US2117180A

US2117180A - Metal container

Info

Publication number: US2117180A
Application number: US44970A
Authority: US
Inventors: Alfred L Kronquest
Original assignee: Continental Can Co Inc
Current assignee: Continental Can Co Inc
Priority date: 1935-10-14
Filing date: 1935-10-14
Publication date: 1938-05-10
Anticipated expiration: 1955-05-10

Description

May 10, 1938.

A. L. KRONQUEST METAL CONTAINER Filed Oct. 14, 1935 Patented May 10, 1938 UNITED STATES PATENT OFFICE METAL CONTAINER Application October 14, 1935, Serial No. 44,970

3 Claims.

The invention relates to new and useful improvements in sheet metal containers, and more particularly to a container which is adapted for the packaging of beverages.

An object of the invention is to provide a sheet metal container which is so constructed that it may be sealed by the clinching of a cap thereto, and wherein the entire inner surface of the container is covered by a plastic non-metallic coating applied to the container after it is completed and ready for filling, which plastic material is of such a character that it remains ductile at refrigerating temperatures and does not break or flake upon bending or flexing of the walls of the container.

A further object of the invention is to provide a container of the above type wherein the plastic material covering the inner surface there- 'of is of such a character that it remains solid and unafiected when submitted to a temperature such as used in the pasteurizing of certain beverages.

In the drawing- Figure 1 is a view showing a portion of a container made from sheet metal which is to be coated for use in the packaging of beverages;

Fig. 2 is a similar view showing the coating applied to the entire inner surface of the container;

Fig. 3 is a vertical sectional view through a container embodying the improvements after the container is filled with the beverage and sealed, and

Fig. 4 is a detail in section showing a slightly modified form of construction.

The invention is directed to a sheet metal container which is especially adapted for the packaging of beverages. In the present illustrated embodiment of the invention, the container includes a body portion made from a sheet metal blank which is bent into cylindrical form. The edges of the blank are united by a solder bonded lock and lap seam 2 of a novel construction not described herein A bottom end 3 is secured t the body portion by a double seam 4. A top end 5 is secured to the body portion by a double seam t. This top end 5 is shaped so as to project upwardly from the double seam 6 as indicated at l. The upwardly projecting portion is provided with an opening centrally of the top end which is used for the filling of the container and for the dispensing of the contents of the container when it is opened. The metal surrounding the opening in the top end is shaped so as to provide a sealing lip B and a locking shoulder 9. The

lip 8 is bent back upon itself as indicated at 8a so that the raw edgev of the metal is well back from the edge of the opening. The container is closed by att ching to this top end a cap I l which is clinched 'neath the shoulder as shown in 5 Fig. 3 of the drawing. This cap is provided with a sealing disk l2 which may be of any suitable material such as cork. In Fig. 4 of the drawing, the metal at the mouth of the nozzle is shown as turned outward and back upon the 10 outer face of the lip as indicated at 8b. This is another way of strengthening the edge of the metal and placing the raw edge so that it will be embedded in the sealing gasket.

In the packaging of certain beverages in containers made of metal it is desirable and sometimes necessary to cover the metal forming the inner surface of the container with a. coating so as to prevent the beverage from contacting with the metal. It is well known, for example, that beer if it contacts with the metal will cloud. Efforts have been made to coat the metal sheets in the flat prior to the construction of the container with an enamel which does not afiect the flavor or color of the beverage. Such enamels are sometimes scratched and fractured during handling and are caused to blister in the region of the side seam during the heat of solder bonding. Eiforts have been made to heal the fractures and cover the side seam by applying to the container body'after it is completed, a coating of enamel in a volatile solvent vehicle, but this has not been altogether satisfactory and requires a baking of each individual container for a long period of time to harden the enamel.

According to applicant's invention, the con-' tainer may be made from sheet metal such as tin plate, and after the container is fabricated and ready for filling, then the container is pro vided on the interior thereof with a thermo- 40 plastic, non-metallic coating. A material suitable for lining such a" container for beverages must have certain characteristics. It should be a thermoplastic material which can be heated and flowed over the surface of the metal parts for the coating of the same. It should be a material which, when reduced to refrigerating temperatures will still be ductile and will not break or flake upon bending or flexing the walls of the container. Then again, it is oftendesirable to pasteurize certain beverages, as for example, in the packaging of .beer it is placed in the receptacle and the receptacle closed, after which the receptacle is heated to a'temperature from F. to F., according to the character of the 55 beer and the desired pasteurizing effect to be obtained. Thematerial used should, therefore, be of a character that will remain solid when heated to a temperature of 160 F. or thereabouts.

Applicant, has found that certain petroleum Waxes derived from the very high boiling of nonvolatile fractions of petroleum oil, have all of the characteristics named. These waxes are commonly separated in the de-waxing'of residual lubricating oils, such as cylinder stocks, and according to their method of production and refining, they are either amorphous or microcrystalline. These waxes are commonly known as petrolatum waxes. One of these waxes is known to the trade as Cerese Wax. This wax, because of its microcrystalline character, is ductile. When formed into thin sheets, it may be subjected to repeated pending stresses without fracture.- When applied to metal sheets and allower to solidify, it adheres tenaciously thereto even at temperatures below its melting point, and when such wax coated sheets of metal are chilled, to temperatures in the neighborhood of 40 F., that is, refrigerating temperatures, the wax does not chip off or flake when the metal is bent so as to permanently indent the same. Then again, this Cerese Wax does not melt under 160 R, which is well above the temperatures used in pasteurizing beer. a

