US2751073A

US2751073A - Container with diaphragm

Info

Publication number: US2751073A
Authority: US
Publication date: 1956-06-19
Anticipated expiration: 1973-06-19

Description

June 1956 s. R. SHEERAN CONTAINER WITH DIAPHRAGM Filed Sept. 11, 1952 :E fl

E i in} 227:1 I f i3 I N VEN TOR.

STAN .E Y RobERT SHEER/m A TTQENEY United States Patent CONTAINER WITH DIAPHRAGM Stanley R. Sheeran, Niagara Falls, N. Y., assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware Application September 11, 1952, Serial No. 308,990

2 Claims. (Cl. 206-46) This invention relates to new and useful improvements in metal containers for storing or shipping liquids generally and specifically for closed containers in which liquids may form undesirable skins at the surface interface between the liquid and the air.

Many liquids, such as suspensions, emulsions, mixtures of components of high and lower vapor pressures, solutions and others have a tendency when in a closed container, such as a shipping drum to form a skin at the surface of the liquid where it has an interface with an air or gas space. It is difficult to avoid such an air or gas pocket especially in shipping drums or containers because these vary slightly in capacity. Also, a gas space permits volume changes due to temperature variation without danger of disruption of the container as is likely to happen if it were filled to 100% capacity.

For example, the shipment of several grades of aqueous emulsions of polyvinyl acetate has caused considerable difiiculty because they have a pronounced tendency to form skins on the liquid at the interface with the air pocket. Such skins are formed when water evaporates from the liquid surface since this causes the emulsions to break down. Such skins are diflicult to redisperse and removing the skin so formed is troublesome. If any small pieces of the skin get into the emulsion they cause trouble in many final applications.

One object of this invention is the provision of means whereby volatilization from the liquid phase in a closed container into a gas phase will be prevented. Another object is to provide a diaphragm which will float on the liquid surface in a closed container and effectively separate the liquid and gas phases. A further object is the combination of a floating diaphragm and gasketing of the closure of a container for shipping liquids. Other objects will be apparent from the following discussion of my invention.

Briefly, I may accomplish my objectives by placing an insoluble impermeable flexible sheet directly over the surface of the liquid in the can or drum and bring the edges of the sheet up and over the open edge of the container in such a manner that the sheet serves to separate the liquid from the gas or air space. Then I place the cover on the container using the interposed flexible sheet as a gasketing means. The sheet must be of suflicient strength relative to the size of container and weight of contents to withstand the physical strain when the container is rolled on its side or is stood upside down in shipping. The sheet must be inert to the contents of the container and substantially impenetrable to both the liquid and gas components.

The accompanying drawings illustrate the essential principles of my invention.

Fig. 1 is a view, part in elevation and part in vertical cross section, of a filled drum with closure at the top.

Fig. 2 is a vertical cross section view of the filled drum of Fig. 1 lying on its side.

In the drawings the liquid 2 in container 1 is separated from the air space 4 by flexible film 3 which latter funcice vapors or liquid into said air space. Closure of the container is effected by cover 5 which is securely fastened to drum rim or lip 7 by a suitable conventional circular clamp 6 fitting around the top or lip of the drum. The flexible film 3 extends over the top of the drum and this portion serves as a gasket between said top or chime 7 and the edge of the cover 5. If desired, additional gasketing material may be used between the drum cover and the chime, depending upon the requirements of each case.

Figure 2 illustrates an important principle of my invention. The flexible film 3 adapts itself to separate the liquid phase 2 from the vapor or gas phase 4 even when the filled drum is on its side. The separating film can adapt itself to any position of the filled drum, although in general it will be preferable to keep the drum in the upright position.

As a floating diaphragm sheet I envisage the use of rubber, natural or synthetic, polyethylene, neoprene, polyacrylonitrile, or other synthetic polymeric materials, cellulosic materials such as cellulose esters, waxed or pachmentized paper, and in fact any material that will form a sheet of sufficient strength and flexibility. The material in sheet form must be impervious to the liquid components concerned and also to the gas or vapors present in the gas phase. Also, the material must be inert to both the liquid and gas.

