US3708952A

US3708952A - Packaging machine with splitter bar fill

Info

Publication number: US3708952A
Application number: US00172034A
Authority: US
Inventors: J Schulze; J Soroka
Original assignee: Rexham Corp
Current assignee: Kloeckner Bartelt Inc
Priority date: 1971-08-16
Filing date: 1971-08-16
Publication date: 1973-01-09
Anticipated expiration: 1990-01-09
Also published as: SE390626B; CH559665A5; FR2150104A5; CA945964A; NL7211196A; GB1350709A; BE787600A; JPS4829590A; DE2239487A1

Abstract

Pouches are filled with a particulate product through a nozzle in a splitter bar. A non-oxidizing gas propels the product through the nozzle while also serving to purge the product and the pouches of oxygen.

Description

United States Patent 1 Schulze et a1. [451 Jan. 9, 1973 [54] PACKAGING MACHINE WITH [56] References Cited PLITTER BAR FILL S UNITED STATES PATENTS [75] Inventors: James R. Schulze; Joe F. Soroka,

both of Rockford Ill 2,863,266 12/1958 Moore ..53/112 B X 3,619,975 11/1971 Johnson et a1. ..53/112 B [73] Assignee: Rexham Corporation, New York,

N.Y. Primary Examiner-Travis S. McGehee [22] F] d A 16 1971 Att0rneyWolfe, Hubbard, Leydig, Volt & Osann 1e ug. 21 App1.No.: 172,034 1571 ABSTRACT Pouches are filled with a particulate product through a nozzle in a splitter bar. A non-oxidizing gas propels SS/11325333932 the product through the nozzle while also Serving to 58 Field o ';;;;|;'llllllillllllilliii5E 112 A 183 purge the pmduct and pwches 11 Claims, 9 Drawing Figures PATENTED JAN 9 I973 SHEET 1 0F 3 J a ad I B M J hm v a z M f"? 0% M WW ml. J m m 7d:

m m j 5 X an r PACKAGING MACHINE WITH SPLITTER BAR FILL BACKGROUND OF THE INVENTION This invention relates to a machine for packaging product in substantially flat, flexible walled pouches which are adapted to be filled and sealed as an incident to being advanced edgewise along a predetermined path. The invention has more particular reference to a packaging machine in which the product is deposited into the pouches through a passage in an elongated splitter bar which overlies and extends along the path and keeps the upper ends of the pouch side walls separated from one another.

While the invention will find wide use in standard packaging machines of general applicability, it is particularly advantageous when utilized in conjunction with a controlled atmosphere packaging machine in which the pouches are filled in the presence of an inert or non-oxidizing gas so as to maintain the product in a substantially oxygen-free environment within the pouches. A recent example of a controlled atmosphere packaging machine is disclosed in Johnson et al. US. application Ser. No. 40,250, filed May 25, l970 and assigned to the assignee of the present invention.

SUMMARY OF THE INVENTION One of the objects of the present invention is to provide a new'and improved packaging machine of the above character which is especially adapted to fill the pouches at a comparatively fast rate with a particulate product such as powdered or granular material and which is characterized specifically by its ability to keep the tops of the pouches relatively clean and free of the product so that good heat seals subsequently may be formed at the tops of the pouches.

An important object is to provide a controlled atmosphere packaging machine which is comparatively simple in construction when compared with prior machines of the same general type, which is capable of packaging the particulate product at high speeds while maintaining a low content of oxygen in the pouches and which, at the same time, keeps the tops of pouches cleaner so as toreduce the number of pouches with defective top seals.

A more detailed object is to achievethe foregoing aims by (a) depositing the product into the pouches through the passage in the splitter bar, (b) assisting the flow of the particulate product through the comparatively narrow passage with pressurized gas which, in a controlled atmosphere machine, is a non-oxidizing gas capable of purging the product and the pouches of oxygen as an incident to the filling operation and (c) clamping the tops of the pouches to the splitter bar as the pouches are filled and purged so as to prevent the product from being blown upwardly into and contaminating the top seal area.

