US3847540A

US3847540A - Blank heating system for carton forming machine

Info

Publication number: US3847540A
Authority: US
Inventors: S Farfaglia; R Bock
Original assignee: Phillips Petroleum Co
Current assignee: Huhtamaki Consumer Packaging Inc
Priority date: 1973-09-07
Filing date: 1973-09-07
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12
Also published as: DE2442858B2; DE7430127U; JPS5072776A; CA1010281A; JPS5331062B2; FR2243078A1; DE2442858A1; DE2442858C3; FR2243078B1

Abstract

In a machine for forming tubular cartons from generally rectangular blanks, the blank is heated by two side margin heaters and a transverse heater employing heated gas. The heated gas is supplied to the side margin heaters in countercurrent directions. The transverse heater can be divided at the midpoint and supplied with heated gas at both ends. A perforated conduit supplied with cool gas can be positioned between the blank magazine and the heaters to provide an air curtain between the heaters and the blanks in the magazine.

Description

Ilnited States Patent [1 1 Farfaglia et al.

[ Nov. 12, 1974 BLANK HEATING SYSTEM FOR CARTON FORMING MACHINE [75] Inventors: Silvio T. Farfaglia; Ronald E. Bock,

both of Fulton, NY.

[73] Assignee: Phillips Petroleum Company,

Bartlesville, Okla.

22 Filed: Sept. 7, 1973 211 Appl. No.: 395,035

[52] US. Cl 432/230, 34/105, 93/DIG. 1, 156/497, 156/498 [51] Int. Cl. F27b 17/00 [58] Field of Search 432/230, 231, 146, 77; 34/105; 93/44.]. R, DIG. 1; 156/497, 498

[56] References Cited UNITED STATES PATENTS 7/1928 Ritter 432/230 Socke 432/230 Kereluk 432/230 Primary Examiner 10hn .I. Camby [57] ABSTRACT In a machine for forming tubular cartons from generally rectangular blanks, the blank is heated by two side margin heaters and a transverse heater employing heated gas. The heated gas is supplied to the side margin heaters in countercurrent directions. The transverse heater can be divided at the midpoint and supplied with heated gas at both ends. A perforated conduit supplied with cool gas can be positioned between the blank magazine and the heaters to provide an air 7 curtain between the heaters and the blanks in the magazine.

10 Claims, 5 Drawing Figures- PAIENTEUuuv 12 I974 sum 2 OF 4 3.847.540

BLANK HEATING SYSTEM FOR CARTON FORMING MACHINE The invention relates to means for heating blanks in a carton forming machine.

In machines for forming tubular cartons from generally rectangular sidewall blanks wherein the blanks are individually withdrawn from a magazine and conveyed through a heating station to a forming mandrel, the heated blank is then wrapped around the mandrel and the overlying side margins are bonded together to form a tube, and a bottom blank is then bonded to the bottom end of the tube, there are problems with achieving a uniform heating of the surfaces to be bonded. It is also desirable that only the portions to be bonded are heated to any significant extent.

Accordingly, it is an object of the present inventio to provide a new and improved means for heating the sidewall blanks. Another object of the invention is to minimize the heating of the portions of the blank which are not bonding surfaces. Yet another object of the invention is to provide more nearly uniform heating of the surfaces to be bonded. Other objects, aspects and advantages of the invention will be apparent from a study of the specification, the drawings and the appended claims to the invention.

In the drawings,

FIG. 1 is a front elevational view of a carton forming, filling and sealing machine embodying the present invention;

FIG. 2 is a diagrammatic view in elevation of the sidewall blank feeding and heating section and the forming turret of the machine of FIG. 1;

FIG. 3 is a simplified top plan view of the sidewall blank feeding and heating section of FIG. 2;

FIG. 4 is an elevational view, partly in cross section, of the transverse heater of FIG. 3; and

FIG. 5 is a simplified perspective view showing the relationship of the three heaters to the sidewall blank being heated.

