US2957394A - Bag - Google Patents

Description

Oct. 25, 1960 R. J. WILLIAMS BAG ' 4 Sheets-Sheet 1 Original Filed Sept. 28, 1956 Oct. 25, 1960 R. J. WILLIAMS BAG 4 Sheets-Sheet 2 Original Filed Sept. 28, 1956 P um, R

Oct. 25, 1960 R. J. WILLIAMS 2,957,394

BAG

Original Filed Sept. 28, 1956 4 Sheets-Sheet 3 FIG .4? (r-w I I4 47 1/5 3 57 a Oct. 25, 1960 R. J. WILLIAMS 2,957,394

BAG

Original Filed Sept. 28, 1956 4 Sheets-Sheet 4 United States Patent BAG Russell J. Williams, Clayton, Mo., assignor to Bemis Bro.

Bag Company, St. Louis, Mo., a corporation of Missouri Original application Sept. 28, 1956, Ser. No. 612,636,

now Patent No. 2,892,580, dated June 30, 1959. Dizisdggsgnd this application July 25, 1958, Ser. No.

6 Claims. (CI. 93-35) This invention relates to the manufacture of bags,

and more particularly to the manufacture of multi-ply paper bags.

' This application is a division of my copending application Serial No. 612,636, filed September 28, 1956, now Patent No. 2,892,580, issued June 30, 1959, entitled Bag.

Among the several objects of the invention may be noted the provision of a method of economically manufacturing bags having folded and pasted end closures with reinforcement to offset the Weakness in the paper otherwise caused by the folding and creasing incident to the forming of the closures in such manner that bags of given strength may be made with fewer plies than the heretofore, thereby effecting great saving of paper in quantity production, and the provision of a method of manufacturing stepped-end bags with such reinforcement. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the methods hereinafter described, the scope of the invention being indi cated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. l is a semi-diagrammatic view in perspective illustrating procedure in the manufacture of stepped-end bags in accordance with this invention;

Fig. 1A is a longitudinal section of a multi-ply web made in accordance with Fig. 1, taken on line 1A-1A of Fig. 2;

Fig. 2 is a plan view of a multi-ply web made in accordance with Fig. 1, with certain plies in part broken away;

Fig. 3 is a plan view on a larger scale than Fig. 2

showing a tube made from the Fig, 2 multi-ply web,

and illustrating at the left thereof how this tube is segmented into individual bag tubes;

Fig. 4 is a view in perspective of an individual bag tube, as viewed from the seamed side of the tube and from above, the outer ply of the tube being partly broken away;

- Fig. 5 is a view in perspective of the bag tube as viewed from its other side and from below, the outer ply and the next ply being partly broken away; 3

Fig. 6 is a cross section taken on line 6-6 of Fig. 5; i Fig. 7 is a view in elevation of a bag tube showing procedure in the formation of end closures for the tube to make a valve bag; and,

Fig. 8 is a view in elevation of a completed bag.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, the manufacture of three.- ply stepped-end bags is shown, but it will be understood that the principles of the invention are applicable to the manufacture of stepped-end or other bags with more than three plies. The showing of the manufacture of three'ply bags has been selected to avoid complication lice of the disclosure. In accordance with this inventionas it pertains to the manufacture of three-ply stepped-end bags, as illustrated in Fig. 1, three webs of paper 1, 3 and 5 of the same width are continuously withdrawn from supply rolls (not shown, but which would be off to the right of Fig. l). Webs 1 and 3 are combined to form a two-ply web W-2 at a combining guide 7, and the web W-Z is combined with web 5 to form a three-ply web W-3 at a combining guide 9. The three-ply web W-3 is continuously fed through a conventional tuber (not shown) to be formed into a three-ply tube T (see Fig. 3) by folding on lines L1 and L-Z.

Guide 7 is shown as a roll. The webs 1 and 3 travel to the roll 7 in spaced paths, converging together at the roll to form the two-ply Web W-2. The web 1, which eventually becomes the inner ply of the three-ply tube, is shown as travelling generally horizontally from its supply roll to a guide roll 11 from which it travels upward to a guide roll 13, thence horizontally forward to a guide roll 15 and thence upward to the combining roll 7. The web 3, which eventually becomes the intermediate ply of the three-ply tube, is shown as travelling generally horizontally from its supply roll below the web 1 and the 'guide roll 11 to a guide roll 17, thence up ward to a guide roll 19, thence in a path inclined upwardly and rearwardly to the roll 7. The web 5, which eventually becomes the outer ply of the three-ply tube, is shown as travelling generally horizontally from its supply roll below the web 3 and the guide rolls 11 and 17 to a guide roll 21, thence upward to a guide roll 23, thence horizontally rearward to a guide roll 25, and thence upward to the combining roll 9. The bite of the webs'l and 3 (i.e., the transverse line on which they come' into engagement to form web W-2) is indicated at A. The bite of web W-2 and web 5 (i.e., thetransverse line on which they come into engagement to form web W-3) is indicated at B. The webs 1, 3 and 5 are combined in laterally offset relation as is conventional in the manufacture of multi-ply paper bags.

As the web 1 travels toward the combining roll 7, it is cut and perforated at bag length intervals on lines for forming stepped-end closures. As shown in Figs. 1 and 2, the web 1 is cut to form four longitudinal slits 27a, 29a, 31a and 33a. Slits 27a and 29a are located on opposite sides of the line L-l and slits 31aand 33a 'are located on opposite sides of the line L-2. The web 1 is perforated on transverse lines 35 and 37 which extend inward from the side edges of the web to the outer slits 27a and 33a, on a transverse line 39 which extends between the inner slits 29a and 31a, on a transverse line 4111 which extends between slits 27a and 29a, and on a transverse line 43a which extends between slits 31a and 330. Line 35 and 37 are transversely aligned. Lines 41a and 43a are transversely aligned and stepped back from lines 35 and 37. Line 39 is stepped back from lines 41a and 43a. The perforating and cutting is effected as by means of a perforator and cutter such as indicated at 45 operating on the web 1 in the reach of the web extending from roll 11 to roll 13.

