US3520471A - Flexible plastic container - Google Patents

Description

July 14, 1970 c. c. FAUST 3,520,471

FLEXIBLE PLASTIC CONTAINER Filed Oct. 9. 1968 INVENTOR CLIFFORD C. F UST ATTORNEY United States Patent 3,520,471 FLEXIBLE PLASTIC CONTAINER Clifford C. Faust, Riverside, Ill., assignor to Union Carbide Corporation, New York, N.Y., a corporation of New York Filed Oct. 9, 1968, Ser. No. 766,147 Int. Cl. B65d 31/12, 33/16, 33/38 US. Cl. 229-56 6 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a sealed container for carrying fluids and more particularly to a flexible plastic container for collecting, storing and dispensing viable fluids such as blood and the like.

Flexible plastic containers for the collection and storage of blood and similar fluids have recently come into use to replace the glass and metal containers heretofore commonly employed for such purposes. The advantages of the plastic containers over the glass and metal containers are obvious: they do not break, are lighter and may be handled and transported more easily. Also, they occupy less storage space. However, these fiexible plastic containers present several problems: the flexible container or bag containing the blood and the blood collecting and dispensing conduits attached to the bag must be kept perfectly leakproof. The container and the conduits must also be kept in sterile condition.

It is an object of the present invention to provide a new and improved flexible plastic film container for a fluid such as blood and the like, comprising a sealed bag, into which the fluid is collected and stored, and fluid collecting and dispensing conduits attached to the bag and sealed in such a manner that the assembly is sterile and leakproof and yet the conduits may be opened when necessary.

Another object of the present invention is to provide a new and improved flexible plastic film container for a viable fluid in which the fluid collecting and dispensing conduits attached to the container are kept in sterile condition before their utilization by being respectively enclosed in compartments integral with the container.

The invention by means of which these objects are achieved will be described with reference to the accompanying drawing wherein:

FIG. 1 is a fragmentary top view of one embodiment of the flexible plastic film container of the invention having a fluid storage compartment extending between a first and a second end compartment integral therewith, the first end compartment enclosing fluid collecting means and the second end compartment enclosing fluid dispensing means;

FIG. 2 is an enlarged fragmentary top view of the second end compartment of FIG. 1 enclosing the fluid dispensing means;

FIG. 3 is a fragmentary top view of the second end compartment of FIG. 1 opened and partly torn away;

FIG. 4 is an enlarged section of the fluid storage compartment and second end compartment taken along line 44 of FIG. 2 to illustrate the position of heat seal bars during the sealing operation of the container walls and of a fluid dispensing conduit to each other;

3,520,471 Patented July 14, 1970 FIG. 5 is an enlarged section taken along line 55 of FIG. 2 similar to that of FIG. 4 during the sealing operation of the walls of the storage compartment of the container to each other; and

FIG. 6 is a fragmentary top view of another embodiment of the flexible plastic container of the invention.

According to the invention, a sealed, flexible, thermoplastic film container is provided, comprising a fluid stor-, age compartment disposed between a first end compartment and a second end compartment. The compartments are defined and separated from each other by a first and a second heat seal extending across the container transverse to its length. A fluid collecting conduit of thermoplastic material is disposed in the first end compartment. A first end of said conduit extends into the storage compartment through the first heat seal and is permanently sealed to inner walls of the container by said first heat seal. In similar manner, a thermoplastic fluid dispensing conduit, disposed in the second end compartment, extends into the storage compartment through the second heat seal and is permanently sealed to inner walls of the container by said second heat seal. The inner walls of each of the collecting conduit and dispensing conduit are releasably sealed together at their respective first ends by the first and second heat seals, respectively. The compartments containing the fluid collecting and fluid dispensing conduits are closed by seals at their extremities. Each compartment of the thermoplastic film container is thus defined by two seals which make it leakproof. The fluid collecting and dispensing conduits are completely enclosed in their respective end compartments and thus retain their sterile condition until use when each of the end compartments may be individually and separately opened and, if desired, removed from the container.

