US3187476A

US3187476A - Method of producing sealed and partially filled packages of equal filling degrees

Info

Publication number: US3187476A
Application number: US192618A
Authority: US
Inventors: Andersson Stig Gunnar
Original assignee: Tetra Pak AB
Current assignee: Tetra Pak AB
Priority date: 1962-04-24
Filing date: 1962-04-24
Publication date: 1965-06-08
Anticipated expiration: 1982-06-08

Description

June 8, 1965 s. (5. ANDERSSON 3,187,476 METHOD OF PRODUCING SEALED AND PARTIALLY FILLED PACKAGES OF EQUAL FILLING mamas Filed April 24, 1962 Sheets-Sheet 1' J Q Lg L m N E V W Si'l'g Gunnar Anclenslson BY m moauzvs June 8, 1965 s. G. ANDERSSON 3, 7, 76

METHOD OF PRODUCING SEALED AND PARTIALLY FILLED PACKAGES OF EQUAL FILLING DEGREES Filed April 24, 1962 2 Sheets-Sheet 2 INVENTOR St/Q Gunnmr Andersson U WJWMMIM ATTORNEV g 3,137,476 METHUD F. PRGDUCING SEALED AN? PARTIALLY FELLED PACKAGES 0F EQUAL FILLENG DEGREES Stig Gnnnar Andersson, Lund, Sweden, assignor to AB Tetra Pair, Lund, Sweden, a cempanyoi' Sweden Filed Apr. 24, 1962, Ser. No. 192,61fi 3 Claims. ll. 53--23) The presentiinvention relates to afmethod of producing.

filling materials in charges, i.e. in fully intermittent action, whereby either conventional dosage or charging pumps or containersfor filling material having filling pipes equipped with valves which open into the interior of the tube, have been resorted to.

of the problem connected with supply of filling material.

Considerable dis-' I advantages are attached to both'thesetechnical solutions l United States Patent 0 perpendicular planes. These packages are filled as they are manufactured with filling material fed into the interior of the tube through a filling pipe 9 entering immediately below the pulley roller 2 between the two edges of the double-folded packaging material and extending downwards through the forming ring 3 and opening out above the forming and sealing part. 1

.The pairs of clamping jaws 6'and 7 are arranged in yokes 1d and 11 respectively, yoke 10 being reciprocatory movable vertically inside the other yoke it. Each yoke is fastenedat the bottom end of two vertical sliding rods l2, l3 and 14, 15 (not visible), which are vertically journalled for displacement in the machine frame.

The vertical movement of each pair of clamping jaws 6 or 7 along the tube axis is timed to the movement in transverse direction of both cooperating jaws in such' away that in an upper position the clamping jaws close to deform the tube wall, whilst in a bottom position they release their grip on the tube by separating. The clamping jaws 6 and 7 are equipped with devices whereby they will, simultaneously with the fiat-pressing, convey the sealing heat to the inside of the tube in the flat-pressed Among these disadvantages attention is drawn to the difiiculty in securing the necessary accelerating and retarding action required at high packing speed in View of the often long supply pipes for filling material from the dosage or charging pumps or the container, or, when using filling pipes equipped with valves, to achieve the mechanical control of it's closing valve within the usually limited space afforded by the small diameter tubes.

It is obvious that a continuous fillingaction from many points of view is superior-"to the intermittent action hitherto known. The invention indicates a procedure movement of the pair of clamping jaws as a unit are which with advantage may be applied in practice and which mainly 'is ch'ar'atcterized'therein that the filling material continuously,'and with constant discharge per time unit, is brought into the interior of the tube and that the metering of the volume required for the package is effected by the flat-pressing of the tube, thereby cutting off the connection betweenthe interior of the package being sealed and the remaining inner space of the tube.

In the following, the invention is described'with reference to the accompanying drawings, FIG. 1 of which in skeleton perspective view illustrates a packaging machine for manufacture of tetrahedron packages operating in accordance with the invention. FIG. 2 is a detail showing an auxiliary jaw arrangement for pinching the tube above the heat sealing jaws so as to shut off feed of filling material to the lower part of-the tube.

