided with an engraved design either by the conventional mill and die method or by the conventional photoengraving process. The design may be of a very intricate nature but for purposes of clarity of illustration a repeated arrow head 11 and a repeated annulus of ring 12 is used herein, which appear as cavities in the female roll 10 (FIG. 2).

The design of this female roll is then transferred to a male mating roll 13 in the conventional manner using an acid resist coating and a suitable metal etching acid.

By way of an example the depth of the female cavities 14 may be .008 inch and the height of the male protuberances 15 is also .008 inch. The male protuberances are then topped with an acid resist such as asphaltum and the root of the protuberances are etched away in such a manner that the height of the protuberance is increased to .010 or more thousands depending on the pattern which is to be used on the top of the protuberance. This topping and acid etching procedure is to prevent marring of the polished surface of the female roll in later transfer mating ope-rations.

According to the concept of this invention the male roll 13 is removed from the transfer machine and is coated with a methyl ethyl ketone soluble acid resist coating 16. This resist 16 is not soluble in turpentine.

This coating is then scraped with a metal doctor blade to remove as much excess resist as possible and the top of the protuberances are further cleaned by means of an emery block to produce an absolutely smooth surface (FIG. 5) receptive to various spray or other methods used to produce an eventual rough surface on the top surfaces of the protuberances.

The smooth, clean, metallic surfaces of the protuberances (FIG. 5) are then sprayed with a turpentine soluble asphaltum acid resist 17 to yield a desired pattern and this sprayed surface of male roll 13 (FIG. 6) is rotated in a bath of suitable etching acid to produce the desired etch pattern or suitable depth. The asphaltum resist may be washed off with turpentine leaving behind the methyl ethyl ketone acid resist 16. Then the turpentine washed male roll 13 may be given a second asphaltum spray and the protuberances again etched in acid to give a novel final etched pattern.

The protuberances 15 of the male roll 13 (FIG. 5) may be given mechanically applied rough top surfaces, if desired, in lieu of the etched asphaltum prepared surface. Also the spray etched surface may be given a mechanical roughness thereto.

Clearly, there are many ways of applying various rough surfaces to the top of the protuberances 15, including brushing on resist in lieu of spraying and machine engraving to give ultimate pleasing rough wearing surfaces of a satin finish, swirl finish, emery finish, pebble grain, and other visual effects.

The use of the asphaltum turpentine soluble resist 17 in conjunction with the methyl ethyl ketone soluble resist 16 permits a washing off or removal of the asphaltum resist and repeated application by re-spraying to give a plurality of varying depths of satin or emery finishes without removal of the background methyl ethyl ketone soluble resist 16.

Where mechanical finishes are applied to the tops of the protuberances 15, the roll is placed in a lathe, grinding machine or engraving machine and the tops of the protuberances are ground, turned or engraved to the desired finish.

After the protuberances have received the final desired pattern 18 the roll 13 is washed free of all resist (FIG. 7).

Next, the top coating of acid resist 16 of the male roll (FIG. 8) is removed and the roll of increased protuberance height is mated to the female roll covered with acid resist, for example, acid resist 16 in the transfer machine.

The male roll is brought up so that the top surfaces 18 of the protuberances 15 contact the bottom walls of the female cavities squeezing out excess acid resist 16 to expose metal having the complementary pattern of the surface 18. The female roll 11} is then rotated in a conventional etching acid bath and the pattern 18X is etched into the bottom walls of the female cavities (FIG. 10). The previous provision of the extra .001 height of the protuberances prevents contact between the shiny, high polish smooth surfaces of the female roll of the original female roll and the male roll 13.

Removal of the resist from the etched roll 10 (FIG. 10) produces the final product female roll (FIG. 11).

When the tw-o final product male and female rolls are brought together (FIG. 12) there is a metal to metal mating of the etched top surfaces 18 of the protuberances 15 and the bottom surfaces 18X of the corresponding female cavities but no metal engagement of the highly polished female surfaces of female roll 10 with the male roll 13.

The embossed foil 19 made of aluminum or other metal or of foil on paper laminate is shown in FIG. 13 showing the wearing surfaces 18X thereon as transferred from the bottom walls of the cavities of the female roll.

This invention is of a generic nature and is not to be limited by the metal used in the embossing rolls, nor to the type of rough wearing pattern transferred by the female roll to the ultimate embossed sheet and it includes 4 all variations obvious to those skilled in the art upon reading this disclosure. Thus, for example, the final production female roll may be buffed to restore or to enhance its polished surface to whatever degree is desired without materially harming the pattern in anyway whatsoever.

Iclaim:

1. The process of preparing mated steel embossing rolls to produce embossed aluminum sheet or foil with protuberances having top rough wearing patterned surfaces comprising preparing a matched set of male and female metal embossing rolls by conventional masking and etching procedure; coating the top male protuberances with acid resist; acid etching said coated protuberances to increase the height of said protuberances; removing said acid resist from said protuberances; roughening the top surfaces of said protuberances of said male roll with a desired pattern and transferring said rough pattern surfaces from said top of said male protuberances to the bottoms of the corresponding female cavities of said female roll by acid resist masking and acid etching whereby the pattern of the top protuberant surfaces of the male roll is transferred to the bottom of the corresponding female cavities.

2. The process of claim 1 wherein the rough pattern of the top surfaces of the protuberances is obtained by mechanical toughening.

3. The process of claim 1 wherein the top surfaces of the protuberances is obtained by coating said protuberances of increased height with methyl ethyl'ketone soluble resist; removing excess ketone resist to present the smooth bare metal top surfaces of said protuberances; spattering said bare metal with turpentine soluble asphalt resist; acid etching said spattered surfaces and removing said asphaltic resist with turpentine to present a rough pattern.

4. The process of claim 3 wherein said rough pattern on said top surfaces of said protuberances is spattered again with asphalt resist; acid etching said respattered protuberances and removing said asphalt resist with turpentine to give a pattern rough surface.

References Cited by the Examiner UNITED STATES PATENTS 764,082 7/1904 Thorpe 156 14 1,329,088 1/1920 Leitner 156-14 1,900,824 3/1933 Lewis 161-125 1,974,011 9/1934 Burgess 156-13 XR 2,068,035 1/1937 Meyer 161-125 2,339,145 l/1944 Callum 101-32 2,390,618 12/1945 Roehm 101-32 2,662,002 12/1953 Sunderhauf et al 156-14 ALEXANDER WYMAN, Primary Examiner. DAVID KLEIN, JACOB STEINBERG, Examiners. J. A, BELL, Assistant Examiner,

Claims

1. THE PROCESS OF PREPARING MATED STEEL EMBOSSING ROLLS TO PRODUCE EMBOSSED ALUMINUM SHEET OR FOIL WITH PROTUBERANCES HAVING TOP ROUGH WEARING PATTERNED SURFACES COMPRISING PREPARING A MATCHED SET OF MALE AND FEMALE METAL EMBOSSING ROLLS BY CONVENTIONAL MASKING AND ETCHING PROCEDURE; COATING THE TOP MALE PROTUBERANCES WITH ACID RESIST; ACID ETCHING SAID COATED PROTUBERANCES TO INCREASE THE HEIGHT OF SAID PROTUBERANCES; REMOVING SAID ACID RESIST FROM SAID PROTUBERANCES; ROUGHENING THE TOP SURFACES OF SAID PROTUBERANCES OF SAID MALE ROLL WITH A