US1974256A - Method of sealing packages - Google Patents

Description

Patente Sept. '18, 1934 riso STATES ism-se PATENT l 7 Claims.

,10 scribed a method of hermetically sealing packages of the type in which overlapped wall portions form closures for the ends oi the packages, with a juncture exposed-along a wall lying at an angle to said overlapped wall, which con- 15 sists in applying a coating oi' a hermetically sealing liquid to an exposed edge juncture of overlapped walls adjacente wall lying at an angle thereto, and thereafter scraping ontV any excessv of liquid from the wall and said juncture.

ab While the method suggested in-my copending application, to which reference has been made, is completely successful in the hermetic seal which it provides, it requires ordinarily an extra manufacturing operation which has cer- 25. tain disadvantages.

In ordinary sealing of cartons and containers, it is usual to move cartons, after being squared up, vertically, with the open ends up and down, and with the two opposite longer panels being 'S0 parallel with the machine, through the sealing apparatus, which apparatus first eeots a seal on the bottom of the carton by rst folding the end sealing naps of the two narrow or front and back walls, thereafter applying adhesive to one or the end sealing naps of one of the wide panels, @olds same over to eiect an esion between the first two folded sealing :dans and the last named sealing flap. Thereafter applyingadhesive to the remaining wide end sealing nap i0 to bring about adhesion between the two opposite wide end sealing aps.

The carton then, with the bottom sealed, is usually moved to the lling machine, where the contents are inserted into. the carton, thereafter it is conveyed and brought in contact with the mechanism that closes the top of said-csr ton, in a similar -imanner m described above for the bottom.

By means oi adjustable scraper-s acting upon the glue wheel, it is possible and necessary to regulate the amount of adhesive the glue wheel carries and it is usually the practice to deposit a thin film of adhesive on the sealing flaps, so as to bring about an effective adhesion between the sealing flaps in as quick a time as possible.

(ci. :i3-e) By this means, there is no difficulty in securing a proper closure or seal but it is impossible to secure a sift-proof or vermin-proof condition, due to the fact that, onall the corners, there remain small openings or pinholes, which permit powders to sift through or vermin to pass in, and to prevent this, it is the usual practice to either first insert such powdered contents into a bag and, thereafter, place it into a carton or to wrap the carton after the contents are in it and sealed.

It is the object of my invention to provide a method of eecting a hermetical seal and thus avoid the necessary labor and material that are being used now to secure 'a sift-proof container, by means of (when applying the adhesive to the sealing aps) a recess cut into the scraper permitting a heavy beadof glue to be carried on that portion of the glue wheel that will deposit this heavy bead over the score line where the wide sealing aps are articulatedl to the main body of the carton, the remaining glue flaps having the usual thin film oi adhesive and, after these panels are folded over, the excessive adhesive on these score lines lls effectively the small corner openings.

There are several ways of carrying out my prgposed new method, and in the drawing I have illustra'ted diagrammatically several proposed varrangements which will found effective.

In the drawing:

Figure 1 is adiagrammatic representation in perspective of a container having the adhesive applied to its side closing flaps.

Fig. 2 shows diagrammatically a detail of amcdiiication of the manner of applying the adhesive to the closure naps of a carton over that shown in Fig. 1.

Fig. 3 shows a detail plan View of the adhesive applying rolls shown in Fig. 1.

Fig. d is an end elevation of. the carton illustrated in Fig. l, after the adhesive nas been applied to it.

Fig. 5 shows a sealed container sealed in accordance with my invention.

Referring rst to Fig. 1, I have shown the con- A veyor belts l, on which the carton indicated at 2 may be fed along. The end closure flaps 3 and 4 have at that stage of the adhesive applying operation illustrated, been folded in at right angles to the end and side walls of the box. The side walls oi the box are indicated at 5. The side closure flap's of the container or carton are indicated at 6, '1, and subsequent to the application of the adhesive to the inner surfaces of theaps 6 and 7,

ics

i respectively, rotate, said glue rolls being preferrz ably mounted on a singleshait such as that indi cated at 12.