In order to obtain the inner releasable seal of the conduits, the transverse heat seals defining the storage compartment may conveniently be made by applying heat onto both exterior walls of the container and, through the walls of the container, onto the walls of the conduit in contact therewith. The expression inner releasable seal as herein employed means a heat seal of the conduit inner wall surfaces to each other. The sealed portion of the conduit is flattened by the seal, which seal may be opened by applying a pinching pressure at an angle of to the flattened sealed portion such as, for example, by pinching said flattened portion of the conduit between the thumb and the forefinger.

Referring now to the drawing, there is shown in FIG. 1 a flexible plastic container according to one embodiment of the invention comprising a flattened tube, generally designated as 10, of biaxially-oriented polyolefin film having a top wall 11 and a bottom wall 12 and divided by a plurality of transverse seals into three sealed, leakproof, sterile compartments, i.e., a fluid storage compartment 14 extending between two end compartments 16 and 18. The first end compartment 16 contains two fluid collecting conduits 20 and 21 made of a resilient thermoplastic material such as polyethylene, for example. The fluid colecting conduits 20 and 21 are completely enveloped within the end compartment 16. The second end compartment 18 contains a fluid dispensing conduit 22, also made of a resilient thermoplastic material such as polyethylene. The fluid dispensing conduit 22 is completely enveloped within the end compartment 18. The conduits 20, 21 and 22 extend into the fluid storage compartment 14. The storage compartment 14 is defined by two leakproof seals 24 and 26 transversely extending across the walls of the tube 10. The seal 26 on the fluid dispensing end of the storage compartment is preferably oblique with respect to the longitudinal axis of the tube 10 to provide a sloping bottom for the storage compartment when the container is held vertically and to thereby facilitate the draining of the fluid from the storage compartment, such as blood, for example.

The end compartment 16 is defined by two spacedapart leakproof seals, i.e., the seal 24 separating it from the storage compartment 14 and a terminal seal 28. The end compartment 18 is also defined by two spaced-apart leakproof seals, the seal 26 separating it from the storage compartment 14 and a terminal seal 30. In the embodient illustrated in FIG. 1, the collecting conduits 2t) and 21 are shown sealed off in two separate pockets formed in the compartment 16 by a seal 29 in order to provide for separate and individual utilization and control of each of the fluid collecting conduits. This separation of the conduits 20 and 21 is optional. Also, the number of collecting conduits may vary and there might be one, or three, or more conduits, according to the kind of fluid and fluid additives to be stored in the container.

The production of the container of the invention will now be described with particular reference to FIGS. 1, 2, 4 and 5. A flattened tube 10 of flexible thermoplastic film material of predetermined length and flat width is provided in a manner well known to those skilled in the art. The two conduits 20 and 21 are inserted between the walls 11 and 12 at one end portion of the tube in such a manner that they are completely covered by the walls and that the walls extend beyond the conduits. The conduit 22 is inserted into the other end portion of the tube 10 in the same manner. The preferred heat sealing operation, by electrical impulse heat sealing means, is illustrated in FIGS. 4 and 5. Two cooperating heat bars 32 and 34 are disposed in close parallel relationship in two parallel vertical planes and brought into opposite engagement with the walls 11 and 12 respectively of the flattened tube, which are clamped therebetween. FIG. 4 shows the conduit 22 between the walls 11 and 12 with one extremity of said conduit being flattened between the heat seal bars 32 and 34. Each of said heat seal bars 32, 34 has an impulse ribbon 33, 35 respectively mounted thereon. The opposite pressure from the bars has urged the inner wall surfaces of the conduit 22 into contacting engagement. Electrical energy is then applied to the impulse ribbons 33 and 35. Because the ribbons are offset with respect to each other, each ribbon makes its own seal, i.e., the heat coming from the ribbon 33 causes the top wall 11 and the wall of the conduit 22 in contact therewith to be sealed to each other and the heat coming from the ribbon 35 causes the bottom wall 12 and the wall of the conduit 22 in contact therewith to be sealed to each other. Because the conduit 22 is flattened by the bars, the heat from both ribbons penetrating through the walls of the tube into the wall of said conduit produces an inner wall-to-wall seal 27 in the conduit. This seal is strong enough to resist leakage due to hydraulic pressure from the fluid stored in the storage compartment but yields and opens under a higher outside pinch pressure applied transversely to the sealed portion of the tube to break the seal. The optimum conditions of time, pressure and heat may be readily determined by trial for the film and tubular conduit materials selected.