On the machine shown a web of double-folded packaging material 1 is carried over pulley roller 2 and is carried substantially Vertically into a horizontal tube forming ring where it is given a tubular shape. The side of the packaging material web 1 corresponding to the inside of the tube is heat-scalable, andtherefore the two web edges on the tube 4 being formed are sealed itogether by a longitudinal seam element 5 below the a cellulose acetate foil laminated to a polyethylene film. The bottom end of the tube 4 extends down to a formmaterial'at its bottom end in the shape of a jet into the interior of the tube 4 which is closed at the bottom end zone with the effect that the two flat-pressed sections of i the wall are heat-sealed to each other. r

Reciprocallyfor the two clamping jaws the transverse and axial movements are guided in such a way that always at least one pair of clamping jaws is in active engagement with the tube 4, which thereby is fed in its 7 direction of growing, i.e. downwards. Both the transverse movement for the individual clamping jaws and the axial transferred from a main shaft of the machine in a way not shown here. I a

' In their movement the pair of-clamping jaws 6 and 7 are guided in such a way and'otherwise so designed and arranged that they at equal time intervals cut off the connection between the interior of the package 8, being finished at the moment of fiat-pressing, and the interior of the tube 4 from which the package has been cut.

In accordance with the invention the filling material.

is supplied continuously and with a constant discharge per time unit via a connection pipe 16 to the filling pipe 5 by an automatic positive displacement pump, not shown. Accordingly the filling pipe 9 continuously and with constant discharge per time unit supplies the filling by the last sealing operation.

The pump for the filling material may preferably be driven by variable speed transmission from the main shaft of the machine in order that it may be possible to set the discharge per time unit at a value which, in the time interval corresponding to the time passing between two consecutive tube dividing fiat-pressing operations of ing and sealing part including two pairs of clamping jaws 6 and 7 which are arranged to'divide the tube 4 into sealed tetrahedron-shaped packages 8 by flattening and heat-sealing the tube 4 in narrow zones running transverse to the tube axis, thereby working in mutually the pair of clamping jaws 6 and 7, gives the filling material volume required for the individual package 8.

The supply of filling material is, however, adjusted in such a way that the filling material volume corresponding to the fiat-pressing time interval as mentioned does not exceed the volume of the individual packages.

The metering of the filling material volume required for each package is effected by the pairs of clamping jaws 6 and 7 which at the respective moment of fiatpressing cut the connection between the interior of the package 8 thereby sealed and the interior of the tube i and consequently prevents further supply of filling material to this package, wherefore the filling material being continuously supplied from the filling pipe 9 is collected in the end of the tube 4 being sealed by the relevant fiat-pressing operation, and so on.

Since the flat-pressing operation'not only divides the tube 4 but also the free flow of filling material, the heat- Patented June 8, 1965 scaling in the flat-pressing zone will have to be effected in at least local presence of filling material between the two flat-pressed sections of the inside of the tube facing each other. It is, however, possible to carry out heatsealing of this type without difliculties for a multitude of goods, liquid as well as pulverized.

Since the time interval between successive flat-pressing operations is decisive for the metering of filling material, and as furthermore the volume of the package is irrelevant to the volume of the filling material, as long as it only exceeds this, it is possible, in retaining the flat-pressing interval, to vary the length of the package by downwards lengthening the tube feeding stroke of the pairs of clamping jaws without changing the metering of the filling material volume. Evan if the position of the pair of clamping jaws along the tube axis should be altered at the moment of flat-pressing this is reflected on the metering of the filling material in a much smaller difference than the corresponding difference in position.

When the filling material consists of granular products, e.g. rice, beans or nuts, the method in accordance with the invention ought to be modified, since the sealing result can be jeopardized, if a too coarse grained product is enclosed in the transverse seam.

A way to solve this problem is to arrange above the sealing jaws and in co-operation with these a pair of pinchers as shown in FIG. 2 which just before each sealing operation are intended to pinch the tube and consequently to shut off the continuous feeding of filling material to the lower part of the tube so that the heat-sealing jaws thereafter immediately can be closed without the presence of filling material in the sealing zone.

These pinchers are not provided with heating elements but may merely be designed as spring loaded pincher bars carried on the top of the heat-sealing jaws. As shown in FIG. 2, the heat sealing jaws 17 are arranged in confronting relation on arms 18 mounted on pivots 19. Arranged at the top of the sealing jaws 17 are a pair of pincher bars 20 having cooperating pinching edges 20a designed to pinch the tube, not shown, between them. The pincher bars 20 are supported for sliding movement in recesses 21 provided in the upper part of the jaw arms 18 and are loaded in the direction towards each other by springs 22 each of which is arranged in compression between the rear end of the pincher bar 20 and the rear end of the recess 21. These spring loaded pinchers carried on the heat-sealing jaws are so timed in relation to the latter that the part of the filling material jet below the pinchers at the pinching moment may pass the intended sealing zone before closing the heat-sealing jaws upon the tube.

