US3195425A

US3195425A - Leakproof carton and method of making same

Info

Publication number: US3195425A
Application number: US200438A
Authority: US
Inventors: Robert E Taggart
Original assignee: American Can Co
Current assignee: Fort James Corp
Priority date: 1962-06-06
Filing date: 1962-06-06
Publication date: 1965-07-20
Anticipated expiration: 1982-07-20

Description

July 20, 1965 R. E. TAGGART 3, ,4

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5 Sheets-Sheet 1 INVENTOR. ROBERT E. TAGGART July 20, 1965 R. E. TAGGART 3,195,425

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5 Sheets-Shet 2 (7 ROBERT E. TAGGART July 20, 1965 R. E. TAGGART 3,195,425

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5 Sheets-Sheet 3 me aaee aegze Rafi Ta INVENTOR. ROBERT E. TAGGART f ATTORNEYS July 20, 1965 R. E. TAGGART 3,195,425

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5 Sheets-Sheet 4 INVENTOR. ROBERT-1;. TAGGART ATTO A/EYS y 1955 R. E. TAGGART 3,

LEAKPROOF CARTON AND METHOD OF MAKING SAME Filed June 6, 1962 5 Sheets-Sheet 5 INVENTOR.

ROB ERT E. TAGGART TTORIQEY5 3,195,425 LEAKPRODF CARTON AND NETHOD OF MAKING SAME Robert E. Taggart, Appleton, Wis, assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed June 6, 1962, Ser. No. 200,438 9 Claims. (Cl. 93--36.01)

This invention relates to an improved lined carton and method of making the same. More specifically, the invention may be used with particular advantage as a carton for packaging frozen foods which require a leakproof, sealed package.

Frozen foods such as strawberries are customarily packaged in a container employing either a separate moistureproof liner, abag or pouch, or else lined with a moistureproof coating applied to the inner surface of the container. In the case of containers employing a separate liner, the liner is usually glued to the blank prior to erection of the carton and designed to fold with blank. Usually the lined containers render the container leakproof only to the upper edges thereof, and if the carton is turned upside down the liquid which serves as the packaging medium Will leak out. Further, since the package is not hermetically sealed, the product is subject to desiccation upon prolonged contact with air. The above noted problems not only make handling more ditficult but also produce a messy, unattractive package. If a separate filled pouch or bag is employed, valuable packing space is lost since the bag or pouch does not completely conform to the contours of the carton.

' It is the purpose of the present invention to eliminate spoilage of packaged products by employing lined cartons in which the attached liner conforms completely to the inner surfaces of the carton. In addition the adjacent edges of the folded-over liner are sealed together to form an essentially airtight package. The invention is particularly advantageous since either locked or sealed cartons can be employed.

It is an object of the present invention to provide a com, pletely moistureproof carton from an integral blank havinga liner laminated thereto in selected areas.

Another object of the present invention is to provide an hermetically sealed carton which inhibits leakage of the packaging medium and desiccation of the product.

Yet another object of the present invention is to provide a simplified, efficient method, suitable for use with automatic machinery, for forming an essentially airtight, leakproof package.

Still another object of the present invention is to provide a method for forming a carton having a receptacle portion and a cover portion, lining said receptacle portion with a deformable, heat sealable film material which has portions extending beyond the "confines of the receptacle portion, filling said carton and sealing said carton to completely I enclose the product in the film material.

"According to the present invention, a completely leakproof carton having receptacle and cover portions is produced by first setting up a blank either by locking or sealing flaps, then laminating a deformable, heat sealable film material to the inside of the cover portion as well as extending panels and flaps, lining said receptacle portion by stretching the film material into essentially complete con- A United States Patent .0

3,195,425 Patented July 20, 1965 tact with the inner surfaces of said receptacle portions, filling, closing and sealing adjacent surfaces of said film ma terial, and finally folding down and attaching the carton flaps and panels to provide a neat appearing, hermetically sealed carton.