The two intermediate wheel rolls i3 and le, are

positioned between the two glue reed rolls l and l1, and the applying rolls and lo, and are adjustable in relation to the glue leed rolls lo and ll. These rolls 13 andile periorln two distinct functions. They carry the glue from the rolls lil i and 1l Yto the rolls l5 and 16, and also by 'their adjustability, control the amount ol glue passing over them to rolls l5 and r16. If the rolls li-l and le are adjusted closely to the rolls l@ and 1l, the iilm oi glue passing through the rolls and on to the applying rolls i5 and 16 will he thin, while il' these rolls 13 and le are adjusted. away from the rolls lil and ll the film of glue will he relatively thick. lo thereore can he readLly seen that il there is any depression or cut out portion in the rolls 13 and lll, the glue carried through the rolls on that portion will be thicker than the glue cars ried through on the restoi thevroll.

The adhesive applying rollers i5, le are those which actually supply the adhesive to the surm faces of the sealing i'iaps of the carton.

By notching the rollers i3, la as indicated at 17, 18, a thicker layer of adhesive in the form of a narrow band 19 is formed at such suitable distance from the articulated corner edges o the side flaps 6 and 7, that narrow hands of adhesive 20 are applied substantially along the lines of are tlculation of the container.

Referring to Fig. 4l, the side closure iilaps d, 7 are clearlyv illustrated, with a thin coating 2l oi adhesive applied to the upper surfaces oi' the flaps. The narrow band of supercoated adhesive is indicated at 20.

When the side ilaps 6 and 'l are )folded in to the position illustrated in Fig. 5, small heads such as are indicated at 22 in Fig. il formed at corner edges so that the usual point openings are hermetically sealed.

ln Fig. 2 l have illustrated an alternate con struction in which the glu-e pan indicated 3a. vA take-oil roller 13d, peripherally engages surfaces oi the adhesive i'eed roll lilo, and a laye er of adhesive is carried by the roller ldd into contact with the surface of the applying roller 15a, which engages the surfaces oi the closing :laps or the carton.

In order to articulate the thickness oi the ad= hesive on the rollers 15d il have shown a scraper knife 23, adjustably mounted in a support 24 and having a recess 25, which Will'perinit an unusually thick band of adhesive to pass around on the roll loa. This adhesive with the narrow band is car=l ried by the take-off roller 13a to the applying roll= er 15a. The take-0E roller ille has a narrow groove 17a so positioned as to register with the narrow band termed on the roll lila hy the scraper and the aperture 25. This groove prevents the take-oil roll 13a from attening out the band formed on the roll 10c. This modification forms the same narrow band in the adhesive on the applying roll, as before described, and causes the narrow bead of adhesive to be iormed at the corner edges of the carton, which eectively terasse forms of the closure ap a hermetic seal for the carton.

Irlille adhesive must necessarily be in a semi-V:

liquid state to make it possible for the glue wheels to spread the glie evenly in as thin a lm as possiole. The adhesive being in semi-liquid form, contains a relatively high proportion of water, and heiore the adhesion takes place therrncisture in the adhesivernust he absorbed in the fibers of the carton material. Y.

When cartons are being sealed at the rate of 'lll to 80 or more per minute, in. order to make it possible to handle these cartons so that they may he removed from the machine, it does not allow maintaining. pressure or contact against the sealing flaps but for a very hrief period. Silence, the. adhesion must take effect as soon as possible and it is for that reason that a thin ilrn of adhesive is necessary to be applied, as the less adhesive is applied, the quicker the adhesion between the sealingilaps will ioe effected. The narrow stripe of the thicker layer of adhesive will not set or dry as quickly as the remaining portion, but that does not prevent the handling or removing oi the cartons from the machine, for the reason that the sealing iiaps have been effectively sealed between the surfaces where the thin hlm was deposited and the bead of adhesive, #20, thereafter, has ample time to dry or set, even after these cartons have been packed in shipping cases, without in any Way effecting the purpose for which the bead of adhesive has been applied.

