US2160367A - Method of making sealed packages - Google Patents

Description

y 1939- D. E. MAXFIELD 2,160,367

METHOD OF MAKING SEALED PACKAGES Filed Nov. 27, 1937 2 Sheets-Sheet l 1 vmu .JR.

ATTORi K Y y 1939- D. E. MAXFIELD 2,160,367

MEFhOD OF MAKING SEALED PACKAGES Filed Nov; 27, 1957 2 Sheets-Sheet 2 gi'tllllll III or!!! 1 nn 4 Patented May 30, 1939 UNITED STATES PATENT OFFICE METHOD OF MAKING SEALED PACKAGES Application November 27, 1937, Serial No. 176,815

3 Claims.

My invention relates to methods of making, filling and sealing containers to form sealed packages, and particularly to methods of making, filling and sealing non-rigid containers for various solid materials.

In accordance with my invention, during formation and/or filling of a container and before its final closure, and preferably before and/or during the filling operation, there is introduced into the container a conditioning agent, specifically a desired gas, vapor, or mixture of gases, or vapors, for beneficially affecting or preserving the package contents, the agent remaining in the package after it is sealed.

More specifically, after formation of a tube from a web of Cellophane, or other suitable flexible material, and closure of the tube at one end to form a receptacle open at its other end, a desired gas, vapor, or mixture of gases or vaally or completely to displace the air therein; preferably, the flow is continued until the receptacle is sealed, as by flattening the walls of the tube, above its contents, into adhesive relation with each other.

Further in accordancewith my invention, there additionally may be introduced with the filling material, a gas or vapor, or mixture of them. of composition the same as, or different from. that previously introduced as aforesaid into the receptacle during its formation, which additional gas or vapor itself, or with the previously introduced gas or vapor, comprises or constitutes the conditioning agent.

My invention further resides in methods having the features hereinafter described and claimed.

For an unders anding of my invention, reference is to be had to the accompanying drawings in which:

Fig. 1; in perspective, illustrates formation of a tube from a web of flexible material:

Fig. 2, in perspective, illustrates closure of one end of the tube of Fig. l and in addition of filling material and a conditioning agent;

Fig. 3, in perspective, illustrates the completed, sealed package, before its severance from the web or strip;

Fig. 4 diagrammatically illustrates elements of a machine for performing the methods of Figs. 1 to 3 and several packages at successive stages of their completion;

Fig. 5 is a plan view in section taken on line 5-5 of Fig. 4';

Fig. 6 is a front elevational view, partly in section, of a modified form of filling tube;

Fig. 7 illustrates the method as applied to formation of square bags and significant parts of a mechanism for performing it;

pors, is caused to flow into the receptacle parti- Fig. 8 is a plan view in 8-8 of Fig. 7;

Figs. 9 and 10 illustrate another mode of making, filling and sealing a container using two webs of flexible material;

Fig. 11, in perspective, illustrates a third continuous method of making, filling and sealing containers;

Fig. 12, in perspective, shows the product resulting from the method of Fig. 11.

In the packaging of materials such as food products, medicinal powders or tablets, tobacco, and other materials, it is frequently desirable to preserve or modify their characteristics during the period elapsing before they are opened for use section, taken on line or consumption of their contents. In some cases,

the nature of the contents of the package may be such the air in the package should be very dry, or again, of moisture content approaching saturation, or, in other cases, the atmosphere may preferably comprise or consist of some gas, such as nitrogen or carbon dioxide.

Although not in all aspects unsuited for use in connection with rigid packages, such as those of tin,glass, pitch-board, fiber or the like, my invention is especially suited for non-rigid sealed packages, particularly those made of flexible materials such as Cellophane, paper, or the like. Referring to Fig. 1, a web or strip W of bag material fed, for example, from a roll A is formed into a tube T and the edges of the strip forming the seam of the tube joined in any suitable manner; for example, the edges of the strip may be overlapped to suitable extent to form a seam S which is made gas-tight in any desired or suitable manner. When the strip is of heat sealing Cellophane, the sealing may be accomplished by applying heat and pressure, as by a corrugated, heated roll, along the overlapping edges 01' the strip.

The tube so formed is flattened, as at E, -to provide a receptacle R closed at its lower end and open at its upper end; the flattened portion E may be sealed in any suitable manner; for example, when the strip S is of moisture-proof heat sealing Cellophane, or of Sylphrap, Maralux" or like papers having a coating of, or impregnated with, a substance which softens upon application ofheat, the sealing may be accomplished concurrently with the flattening of the strip by heated, clamping tools, preferably corrugated.

The contents of the package, such as candies, potato chips, soap flakes, or the like, is introduced into the tube or open end of the receptacle, which is thereafter closed and sealed, in any suitable manner, and particularly as hereinafter described. After formation of the seam S andclosure E, and before, or during, addition to the receptacle R of the package contents or filling material F, the desired or selected conditioning agent is introduced into the receptacle, as through the tube I. When the conditioning agent is gaseous, such as dry or moist steam, carbon dioxide, nitrogen or the like, the addition of the conditioning agent may be for a predetermined time, by a predetermined amount, or may be continuous throughout the formation, filling and closing of the package.