My invention is suitable for packaging for shipment or for storage in closed containers any liquid material such as emulsions of polyvinyl acetate or other ester derivatives of polyvinyl alcohol. Any liquid which may tend to undergo separation of a component whereby a film is formed when packaged in a closed container with an air or gas pocket will benefit by the use of a flexible diaphragm floating on the liquid surface and separating the two phases. Also, where a component in the air or gas pocket will react undesirably with a liquid component the use of a diaphragm is indicated, such as in inks, paints, varnishes, etc.

Certain liquids which contain corrosive materials such as petroleum products containing hydrogen sulfide will cause corrosion by concentrating in condensed droplets of liquids such as water on the container walls above the liquid level. In these cases a floating diaphragm separating the gas and liquid phases is often very useful in shipping containers.

Specifically, my invention has been found useful for the shipment of aqueous polyvinyl acetate emulsions. The tendency of such emulsions to form undesirable films at the air-liquid interface has been stopped by the use of the flexible filrn or diaphragm which separates the liquid and gas phases in the container.

I claim:

1. In a shipping drum having an opening of substantially the same diameter as the side wall of the drum at the section where the cover is applied, the combination when said drum is in the upright position comprising a liquid in said drum, the upper level of said liquid being in spaced downward relationship to the lip of said drum, a rigid removable cover secured to the lip of said drum, the inner surface of said cover being in upwardly spaced relationship to the upper surface of said liquid, and a flexible diaphragm impervious to said liquid, said diaphragm floating on the upper surface of said liquid and completely covering said liquid in said drum and having the edge of said diaphragm securely fastened between the cover and the lip of said drum, said diaphragm substantially completely separating the liquid and the gas phases in said drum.

2. In a shipping drum having an opening of substantially the same diameter as the side wall of the drum at the section where the cover is applied, the combination when said drum is in the upright position comprising a tions as an impervious diaphragm to prevent passage of polyvinyl acetate emulsion in said drum, the upper level d laid emulsion being :in spaced downward relationship to the lip of said drum, a rigid removable cover secured to the lip of said drum, the inner surface of said cover being in upwardly spaced relationship to the upper surface of said anulsion, and a flexible diaphragm impervious 5 t0, said-emulsion, said diaphragm floating on the upper Surface of said emulsion and completely covering said emulsion-in said drum and having the edge of said diaphragm securely fastened .between the cover and the lip of said drum, said diaphragm substantially completely 10 separating the emulsion and the gas phases in said drum.

References Cited in the file of this patent UNITED STATES PATENTS Keane Oct. 12, 1898 Althoff Apr. 16, 1929 Acly May 15, 1934 Graser Dec. 8, 1936 Scudder Dec. 22, 1936 Florian Feb. 17, 1942 Shores May 12, 1942 De Kiss June 19, 1945 FOREIGN PATENTS Great Britain 1844

Claims

1. IN A SHIPPING DRUM HAVING AN OPENING OF SUBSTANTIALLY THE SAME DIAMETER AS THE SIDE WALL OF THE DRUM AT THE SECTION WHERE THE COVER IS APPLIED, THE COMBINATION WHEN SAID DRUM IS IN THE UPRIGHT POSITION COMPRISING A LIQUID IN SAID DRUM, THE UPPER LEVEL OF SAID LIQUID BEING IN SPACED DOWNWARD RELATIONSHIP TO THE LIP OF SAID DRUM, A RIGID REMOVABLE COVER SECURED TO THE LIP OF SAID DRUM, THE INNER SURFACE OF SAID COVER BEING IN UPWARDLY SPACED RELATIONSHIP TO THE UPPER SURFACE OF SAID LIQUID, AND A FLEXIBLE DIAPHRAGM IMPERVIOUS TO SAID LIQUID, SAID DIAPHRAGM FLOATING ON THE UPPER SURFACE OF SAID LIQ UID AND COMPLETELY COVERING SAID LIQUID IN SAID DRUM AND HAVING THE EDGE OF SAID DIAPHRAGM SECURELY FASTENED BETWEEN THE COVER AND THE LIP OF SAID DRUM, SAID DIAPHRAGM SUBSTANTIALLY COMPLETELY SEPARATING THE LIQUID AND THE GAS PHASES IN SAID DRUM.