The invention also resides in the novel construction of a dispenser for filling the pouches, in the unique purging of the pouches through the splitter bar after filling of the pouches and preparatory to scaling, and in the novel use of staggered rails located alongside the pouches to exclude ambient air from the filled and purged pouches as the latter are advanced toward the sealing station.

These and other objects and advantages of the invention will become more apparent from the following detailed description when taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of a new and improved packaging machine embodying the novel features of the present invention.

FIG. 2 is a perspective view of part of the splitter bar. FIG. 3 is a fragmentary cross-section taken along the line 3--3 of FIG. 2.

FIG. 4 is a fragmentary vertical cross-section taken DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings for purposes of illustration, the invention is embodied in a packaging machine for filling flexible walled pouches 10 of heat sealable material with product and for sealing the pouches to enclose the product therein. The basic machine is of the same general type disclosed in Bartelt US. Pat. No. 2,649,671 and includes a movable chain-type conveyor 1 1 (shown schematically in FIG. I) mounted on a main frame 13 and carrying clamps 14 which grip the pouches and advance the latter edgewise and open end up along a horizontal path through various operating stations located at horizontally spaced positions along the path.

Each set of clamps l4 initially picks up the leading pouch 10 of a strip of interconnected and newly formed pouches advanced toward the upstream end of the conveyor 11 by feed rolls 15 (FIG. 1), and grips the leading pouch as the latter is severed from the strip by a cutting mechanism 16. The conveyor, the feed rolls and. the cutting mechanism herein are driven intermittently and in timed relationby a power-actuated cycle shaft 17 extending beneath the frame 13. The pouches thus are advanced by theconveyor with a step-by-step motion and are opened, filled and sealed at spaced opening, filling and sealing stations 18, 19 and 20 (FIGS. 1 and 4) during the dwell periods which occur between successive steps.

After being picked up by the conveyor 11 and before being filled, each initially flat pouch 10 is partially opened by a shot of gas injected into the pouch. For this purpose, an elongated horizontal splitter blade or bar 21 (FIGS. 1, 4 and 5) of narrow width is supported on the frame 13 by brackets 23 and extends along and overlies the pouch path so as to be straddled by the upper edge portions of the pouches as the latter are picked up and advanced by the clamps 14. The splitter thus keeps the upper edges of the side panels of the pouches separated from one another. Formed in the splitter and opening out of the lower edge thereof is an upright passage 24 (FIGS. 4 and 5) which communicates with a cylinder 25 (FIG. 4) of pressurized gas through a line 26 and a valve 27. As each pouch dwells beneath the passage, the valve is opened momentarily and a shot of gas at a pressure of about 8 to 10 psi, is blown into the pouch to separate the side panels 'as shown in FIG. 5. Rubber pressure pads 29 disposed on opposite sides of the splitter bar serve to clamp and partially seal the upper edge portions of the pouch against the splitter to enable the gas to expand the side panels. The pads are carried on generally upright rods 30 pivoted on the frame 13 and are swung toward each pouch as the latter dwellsand then are retracted to leave the pouch free to advance. Swinging of the rods is effected by a cam fast on the cycle shaft 17 and operably connected to the lower ends of the rods.

Each pouch .10, after being blown open, is advanced to the filling station 19 where a measured charge of particulate product is deposited into the pouch. While various granular and flake-like food products may be packaged by the machine, the latter is especially useful in packaging a finely powdered food product such as instant coffee. Herein, the product is delivered from a dispenser 33 which comprises a hopper 34 disposed in the filling station and a vessel-like collector 35 located beneath the hopper and having a lower cylindrical discharge spout 36, (FIG. 6). As each pouch dwells in the filling station 19, a power-rotated auger 37 delivers a measured amount of product from the hopper into the collector, the auger being located in an outlet tube 39 projecting downwardly from the lower end of the hopper and extending through a cover plate 40 on the collector. The product passing through the outlet tube falls onto a dish 41 located intermediate the ends of the collector and secured to the, auger so as to throw the product outwardly into the collector by centrifugal force. The product thrown from thedish falls downwardly through the discharge I spout 36. for delivery into the pouch dwelling in the filling station.