Further details, advantages and objects of the invention will be apparent from the following specification and appended drawings wherein:

FIGURE 1 is a plan view of an integral blank suitably cut and scored to form a carton having a receptacle portion and a cover portion,

FIGURE 1a is an enlarged fragmental view of the portion of the blank enclosed by a broken line in FIGURE 1,

FIGURE 2 is a perspective view of the blank of-FIG- URE 1 set up,

FIGURE 3 is a diagrammatic representation of a preferred method of laminating a stretchable film material to the set up carton in a female die,

FIGURE 4 is a perspective view of the set up carton with the film laminated thereto,

FIGURE 5 is a sectional View of the carton in the female die as the film material is stretched down into the receptacle portion of the carton,

FIGURE 5:: is an enlarged fragmental view of the portion of FIGURE 5 enclosed a broken line, including a portion of the blank and die, and showing the vacuum application channel,

FIGURE 6 is a perspective view of the carton with the cover portion folded to overlie the receptacle portion,

FIGURE 6:: is a partial section of the carton taken along line err-6a of FIGURE 6,

FIGURE 7 is an end elevational view of the carton showing pressure applying means for heat sealing adjacent layers of film material together,

FIGURE 8 is a perspective view of the carton at a further stage of sealing,

FIGURE 9. is a perspective view of the carton of the completed carton,

FIGURE 10 is a plan view of a modified carton blank according to the present invention employing locking means, and

FIGURE 11 is a perspective View of the completed carton.

Referring first to FIGURE 1, the carton is made of a single foldable blank A of flexible material such as paperboard. The blank is divided by score lines 10-24 into hingedly connected panels and fiaps including front cover panel 30, cover panel 31, rear panel 32, bottom panel 33, front panel 34,

end cover panels

35, 45,

glue flaps

36, 39, 41, 44,

end panels

37, 42,

edge flaps

38, 40 and 43. FIGURE la shows in detail holes 25 along score line 12 in the area indicated by the broken lines in FIGURE 1. Similar holes are located along the

score lines

13, 17 and 21. The function of the holes will be described more fully hereinafter.

The blank has a thermoplastic adhesive preapplied thereon the stippled areas. Any adhesive which can readily be applied and is activated easily is suitable for use. Particularly suitable are wax based compositions employing any of a variety of additives including resins and polymers.

The blank A is formed into a carton by first applying adhesive to the outer surfaces of

glue flaps

36, 39, 41 and 44 and infolding them about

scores

20, 22, 18, and 16 respectively to form an angle of less than with the panels 1 J; to which they are connected, i.e. 32 and 34.

and 13, respectively, to positions at right angles with bottom panel 33.

End panels

37 and 42 are then infolded about score lines 21 and 17 so that the inner end. surfaces of the end panels become adhered to the adhesive-bearing surfaces of the glue flaps;

Rear 7 and front panels, 32and 34, are infolded about score lines 12 film sheet down into deep cavities in the die can be ma terially aided in the first instance byprevi-ously'heating theisheet niateri-al'and in the second instance by heatirig the ,air or gas.

Edge flaps '38, 40 and 43am 1 folded outwardly to lie in a common plane with'cover

panels

30,31, 35 and 45 as shown in FIGURE 2;

The set up carbon is then placed in a'female die 59 as shown, in FIGURE .3 and is passed under a heating element 57 to activate the prea'pplied adhesive: Located" above the path of travel of the die 59 is a series of

rollers

51, 52, 53 and 56. A roll of deformableheat scalable material 50 is mounted to unwind with the web pass-;

ing around 'roll 51 and between a pair of nip rollers 52, 53 which provide .a positive pulling action on the web to unwind it from the roll 50. Afterpassing through the nip rolls the web passes over' a support 54whose edge -coacts with cutting edge 55 to sever a sheet 58. from the traveling web. As the leadinglportion of the die 59 adjacent thefron-t edge flap 40 passes under sup- 7 port 54, the leading edge of the web attaches itself to Depending upon the speed of op er-ation and the amount of heat applied,heating element 57 which activates the adhesive may also serve to partially heat the film sheet, increasing its stretchability without tearing. 7

