US2223754A - Art of sterile packaging - Google Patents

Description

D- 3, 1940- H. F. w'rx-:Rs

ART OF STERILE PACKAGING Filed June 4, 1940 2 Sheets-Shea?l 1 IN VEN TOR. HHH/f? Y A' WH 7.5/95

HTTOR/VEY `D-`3, 1940- H. F. WATERS 2,223,754

ART OF STERILE PACKAGING Filed June 4, 1940 2 sheets-sheet 2 I INVENTOR. HHRRY FWHTE/Y' BY ngel* FITTOR/VE'Y Patented Dec. 3, 1940 UNITED STATES PATENT OFFICE 16 Claims.

The present invention relates tothe packaging art, and, more particularly, to the art of packaging materials, including solid and liquid foodstuffs, in a sanitary and sterile manner.

As .those skilled in the art know, collapsible packages and containers made of paper and of similar iiexible materials were used to an ever increasing extent in the past, Generally speaki ing, these collapsible containers comprised a bag for holding the material to be packaged. This bag or envelope was frequently inserted into a carton to further reinforce the sam'e and to impart a generally rectangular form thereto. This type of packaging offered great advantages, particularly when it was desired to package materials in such a manner as to hermetically seal them against the effect of external influences. In this case, generally, a fluid-tight and fusible liner was employed for making the inner container and bag and this/liner was hermetically sealed by means of heat fusion of the fusible material or layer thereof. It has been found that containersof this type can be successfully employed even for packaging liquids.

'Ihe principal advantages of these huid-tight containers resided in their low` price, great strength and attractive appearance. In addition, this type of container could be shipped in a knock-down or collapsible form, whereby a very substantial saving in shipping space and cost could be obtained. While thesevrluid-tight collapsible containers practically revolutionized the packaging industry, some difliculty was experienced when packaging certain foodstuffs which have to be maintained in the condition of extreme purity. Such was the case particularly in packaging milk where it is imperative to maintain thel milk in a completely pure andsterile condition. As is known, milk is an ideal breed- 4o ing ground for microorganisms of the most varied type and contamination of the milk causes great danger to the health of the consumer, including children and infants, having a relatively low resistance to infectious diseases. Ihis proh-` lem was relatively simple to solve in the case of conventional milk bottles which could be sterilized before filling atv high temperatures. By carefullcontrol of the manufacturing process, it was possible to obtain the initial purity and sterility of collapsible' containers; there was no guarantee, however, against the` introduction of germs, micro-organisms and other deleterious agents of an organic or inorganic character into the interior of the container during the time interval which elapsed between manufacturing the i container and filling the same., Due to the fact that the laws regulating the distribution and sale of milk and similar commodities are extremely severe, a serious problem existed in the packaging art in connectionxwith the manufacture and use 5 of collapsible milk containers.

It is an object of the present invention to provide a solution -for the outstandingproblem and to provide the art with a collapsible container for milk, and the like, which is capable of maintainl0 ing at least the same high standards of purity and sterility as may be maintained -at present ,with conventional milk bottles.

It is another object of the present invention toY provide a method of sterile packaging which posil5 tively prevents the entrance oi' deleterious organic or inorganic impurities into the interior of the container intended for shipping and distributing milk and similar commodities.

It is-a further object of the present invention 20 to provide a novel and improved method of aseptical packaging which involves hermetically sealing the packaging medium immediately after it is manufactured, maintaining such seal until such time as the package is illled with the com- 25 modity to be distributed, and thereafter re-sealing such package.

Still another object of the invention is the provision of a novel and improved collapsible container which may be readily and hermetically 30 sealed during its manufacture Yand which may be readily opened to perform the filling and re-sealing operation whereby said container is maintained in the time interval between its manufacture and ultimate use in a sterile and hermetically sealed condition.

