US3548722A - Manufacture of valve bags - Google Patents

Manufacture of valve bags Download PDF

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Publication number
US3548722A
US3548722A US757207A US3548722DA US3548722A US 3548722 A US3548722 A US 3548722A US 757207 A US757207 A US 757207A US 3548722D A US3548722D A US 3548722DA US 3548722 A US3548722 A US 3548722A
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United States
Prior art keywords
valve
web
film
panels
panel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US757207A
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English (en)
Inventor
Elwyn David Jones
Edward Kenneth Rowley
Douglas Reynolds Shepherd
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PPG Architectural Coatings Canada Inc
Original Assignee
Canadian Industries Ltd
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Publication date
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31D—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER, NOT PROVIDED FOR IN SUBCLASSES B31B OR B31C
    • B31D5/00—Multiple-step processes for making three-dimensional articles ; Making three-dimensional articles
    • B31D5/0034—Multiple-step processes for making three-dimensional articles ; Making three-dimensional articles for making valve inserts for bags
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B2150/00—Flexible containers made from sheets or blanks, e.g. from flattened tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B2160/00—Shape of flexible containers
    • B31B2160/20—Shape of flexible containers with structural provision for thickness of contents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B70/00—Making flexible containers, e.g. envelopes or bags
    • B31B70/74—Auxiliary operations
    • B31B70/81—Forming or attaching accessories, e.g. opening devices, closures or tear strings
    • B31B70/84—Forming or attaching means for filling or dispensing contents, e.g. valves or spouts
    • B31B70/844—Applying rigid valves, spouts, or filling tubes