In accordance I with the present invention, the product discharged from the spout 36 is delivered into the pouches loithrough a passage'43 in the splitter bar 21 and ispropelled into thep'ouchesby pressurizedgas which .is injected into the passage and keeps the particulate product from clogging the passage. Moreover, the upper-ends or top sealareas of the side panels of each pouch are-clamped to the splitterbar during-filling of the pouchso asto reduce thedanger of the product particlesblowing upwardly and contaminating the top; seal areas and spoiling the heat'seals subsequently effected at the sealing station.

In addition to. the aforementioned advantages which are applicableto packaging machines in general, the invention finds" especially advantageous'use in conjunction with a so-called controlled atmosphere packaging machine of the .type disclosed herein. In such a machine, a non-oxidizing gas is injected into the passage 43. in the splitter bar 21 and serves to purge the product and the pouches of oxygen as well as to assist the flow of product through'the passage. By using a non-oxidizing gas and by keeping the pouches in a purged condition until the tops are sealed, the product may be packaged ina'substantially oxygen-free environment in Ithe pouch to help preserve the freshness nozzle defines a narrow downwardly opening discharge orifice 44 (FIG. 3) whose dimension along the lengthof the splitter is several times greater than the width of the orifice across the. splitter. Upwardly from the orifice, the nozzletapers along the length of the splitter while expanding laterally across the width of the splitter (see FIG. 2) and terminates in a generally cylindrical upper mouth 45 which receives the discharge spout 36 of the collector 35, a gasket 46 (FIG. 6) establishing a seal between the spout and the mouth.

In the controlled atmospherepackaging machine illustrated in the drawings, a non-oxidizing gas which is inert to the product being packaged is introduced into the collector 35 continuously at a rate of about 50 cubic feet per hour through a' line 50 (FIGS. 4 and 6) pouches during the interval between filling and sealing of the pouches. I

The carbon dioxide admitted into the upper portion of the collector 35 through the port 51 is manifolded downwardly within the collector through a series of an-.

gularly spaced holes 53 (FIG. '6) formed in an intermediate wall or plate 54 located just above the lower end of the auger 37 and fastened to'the outlet tube 39 by a screw 55. The carbon dioxide thus is dispersed throughout the downwardly falling product and drives off the ambient air contained in the collector and the product, the ambientair escaping upwardly through a vent passage 56-located alongside the outlet tube 39. Accordingly, the product is purged and,'as the carbon dioxide passes through the nozzle 43 and into the pouch 10 with the product, ambient air also is driven from the pouch. When the cylinder 25 contains carbon dioxide or other non-oxidizing gas, the pouch also receives a pre-purging as it is opened'by the gas in-' jected'through'the upstream passage'24 in the splitter bar 21 so that the pouch advanced into'the filling station 19 contains mostly carbon dioxide rather than air.

lmportantly, the carbon dioxide flowing from the collector 35 through the nozzle 43 assists the. flow of the product through the nozzle'andv out of the narrow orifice 44. This is particularly advantageous when the product being packaged isof 'a powdered and rather coherentnatur since the propelling force provided by the. pressurized carbon dioxide prevents the product from clogging in the nozzle.

As each pouch 10 is filled, the upper ends of its side panels are clamped againstv the splitter bar 21 as shownv in F IG; '6 by pressure pads 60'carried on the rods 30. As a result of the clamping, there is less danger of the product being blown upwardlyfrom the pouch by the carbondioxide and accumulating on the top seal areas of the pouch. The clamping is particularly important when a rather finely powdered product is being packaged since such a product tendsto severely dust when deposited into the pouch.