Referring now to the drawings in detail and to FIG. 1 in particular, the carton forming, filling and sealing machine comprises a forming section 11 and a filling and sealing section 12. The forming section 11 comprises a sidewall blank feeding and heating subsection 13, a bottom blank feeding and heating subsection 14, a forming. subsection 15, and a transfer subsection 16. The filling and sealing section 12 has two parallelendless conveyor systems 17, and each conveyor system comprises a filling subsection 18 occupying five conveyor stations, a defoaming station 19, a score breaking station 20, a top heating station 21, a folding and seal-,

ing station 22, a secondary sealing station 23', a branding station 24, and a transfer station 25.

The sidewall blanks 31 manually placed in the sidewall blank magazine 32 are flat, relatively stiff single sheets of paperboard, rectangular in shape, scored to provide five longitudinal panels and a gable-top structure, and coated on both the top and bottom surfaces of each sheet witha thermoplastic material, e.g., polyethylene. The sidewall blanks are successively withdrawn from magazine 32 and advanced through the sidewall blank heating station 33 to the sidewall blank receiving station 34 for turret 35. At the sidewall blank heating station 33, the side margins to be'overlapped and the bottom margin of the sidewall blank are heated to a bonding temperature for the thermoplastic coating.

The turret 35 is journalled on a horizontal axis and carries eight circumferentially spaced apart mandrels 36 extending radially from the axis of turret 35. The cross section of each of mandrels 36 in a plane perpendicular to its longitudinal axis is generally rectangular. Suitable drive mechanism is provided for indexing or effecting intermittent rotation of the turret 35 to move each mandrel from the sidewall blank receiving station 34 through a blank folding station 37; a bottom end closure forming, applying and sealing station 38; a secondary bottom sealing station 39; a stripping station 40; and three successive

nonoperating stations

41, 42 and 43.

The tubular carton body having a bottom closure sealed thereto is removed from the mandrel 36 at the stripping station 40 and is transferred to a conveyor pocket 45 of one of the two conveyor systems 17. The product to be packaged is introduced into the opentopped tubular carton in the filling subsection 18. If desired, any foam resulting from the filling operation can be removed at defoaming station 19. The scores for the gable-top structure can be initially folded in the score breaking station 20, resulting in the conventional sixsided top structure. The gable-top ridge panels of the carton are heated in station 21 to a temperature at least as high as the thermal bonding temperature of the thermoplastic coatings on the carton. The heated superstructure is then folded into contact under pressure at the folding and sealing station 22 to effect the bonding of adjacent ridge panels. Secondary sealing station 23 applies pressure to the ridge panels during cooling of the thermoplastic bond. If desired, a data indicia, plant identification orother information can be applied to the bonded ridge panels of the sealed carton at branding station 24. The formed, filled and sealed carton is removed from its conveyor pocket 45 at the transfer station 25 and placed on a delivery conveyor 46.

Referring now to FIG. 2, the turret 35 is intermittently rotated in a clockwise direction, as shown on the drawing, by suitable means, not shown. Chain 51 is driven by turret 35 and in turn drives shaft 52. Shaft 52 intermittently drives sidewall conveyor chains 53.

Conveyor chains 53 have dogs 54 to engagea sidewall blank 31 after it has been withdrawn from the stack to-move the sidewall blank to the heater station 33 and then to the position where the blank can be engaged by the fingers 55 and moved onto the mandrel 36 in'the blank receiving station. The heater station 33 has electrically heated hot air heater 56 which heats the upper surface of one side edge of sidewall blank 31, heater 57 which heats the lower surface of the opposite side edge of sidewall blank 31, and transverse heater 58 which heats the upper surface of the trailing end of sidewall blank 31. An air curtain is produced by down-.

wardly directed jets of unheated air from air supply tube 59 when the operation of the machine is interrupted, thereby providing cooling for the sidewall blanks in the stack as a protection against damage of the sidewall blanks in the stack by excessive exposure to the hot air from

heaters

56, 57, and 58..