Definitions

  • SHEET 3 [1F 6 H- INVENTORS Elwyn Duv id JONES Edward Kenneth ROWLEY Douglas Reynolds SHEPHERD mamw PATENT AGENT PATENTED [m2 I978 SHEEI 5 [IF 6 lNVFZiVTORS ".11 um I Elwyn David JONES Edward Kenneth ROWLEY Douglas Reynolds SHEPHERD M19. flaw PATENT AGENT PATENTEB UEE22 I970 SHEET 8 [IF 6 PATENT AGENT the valve panels and the free edges *1 MANUFACTURE or VALVE mics manufactured on commercial bag making machines they normally are made end' to end and the 'formingof the valve element between successive bags is complicated. This results in slowa'nd costly operation. There is thus need fora simpler method of manufacmring plastic valve bags using automatic bagrnaking machinery. v 1
  • valve bags can be made from a double ply 'web of heat-scalable plastic film by a novel method'whereby the valve element is attachedto the double edge of the web prior to scaling and severing the individual bags.
  • the bottom and mouthof the bag thus are fonned from the edges of the webL
  • the apparatus for making bags by'this method operates'automatically, is relatively simple and can be operated at high-production rates relative to the cost of the equipment.
  • the valve bagof this invention comprises front and back panels joined along two opposed edges toform a flattened tube, the remaining two opposed edges of the front and back panels forming the bag bottom and valved bag closure respectively, said valved closure being formed of two end panels joined to lengths less than the length of bag end andoverlapping at their inner extremities, the inner extreme edge of each end panel being free, thus fonning thevalve'. It is convenient toemploy thinner gauge-film at the free extremities of the valve panels, the thinner extension in being folded-back to lie incontact'withthe internal valve panel.
  • the preferred design of ,valve'bag is described in Pat. application Ser'. No. 7 30,384.A suitable heat-scalable plastic ispolyethylene' V
  • the method formanufacturing the valve bag comprises;
  • the two-ply web of film is provided from ⁇ flattened tubular film
  • valvelieleme'nt is formed by joining the two free edges of the web together with a series of overlapping panels of film. These panels preferably are composed of two'sdjacent sections, the main section being of film of the lap type which provide greater strength. With the valve panels sealed in place a tube with a series of valved openings is provided. Gusset folds are next formedin both the valve sec tion and the oppositely located web fold, such folds defining the depth of a square ended bag.
  • V-shaped seals are made at transversely adjacent positions in the two gussets, theapex ofthe seal being inward, the seals extending from the corner fold to the reentrantangleofthegusset.
  • V-shaped seals are made 5 in-' pairs at distances separated by one bag width and at a position intermediate the overlap of the valve panels.
  • the triangular sections external to the V-shaped gusset folds are removed.
  • transverse double seals are made across the web between the apices of I matching V-shaped gusset seals and "the film is' severed between the double seals.
  • the resultinggvalve bag when. filled will be square ended with transverse and diagonal seals located in side panels. f
  • the valve bag may be manufactured asing-known bagmalring'equipment to which has been. added apparatus for attaching the valve panels to the web. The means for activating the valve attaching apparatus isco'ntrolled by the control of the parent bagmaking machine.
  • the joining of. the overlapping valve panels to the free edges of the web may be carried out automatically, employing an apparatuscomprising: 1. means for separating the free edges-oftheweb; 2. means for providing a panel of adapted to form the matching parts of valves in twozsuccessively produced s 1 I 3. means for joining said panel along its'longitudinal edges to the adjacent free edges of the web; and 4. control means for actuating the joining means at times corresponding to positions of successively produced bags.
  • the forming of the transverse seals and transverse severing of the film may be carried out convenientlyernploying an apparatus as described in Canadian Pat. No. 746,689 issued on Nov.
  • FIG. 1 is a perspective view of filled bag
  • FIG. 2 is a perspective/view of the bag of FIG. 1 in a-collapsed configuration
  • FIG. 3 is a sectional view of simple valve
  • FIG. 4' is a sectional view-of a-valve having anextensionof v operation of the invention
  • the smaller section forming the inner lip of the valve comprising film of lighter gauge to provide effective valve closure.
  • the seals between panels of a bag panel is disposed in parallel relationship-to the front panel.
  • FIG. 10 is a side elevation, partly in section, of an apparatus for metering plastic filmfor valve panels and heat sealing the panels to the lower ply of a two-ply web of plastic film,
  • FIG. 1 1 is a rear elevation of the apparatus of FIG. 10,
  • FIG. 12 is a rear elevation'of the metering roll assembly of FIG.'10.
  • FIG. 13 is a front perspective view of the valve panel metering assembly of FIG. 10. I v a inFIGS. 'l and 2 front and back Referring to the drawings,
  • FIG. 8 is a diagrammatic plan view 'of apparatus of FIG.
  • FIG. 9 is a diagrammatic view of the panel attaching is filled.
  • a bag bottom At 4 is shown a bag bottom.
  • a valve structure is shown at 5 and 6, 5 being the outer portion of the valve and 6 the inner portion of the valve. It is to be noted that the two portions of the valve overlap at their inner extremities. The two valve portions are sealed to the front and back panels along seals 3 and 9.
  • FIG. 3 is shown a section through a valve of configuration of that illustrated in FIGS. 1 and 2.
  • an extension of thinner gauge film 7 is joined to the inner wall 6.
  • thinner gauge extensions to both walls of the valve are shown, extension 8 being folded back to lie parallel to the inner side of outer walls.
  • FIG. 6 is a sectional view showing the lap sealitig of valve portions 5 and 6 to the front and back panels along seal 9.
  • valve bag is conveniently manufactured employing a bagrnaking machine wherein a web offilm is advanced intermittently in units of one bag dimension (width or length of bag), the sealing operations taking place during stationary periods of the web.
  • FIGS. 7 and 8 illustrating an apparatus suitable for the manufacture of the valve bag
  • a reel of lay-flat tubing is shown at ll).