' The invention also contemplates a novel collapsible container for the purpose of aseptical packaging of foodstuffs', therapeutic agents, surgical cotton, and the like, which is simple in fm structure and which may be readily manufactured on a practical and commercial scale at a tainer embodying the invention'vl during one of its preliminary steps of manufacture in which the two halves of the carto'n blank and layer are folded together and the resulting envelope is heat-` sealed; i-

liig.y 4 is a perspective view of the container of the invention in its finished and collapsed condition ready for shipment and storage;

Fig. 5 illustrates a perspective view of the container of the invention in its squared-up condition and ready for the filling operation;

Fig. 6 depicts a similar View of the container lhaving theA mouth portions of the inner envelope or bag flattened into `a face to face relationship;

Fig. 7 shows a perspective view of the container with the top marginal portions of the inner bag bent upwards for the purpose of hermetically sealing the content thereof;

Fig. 8 is a similar view of the container after the heat-sealing operation showing the resulting tabs folded towardsv each other, the flaps of the carton being illustrated in their opened condition for reasons of clarity.

is rendered impossible because even though such matter might be of a microscopic character, the hermetic seal will offer an effective obstacle against their entrance. Thus, while in prior practice the interior of collapsible containers was exposed to germs, and the like, during shipment and storage, such contamination of the container is rendered impossible by my invention.

My invention may take various forms in accordance with the type of container contemplated. Thus, in the simplest case where the collapsible container is of the heat-sealed envelope type, I prefer to employ a flexible sheet which is fluidtight and fusible on at least one face. thereof and is folded over along a medial line to bring its edges into registering position. This operation leaves three open edges which may be individually heat-sealed by' applying heat and pressure along a narrow marginal strip thereof. In most cases, however, it is preferred to apply this heat-seal simultaneously to al1 of these three marginal portions in .the shape of a continuous and U-shaped heat-seal which hermetically seals the interior of the envelope against external influences. In this condition the envelope may be preserved in a sterile and unaffected condition,

indefinitely. When it is desired to ll this envelope with material of any description, a restricted opening may be made therein or for example, a

Anarrow strip including one of the heat-sealed seams maybe cut off to provide a filling opening.

Through this filling opening the contents may bel introduced and then the envelope maybe resealed. As a rule, it will be preferred to employ an envelope or bag in combination with an outer supporting carton which imparts additional strength to the inner bag or envelope. vIn my application,

to which a liner fusible on at least the top surface thereof is adhesively secured. The carton blank .3

and the liner are so constructed and arranged that manipulating and folding the carton along predetermined score lines will cause folding of the liner into a position in which it may be heatsealed while it is still resting on the carton blank. While'in prior practice this folded liner was heatsealed along only two of its edges to retain a filling opening, in accordance with the present invention the folded liner is completely sealed along all three edges whereby a completely and hermetically sealed structure is provided. In order to permit removal of a portion of this inner bag or envelope of completely sealed character and still retain a sufcient marginal portion for resealing, it is desirable to have the liner extend slightly longer than this was necessary or customary in prior practice. On the other hand, since for simplicity of manufacture it is desirable to heat-seal the liner while resting on the carton blank of the container the upper flaps associatedA with `the blank have to be slightly extended corresponding to the extension ofthe liner. This makes it possible to cut off a strip of the finished and collapsed carton and liner in a single operation and thereby to prepare the container for filling, as this will be explained more fully as the description proceeds.