The gas or vapor, or mixture of them, introduced into the open-ended receptacle or bag more or less completely displaces the air therefrom and maintains its distended form to receive its intended solid contents, whether they be in the form of powders, flakes, tablets, or any other shape or form.

After or during introduction of the conditioning gas, the strip W, or tube T, is fed to bring the solid contents suitably below the lower end of the tube l, whereupon the tube T is again flattened, as in Fig. 3, to form the second seal E for the uppr end of the package or receptacle R. The completed package containing the filling material F and the conditioning gas is then severed from the strip. For continuous flow of the conditioning agent through the pipe I, the clamping of the tube to form the upper seal E serves as an automatic cut-oil preventing further addition of gas to the receptacle or escape of gas when the strip is severed as hereinafter described.

The clamping of the tube as foresaid to provide the top seal for package R concurrently forms the bottom closure for the next receptacle RI which, for continuous flow of gas through pipe I, immediately begins to receive conditioning agent before or during addition of the filling material.

As thus far described, the packages are in a continuous string attached to each other by the flattened portions E of the strip or web; to form individual packages, each of the seals E is cut crosswise, as in Fig. 4, by a knife l4 or the like.

Although not limited to any particular mechanism, my method may be conveniently performed by suitable modification of known types of package-forming and filling machines, for example, a machine of the type illustrated and described in Zwoyer Patent #1,986,422 or of the type shown in Aldrich Patent #1,937,501.

Referring to Fig. 4, the web W is'threaded over the shoulder plates 2, 2, and thence downwardly between the outer former-tube 3 and inner former-tube or mandrel 4. The edges of the strip are led downwardly and across, one inside the other, to form a seam; the left-hand edge of the strip is led to the right by the guide piece 5, 'while the right-hand edge of the strip is led to the left by the guide piece 6. Thus there is formed on the outside of the inner former-tube 4, a tube T of flexible bag material with a longitudinal seam comprised of the overlapping edges of the web or strip. A heated corrugated roll presses the overlapping edges of the web against tube 4 to form the seal S. The flexible tube T is flattened, beyond the former-tube 4, to form the seal E bythe heated clampingtools I which move from the dotted to the solid line positions indicated in Fig. 4, to draw further web material from the roll A for shaping into tubular form as above described. The flattening of the tube T at E forms a receptacle whose lower end is closed and whose upper end surrounds the former-tube 4.

The contents of the bag are fed thereinto, by gravity or some positive feeding means, through the passage or tube 8 disposed within the inner As appears in Figs. 4 and 5, the space between the filling tube 8 and the inner former-tube 4 is divided, as by partitions 9, 9, into two chambers Ill, l2, which extend lengthwise of the filling tube 8 and which are out of communication with each other except at their lower ends. At its upper end the chamber [0 is in communication with a pipe or conduit l I extending to the source of conditioning gas or vapor. In the communication line between the gas source and chamber l0 there may. be interposed any suitable valve mechanism for controlling the pressure or rate of flow of gas and/or suitable valve mechanism operated manually, or automatically,- in timed relation to the formation, filling and closing of packages on and below the tube-forming mandrels 3 and 4.

The upper end of chamber I2 is in communication with a pipe or conduit l3 which may dis- ,charge to waste or to reclamation apparatus.

In the absence of control valves in the supply line I I, gas flows continuously from the source through chamber l0 into the closed tube or partially formed package extending from the former-tube 4 to the clamping tools I, and thence upwardly through chamber l2 and out of the discharge pipe l3 which is preferably provided with a check-valve not shown.

i The flow of gas or vapor replaces the air within the receptacle including any air which may have been entrained by the filling material during its movement from a hopper or other source of supply downwardly through tube 8. Preferably the flow of conditioning gas continues, insofar as any particular receptacle is concerned, until after it has been filled and the clamping tools have flattened'the tube T above the contents or filling material to complete the sealing of that receptacle. My invention is not limited, however, to such continuous flow of conditioning agent, for a valve in the gas-supply line may be timed to provide for introduction of a predetermined amount of conditioning agent into each package.

After each package has been filled and sealed, it is severed from the continuous strip as by a knife I 4, Fig. 4, which cuts midway of the fiattended portion E between two successive packages. If desirable or necessary, a suitable strip of metal or foil may be applied to embrace the ends of the packages to add strength to the seal. For most applications this is not necessary, particularly when the strip is moisture-proof, heatsealing Cellophane, since the heat and pressure applied to the ends and seam form a joint which remains gas-tight for all ordinary handling.

When the material is not free-flowing and tends to jam in the tube 8, there may be provided a feed auger l5, Fig. 6, extending lengthwise and interiorly .of the tube 8. Such an auger also may be utilized to provide for feed of a predetermined amount of material to each receptacle in turn; in such case, the auger i5 is intermittently actuated to rotate a predetermined angular extent between successive strip-feeding movements of the clamping tools I.

When it is desired to make bags of the square type, the shape of the inner former-tube is coramuse? outlet duct I2 are formed in the walls of a member 4A whose hollow center provides for fiow of the filling material to the receptacles, and whose outer perimeter corresponds in shape to the receptacles to be formed. In the particular example shown, the interior configuration of the passage for filling material is suited for crackers or wafers C.