  • Tubing unwound from reel 10 passes over feed rolls 11 and 12 and floating accumulator roll 13.
  • Roll 13 serves to maintain the film taut as it advances intermittently in steps equal to bag widths.
  • the flattened tubing next passes over edge guide roll 14 and proceeds to edge slitter 15 which slits the tube at the fold position.
  • the device at 15 could be adapted to trim away a narrow border encompassing the edge fold.
  • the edge slitter serves also to separate the cut edges of the two plies of film.
  • the upper ply of the web must be raised sufficiently to avoid fouling the sealing element of the-valve inserting station.
  • valve inserting station 17 where one longitudinal edge of.-a valve panel is inserted under the edge of the lower ply'of film and under the trailing edge of the valve panel of the preceding bag.
  • the lower ply of the web and the previously inserted valve panel can be raised by a mechanical guide or by an air jet so that the valve panel edge can be inserted beneath them.
  • the extent of valve panel overlap is dependent upon the unit of web advance.
  • the overlapping valve panel is next heat sealed to the superimposed edge of the lower ply of the web.
  • the valve inserting apparatus is shown in greater detail in FIGS. 10,11, 12 and 13. In FIG.
  • valve inserting station 17 operates when the film is stationary.
  • the two-ply web of film with overlapping valve panels 21 sealed to the edge of the lower ply next passes over a forming plate 22.
  • This plate is anchored to the frame of the bagmaking machine at 23.
  • the plate 22 floats between the two plies of the web, the lower ply of the web passing over rolls not shown.
  • folding device 24 As the web of film with valve panels attached to the lower ply advances the valve panels 21 pass over folding device 24 which folds the valve panels so that their free longitudinal edges lie above the edge of the upper ply of the web, the said upper ply riding on forming plate 22.
  • the web and overlapping valve panels next pass to sealing station 25.
  • a heat sealing element 26 seals the upper edges of the overlapping valve panels to the edge of the upper ply of the plastic-web, former 22 serves as anvil for the sealing element. The sealing operation takes place while the web is stationary. The operations involved in attaching the valve panels are shown in greater detail in FIG. 9.
  • the product comprises a flattened plastic tube having a strip of overlapping panels inserted along one edge. Be sealing transversely it is possible to form pillow-type bags from the tube as it is at this stage, but bags with gusseted tops and bottoms are preferred.
  • the next operation serves to form gussets in both edges of the flattened tube.
  • Four sets of double discs 27 and 28 are carried inside the tube by support linkage 29 which is attached to former 22.
  • Discs 27 and 28 shape the tube into a rectangular cross section. Gusset forming discs 30 fit between double discs 28 and cooperate therewith to from a gusset fold in each edge of the web.
  • the gusseted' tube is next flattened by matching rolls 31 and double plates 32.
  • the flattened gusseted tube next passes through drive rolls 33 which are adapted to run intermittently so as to advance the plastic web in units of one bag width. The rolls are actuated in response to a photoelectric cell mounted in monitoring unit 34 which responds to fiduciary marks printed on the film web at distances equivalent to one bag width. 4
  • the flattened tube next passes to gusset sealing station 35 where V-shaped seals are made between the four comer folds of the gussets at positions separated by units of one bag width and intermediate the overlap positions of the valve panels.
  • the film external to the V-shaped seals is cut out at this station.
  • the apex of the V-shaped seal is located at the position of the reentrant fold of the tube gusset.
  • Unit 37 is fitted with double transverse sealing elements whose action is controlled to make a double transverse seal between the two-ply web lying between the apices of two matching V-shaped gusset seals. These two transverse seals form the sidewall seals of two consecutive bags.
  • Unit 37' is equipped with a transverse cutting device whose action is controlled to sever the two-ply web at a transverse position lying between the two transverse seals, thus separating consecutive bags.
  • a separated bag is shown at 38;
  • FIGS. 10, 11, 12 and 13 is illustrated an apparatus for automatically sealing two thicknesses of film to form composite valve panels, metering a predetermined length of valve panel, positioning the panel in correct position with respect to the two-ply web and the preceding valve panel, and sealing overlapping valve panels to the edge of the lower ply of the web.
  • FIGS. 10 and l 1 reels of lengths of plastic film l8 and 19 are shown supported by brackets 39 and 40 fixed to the frame 41 of the apparatus. Film from reel 19 passes over feed roll 42 to rolls 43 and 44 where it overlaps film from reel 18.
  • Sealing device 20 located between rolls 43 and 44 seals the two strips of film together at the position of overlap to form a length of film of two thicknesses suitable for valve panels.
  • Sealing device 20 is constituted by heat-sealing element 45 carried by frame 46.
  • Frame 46 is mounted in yoke 47 to pivot about a midpoint of the frame.
  • the pivoting action of the frame 46 is controlled by air piston and cylinder unit 48 acting against springs 49.
  • Heatsealing element 45 acts against an anvil attached to the end of plate 50 which yoke 47, air piston 48 and springs 49 also are attached. Plate 50 is fixed to the frame of the apparatus.
  • FIGS. 12 and 13 show the details of the valve panel metering device.
  • the metering rolls are mounted rotatably on shafts 53 and 54 which fit in hearings in matching support plates 55.
  • Shaft 53 is free to rotate with respect to support plates 55, but shaft 54 is fixed rigidly to said plates preventing its rotation.
  • Support plates 55 are fastened to side plates 56 of the upper frame of the apparatus. Rectangular cutouts in plates 56 expose the shaft bearing positions of the metering rolls.
  • Each metering roll carries a spur gear 57, 58. These gears being in mesh assure that the metering rolls turn with the same peripheral speed but in reverse sense.