Referring now more particularly'to the drawings, a preferred embodiment of the invention will be explained. Fig. 1 illustrates a plan view of a carton blank I0, having ya plurality of score lines defining main panels il and I2 and end panels I3 and Ill. Flaps I5 and IG are hingedly connected with main panels Il and l2, respectively. Flaps Il and I8 are provided at the'ends of end panel I3 and similar flaps I9 and 20 are provided at the ends of end panel Ill. It will be noted in Fig. l that main panels II and I2 are connected by means of 'a bottom panel 2l of special character having a medial score line Zia permitting the carton blank to be folded so as to bring the main panels into a substantially registering position. Main panel I 2 has glue flaps 22 and 23 at the two lateral edges thereof. End panels I3 and I4 have medial score lines 24 and type is disclosed in my copending application, Serial No. 255,030, filed on Feb. 7, 1939, so that no detailed description of its operation will be necessary. It will be sufficient to state that by bringing the main panels into superposed registering position and by folding back the portions of the end panels beyond medial lines 24 and 25, such portions of the end panel may be glued to glue flaps 22 and 23 of main panel I2 whereby a flattened six sided box is obtained capable of being converted or squared-up into a rectangular package. It is to be observed that top flaps I5, I1 and I 9 are considerably longer than the corresponding flaps I 8, 20 and 2 I. The object of the accentuated length of these' flaps is to provide a backing surface of a liner of likewise accentuated length which at a later time is converted into a structure of standard length by cutting off the excess length, as this will appear more fully hereinafter.

The first step in the preparation of my improved sterile collapsible container is to adhesively secure a liner 26 to the carton blank by means of adhesive lines 21. As it will be best observed in Fig. 2, this liner is generally constituted of a 25 respectively. A carton blank of this general i The liner has such dimensions as to extend from the region of score line 2Ia oi' carton blank III structure depicted in Fig. 3. This operation will` fold the liner along its transverse 'medial line and will bring its edges into registering position. At the same time main panels I I and I2 will like wise be brought into a superposed registering lposition and will have the folded' liner therebetween.

pressure in separate operationsM along each of the A exposed marginal strips of the folded liner. As a rule, however, I prefer to apply al continuous U-shaped seam to these marginal portions by a means of a special U-shaped heat-sealing member so that a continuous hermetical seal 28 will be obtained. This seal converts the folded'gliner sheet 26 into a completely sealed envelope into which the access of any external substance, including that of atmospheric air, is prevented. End panels I3 and I4 are now folded along their medial score lines] 24 and 25 and their inner surface is adhesively secured to glue flaps 22 and 23 of main panel I2. It will be noted that folding of the end panels along their medial score lines will cause folding of the sealed envelope about the edges of glue flaps 22 and 23 so that a fold will be introduced into the portion of the envelope before the seam. This will protect the seam from the effect 'of internal pressure after the container has been filled and sealed.

The finished container in its collapsed form, as it is shipped and stored, is shown in Fig. 4. Due

to the fact that in this condition theyinner enve- 1 lope is completely sealed, the container may be preserved in the sterile condition indefinitely. A further interesting result of this completely sealed structure is that the external atmospheric pressure prevents squaing-up lthe collapsible container due to the fact that no air is admitted thereto and squaring-up would create a vacuum therein. In other words, the containers of the invention will be automatically maintained in a completely fiattened condition which is an important advantage in that it reduces the space required for shipping and storage of the containers to a minimum. K

When it is desired to use and to iill the container, it is necessary to provide a lling opening therein through which first air may be admitted into the interior, permitting squaring-up of the container and subsequently the filling operation may be performed and the filled container may be resealed. The filling opening may be provided in various ways, such as by punching a small opening or by cutting oif one of the edges of the container, as this is indicated by dotted line 23 in Fig. 4. It is preferred, however, to cut olf a Laterally the liner extends across.

transverse marginal portion ofthe inner envelope, and the container shown in the drawings is especially adapted for this type of manipulation. According to this preferred procedure, a top marginal strip 30 of the collapsible container is removed by cutting the ,container along a line 3I- indicated in dotted lines in Fig. 4. This operation will remove the topl marginal portions of both the inner envelope and of the external carton. 'I'his will have the result of admitting air into the interior of the envelope and at the same time removing the excess portions of top flaps I5, I1 and I3 which will now have the same length as the corresponding bottom flaps I6, 20 and2l. The flattened container may now be squared-up and assumes the shape illustrated in Fig. 5. It will be noted that the squared-up and opened envelope has two lateral fins 32 and 33 which are nattened in the direction of the end panels I3 and I4. The material to be packaged', such as, milk, cream, or some other commodity, may now be introduced through a filling spout 34 connected with a storage tank and with a suitable measuring device which introduces a predetermined unitary amount of the material to be packaged.