After the depression I of the film sheet intothe V receptacle portion, cover panel 31 is infolded about score line llso that-cover panelsj30, 35 and 45 overlie edge flaps 1 40, 38 and 43, respectivelyp as shownin FIGURE 6. FIGURE, 6a, which is a partial section of the canton shows edge flap 40 and superposed front cover-=panel 30 ,withradjacent layers of film sheet 5-8 'interposedthere- ,between. The faceto face film surfaces are then sealed together by thsa pueauon' of heat Tand pres-sure via heated bars 64 and 65. While upper bar 6 4 can'be a fiat solid plate, lower bar 65 must bU-Shapedto conthe activated adhesive-bearing surface offiap 404 The travel :of the die 59 and the web of film material is regulated by means not shown so that the leading edgeslof the web :and the flap '40 coincide. As the carton land film pass under the roller 56 the pressure laminates the .film material '58 to the heat activated adhesive bearing'surfaces of the cart-on;v The film is severed'from the remainder of the'we'b by cutting edge 55 when the'traih ing edge of, front, cover flap is reached? The carton with the deformable, heat sealablesheet material attache-dis .shown'in FIGURE 4.

Thermoplastic deformable ,film materials having the desirable permeability andnd-eformabili-ty characteristics include those well known in the art such as: rubber hydrochloride sold commercially under the trademark Pliofilm; polymers and copolymers of-polyvinylidene chloride such as Cry-O-Vac and Sarang'vinyl and vinyl copolymers or combinations; and polyester films such" as Mylar. 'A highly preferred material is-Za laminate consisting of a polyethylene terephthalate (Mylar) approximately. .0005" in thickness, laminated-to a polyethylene film approximately .0025! in thickness.

FIGURE 5 illustrates the method by which' the deformable, heat sealable film is forced down into con-' tact with the surfaces of the receptacle portion. Initially; a pressure sealer 63 is applied to the upper surface 01 film sheet 58 on the portions overlying the .a reaof cover panel 31 adjacent the receptacle portion and edge flaps 38, and 43, sealing off the carton receptacle portion bars 64 'and 65 during theface to face sealing of the Ij I As an alternativeto the embodiment descri form to the configuration of three sides of the carton.

j Endicover' panels 35 and *areithen'folded down against the

underlying end panels

37 and 42, respectively,

.as shown'in FIGURE 8. Thei rclosure is completed by forming triangular folds in the unsupported projecting portions of film sheet 58 while folding front cover panel 1 30 downwardly about score 10/:0 lie against front panel a 34. The cover panels 30, 35.and 45 are readily sealed to the underlying front and end

panels

34, 37 and 42,

respectively, by 'm-eans. of the interposed heat scalable.

film material. Having been heated substantially by t-he film, the film readily seals to the carton surfacewith the use of heat and pressure. The completed carton is shown inFIGURE 9. If desiredfan adhesive may beemployed to implement the bonding-of panels 30, '35 and 45 to they respective underlying. panels in case the heat sealing properties 'of the tfilmrnaterial. to the paperboard should prove 'insufiicient to' produce the. required bond. V r 7 'bed above, the-lined carton maybe fo'rmedi'from a blank employing locking means forcrection and closing. The modimaintained in the cavity of" the female die 59.3 A vacu-2 um is then drawn thnou gh connectingchannelsfit), adf

jacent the bottom-edges of the, receptacle portion, and.

through channel 61 leading to. the vacuum'source The nels :-and'the hole. 25 through which't-he vacuum; is

. a a '1 Y Alternatively, the film can be forced downinto the die drawn.

. companying description.

V ffiedlblank" B as showninrFIGUR'E, 10 is divided by score lines -116 and cut lines 117 into hingedly con.

nected' panels and flaps including front cover panel 120,

cover panel 121, rear panel 12 2,bot-tom' panel 123, front "panel- 124, end coverpanels 125, 133, locking

flaps

126, 129 ,ef1d p-anels.127, 13:1, edge flaps 128, 130 and 132, and locking tab 134. Cut lines define female locking slits 138, 139, 140 and 142

whichreceivemale locking tabs

137, 141, 136 and-135,respectively, as shown in FIGURES 'loxland l1; v

'. TheblankB is formed into a carton by engaging locking tabs 13 7 in slits 138 and locking'tabs 141 in slits 139. The, set up carto'n is similar in appearance at'this stage to the first embodiment shown in FIGURE 2. After erection, thefcarton is'lined and the; film'material sealed by the method set fonth in-FIGURES 3-7 and the ac-. The closure of the carton is.