During the time each pouch 10 is clamped to the splitter bar 21' and is being filled, some carbon dioxide escapes or bleeds upwardly from the upper end of the pouch as a result of the pouch being somewhat overpurged with carbon dioxide. Advantageously, the upwardly bleeding carbon dioxide is conserved and is returned to the hopper 34 so as to be re-circulated through the product. For this purpose, two passages 61 (FIGS. 2 and 4) are formed through the splitter bar on opposite sides of the nozzle 43 and communicate with the hopper through lines 62 (FIG. 1) connected at their lower ends to the passages and connected at their upper ends to a single line 62a leading into the hopper. Thus, the excess carbon dioxide flows upwardly through the lines 62 and 62a and into the hopper when the carbon dioxide is forced from the pouch as the latter is clamped against the splitter and filled. To help keep in the area of the pouch any excess carbon dioxide which might seep past the pads 60, a small hood overlies the splitter bar adjacent the pads and the nozzle 43, the hood comprising a top plate 63 (FIG. 6) having a depending skirt 64 which surrounds the nozzle just above the pads so 'as to establish a flow-retarding curtain over the top of the pouch.

After being filled, each pouch is advanced one step to a purging station 65 (FIGS. and 4) where an additional shot of carbon dioxide is injected into the pouch to effect a final purge of the pouch and the product preparatory to sealing of the pouch. As shown in FIG. 4, an additional passage 66 is formed through the splitter bar 21 at the purging station and communicates with the cylinder 25 through a line 67 and the valve 27. Accordingly, carbon dioxide is injected intermittently through the passage and into the filled pouches as each pouch dwells at the'purging station. As each pouch is purged, its side panels are confined and shaped by generally vertical paddles 69 (FIG. 7) located on opposite sides of the pouch and carries on swingable rods '70. Pressure pads 71 locatedat the upper ends of the paddles clamp the tops of the pouches to the splitter bar 21 during purging but not so tightly as to prevent the upward escape from the pouch of any ambient air which remains in the pouch after filling. 1

The purged pouches 10 next are advanced toward the sealing station 20. As each pouch dwells between the purging and sealingstations 65 and 20, thetops of the side panels arevibrated to shake loose and insure the removal of any product which might possibly have accumulated on the top sealareas. For this purpose, a rubber blade 74 (FIG. 1) is positioned above the path of the pouches and is rotated transversely of the path bya small motor 75' supported on the 'frame 13. The

Being heavier than air, the carbon dioxide injected establish a temporary labyrinth sea] at the tops of the pouches and also serve to crease the pouches.

As shown in FIG. 8, the rails 77 are located on opposite sides of the pouches 10 just below the upperedges thereon. The two rails 'are spaced vertically from one another and, in addition, the inboard edges of the rails overlap each other so that a labyrinth path is defined between the two edges. As each pouch is advanced between the rails, one deflects the tops of the side panels laterally in one direction while the other deflects the tops in the opposite direction thereby tending to crease and pinch off the top of the pouch to retard the entry of ambient air.

At the sealing station 20, the upper ends of the pouches 10 are sealed closed by a pair of opposed heated sealing bars 80 (FIGS. 1 and 9) carried on swingable rods 81. The pouches thus are maintained in a substantially oxygen-free condition. Because the top seal areas are clean, air-tight seals are effected to keep the pouches and the product free of ambient air.

From the foregoing, it will be apparent that the present invention brings 'to the art a new and improved packaging machine in which the flow of product through the splitter nozzle 43 is assisted by pressurized gas to prevent clogging of the nozzle, the gas being effective at the same time to purge the product and the pouches. The machine is relatively simple in construction when compared with prior controlled atmosphere packaging machines and is capable of filling over pouches per minute with less than two percent oxygen in the packaged product.