Furthermore, the spring forces actuating the pinchers .are chosen in such a way as, on one hand to make possible operative pinching of the tube jet, on the other hand not adversely alfecting the sealing pressure of the heatsealing jaws.

I claim:

1. In the method of producing sealed packages filled to less than their volumetric capacity and containing equal amounts of a fluent filling material which comprises forming a web of flexible material into a continuous tube, moving said tube longitudinally of itself, supplying a fluent filling material into said tube, and periodically flat pressing and sealing said tube in zones extending transversely of the longitudinal axis thereof and at predetermined distances therealong to establish individual packages between successive seal zones, the improvement wherein said filling material is supplied into said tube in the form of a continuous jet and at a constant discharge rate so correlated to said periodic flat pressing operating that the volume of filling material fed into said tube above a lower already formed transverse seal zone of a package being filled in the period between successive flat pressing operations is less than the volumetric capacity of the individual packages thereby establishing partially filled packages and effecting said transverse fiat pressing operations on said tube always at a level above the level of the filling material therein.

2. The method of producing sealed and partially filled packages as defined in claim 1 wherein said fiat pressing and sealing operation also effects a pinching off of said jet of filling material.

3. The method of producing sealed and partially filled packages as defined in claim 1 wherein said filling material has a granular characteristic and which further includes the step of pinching off said jet of filling material above and in advance of said flat pressing operation.

References Cited by the Examiner UNITED STATES PATENTS 2,741,079 4/56 Rausing 53-180 2,928,219 3/60 Gubler 53180 2,956,383 10/60 Gausman 53-182 X 2,960,808 11/60 Pike 53182 X 2,962,843 12/60 Hoelzer et al. 53-180 X 3,026,658 3/62 Schneider et a1. 53-182 X 3,040,490 6/62 Virta 53-180 X 3,057,129 10/62 Meissner 53-28 3,082,586 3/ 63 Schneider et al 53-182 FRANK E. BAILEY, Primary Examiner.

ROBERT E. PULFREY, Examiner.

Claims

1. IN THE METHOD OF PRODUCING SEALED PACKAGES FILLED TO LESS THAN THEIR VOLUMETRIC CAPACITY AND CONTAINING EQUAL AMOUNTS OF A FLUENT FILLING MATERIAL WHICH COMPRISES FORMING A WEB OF FLEXIBLE MATERIAL INTO A CONTINUOUS TUBE, MOVING SAID TUBE LONGITUDINALLY OF ITSELF, SUPPLYING A FLUENT FILLING MATERIAL INTO SAID TUBE, AND PERIODICALLY FLAT PRESSING AND SEALING SAID TUBE IN ZONES EXTENDING TRANSVERSELY OF THE LONGITUDINAL AXIS THEREOF AND AT PREDETERMINED DISTANCES THEREALONG TO ESTABLISH INDIVIDUAL PACKAGES BETWEEN SUCCESSIVE SEAL ZONES, THE IMPROVEMENT WHEREIN SAID FILLING MATERIAL IS SUPPLIED INTO SAID TUBE IN THE FORM OF A CONTINUOUS JET AND AT A CONSTANT DISCHARGE RATE SO CORRELATED TO SAID PERIODIC FLAT PRESSING OPERATING THAT THE VOLUME OF FILLING MATERIAL FED INTO SAID TUBE ABOVE A LOWER ALREADY FORMED TRANSVERSE SEAL ZONE OF A PACKAGE BEING FILLED IN THE PERIOD BETWEEN SUCCESSIVE FLAT PRESSING OPERATIONS IS LESS THAN THE VOLUMETRIC CAPACITY OF THE INDIVIDUAL PACKAGES THEREBY ESTABLISHING PARTIALLY FILLED PACKAGES AND EFFECTING SAID TRANSVERSE FLAT PRESSING OPERATIONS ON SAID TUBE ALWAYS AT A LEVEL ABOVE THE LEVEL OF THE FILLING MATERIAL THEREIN.