I have found that in order to provide a her metical seal of the package and to positively prevent leakage from such sealed package, it is critically important to provide a seal of such character in which only two layers of material are placed into a face to face relation and from which intervening layers, re-entrant folds and similar danger points of leakage are positively eliminated. Therefore, in order to obtain the desired hermetical seal and the face to face relationship of only two layers of material in the mouth portions of the envelope, a special procedure has to be used. This consists in bringing together the flattened mouth portions ofthe envelope into a face to face relation and folding down the'resulting flattened mouth portions into the plane delined by the hinge lines of the top flaps. Attention is directed to the circumstance that this folding down of the flattened `marginal portions is possible only in the direction in which iins 32 and 33 are pointing due to the fact that these fins act much in the same manner as reinforcing ribs which are almost completely rigid inother directions. This operation provides the structure depicted in Fig. 6. Of course, the top marginal strip 35 of the package embodying the invention may be heat-sealed already in this position by means of a heat-sealing device of suitable character. Generally, I prefer, however, to fold this region 35 to be heat-sealed verticallyupwards (Fig. 7) whereby it is more readily accessible to a heat-sealing member and backing member of standard type. It will also be noted that region 35 represents'a completely at seal area in which even the terminal portions of ns 32 and 33 are straightened out in the direction of the rmouth walls of the envelope whereby the critically important completely fiat seam may be readily obtained. After heat-sealing, the resulting tabs 36 and 3l may be `folded towards each other along lines 3s ao as as this is showrrI in Fig. s and the flaps of the carton may be closed and adhesively secured thereabout. This completes the package of the invention.

It will be noted that the present invention provides important advantages. The method of the invention makes it possible for the first time in the history of the art to maintain the originally contamination of the interior ofthe container by micro-organisms. Of course, this is of extreme importance particularly when it is desired to employ collapsible containers for the purpose of packaging milk, cream and similar foodstuffsand may be manufactured, sold and used on a practical and commercial scale at a very low price. f

Although the present invention has been described in connection with a few preferred embodiments thereof, variations and modifications lmay be resorted to by those skilled in the art without departing from the principles of the present invention. I consider all of these vanations and modifications as within the true spirit and scope of the present invention, as disclosed in the foregoing description, and defined by the appended claims.

I claim:

1. The method of packaging foodstuffs and similar commodities in a substantially sterile condition which comprises providing a substantially iiuid-tight and sterile collapsible container adapted to be hermetically sealed, collapsing said container, hermetically sealing said collapsed container to prevent the entrance of foreign and septic matter thereinto, and maintaining said container in a hermetically sealed condition until such timeas it is filled with a commodity whereby the atmospheric pressure will maintain said container in completely collapsed position. I 2. The method of packaging foodstus and similar commodities, including milk, in a substantially sterile condition which comprises providing a substantially fluid-tight and sterile collapsible container adapted to be heat-sealed, co1- lapsing said container, hermetically heat-sealing said collapsed container to positively prevent the entrance of foreign and septic matter into the interior thereof, and maintaining said container in a. hermetically sealed condition until such time as it is filled with a commodity whereby the atmospheric pressure will maintain said container in completely collapsed position.

.3. The method of packaging milk and similar liquid perishable commodities in a substantially sterile condition which comprises providing a. substantially fiuid-tight and sterile collapsible container fusible at least on the inner surface thereof, collapsing said container, applying heat and pressure to a predetermined region of said container to hermetically seal the same and thereby to positively prevent the entrance of detrimental matter into the interior of said container, maintaining lsaid container in a hermetically sealed condition until such time as it is filled whereby the atmospheric pressure will maintain said container in completely collapsed position, opening said hermetically sealed container, filling said open container with the commodity to be packaged, and then hermetically resealing said container.