In similar manner, a conditioning agent may be introduced into packages, formed from two webs of flexible material, during their formation, before and/or during filling thereof, and before their severance from the two webs after sealing.

Referring to Fig. 9, the two webs WI, W2, of any of the flexible materials herein contemplated, are

drawn from rolls Al, A2 and shaped, as about former-tube 4, into a tube T2. Each of the webs is of a width somewhat greater than half the circumference of tube 4 to provide margins or flanges eventually to be joined, as by application of heat and pressure to form the seams SI, S2 extending from tube T2, Fig. 10. As in the preceding methods, the tube T2 is flattened below the lower end of the former-tube 4 to provide an end seal E for the lower end of a bag or receptacle R8 whose upper end at that time snugly fits the former-tube 4. Before and/or during the filling of the bag with candies, powders, or the like, which are introduced into it through the fill ing conduit 8, a conditioning gas is permitted or caused to flow into the bag from duct ID, the excess flowing out of the bag through duct l2. The tube of web material is then flattened and sealed above the filling material to form a closed package R'l, which is subsequently severed from the web, as indicated in Figs. 9 and 10, and so then becomes a separate individual package R6.

In the method illustrated in Fig. 11, the edges of a single web W3 of package material, instead of being overlapped as in Fig. 1, are brought into face to face engagement to form a seal S3 extending outwardly from the former-tube 4. As in the prior methods described, during the formation of a package, a conditioning gas is introduced thereinto, preferably before or during filling of the bag, when in the position of bag Rl l. After the bag is sealed above the contents, as indicated by bag RIO, it is detached from the web by cutting of seal E transversely of the web to form the completed package R9 containing solid contents and a conditioning agent therefor.

Though in the methods specifically described, I prefer to use, because of simplicity of seal-formation, web material coated or impregnated with a which may be the same as or different from that introduced through pipe I of Fig. 2 or duct ll of Figs. 4, 6, 7, 9 or 11. This is readily accomplished when the gas is heavier than air by utilizing, for the solid material to be packaged, a hopper of considerable depth. When heavy gas, for example, carbon dioxide, is supplied to the hopper, it sinks toward the bottom thereof to displace air which otherwise would pass with the material to the bags during the filling operation. The downward movement of tube T or Tl by the clamping tools affords a pumping action which may be utilized to draw the heavy gas from the hopper through conduit 8 into the receptacles as they are successively formed. I

What I claim is:

1. The method which comprises intermittently flattening and transversely sealing a tube of web material to form flattened seal sections spaced longitudinally of the tube, solely by intermittently pulling the flattened web material over a tubular form pulling from a supply sufficient web material to form a container, solely by so pulling the Web material over the form intermittently reducing the pressure within the tubular form, during each pull upon the web material joining the edges thereof before they pass beyond said form, between successive pulls upon the web material introducing solid filler and conditioning gas into each container in succession through the form in which obtains reduced pressure as aforesaid sufilcient alone to draw adequate conditioning gas into the tube, and severing the web through the seal sections to detach the filled containers.

2. The method of producing containers and filling them with solid material and a'conditioning gas or vapor therefor which comprises intermittently forming flattened seal sections spaced along a tube of web material, intermittently feeding the web material solely by pulling over a form a supply thereof sufficient web material to form a container, solely by so pulling the web material over the form intermittently effecting reduced pressure within the form sufficient alone to draw conditioning gas or vapor into the tube, introducing solid material into each container concurrently with or after introduction of the aforesaid gas or vapor, and severing the web material through said flattened seal sections to detach filled containers.

3. The method of producing containers and filling them with solid material and a conditioning gas or vapor therefor which comprises drawing web material over a tubular form to shape it into a tube, sealing the longitudinal edges of the t be to each other, intermittently transversely flattening the tube to form seal sections spaced longitudinally of the tube, bringing into mixture with each other the solid material and the conditioning gas or vapor, to constitute a bulk supply thereof suflicient for filling many containers therewith, effecting aforesaid drawing of web material over the form solely by pulling the flattened web material, solely by so pulling the web material over the form efiecting reduced pressure therein sufficient alone to draw the gas into the tube, after formation of each seal feeding the mixture fromsaid supply through the tubular form into the tube shaped as aforesaid, and severing the web material through said flat- DANIEL E. MAXFIELD.

\ CERTIFICATE OF CORRECTION.

Patent No. 2,160,567. May 50, 1959.

' DANIEL E. MAXFIELD.

It is herebycertified that error appears in the above numbered patent requiring correction as follows: In the grant, line 2, and in the heading to the printed specification, address of assignee, after Summerdale, in-

sert --Philadelphia,-; as shown by the record ofassignmentsin this office;

page 1, first column, line 1 11,, strike out the Word "in" before "addition";

page 5, second column, line LLl, claim 2, after "form" insert -from--; and

that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed end sealed this 28th day of January, A. D. 19in.

Henry Van Arsdale,

(Seal) Acting Commissioner'of Patents.

Images