We claim as our invention:

1. In a machine for filling measured charges of particulate product into pouches having comparatively flat flexible side panels, the combination of, mechanism for advancing the pouches open end up and in spaced edgewise relation through a filling station along a predetermined path, an elongated horizontal splitter bar of narrow width overlying said path and extending through said filling station, said splitter bar being positioned to be straddled by the upper ends of said side panels so as to keep said side panels separated at said upper ends, a nozzle extending vertically through said splitter bar at said filling station and defining a downwardly opening elongated orifice in the lower edge of the splitter bar, the length of said orifice along said splitter bar being greater than the width of the orifice across/the splitter bar, means in said filling station fordispensing measured charges of particulate product into said nozzle for flow out of said orifice and into said pouches, and means for injecting pressurized gas into said nozzle to assist the flow of the product through the nozzle and out of said orifice.

2. A machine as defined in claim 1 in which said dispensing means includes a vessel, a generally cylindrical spout at the lower end of' said vessel and communicating with said nozzle, and said injecting means communicating with said vessel. whereby said gas flows first into saidivessel and then into said nozzle.

3. A machine-as defined in claim 1 further including means in said filling station for clamping the upper ends of the side panels of said pouches to the splitter bar as the pouches are filled with product-Q I I 4. In a controlled atmosphere packaging machine for filling measured charges of product into pouches having comparatively flat flexible side panels, the combination of, mechanism for advancing the. pouches open end up along a predetermined path through a.

filling station, an elongated horizontal splitter bar-of narrow width overlying said path and extending through said filling station, said splitter bar being positioned to be straddled by the upperends of said side panels so, as to keep said side panels separated at said upper ends, a passage extending vertically through said splitter bar at :said filling station and defining a downwardly opening orifice in the lower edge of said splitter bar, the length of the orifice along said splitter bar being several times greater than the width of the orifice across the splitter bar, a dispenser in said filling station and including a vessel having an upright spout communicating with said passage, said dispenser being operable to discharge measured charges of product into said vessel for flow into said spout and said passage and then out of said orifice and into said pouches, and means for injecting pressurized non-oxidizing gas into said vessel to purge the product and the pouches of ambient air.

I 5. A controlled atmosphere packaging machine as defined in claim- 4 further including a purging station located downstream of said filling station, a passage opening out of the lower edge of said splitter bar at said purging station, and means for injecting pressurized non-oxidizing gas into the latter passage to .purge the pouches and product of ambient air after filling of the pouches. Y i

6. A controlled atmosphere packaging machine as defined in claim 5 further including means at said filling and purging stations for clamping the upper ends of said side panels to saidsplitter bar during filling and purging of the pouches. I

7... A controlled atmosphere packaging machine as defined in claim 4 further including a sealing station located downstream of said filling station, rails above the lower end of the auger and defining a horizontal wall extending across the vessel, said gas injecting means communicating with said vessel above said plate, and a series of angularly spaced hole's formed through said plate whereby gas injected into said vessel passes throu h said holes and is dispersed in said product as the lat er is discharged by said auger through said opening, filling and purging stations, said disposed on opposite sides of said path adjacent the upper ends of said sidepanels and located between said fillin g and sealing stations, said rails being spaced vertically from each other and having inner sides overlapping o ne another to deflect the upper ends of said side panels first laterally in one direction and then in the opposite direction to retard the escape of said gas out of and the entry of ambient air into said pouches as the latter approach, said sealing station", and a sealing unit disposed in said sealingstation for sealing the upper ends of said pouches. .v 8. A controlled atmosphere packaging machine as defined inrclaim 4 in which said passage defines a nozzle which tapers along the length of the splitter bar and expands across the width of the splitter bar as the nozzle .pi'oceedsupwardly fro msaid orifice, said nozzle defining a circular mouth adjacent the upper edge of said splitter bar for receiving said spout.

9. A controlled atmosphere packaging machine as defined in claim 8 further including additional passages extending through said splitter bar on opposite sides of. said nozzle and communicating with said dispenser to direct excess gas from said pouches into said dispenser.