The rolls l3 and 14 and the scraper knife 23 are adiustably mounted so that the narrow stripes of adhesive Which form the corner closures may he adjusted to various widths or" cartons.

By tests made with cartons sealed in accordance with the invention described herein it is unnecessary to further wrap the packages, as with wax paper, or to carry out the steps of my process described in my co-pending application, Serial No. 603,064, and a sift-proof package which is substantially hermetically sealed may thereby he formed.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent. is':

l. The method ci sealing the closure naps or cartons which consists in applying thin coatings oi adhesive to the contact surfaces or opposed pairs or closure flaps with thicker stripes of adhesive applied along the lines of articulation of the closure flaps and the carton walls, and then folding over the closure :Flaps to supernosed position, one on the other, whereby a head of adhesive i is iormed at the corner edges oi the under surface oi the closure naps.

2. The method of sealing cartons having end and side closure flaps, which consists in folding in the end closure flaps, applying adhesive in a thin layer to the contact surfaces or" the side closure flaps, leaving a thicker band along each of the lines of articulation of said closure aps, then folding said side closure flaps into overn lapping relation, thereby causing the adhesive from the thicker bands to exude along the under surface oi the side closure flaps forming hermetically sealing masses of adhesive at said corner edges.

3. The method oi hermetically sealing the cor- Y' iso - securing them in folded down condition.

4. A processof sealing the closure portions of containers adhesively, which comprises spplyin'g adhesive upon the surface of a closure portion ina thin layer to permit rapid adhesion and setting, and also applying adhesive thickly to a selected part of the surface of a closure portion whereby said thick application of adhesive is enabled to seal, by iilling, a crevice formed by the interengagement of said closure portions.

5. The method of insuring sealed closure of the crevices left in the corners of a carton at the ends of its ap folds, which naps are provided with means for holding said flaps in folded clcd condition, consisting in applying adjacent to the nap folds a sealing substance in such greater quantity than would be proper for adhesion of the flaps, and of such consistency. as to squeeze into said crevices incident to the folding of said naps into folded closed condition, and then folding said flaps into said condition and holding said flaps in said condition by said holding means, whereby said,

substance may assume a permanent sealing relation to said crevices while held by the folded and held aps.

6. The method of insuring sealed closure of the crevices left at thecorners of a carton at the ends of its nap folds. which consists in providing said aps with means for holding them in folded closed condition which becomes effective in the course of rapid machine folding and closing Aof the flaps. and providing adjacent to `carton may have,

theiiapfoldsasealinginsuchgreater quantity than would be proper for adhesion of theflapaandofsuchconsistencmastosqueeze into said crevices incident to the folding and closing of the flaps, and then folding and closing the flaps and causing said holding means to' become eifective as aforesaid. whereby said sealing medium may assume a permanent sealing relation to said'crevices while .held by the folded and held flaps during a period of time exceeding that required for the rapid machine folding and clos-i ing of said naps.

7. The method of sealing the crevices at the comers of a carton, at the ends of its flap folds, independently of any lining element which the which.V consists in providing sealing substance interiorly of the carton naps in such greater quantity than would be proper for adhesion of the flaps and of such consistency and so located as to be squeezed into said orevices incident to folding and closure of the flaps, and additionally providing for holding the flaps in their folded and closed condition by means ericctive in the course of rapid machine operation, folding and closing said flaps by said operation and thereby causing said holding means to become effective as aforesaid, and allowing said sealing substance to assume a permanent sealing relation to said crevices while held by the folded and held flaps during a period of time exceeding that required for the rapid machine folding and closins 0f. the flaw SAMUEL

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