US2364009A - Method and means for making bags - Google Patents

Description

1944- c. TESSENDORF ET AL 2,364,009

METHOD AND MEANS FOR MAKING BAGS Filed Nov. 9, 1942 5 Sheets-Sheet l a W L/r we Z M Nov. 28, 1944- c. TESSENDORF ET AL 2,364,009

7 METHOD AND MEANS FOR MAKING BAGS Filed Nov. 9, 1942 5 Sheets-Sheet 2 1944' C. TESSENDORF ET AL METHOD AND MEANS FOR MAKING BAGS 5 Sheeis-Sheet 3 Filed NOV. 9, 1942 y 9 W 5 m m3 2 a 4 [11'] 35; 2 f 0 "m Q M m ,7 :r E 9 w Patented Nov. 28, 1944 METHOD AND MEANS FOR MAKING BAGS Charles Tessendorf, Neenah, and Frank J.

Gruper, In,

Menasha,

With, assignors to Marathon Corporation, a corporation of Wisconsin Application November 9, 1942, Serial No. 465,016

6 Claims.

This invention relates to a method and means for heat sealing bags. More specifically this invention relates to providing an open-ended tube with a heat-sealed seam by suitable application of heat and controlled rolling pressure followed by subsequent chilling and setting of the seam under rolling pressure.

The packaging of dehydrated foods and other substances in non-metallic containers has been widely adopted recently owing to the convenience and efliciency of such packaging. In order to prevent access of moisture to the contents in such packages which will cause deterioration of the contents, it has been found that the packages must be securely and hermetically sealed. In making such packages from tubes or envelopes the production of seams which will not open or permit access of air and moisture to the contents has. presented many difiiculties, particularly when the tubes are formed from sheet materials coated with a heat-scalable composition so as to permit formation of seams autogenously by applying heat and pressure to the portions to be sealed.

According to the present invention the dimculties hitherto encountered in forming effective heat-sealed seams have been successfully solved by carefully controlling the conditions and sequence of steps in forming the seams.

Further details of the invention will be more fully explained by reference to the drawings and specification.

Figure l is a perspective view of the tube sealing unit,

Figure 2 is an elevational view taken on lines 2-2 of Figure 1.

Figure 3 is a cross-sectional view taken on lines 33 of Figure 1,

Figure 4 is a sectional view taken on lines 44 of Figure 3,

Figure 5 is a sectional view of the heat-sealed tube taken along lines 5-5 of Figure l,

Figure 6 is a sectional view taken on lines 6-6 of Figure 2,

Figure 7 is a sectional view taken on lines 1-! of Figure 2,

Figure 8 is a perspective view of the tube before sealing one end thereof, and

Figure 9 is a perspective view of the completed tube or bag, being partlycut away to show its sealed end.

Referring to the drawings, Figure 8 illustrates a tube Ill open at both ends made from any suitable sheet material such as paper, glassine,

Cellophane (regenerated cellulose), ethyl cellulose, cellulose acetate and the like and coated with a suitable heat-scalable coating on both surfaces or at least on its inner surface II which will form an autogenous seal by application of heat 'and pressure. Suitable coating compositions for this purpose are, for example, disclosed in Patent Nos. 1,997,583 and 2,054,113. Any other suitable and available heat-sealable sheets may be utilized. The tube may be formed in any suitable manner by any conventional apparatus such as, for example, by continuously folding a travelling web and sealing the overlapped portions by heat and pressure alone or by means of a suitable adhesive applied to the overlapped longitudinal margins. The continuous tube so formed is then cut into open-ended tubes In of suitable dimension as illustrated in Figure 8. One end may be provided with a semi-circular cut-out portion l2 as a finger-grasping portion for facilitating opening of the tube after sealing same. The longitudinal side margins I3 and ll of the tube may be subjected to heat and pressure to form autogenously sealed longitudinal seams in order to reinforce the tube at the lateral margins and to insure hermetic sealing of the contents. A bottom seam HI is then formed as illustrated in Figure 9 in accordance with the present invention.

A spaced series of tubes ID are continuously fed to the sealing mechanism illustrated in Figure 1 forming the subject-matter of this inven-- tion. The tubes l0 travel from the chute l6 onto an endless travelling conveyor belt l1 guided on rolls I8 and I9 supported in frame 20, moving in the direction of the arrows indicated in Figure 1. As theconveyor passes over roll l9 the tubes l0 fall onto an endless travelling conveyor 25 guided over rolls 26 and 21 moving in the direction indicated by the arrows in Figure 1. The bottom portion of the tubes l0 contact a guide bar 28 which guides the tubes into proper alignment with the bottom seam forming elements. The guide bar 28 is slightly inclined, say about 2, toward the line of travel of the tubes III on conveyor 25.