The seal 24 of the fluid collecting side of the storage compartment and the inner seals 27 in the fluid collecting conduits 20 and 21 are effected in the same manner.

While the above-described method of heat-sealing is preferred, the heat seals may also be effected in other manners. For example, the flattened tube and the conduits may be horizontally positioned and clamped in conventional manner between a pair of heat seal bars disposed parallel to each other within a common vertical plane. Heat energy may then be applied to the bars by conventional electrical impulse sealing equipment to heat seal the walls of the tube to each other and to the conduits. However, when heat is applied simultaneously from both sides, the conditions of time, temperature and pressure must be carefully controlled. The bars must provide sufficient heat to permanently seal the walls of the flattened tube to each other and to the conduits, but the inner walls of the flattened conduits must not be permanently welded to each other. One way of overcoming this problem is to successively apply the impulse electrical energy to one bar and then to the other, with a cooling cycle inbetween. But this method is not commercially attractive because it increases the time of making the container considerably. It has been found that the problem could best be solved by positioning the bars in two parallel, closely spaced, vertical planes and applying electrical energy simultaneously to the ribbons on both bars, as above described. A further advantage of this method is that it produces a double seal, one from each side of the flattened tube, or a seal about twice as wide as if the bars had been in the same vertical plane. Such a seal insures a leakproof storage compartment.

The terminal seals 28 and 30 are then made transverse to the flattened tube 10 to close the end compartments 16 and 18 and completely envelope and seal the sterilized tubes 20, 21 and 22 therein, and thus keep them in their sterile condition. These terminal seals may be effected in any convenient manner, i.e., by heat sealing or by the use of an adhesive. If desired, the seal 29 separating the fluid collecting conduits enclosed in the end compartment 16 may be made at the same time. A further advantage of the sealed end compartment 18 is that in case of a leak through the seal 27 in the dispensing conduit, the compartment 18 constitutes an additional reservoir for the fluid stored in the storage compartment 14.

If desired, a secondary inner wall-to-wall seal 27' may be made in the dispensing conduit 22 before inserting said conduit into the tube 10. This secondary seal serves as a safety seal to prevent leakage from the storage compartment 14, should some leakage occur through the releasable seal 27 and may be opened in any conventional manner. Instead of a secondary seal, an elongated plug inserted into the dispensing conduit may also be used. Preferably, the collecting and dispensing conduits should not contain any of the fluid stored in the compartment 14, in spite of the fact that said conduits, and the whole container assembly, are in a sterile condition. The reason is that these fluids, such as blood, for example, might contain preservatives and the homogeneity of the resulting blood mixture might be more ditficult to maintain if some blood were to stand and be trapped in the conduits to form a pool. The seals 27 in the conduits, which coincide with the seals 24 and 26 defining the storage compartment, eliminate this possibility. For the same reason, a plug might be preferred to a secondary seal in the dispensing conduit.

A notch 36 is provided at one end of the terminal seals 28 and 30 to facilitate tearing of said seals and removal of the end compartments 16 and 18 as shown in FIG. 3. The notch 36 is preferably disposed at an acute angle with respect to the seals 28, 30 so as to direct the tear below the seals and to permit removal of the end compartments without destroying the sterility of the conduits.