The wax is reduced to a molten condition by applying heat thereto. It is preferably heated to a temperature of 250 F. or more and the liquid wax is then caused toflow over every part of the interior surface of the container. The container is then inverted for draining the wax therefrom. As the wax flows from the mouth of the container it will contact with the edge thereof and flow by capillary attraction some distance on to the outer surface of the lip. Therefore, when the container is cooled, it-will be lined with a coating of wax which tenaciously adheres to the metal. This wax covers every particle of the metal, and extends even through the mouth to the outer face of the container. When the closure cap is applied to the container, therefore, the lining thereof will contact with the lining of the container, and when the container is sealed, every particle of metal throughout the entire container including the closure is covered by a material which is chemically inert to the action of the beer thereon, so that the beer will not cloud or be otherwise affected through contact with the metal.

The application of the hot wax to every part of the interior of the container renders the surface of the container completely sterile. When the container is cooled, a coating or lining is formed which tenaciously adheres to the walls thereof covering the side seam and the double seams at the top and bottom of the container so that when filled with a beverage there is no chance of its contacting with the metal.

After the container has been coated with the wax, and the wax properly set or hardened by cooling, the container is then preferably passed immediately, while still sterile,'into a filling machine where it is filled with the beverage that is to be stored therein.

Instead, however, of applying the coating at the time when the'container is to be filled, it may be coated by the manufacturer of the container rather than by the packer.

In the packaging of beer, the containers are passed through a suitable apparatus for imparting heat to the contents so as to bring the beer to the proper pasteurizing temperature. This varies with the character of the beer from F. to F. This heating of the container does not, in any way, affect the wax lining, as the wax, as above noted, has a melting point well above that used in the pasteurizing of the beer.

In the pasteurizing of the beer, a pressure is developed on the container of F approximately ninety pounds per square inch. This pressure on the lining in the region of the seams does not cause the beer to break through the coating, as the liquid wax penetrates into the crevices between the metal parts filling the same so that the internal pressure developing on the container merely forces the wax coating more firmly into the crevices and prevents the beverage from in any way, reaching the metal parts or the solder bond joining the same.

During the handling of the beer container and the storing of the same in refrigerators, they are often knocked and the thin walls indented. The coating is so tenaciously adherent to the metal and so ductile that it will bend with the wall without fracturing or flaking, even when the wax is at a refrigerating temperature.

The container produced above has all the advantages of the glass bottle, both as to ease in sealing and opening the container, and as to non-injurious effects upon the beverage. It has the added advantage that it does not transmit lightjso that the beverage is maintained free from any injurious effect of light rays thereon. The,container as described has the further advantage of cheapness in cost of manufacture so that it may be thrown away after it is opened and the beverage dispensed therefrom, and thus the expense of reclaiming the container for use is avoided. Nevertheless, the containers may be re-used, if desired, and can be readily cleansed and sterilized, ready for refilling through the applying of a new coating of the petroleum wax to the interior thereof.

This application is a continuation in part of my application Serial No. 23,751, filed May 27, 1935.

While the invention as illustrated is applied to,a container wherein one of the ends has a filling and pouring opening, closed by a cap, it will be understood that the shape of the con tainer and the manner of closing the same may be greatly varied without departing from the spirit of the invention set forth in the appended claims. While it may be practicable to coat a sheet of metal with an enamel and die shape a blank out therefrom to form a can end without breaking the enamel, abody for a container cannot be formed by coating the metal in the fiat with an enamel and thus produce a protection so that the contents of the can will not come in contact with any metal whatever, for the reason that after the body portion is formed and the edges interlocked a solder bond is necessary toseal the side seam and the liquid content under pressure may work into the side seam and contact with the solder. It is essential therefore that the body portion at least of the container shall be coated with the petroleum wax, so as to completely cover the crevice leading to the solder bonded side seam.

Having thusdescribed the invention, what I claim'as new and desire to secure by Letters- Patent, is-

1. A container for beverages including a body portion and a lining completely covering and tenaciously adhering to the inner surface of the body portion, said body portion being formed of sheet metal, said lining being formed from petrolatum waxesseparated in the de-waxing of residual lubricating oils and characterized by having a. melting point of approximately 160 F., and of being ductile at approximately 40 F., whereby the lining is undisturbed in the pasteurizing of the beverage and remains unbroken upon the bending or flexing of the body wall of the container at refrigerating temperatures.

2. A container for beverages comprising a sheet metal body portion, sheet metal ends seamed thereto, one of said ends having a fllllng and pouring opening and a closure for said opening, and a lining completely covering and 'tenaciously adhering to the inner surface of the body portion and the ends, said lining being formed of petrolatum waxes separated in the de-' waxing of residual lubricating oils and characterized by having a melting point of approximately 160 F. and of being ductile at approximately 40 F., whereby the lining is undisturbed in. the pasteurizing of the beverage and remains unbroken upon the bending or flexing of the body wall of the container at refrigerating temperatures.

3. A container for beverages including a body portion and a lining completely covering and tenaciously adhering to the inner surface of the body portion, said body portion being formed of sheet metal, said lining being formed from petrolatum waxes characterized by having a melting point of approximately 160 F., and of being ductile at approximately 40 F., whereby the lining is undisturbed in the pasteurizing of the beverage and remains unbroken upon the bending or flexing of the body wall of the container at refrigerating temperatures.

ALFRED L. KRONQUEST.