The bottom seam forming elements comprise a large rotating supporting roll 30 on which a spaced series of the tubes ID are supported while travelling continuously. Roll 30 is driven by motor I through belt 2 and shaft 3. As the tubes l0 leave the conveyor 25 they are guided by curved guide bar 29 and the bo'tom portions thereof which will form the seam 15 are brought successively into direct contact with roll 30 at which point endless belt 3| engages the successive tubes ill and carries them under rolling to control the pressure applied to the bags II pressure into contact with roll 30. Belt 3| is supported on roll 60. Roll 80 is chilled in any carrled'over rolls 32, 33 and 3| which are posiplied to the bottom portion of tube it for forming on eutogenousiy welded bottom seen It.

on the seams by means of pressure roll it which is adjustably positioned so as to apply predetermined pressure directly on belt 3| which in turn is firmly pressed against roll 30. Roll 35 is positioned about the middle of the arc of travel or the tubes III on roll 30. The roll 30 is heated in any suitable manner. As shown in F'lgure '7, an internal arcuate stea'm jet 40 is provided internally 01 the roll 30 and steam is supplied to the j at through tube 1 l extent ding con- shaft 45. e out. through pi e .2 exaft the en or the 1 111g cnt1nu r a su.

re to body ortion of me tu 1s engage-a by 003. travelling belts so and I Belt is guided 5 1' rolls 34 and 52 and belt 5| is guided over rolls 5i and ii in the direction of the arrows as shown in Figure 2. The seam portion I5 01 the bags I'll is not engaged by belts 50 and 5| but extends freely and uncontacted beyond the belts during travel therebetween in the relation shown in Figures 1 and 4. A blast of cold air is supplied by a blower 55 to chill the seam portion during this portion of the travel, but without application of any pressure thereto. During travel of the bags between belts 50 and 5| the bags are flattened into substantially fiat planar condition.

The bags Ill are then conveyed into contact with a chilled supporting roll with the seam portion l5 in direct contact with roll 60. The bottom seams of the bags are retained under pressure against roll 60 by means of endless belt 6| travelling in the direction of the arrows shown in Figure 2 coacting with about half of the periphery of roll 60. Belt 6| is supported on rolls 52, 62 and 63. Roll 62 is adjustably positioned so as to regulate the tension of belt 6| in Order suitable manner such as by cold circulating water which is sprayed internally as shown in Figure 6. Cold water enters through pipe Ill and es. capes through sprayhead 12. The water is with.

I drawn through tube 13 by a suction pump. Pipes 11 and 13 are stationary and extend through the shaft 16 supporting roll '60. Rolls 30 and 60 are preferably of the same diameter and are synchronousiy' driven by motor I through belts i andlasshowninligure 1.

and the adhesive finally set or congealed while subjected to rolling pressure and cold as they mechanism for Lung the with any After flnm formin n3 the tubes in an cuaee con- 8 and. app yin pre ure thereto to set the Sald scams.

2. Apparatus for formin bags from tubes of heat-scalable sheet material which comprises a heated supporting roll and a spaced chilled supporting roll, guide means for aligning One end of said tubes with the heated supporting roll, an endless belt coacting with the periphery of said supporting roll to flex and apply pressure to said tubes for forming a seam while carried on said supporting roll, a pair of endless travelling belts for receiving the tubes from said supporting roll and conveying said tubes to said chilled supporting roll, and an endless belt coacting with the periphery of said chilled roll to flex and apply pressure to said seams and convey the tubes on said supporting roll.

3. Apparatus for forming bags from tubes of heat-scalable sheet material which comprises a conveyor for continuously feeding a plurality of spaced tubes, a heated supporting roll and a spaced chilled supporting roll; guide means for aligning one end of said tubes with said heated supporting roll, an endless belt coacting with about half the periphery of said Supp rting roll to flex and apply pressure to said tubes for forming a seam while carried on said supporting roll, a pair of endless travelling belts for receiving the tubes from said supporting roll and conveyingsaid tubes to said chilled supporting roll, and an endless belt coacting with about half the pe- A riphery of said chilled roll to flex and apply pressure to said seams and convey the tubes on said supporting roll.

4. Apparatus for forming bags from tubes oi heat-scalable sheet material which comprises a conveyor for continuously feeding a plurality of spaced tubes, a heated supporting roll and a spaced chilled supporting roll, guide means for aligning one end of said tubes with said heated supporting roll, an endless belt coacting with the periphery of said supporting roll to flex and apply pressure to said tubes for iorming a seam while and convey the tubes on said supporting roll.

5. Apparatus for forming bags from tubes or .heat-sealable sheet material which comprises a.

conveyor for continuously feeding a plurality or spacedtubeaaheatedsupportingrollanda spaced chilled supporting roll, guide means for aligning one end of said'tubes with said heated mpporting roll, an endless belt coacting with the periphery of said supporting roll to flex and apcurrent of air against the seams while travelling plypnessuretosaidtubestoriorming-aseam while carried on said supporting roll, a pair oi endless travelling belts for receiving and engaging the body portion of the tubes from said supporting roll, and conveying said tubes to said chilled supporting roll, a blower for directing a with said pair of endless travelling belts, and an endless belt coacting with the periphery of said chilled roll to flex and apply pressure to said seams and convey thetubes on said supporting roll.

6. Apparatus for formin bags from "tubes of heat-scalable sheet material which comprises a conveyor for continuously feeding a plurality of spaced tubes, a heated supporting roll and a spaced chilled supporting roll, guide means for aligningoneendofsaidtubeswithsaidheated supporting roll, an endless belt coacting with about half the periphery of said supporting roll toflex andapply pressuretosaidtubes for formingaseamwhilecarriedonsaidsupporflngmil,

e ollf ap ri s egulated asainstsaidendlessbeltwhileincontactwith .saidsupportingmlhapairotendlesstmvelling beitsi'orreceivingthetubesfromsaidsmortingmllandconveyingsaidtubestosaidchilled supporting roll, a blower for directing a current ofairagainsttheseamswhiletravellingwithsaid pairorendlessu-avellingbelmandanmdless beltcoactingwithabouthalttheperipheryot saidchilledrolltoflexandapplypressureto saidseamsandeonveythetubesonsaidsupportingroll. i

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