  • Metering roll shaft 53 carries affixed to each extremity spur gears 59. These gears engage matching racks 60 which slide horizontally in guides 61 attached to side plates 55. The endsof racks 60 are attached at the output side of the metering rolls to a film support plate 62. The action of racks 60 are such that when the metering rolls discharge a length of valve panel, film support plate 62 moves forward supporting the film.
  • a valve panel cutoff device which comprises a movable clampinggmember 63 carried by U-shaped frame 64 and fixed slotted cutting member 65.
  • Frame 64 is hinged about set in side plates 55.
  • Clamping member 63 is forced into I contact with cutting member 65 by the action of air cylinder. and piston units 67 whose pistons press against pins 68 carried by frame 64.
  • Helical springs 69 acting against the pressure of the pistons of 67 tend to maintain clamping member 63 in araised position.
  • Cutting member 65 carries a movable knife 70 mounted on pivoted links 71 and 72.
  • Helical spring 73 attachedto the lower extremity of link 72 tends to maintain knife 70 in a retracted position.
  • the lower surface of clamping member 63 is slotted corresponding to the slot in 65 so that knife 70 when raised will cut film clamped between 63 and 65.
  • the metering rolls are driven by arack75 and pinion 76,
  • Pinion 76 is mounted on the extremity of shaft 53 of lower metering roll 51. Pinion 76 meshes with rack 75 being held ,in mesh by theaction of roller 78.
  • the lower extremity of rack 75 is joined to rod 80 which carries an adjustable collar 81.
  • Rod 80 passes at its lower extremity through a bore in bracket. 82.
  • Collar ,81 is too large to pass through the bore of bracket 82 and so acts to limit the travel of rack 75 andthus the rotation of metering rolls 51 and 52.
  • Piston 79 can be controlled to occupy either an advanced or retracted position, however only during advance does it cause motion of the metering rolls. This is because metering rolls 51 and 52 are connected to shafts 53 and 54 respectively by unidirectional clutches 83 and 84. Shaft 54 remains stationary, the motion of roll 52 being linked to that of roll 51 by meshing spur gears 57. and 58.
  • valve panel film After passing through the metering rolls the valve panel film passes between raised clamping element [63 and cutting a member 65, being supported, by plate 62. The film is advanced until its extreme edge lies over anvil 86 but underneath the edge of the lower ply of the web and; the'trailing edge of the preceding valve panel.
  • Heat-sealing element 87 carried in frame 88 is adapted to press the layers of film against anvil 86 to produce a heat seal.
  • Frame 88 is geherally U-shaped being linked to main frame 56 by hinge 89 so as to permit raising and lowering the heat-sealing element 87.
  • the motion of frame 88 is controlled by two pistons 90 and 91 working in air cylinders 92 and 93. Air cylinders 92 and 93 are linked-to frame crosspiece 94, and the cooperating pistons 90 and 91 are linked to the forward part of heat-sealer frame 88.
  • the valve panel inserting apparatus can conveniently be film clamping and severing device.
  • the air supply to these cylinders is controlled by the programmed controller 103 of the bagmaking machine so that the operationof'the valve in serter is coordinated with the operation of the other units of the machine. This is necessary sincethe sealing of the valve panels takes place while the web is stationary.
  • valve panel inserting and attaching apparatus goes through the following cycle.
  • Air is then admitted to cylinders 92 and 93 to force heatsealing element 87 against the superimposed layers of film lying on anvil 86 to'heat-seal the valve panel edge to the edge of the lower ply of the web in a lap seal.
  • Air is next admitted to cylinder 77 to retract the piston 79 and draw rack 75 upward and retract support plate 62 to a position interior to cutting member 65. Owing to the action of clutches 83 and 84 rolls 51 and 52 remain stationary.
  • Air is then admitted to air cylinders 67 to force clamping member 63 against cutting member 65, followed by admission of air to air cylinder 74 to raise knife 70, and cutting the clamped valve panel film to-the desired panel size.
  • air pressure-to cylinders 67 and 74 is released springs-69 and 73 return clamping member 63 and knife 70 respectively to their original positions.
  • Air is next admitted to air cylinders 92 and 93 so as to retract pistons 90 and 91 and raise heat-sealing element 87.
  • the coordinated controls of the bagmaking machine next advance the two ply web with valve panel attached by a distance equivalent to one bag width andfthe cycle-of the valve panel attachment is repeated while the web is stationary.
  • the method of the present invention has the advantage that it permits the manufacture of valve bags in a continuous manner from a web of plastic film, the valve being inserted automatically in the edge of the web.
  • the method is readily car ried out by a modification of known bagmaklng machines.
  • valve bags as claimed in claim 1 wherein, subsequent to the sealing of the valve panels to the main web, gusset folds are formed in the two edges of the web including the edge constituted by the valve panels.
  • valve panels are preformed in two sections of different film thickness by sealing together the two film sections along a seal direction perpendicular to the edge of the main web of film.
  • valvebags as claimed in claim 1 wherein the valve panels are sealed to the edges of the main web of film by lap seals.
  • a valved end panel to the bag which comprises (1) means for separating the free edges of the web, (2) means for providing a rectangular panel of film adapted to form the matching parts of valves in twosuccessively produced bags, (3) means for joining said panel along its longitudinal edges to the adjacent free edges of the main web at a position corresponding to two successively produced bags, and (4) control means for actuating the joining means at times corresponding to positions of successively produced bags.
  • valve panels comprises means for metering from stock sufficient film to form the panel and means for cutting off the metered panel.
  • valve panels comprises means for sealing together portions of film of different thickness along a seal line running perpendicular to the direction of travel of the main web of film, thus to form composite valve panels.
  • the means for joining the valve panel to the main web comprises a heatsealing bar and cooperating anvil adapted to seal the longitudinal edges of the panel and main web in a lap seal.