10. A controlled atmosphere packaging machine as defined in claim 4 in which said dispenser includes an upright auger extending into said vessel for delivering said product into the vessel, said auger terminating short of said spout, a plate disposed within said vessel splitter bar being positioned to be straddled by the upper ends of said side panels so as to keep the latter separated at said upper ends, passages opening out of the lower edge of said splitter bar in said opening and purging stations, a passage extending vertically through said splitter bar at said filling station and defining a downwardly opening orifice in the'lower edge of said splitter bar, the length of said orifice along said splitter bar being several times greater than the width of the orifice across the splitter bar, a dispenser in said filling station and includinga vessel having an upright spout communicating with the filling passage in the filling station, said dispenser beingfoperable' to discharge measured charges ofparticulate product into said'vessel for flow into said spout and said filling passageand then out of said orifice and into said pouches, means for injecting pressurized non-oxidizing gas into said vessel and into the passages in, said opening and purging stations whereby (a) the gas injected into the passage in the opening station blows open and purges each pouch preparatory to filling; (b) the gas injected into said vessel. flows into said filling passage and out of said orifice with the product to assist the flow of. product through the orifice while purging the product and thepouches of ambient air and; (c) the gas injected into the passage in' said purging station effects a final ,purge of the product and pouches preparatory to sealing, means in each of said opening, filling and purging stations for clamping the, upper ends'of said side panels against said splitterbar as the gas flows into the pouchesQrails disposed on opposite sides of said path adjacent the upper ends of said panels and extending between said purging and sealing stations,said rails. being spaced very tically from each other andhaving inner sides which overlap one another so as to deflect the upper ends of said side panels laterally to retard the'escape of said gas out of and the entry of ambient air into said pouches, and a sealing unit disposed in said sealing station for sealing the upper ends of said pouches.

Claims

1. In a machine for filling measured charges of particulate product into pouches having comparatively flat flexible side panels, the combination of, mechanism for advancing the pouches open end up and in spaced edgewise relation through a filling station along a predetermined path, an elongated horizontal splitter bar of narrow width overlying said path and extending through said filling station, said splitter bar being positioned to be straddled by the upper ends of said side panels so as to keep said side panels separated at said upper ends, a nozzle extending vertically through said splitter bar at said filling station and defining a downwardly opening elongated orifice in the lower edge of the splitter bar, the length of said orifice along said splitter bar being greater than the width of the orifice across the splitter bar, means in said filling station for dispensing measured charges of particulate product into said nozzle for flow out of said orifice and into said pouches, and means for injecting pressurized gas into said nozzle to assist the flow of the product through the nozzle and out of said orifice.

2. A machine as defined in claim 1 in which said dispensing means includes a vessel, a generally cylindrical spout at the lower end of said vessel and communicating with said nozzle, and said injecting means communicating with said vessel whereby said gas flows first into said vessel and then into said nozzle.

3. A machine as defined in claim 1 further including means in said filling station for clamping the upper ends of the side panels of saId pouches to the splitter bar as the pouches are filled with product.

4. In a controlled atmosphere packaging machine for filling measured charges of product into pouches having comparatively flat flexible side panels, the combination of, mechanism for advancing the pouches open end up along a predetermined path through a filling station, an elongated horizontal splitter bar of narrow width overlying said path and extending through said filling station, said splitter bar being positioned to be straddled by the upper ends of said side panels so as to keep said side panels separated at said upper ends, a passage extending vertically through said splitter bar at said filling station and defining a downwardly opening orifice in the lower edge of said splitter bar, the length of the orifice along said splitter bar being several times greater than the width of the orifice across the splitter bar, a dispenser in said filling station and including a vessel having an upright spout communicating with said passage, said dispenser being operable to discharge measured charges of product into said vessel for flow into said spout and said passage and then out of said orifice and into said pouches, and means for injecting pressurized non-oxidizing gas into said vessel to purge the product and the pouches of ambient air.