4. The method of aseptical packaging which comprises providing a fiat and collapsed envelope fluid-tight on at least the inner face thereof, hermetically sealing said collapsed envelope to prevent the entrance of deleterious microscopic matter thereinto, maintaining said envelope in such sealed condition until the time of filling whereby` the atmospheric pressure will maintain said envelope in completely collapsed position, opening said envelope immediately prior to filling, thereafter filling said opened envelope with contents, and then hermetically resealing said filled container.

5. The method of aseptical packaging which comprises providing a collapsed envelope fiuidtight and fusible on .at least the inner face thereof, heat-sealing said envelope along its marginal portions to prevent the entrance of microorganisms thereinto, `maintaining said envelope in such sealed condition until the time -of filling thereby holding the inner Walls thereof in a face and sterile collapsible container adapted to be heat-sealed, collapsing said container to bring its opposed walls into a face to face position and to reduce its volumetric content substantially to zero, hermetically heat-sealing said container while in .such collapsed condition whereby the external atmospheric pressure will maintain said container in collapsed condition and entrance of deleterious microscopic matter into the interior thereof is positively prevented, and maintaining said container in a collapsed and hermetically sealed condition until such time as it is filled with a commodity.

7. The method of aseptical packaging which comprises providing an envelope fluid-tight and fusible on at least the'inner face thereof, collapsing said envelope to bring its opposed walls into a face to face position and to vreduce its internal capacity substantially to zero, hermetically heat-sealing said envelope along its marginal portions whereby the external atmospheric pressure will maintain said envelope in c'ollapsed condition and the entrance of microorganisms into the interior of the envelope is positively prevented, maintaining said envelope in such col` `lapsed and sealed condition until the time of through said filling opening, and' then hermetically resealing said filling opening.

8. The method of aseptical packaging which comprises providing a fiat envelope constituted of a sheet .iiuid-tight and fusible on at least one face thereof folded along a line to have its edges in a substantially registering position, heat-sealing said envelope along three marginal strips to provide hermetic closure thereof and to prevent the entrance of organic and inorganic impurities, maintaining said envelope in such sealed condition until the time of filling thereby holding the inner walls thereof in a face to face position by means of the atmospheric pressure, cutting off a marginal strip of material from said envelope toremove one of said sealed marginal strips and to provide a filling opening, thereafter filling said envelope with contents through said filling opening, and then resealing said filling opening by a heat-sealed seam parallel with said cut-off marginal strip.

9. 'Ihe method of aseptical packaging which velope and the attached carton in collapsed position, providing a filling opening in said closed envelope, squaring-up said carton thereby simultaneously squaring-up said envelope, thereafter filling said envelope with contents through said filling opening, and then resealing said. filling opening and closing the flaps thereabout.

10. The method of aseptical packaging which comprises providing a flat folded carton having at least four parallel score lines and closing flaps at the ends thereof, said carton having adhesively secured to its inner surface a liner fluid-tight and fusible at least on the inner surface thereof longitudinally projecting beyond the hinge lines of saidclosing iiaps and free of attachment thereto, heat-sealing said liner along its longitudinal and its transverse edges to convert it into a hermetically sealed envelope protected against the en.

trance of microorganisms'into the interior thereof, maintaining said envelope in such hermetically ysealed condition until the time of filling whereby the atmospheric pressure will maintain both the envelope and the attached carton in collapsed position, cutting oif the top sealed portion of said envelope to provide a filling opening, squaring-up said carton thereby simultaneously squaring up said envelope, thereafter filling said envelope with contents through said filling opening, and then sealing said filling opening and closing said flaps.