A supply magazine cage 32 for the storage of sidewall blanks 31 is formed by opposing side elements 61 and opposing side elements 61 and 62 and opposing

end elements

63 and 64 to engage marginal portions of the bottom surface of the lowermost sidewall blanks 31 to support the stack of a plurality of sidewall blanks in cage 32. The magazine cage 32 is supported above the upper run of conveyor chains 53. The blank transfer means for successively withdrawing individual blanks 31 from the magazine cage 32 and depositing the withdrawn blanks on the upper run of conveyor chains 53 comprises vacuum cups 67 and the associated mecha nism. Vacuum cups 67 are mounted between conveyor chains 53. Cups 67 are reciprocated vertically through openings 68 in plate 69 to engage the bottom surface of central portions of the lowermost sidewall blank and to remove the lowermost sidewall blank 31 from the stack of sidewall blanks in cage 32 by causing the lowermost sidewall blank to move inwardly and slip past ledges 66. Vacuum cups 67 are connected to a suitable vacuum source 71. In their lower position, cups 67 are below the upper surface of plate 69 and the upper edges of conveyor chains 53 so as not to interfere with the lateral movement of a blank by conveyor chains 53.

Each vacuum cup 67 is supported by a sleeve 72 attached to a connecting bar 73 by an arm 74. The connecting bar 73 is attached to the upper end of shaft 75. Shaft 75 is reciprocated vertically by linkage 76 and drive cam 77 during the dwell portion of each index cycle for conveyor 54.

Referring now to FIGS. 25, the edge heater 56 comprises an electrical heater 78 having an air passage therethrough, conduit means 79 connecting the air inlet of heater 78 to a source of air under pressure, not shown, and a U shaped tube having an upper leg 80 and -a lower leg 81. One end of leg 80 is connected to the hot air outlet of heater 78'and the remote end of leg 81 is closed. Leg 811 is provided with a series of orifices 82 spaced along the length of the lower surface thereof in a pattern which overlies the top surface of the left side (as viewed from magazine 32) margin of blank 31 in heating station 33 to direct jets of heated air against the top surface of said left margin to heat the thermoplastic coating thereon to a suitable bonding temperature. The lower surface of leg 81 is parallel to the left side edge of blank 31 and spaced therefrom, and preferably directly overlies the margin to be heated so that the hot air jets strike the blank 31 at angles of approximately 90, although the angle of impingement of the jets on the blank can vary from 90. The length of the pattern of orifices 82 is preferably coextensive with the length of the side edge of blank 31.

The edge heater 57 comprises an electrical heater 83 having an air passage therethrough, conduit means 84 connected to a suitable source of air underpressure, and an L shaped

conduit comprising leg

85 and 86. One end of conduit 85 is connected to the heated air outlet of heater 83 and the remote end of leg 86 is closed. Leg 86 is provided with a series of orifices 87 in the upper surface thereof in a pattern which is at least substantially coextensive'with the length of the right side edge of blank 31 and which preferably is directly below the right side margin of blank 31 in the heating station 33, so that the jets of heated air strike the lower surface of the right side margin to heat the thermoplastic coating thereon to a suitable bonding temperature. The upper surface of leg 86 is at least substantially parallel to and spaced from the right side edge of blank 31. As shown in FIG. 5 the inlet to the leg 81 is at the top edge of the blank 31 while the inlet to leg 86 is at the bottom edge of blank 31. Thus the initial orifice ofleg 81 is adjacent the top margin of blank 31 while the initial orifice of leg 86 is adjacent the bottom margin of blank 31. This opposite positioning of the two side heaters compensates for any drop in the temperature of the heated air occurring along the length of

legs

81 and 86 and provides a substantially uniform temperature in the bonding area when the heated margins are joined.

In the presently preferred embodiment illustrated in the drawings, the transverse heater 58 comprises first and second

electrical heaters

88 and 89 having the hot air outlets thereof connected to

conduits

90 and 91, respectively. The remote ends of

conduits

90 and 91 are joined together by partition plate 92 to provide two separate plenum chambers. The air inlets of

heaters

88 and 89 are connected to suitable sources of air under pressure by

conduits

93 and 94, respectively.