When the container is ready for use, the compartment 16 enclosing the collecting conduits is opened by tearing the seal 28. The inner seals 27 in the collecting conduits 20 and 21 are opened by exerting pressure on said tubes and the storage compartment 14 is filled with the fluid to be stored therein. Once the storage compartment is full, the conduits 20 and 21 are closed by flattening them and effecting a permanent heat-seal across their flattened walls in a conventional manner. To drain the container, the seal 30 of the compartment 18 is broken and the compartment removed as shown in FIG. 3. The dispensing conduit 22 is connected to other fluid conveying means and the inner seal 27 is opened to drain the container.

In FIG. 6 is shown another embodiment of the container of the invention. The container of FIG. 6 is similar to that shown in FIG. 1 with the exception of the collecting and dispensing conduits 38, 39 and 40 which are longer and coiled in their respective compartments 16 and 18. An additional heat seal 42 is made adjacent to the seal 26 to provide a sealed area at the edge of the container for a deep notch 44. This notch in the sealed area makes it possible to make a clean tear across the container along the seal line 26 and to separate the compartment 18 from the storage compartment 14 thereby fully exposing the conduit 40 for dispensing the stored fluid.

Various thermoplastic materials are suitable for making the container and conduits of the invention. The flexible film of the container walls and the material from which the conduits are made must, of course, be heat-sealable to each other, but do not necessarily have to be made from the same material. Illustrative of such suitable materials are homoand copolymers of olefins such as ethylene and propylene, for example, or vinyl chloride homopolymers or copolymers, and the like. A biaxially oriented polyolefin film, such as that described in US. Ser. No. 698,771, W. F. Underwood et al., is preferred in the manufacture of containers which will be used for storing fluids at cryogenic temperatures, i.e., about l96 C. because of the good properties of such a film at these very low temperatures. The possibility of employing the container of the invention for storing fluids not only at the commonly used temperatures of from about 4 C. to C. but also for freezing the collected fluid in the container and storing the frozen fluid at cryogenic temperatures is a great advantage over known containers. For example, in freezing the collected fluid in the storage compartment, the surface to volume ratio of the fluid may be adjusted by flattening said storage compartment to obtain a maximum rate of cooling. Thawing of the frozen fluid and/or admixture of stored fluids may be facilitated by kneading the flexible wall of the storage compartment, if desired.

What is claimed is:

1. A sealed, flexible, thermoplastic container which comprises:

a fluid storage compartment extending between a first and a second end compartment integral therewith, said storage compartment being defined and separated from said first and second end compartment respectively by a first and a second heat-seal extending across said container transverse to its length;

a fluid collecting conduit of thermoplastic material disposed in said first end compartment and having a first end extending into said storage compartment through said first heat-seal and permanently sealed to the inner walls of said container thereby;

a fluid dispensing conduit of thermoplastic material disposed in said second end compartment and having a first end extending into said storage compartment through said second heat-seal and permanently sealed to the inner walls of said container thereby;

the inner walls of each of said collecting conduit and said dispensing conduit being releasably sealed together at their respective first ends by said first and second heat-seals respectively;

said container being closed by seals at the extremities thereof.

2. A container as claimed in claim 1, which comprises a plurality of thermoplastic fluid collecting conduits in the first end compartment.

3. A container as claimed in claim 2, in which each thermoplastic fluid collecting conduit is separately enclosed in the first end compartment.

4. A container as claimed in claim 1 in which each of the first and the second transverse heat-seals consists of two closely spaced parallel seals.

5. A container as claimed in claim 1, in which the second transverse heat-seal extends obliquely across the container.

6. A container as claimed in claim 1, in which the walls of said container are made of a bioriented polyolefin film and a notch is provided at one end of each of the seals closing the extremities of said container, said notch being disposed at an acute angle with respect to each of said seals.

References Cited UNITED STATES PATENTS 2,766,907 10/1956 Wallace 22294 3,211,144 10/1965 Nehring 150-1 X 3,331,421 7/1967 Lambert l-9 DONALD F. NORTON, Primary Examiner US. Cl. X.R.

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