5. A controlled atmosphere packaging machine as defined in claim 4 further including a purging station located downstream of said filling station, a passage opening out of the lower edge of said splitter bar at said purging station, and means for injecting pressurized non-oxidizing gas into the latter passage to purge the pouches and product of ambient air after filling of the pouches.

6. A controlled atmosphere packaging machine as defined in claim 5 further including means at said filling and purging stations for clamping the upper ends of said side panels to said splitter bar during filling and purging of the pouches.

7. A controlled atmosphere packaging machine as defined in claim 4 further including a sealing station located downstream of said filling station, rails disposed on opposite sides of said path adjacent the upper ends of said side panels and located between said filling and sealing stations, said rails being spaced vertically from each other and having inner sides overlapping one another to deflect the upper ends of said side panels first laterally in one direction and then in the opposite direction to retard the escape of said gas out of and the entry of ambient air into said pouches as the latter approach said sealing station, and a sealing unit disposed in said sealing station for sealing the upper ends of said pouches.

8. A controlled atmosphere packaging machine as defined in claim 4 in which said passage defines a nozzle which tapers along the length of the splitter bar and expands across the width of the splitter bar as the nozzle proceeds upwardly from said orifice, said nozzle defining a circular mouth adjacent the upper edge of said splitter bar for receiving said spout.

9. A controlled atmosphere packaging machine as defined in claim 8 further including additional passages extending through said splitter bar on opposite sides of said nozzle and communicating with said dispenser to direct excess gas from said pouches into said dispenser.

10. A controlled atmosphere packaging machine as defined in claim 4 in which said dispenser includes an upright auger extending into said vessel for delivering said product into the vessel, said auger terminating short of said spout, a plate disposed within said vessel above the lower end of the auger and defining a horizontal wall extending across the vessel, said gas injecting means communicating with said vessel above said plate, and a series of angularly spaced holes formed through said plate whereby gas injected into said vessel passes through said holes and is dispersed in said product as the latter is discharged by said auger and falls downwardly through said vessel and into said spout.

11. In a controlled atmosphere packaging machine for filling measured charges of particulate product into pouches having comparatively flat flexible side panels and for thereafter sealing the pouches, the combination of, mechanism for advancing the pouches open end up and in spaced edgewise relation along a predetermined path through horizontally spaced opening, filling, purging and sealing stations, an elongated horizontal splitter bar of narrow width overlying said path and extending through said opening, filling and purging stations, said splitter bar being positioned to be straddled by the upper ends of said side panels so as to keep the latter separated at said upper ends, passages opening out of the lower edge of said splitter bar in said opening and purging stations, a passage extending vertically through said splitter bar at said filling station and defining a downwardly opening orifice in the lower edge of said splitter bar, the length of said orifice along said splitter bar being several times greater than the width of the orifice across the splitter bar, a dispenser in said filling station and including a vessel having an upright spout communicating with the filling passage in the filling station, said dispenser being operable to discharge measured charges of particulate product into said vessel for flow into said spout and said filling passage and then out of said orifice and into said pouches, means for injecting pressurized non-oxidizing gas into said vessel and into the passages in said opening and purging stations whereby (a) the gas injected into the passage in the opening station blows open and purges each pouch preparatory to filling; (b) the gas injected into said vessel flows into said filling passage and out of said orifice with the product to assist the flow of product through the orifice while purging the product and the pouches of ambient air and; (c) the gas injected into the passage in said purging station effects a final purge of the product and pouches preparatory to sealing, means in each of said opening, filling and purging stations for clamping the upper ends of said side panels against said splitter bar as the gas flows into the pouches, rails disposed on opposite sides of said path adjacent the upper ends of said panels and extending between said purging and sealing stations, said rails being spaced vertically from each other and having inner sides which overlap one another so as to deflect the upper ends of said side panels laterally to retard the escape of said gas out of and the entry of ambient air into said pouches, and a sealing unit disposed in said sealing station for sealing the upper ends of said pouches.