completed 'by folding the

cover'panels

120, 125 and 133 downwardly about/score lines 100,- 105 and 114 respectively. Male locking tabs, and .136Tare inserted in female locking slits 142. and 140, respectively, to pro- 'duce the completed closedcarton shown in FIGURE cavity by air or gaspressure. In this'method, the edges of the film sheet '58 adjacent the receptacle portion are again sealed offby pressure toprevent leakage. A press ing form 62 then descends on pressure sealer 63 form-,

Air or' gas under pressure is.

ing another airtight seal.

then forced down through the centralshaft of the press- 11.{ The adhesive, indicated by the :stippled'are'a in'FIG- UR E- 10, is purposely omitted from locking tabs 134,

135, l3 6=to prevent undesirable adhesion of the; liner to the surfaces of. these components of the carton. I It as obvious, of course, that the particular configuration of the locking means can be changed as desired.

carton having. side and bottom panels'and edge fiapsf If desired, the coverpanel may be. omitted and" a hingedly connected to the upper'edge's of the sidepaliels ing form 62 depressing thefilm sheet .58 until it con forms tothe configuration of the receptacle portion.

In the methods described abov-e the stretching of -the may be employed. ,The sheet material'ia'then, adhered to.-a.ll;edge;fiaps -and subsequently depressed intothe 75 receptaclei'portionfin the mannerpreviously described.

To close the car-ton after filling, the extended free end of the film is folded over to cover the receptacle and the edge fiaps and adhered to the underlying film in the edge flap areas. The edge flaps are then folded down and sealed to the outside carton side panels as previously described. A significant saving in sheet material may be realized by a slight modification in the above procedure, in which the edge flap from which the free end of the sheet material extends is folded inwardly to partially coverthe contents of the carton and the extended film then sealed to the remaining edge flaps in the regular manner. These flaps are then folded out and down to be sealed to the carton side panels as previously described.

The present invention provides a lined carton using a single blank and a single liner. The carton can readily be set up, lined, filled with the commodity to be packaged, and closed by automatic machinery. The contents are encompassed by an essentially airtight, leakproof, hermetically sealed construction which insures freshness and retards spoilage. Both the size and configuration of the adhesive patterns used to heat seal the deformable, heat scalable film material to the carton blank can be varied as desired.

It is understood that the description of the carton construction given herein is merely illustrative of the essential features of the invention, and is not limited to the specific dimensions or contours, which may be greatly varied or modified and which variations are intended to be included within the scope of the appended claims.

I claim:

1. A method of forming from an integral carton blank an essentially hermetically sealed carton having a perforated bottom panel, hingedly connected side panels, and edge flaps hingedly attached to the upper edges of said side panels, which method comprises applying an adhesive to said edge flaps; setting up said blank to form a carton having the adhesive bearing surfaces of said edge flaps facing upwardly; attaching a deformable, heat sealable sheet material to the adhesive bearing surfaces of said edge flaps with said sheet material extending outwardly an appreciable distance from one side of the carton; depressing said sheet material into said carton to conform to the configuration thereof; folding over said extended sheet material and sealing the edges to the underlying portions of said sheet material which are adhered to said edge flaps.

2. A method of forming from an integral carton blank an essentially hermetically sealed carton having a bottom panel defined by perforated score lines, hingedly connected side panels, and edge flaps hingedly attached to the upper edges of said side panels, which method comprises applying an adhesive to one surface of each of the edge flaps; setting up said blank to form a carton having said edge flaps extending outwardly in a common plane and their adhesive bearing surfaces facing upwardly; adhering a deformable, heat scalable sheet material to the adhesive bearing surfaces of said edge flaps with said sheet material extending outwardly an appreciable distance from one side of the carton and being at least twice the size of the area defined by the outer edges of said edge flaps; applying pressure means to hold said sheet material in airtight contact, with the upper edge of said carton; depressing said sheet material into said carton to permanently conform to the configuration thereof; folding over said extended sheet material and sealing the edges to the underlying portions which are adhered to said edge flaps.

3. The method of claim 2 wherein said sheet material is depressed by gas under pressure directed down on top of said sheet forcing the air under said sheet outwardly through the perforations in said score lines.

4. The method of claim 2 wherein said sheet is depressed by a vacuum drawn through the surfaces in the score lines defining the bottom panel of the carton.

5. The method of claim 1 wherein said sheet material is depressed by gas under pressure directed down on top of said sheet material forcing the air under said sheet material outwardly through the perforations in the bottom panel.