11. 'I'he method of aseptical packaging which comprises providing a fiat folded carton having at least four parallel score lines at the ends thereof, said carton having adhesivelyy secured to its inner surface a liner huid-tight and fusible at least on the inner surface thereof longitudinally projecting beyond the hinge lines of said closing flaps at least at one end of said carton and free of attachment thereto, heat-sealing said liner along a U-shaped strip adjacent to its longitudinal and its transverse edges to convert it into a hermetically sealed envelope protected against the entrance of microorganisms into the interior thereof, maintaining said'envelope in such hermetically sealed condition until the time of iilling whereby the atmosphericpreslsure will maintain both the envelope and the attached carton in collapsed position, providing a restricted opening in the top portion of said envelope to permit the entrance of air thereinto, squaring-up said carton thereby simultaneously squaring-up said envelope, cutting off the top marginal portion of said envelope to provide a filling opening, thereafter filling said envelope with contents through said filling opening, and then heat-sealing said iilling opening and closing said iiaps.

12. The method of aseptical packaging which comprises providing a flat folded carton having a plurality of longitudinal lines deiining a pairof end panels with medial crease lines therein and a pair of main panels and having:l closing aps at the end of at leastsome of said panels, said carton having adhesively secured toits inner sur face a liner fluid-tight `and fusible at least on the inner surface thereof longitudinally projecting beyond the hinge lines of said closing flaps and disconnected .therefrom at least at one end of said panels, heat-sealing said liner along its longitudinal and transverse edges to convert it into a hermetically sealed envelope protected against the entrance of microorganisms into the interior thereof, maintaining said envelope in lsuch hermetically sealed condition until the time of filling whereby the atmospheric pressure will maintain both the envelope and the attached carton in collapsed position, cutting off one of the vterminal portions of said flat folded carton and thereby simultaneously cutting olf a sealed terminal portion of said envelope to permit the entrance of air thereinto, squaring-up said carton thereby simultaneously squaring-up said envelope, thereafter filling said envelope with contents, and then resealing said envelope and closing said flaps.

13. The method of making a sterile package which comprises bringing together the marginal regions of a liiexible material into a contacting relation, and sealing suchmarginal regionsv to provide a completely sealed structure maintained -in collapsed position by the atmospheric pressure whereby contact of the inner surfaces of such structure with the atmosphere is prevented,

' said structure being adapted to be opened immediately prior to filling and to be resealed after filling. a 4

14. The method of making a sterile packaging medium which comprises bringing together the marginal regions of a sheet integrally constituted of a thermoplastic material into a contacting relation, and applying heat and pressure to such marginal regions to hermetically heat-seal the resulting structure and to maintain the same in collapsed position by the atmospheric pressure whereby contact of the inner surfaces of such structure with the atmosphere is positively prevented, said structure being adapted to be opened immediately prior to filling and to be resealed after filling.

15. The method of making a sterile packaging unit which comprises folding over a iiexible sheet fluid-tight and fusible on at least one face thereof along a line to bring its edges into a substantially registering position, and heat-sealing said folded sheet along the marginal regions of said registering edges to provide a hermetically sealed envelope proof against the entrance of deleterious matter thereinto, said sealed envelope being held in collapsed position by the atmospheric pressure and adapted to be preserved indefinitely in its original-sterile condition and capable of being opened prior to filling and of being resealed after filling.

16. The method of making a sterile packaging unit which comprises forming a xfour-walled carton blank having medial score lines in two oppositely disposed Walls thereof, adhesively securing a substantially rectangular liner to said blank having at least its top surface iiuid-tight and fusible, simultaneously folding over said carton blank and liner to form an envelope open at three edges, heat-sealing all of these three edges of saidenvelope While it is resting on said blank to hermeticallyseal the same and to positively prevent the admittance of deleterious matter thereinto, and subsequently adhesively securing the ends of said carton blank together whereby the atmospheric pressure will maintain both the l envelope and the attached carton in collapsed position, said hermetically sealed envelope being

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