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US757207A 1967-08-21 1968-08-16 Manufacture of valve bags Expired - Lifetime US3548722A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3846467 1967-08-21

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US3548722A true US3548722A (en) 1970-12-22

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US757207A Expired - Lifetime US3548722A (en) 1967-08-21 1968-08-16 Manufacture of valve bags

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US (1) US3548722A (enrdf_load_stackoverflow)
CH (1) CH507807A (enrdf_load_stackoverflow)
FR (1) FR1577706A (enrdf_load_stackoverflow)
GB (1) GB1232028A (enrdf_load_stackoverflow)
IL (1) IL30569A (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3646856A (en) * 1969-02-17 1972-03-07 Canadian Ind Method of making a valve bag
US4273549A (en) * 1978-06-26 1981-06-16 W. R. Grace & Co. Process for making multi-walled plastic bag
US4481669A (en) * 1978-06-26 1984-11-06 W. R. Grace & Co., Cryovac Div. Multi-walled plastics bag
US4526565A (en) * 1983-02-23 1985-07-02 Linear Films, Inc. Method of making flat bottom plastic bag
US4561107A (en) * 1979-05-11 1985-12-24 Wavin B.V. Web of plastic bags
US4725262A (en) * 1981-12-29 1988-02-16 Masayoshi Yokomatsu Process and apparatus for the manufacture of a valved sack with self-sealing valve

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5538573A (en) * 1994-12-02 1996-07-23 Cti Industries Corporation Automatic valve insertion method and apparatus therefor
CN113635609A (zh) * 2021-09-07 2021-11-12 瑞安市松盛机械有限公司 一种高速内膜制袋机及双工位装置

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3646856A (en) * 1969-02-17 1972-03-07 Canadian Ind Method of making a valve bag
US4273549A (en) * 1978-06-26 1981-06-16 W. R. Grace & Co. Process for making multi-walled plastic bag
US4481669A (en) * 1978-06-26 1984-11-06 W. R. Grace & Co., Cryovac Div. Multi-walled plastics bag
US4551125A (en) * 1978-06-26 1985-11-05 W. R. Grace & Co., Cryovac Div. Apparatus for making multi-walled plastic bags
US4561107A (en) * 1979-05-11 1985-12-24 Wavin B.V. Web of plastic bags
US4636190A (en) * 1979-05-11 1987-01-13 Wavin B.V. Apparatus for manufacturing a web of plastic bags
US4783178A (en) * 1979-05-11 1988-11-08 Wavin, Bv Method of manufacturing a web of plastic bags
US4725262A (en) * 1981-12-29 1988-02-16 Masayoshi Yokomatsu Process and apparatus for the manufacture of a valved sack with self-sealing valve
US4526565A (en) * 1983-02-23 1985-07-02 Linear Films, Inc. Method of making flat bottom plastic bag

Also Published As

Publication number Publication date
FR1577706A (enrdf_load_stackoverflow) 1969-08-08
GB1232028A (enrdf_load_stackoverflow) 1971-05-19
IL30569A0 (en) 1968-10-24
IL30569A (en) 1973-02-28
CH507807A (de) 1971-05-31

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