6. The method of claim 1 wherein said sheet material is depressed by a vacuum drawn through the perforations in the bottom panel.

7. A method of forming from an integral carton blank an essentially hermetically sealed carton having a bottom panel defined by perforated score lines, hingedly connected side panels, and edge flaps hingedly attached to the upper edges of said side elements, which method comprises applying an activatable adhesive to one surface of each of said edge flaps; setting up said blank to form a carton having said edge flaps extending outwardly in a common plane and having their-adhesive bearing surfaces facing upwardly; passing said carton through means to activate the preapplied adhesive; adhering a deformable, heat-scalable sheet material to the upper adhesive bearing surfaces of said edge flaps with said sheet material extending outwardly an appreciable distance from one side of the carton and being at least twice the size of the area defined by the outer edges of said edge flaps; applying pressure means to hold said sheet material in airtight contact with the upper edges of said carton; de' pressing said sheet material by means of a Vacuum drawn through the perforations in said score lines into said carton to permanently conform to the con-figuration thereof; folding over said extended sheet material; sealing the edges to the underlying portions adhered to said edge flaps; and folding down said edge flaps into engagement with said side panels and sealing them together by said heat-scalable material.

8. A method of forming from an integral carton blank an essentially hermetically sealed carton having a bottom panel defined by perforated score lines, hingedly connected side panels, and edge flap-s hingedly attached to the upper edges of said panels, which method comprises applying an adhesive to one surface of each of said edge flaps; setting up said blank to form a carton having the adhesive bearing surfaces of said edge flaps facing upwardly; attaching a deformable, heat-scalable sheet ma terial to the adhesive bearing surface of said edge flaps with said sheet material extending outwardly an appreciable distance from one side of the carton; depressing said sheet material into said carton to conform to the configuration thereof by directing gas under pressure downwardly on top of said sheet material forcing the air under said sheet material outwardly through the perfo rations in said score lines; and folding over said extended sheet material and sealing the edges to the underlying portions of said sheet material which are adhered to said edge flaps.

9. A method of forming from an integral carton blank an essentially hermetically sealed carton having a bottom panel define-d by perforated score lines, hingedly connected side panels, and edge flaps hingedly attached to the upper edges of said panels, which method comprises appl ing an adhesive to one surface of each of said edge flaps; setting up said blank to form a carton having the adhesive bearing surfaces of said edge flaps facing upwardly; attaching a deformable, heat-scalable sheet material to the adhesive bearing surface of said edge flaps with said sheet material extending outwardly an appreciable distance from one side of the carton; depressing said sheet material into said carton to conform to the configuration thereof by drawing a vacuum through the perforations in the score lines defining the bottom panel of the carton; and folding over said extended sheet material and sealing the edges to the underlying portions of said sheet material which are adhered to said edge flaps.

(References on following page)

Claims

1. A METHOD OF FORMING FROM AN INTEGRAL CARTON BLANK AN ESSENTIALLY HERMETICALLY SEALED CARTON HAVING A PERFORATED BOTTOM PANEL, HINGEDLY CONNECTED SIDE PANELS, AND EDGE FLAPS HINGEDLY ATTACHED TO THE UPPER EDGES OF SAID SIDE PANELS, WHICH METHOD COMPRISES APPLYING AN ADHESIVE TO SAID EDGE FLAPS; SETTING UP SAID BLANK TO FORM A CARTON HAVING THE ADHESIVE BEARING SURFACES OF SAID EDGE FLAPS FACING UPWARDLY; ATTACHING A DEFORMABLE, HEAT SEALABLE SHEET MATERIAL TO THE ADHESIVE BEARING SURFACES OF SAID EDGE FLAPS WITH SAID SHEET MATERIAL EXTENDING OUTWARDLY AN APPERCIABLE DISTANCE FROM ONE SIDE OF THE CARTON; DEPRESSING SAID SHEET MATERIAL INTO SAID CARTON TO CONFORM TO THE CONFIGURATION THEREOF; FOLDING OVER SAID EXTENDED SHEET MATERIAL AND SEALING THE EDGES TO THE UNDERLYING PORTIONS OF SAID SHEET MATERIAL WHICH ARE ADHERED TO SAID EDGE FLAPS.