Conduits

90 and 91 are provided with a series of orifices 95 in the lower surface thereof in a pattern which is at least substantially coextensive with the width of the bottom edge of blank 31, and which preferably directly overlies the top surface of the bottom margin of the blank in the heating station 33. The utilization of two

heaters

88 and 89 and the partition 92 at approximately the midpoint of the width of the blank 31 minimizes the variation in the temperature to which the various portions of the bottom margin are heated. The

conduits

90 and 91 are positioned with the lower surface thereof at least substantially parallel to and spaced from the bottom edge of blank 31 inthe heating station 33.

A valve means 96 is positioned between conduit 97 and air tube 59. Conduit 97 is connected to a suitable means of at least substantially unheated air under pressure. Conduit 59 is provided with a series of orifices in the lower surface thereof to direct jets of cool air downwardly to form an air curtain between magazine 32 and transverse heater 58. Valve 96, which is normally closed, is actuated to the open position by suitable control means whenever the machine is energized but conveyor 53 is deactuated. This air curtain protects the blanks 31 in the magazine 32 against excessive temperatures, while avoiding the operational difficulties which would be incurred if heaters 56, S7 and 58 had to be deactuated whenever conveyor 53 became deactuated. With this system the

heaters

56, 57 and 58 continue normal operation and only the blank 31 in the heating station 33 is damaged. The damaged blank can be readily removed by the operator before restarting conveyor 53.

While the invention has been illustrated with rectangular blanks for gable-top cartons, the invention can be utilized with blanks of other generally rectangular configuration, for example the approximately trapezoidal blanks for frustoconical cartons. In this latter case,

heaters

56 and 57 would remain parallel to the edges to be heated but would not be parallel to each other, and

conduits

90 and 91 could have arcuate configuration conforming to the shape of the bottom edge of the blank.

Reasonable variations and modifications are possible within the scope of the foregoing disclosure, the drawings, and the appended claims to the invention.

Thatwhich is claimed is:

1. In a machine for forming a tubular carton from a generally rectangular flat sidewall blank having thermoplastic coating on the upper and lower surfaces thereof and having first and second side margins and top and bottom margins, wherein the sidewall blanks are individually removed from a sidewall blank magazine and conveyed through a heating station to a forming mandrel, the heated sidewall blank is wrapped around the forming mandrel and the overlapping first and second side margins are bonded together, the improvement comprising a first conduit means positioned in said heating station at least generally parallel to and spaced upwardly from the location which would be occupied by the upper surface of the first side margin of one of said blanks in said heating station, said first conduit having orifices therein spaced along the length thereof and directed at the location which would be occupied by said upper surface of said first side margin of the blank in said heating station, a second conduit means positioned in said heating station at least generally parallel to and spaced downwardly from the loca-.

tion which would be occupied by the lower surface of the second side margin of the blank in said heating station, said second conduit means having orifices therein spaced along the length thereof and directed at the location which would be occupied by the lower surface of said second side margin of the blank in said heating station, and means for supplying a hot gas to said first and second conduit means.

2. Apparatus in accordance with claim 1 further comprising third conduit means positioned in said heating station at least generally parallel to and spaced from the location which would be occupied by the upper surface of the bottom margin of the blank in said heating station, said third conduit means having orifices therein spaced along the length thereof and. directed at the location which would be occupied by the upper surface of said bottom margin of the blank in said heating station, and means for supplying hot gas to said third conduit means.

3. Apparatus in accordance with claim 2 wherein the means for conveying the individual blanks through said heating station is periodically actuated to index a blank into position with respect to said first, second and third conduit means.

4. Apparatus in accordance with claim 3 wherein the initial orifice in one of said first and second conduit means isadjacent the location which would be occupied by the top margin of the blank in said heating station and the initial orifice of the other of said first and second conduits is adjacent the location which would be occupied by the bottom margin of the blank in said heating station.

5. Apparatus in accordance with claim 4 wherein said third conduit means has a partition therein at about the midpoint of the width of the space which would be occupied by the blank in the heating station to form separate plenum chambers, and wherein said means for sup plying hot gas to said third conduit means comprises means for supplying hot gas to each of said plenum chambers at locations remote from said partition.

6. Apparatus in accordance with claim 5 further comprising a fourth conduit means positioned between said magazine and said heating station, said fourth conduit means having a series of orifices therein spaced along the length thereof to form an air curtain between said magazine and said heating station, and means for providing cool gas to said fourth conduit means.

7. Apparatus in accordance with claim 6 wherein said means for providing cool gas to said fourth conduit means is actuated only when the machine is actuated but said means for conveying is deactuated.

8. Apparatus in accordance with claim 1 wherein the I initial orifice in one of said first and second conduit means is adjacent the location which would be occupied by the top margin of the blank in said heating station and the initial orifice of the other of said first and second conduits is adjacent the location which would be occupied by the bottom margin of the blank in said heating station.

9. Apparatus in accordance with claim 2 wherein said third conduit means has a partition therein at about the midpoint of the width of the space which would be occupied by the blank in the heating station to form separate plenum chambers, and wherein said means for supplying hot gas to said third conduit means comprises means for supplying hot gas to each of said plenum chambers at locations remote from said partition.

10. Apparatus in accordance with claim 1 further comprising a fourth conduit means positioned between said magazine and said heating station, said fourth conduit means having a series of orifices therein spaced along the length thereof to form an air curtain between said magazine and said heating station, and means for providing cool gas to said fourth conduit means.

Claims

1. In a machine for forming a tubular carton from a generally rectangular flat sidewall blank having thermoplastic coating on the upper and lower surfaces thereof and having first and second side margins and top and bottom margins, wherein the sidewall blanks are individually removed from a sidewall blank magazine and conveyed through a heating station to a forming mandrel, the heated sidewall blank is wrapped around the forming mandrel and the overlapping first and second side margins are bonded together, the improvement comprising a first conduit means positioned in said heating station at least generally parallel to and spaced upwardly from the location which would be occupied by the upper surface of the first side margin of one of said blanks in said heating station, said first conduit having orifices therein spaced along the length thereof and directed at the location which would be occupied by said upper surface of said first side margin of the blank in said heating station, a second conduit means positioned in said heating station at least generally parallel to and spaced downwardly from the location which would be occupied by the lower surface of the second side margin of the blank in said heating station, said second conduit means having orifices theRein spaced along the length thereof and directed at the location which would be occupied by the lower surface of said second side margin of the blank in said heating station, and means for supplying a hot gas to said first and second conduit means.

2. Apparatus in accordance with claim 1 further comprising third conduit means positioned in said heating station at least generally parallel to and spaced from the location which would be occupied by the upper surface of the bottom margin of the blank in said heating station, said third conduit means having orifices therein spaced along the length thereof and directed at the location which would be occupied by the upper surface of said bottom margin of the blank in said heating station, and means for supplying hot gas to said third conduit means.

4. Apparatus in accordance with claim 3 wherein the initial orifice in one of said first and second conduit means is adjacent the location which would be occupied by the top margin of the blank in said heating station and the initial orifice of the other of said first and second conduits is adjacent the location which would be occupied by the bottom margin of the blank in said heating station.

5. Apparatus in accordance with claim 4 wherein said third conduit means has a partition therein at about the midpoint of the width of the space which would be occupied by the blank in the heating station to form separate plenum chambers, and wherein said means for supplying hot gas to said third conduit means comprises means for supplying hot gas to each of said plenum chambers at locations remote from said partition.

8. Apparatus in accordance with claim 1 wherein the initial orifice in one of said first and second conduit means is adjacent the location which would be occupied by the top margin of the blank in said heating station and the initial orifice of the other of said first and second conduits is adjacent the location which would be occupied by the bottom margin of the blank in said heating station.