As the web 3 travels toward the combining roll 7, it is cut and perforated at bag length intervals on lines for forming stepped-end closures. As shown in Fig. 2, the web 3 is cut to form four longitudinal slits 27b, 29b, 31b and 33b corresponding to slits 27a, 29a, 31a and 33a. It is perforated on a transverse line designated in its entirety by reference character 46 which extends completely across web 3 intersecting the slits at their central points. Line 46 thus consists of transverse lines 41b and 43b corresponding to lines 41a and 43a between the slits, lines 47 and 49 which extend inward from the side edges of the web to the outer slits 27b and 33b, and a line 51 which extends between the inner slits 29b and 31b.

perforating and cutting is elfected as by means of a perforator and cutter such as indicated at 53 operating on the web 3 in the reach of the web betwwen the rolls 17 and 19.

As the web 5 travels toward the combining roll 9, it is cut and perforated and cut at bag length intervals on lines for forming stepped-end closures. As shown in Fig. 2, the web 5 is cut to form longitudinal slits 27c, 29c, 31c and 330 corresponding to slits 27a and 27b, 29a and 29b, 31a and 31b, 33a and 33b, and perforated between the slits on transverse lines 410 and 43c corresponding to lines 41a and 41b, 43a and 43b. It is perforated on transverse lines 55 and 57 which extend inward from the side edges of the web to the outer slits 27c and 330, and on a transverse line 59 which extends between the inner slits 29c and 31c. Lines 55 and 57 are transversely aligned and stepped back from lines 410 and 430, and lines 41c and 430 are stepped back from line 59. The perforating and cutting is efiected as by means of a perforator and cutter such as indicated at 61 operating on the web 5 in the reach of the web extending from roll 21 to roll 23.

The webs 1, 3 and 5 all travel at the same speed. The timing of the perforating and cutting devices 45, 53 and 61 is such that slits 27a, 29a, 31a and 33a and the lines of perforations 41a and 4311 made by the device 45 in web 1 come into register with slits 27b, 29b, 31b and 33b and lines 41b and 43b made by device 53 in web 3 at the combining roll 7, and slits 27c, 29c, 31c and 33c and lines 410 and 43c made by the device 61 in web 5 come into register with the slits 27a-b, 29a-b, 31a-b and 33a-b and lines -41a-b and 43a-b in web W2 at combining roll 9. Accordingly, in the three-ply web W-3, at each bag length interval, there is a group of slits and lines of perforations as follows: four longitudinal slits 27, 29, 31 and 33 (constituted by the registering slits 27a, b, 29a, b, 0; 31a, b, c; and 33a, b, c); a transverse line of perforations 41 (constituted by the registering line 41a, b, c); a transverse line of perforations 43 (constituted by the registering lines 43a, b, c); transverse lines of perforations 35, 39 and 37 in Web 1; transverse lines of perforations 47, 51 and 49 in web 3; and transverse lines of perforations 55, 59 and 57 in web 5. In each group, lines 35 and 37 in web 1 are aligned with line 59 in web 5. Lines 47, 51 and 49 in web 3 are stepped back from lines 35, 37 and 59, and register with lines 41 and 43. Lines 55 and 57in web are aligned with line 39in web 1.

As the webs 1 and 3 are combined at the combining roll 7, transverse reinforcing bands 63 are fed in between the webs 1 and 3 and pasted in between them, the bands 63 being spaced at bag length intervals along the length of the composite two-ply web W-2 formed at the roll 7 from webs 1 and 3. The bands 63 are severed from a continuous web 65 of band material drawn from a supply roll (not shown). This material is preferably paper, but it may be any other suitable reinforcing material such as cloth. The width of the web 65 and its lateral register are preferably such that the bands extend from near one edge of web 1 to near the opposite edge of web 5 (see Fig. 2). The web 65 is drawn from its supply roll at a speed less than the speed of webs 1 and 3 by a pair of draw rolls 67. It travels from its supply roll between webs 1 and 3 to a guide roll 69, thence up to the draw rolls 67. It is fed upward by the draw rolls through a cutter 71 and between the converging webs 1 and 3 into the bite A of these webs.

The cutter 71, as shown, may comprise an anvil roll 73 and a rotary blade 75, and is adapted to sever the web into bands 63 which are of an appropriate dimension in the longitudinal dimension of webs 1 and 3. What the appropriate longitudinal dimension is will be later made clear in reference to the finished bags.

The line on which the cutter 71 cuts the web 65 is preferably spaced from the bite A of W b l and 3 a dis tance corresponding generally to the desired longitudinal dimension for the band. The timing of the cutter is such that it severs the web 65 to form a band substantially at the instant that the end of the web 65 is caught in the bite of webs 1 and 3, and the severed band is thereupon drawn in between the webs 1 and 3 at the speed at which webs 1 and 3 are travelling. The band is pulled away from the freshly cut end of web 65 since web 65 is fed by the draw rolls 67 at a speed lower than the speed of the webs 1 and 3, and the bands drawn in between the webs 1 and 3 are spaced along the length of the web W2 at equal intervals. The speed of web 65 in relation to the speed of webs 1 and 3 is such that the spacing of the bands corresponds to the desired length of the bags to be manufactured.

As webs W-Z and 5 are combined at the combining roll 9 to form web W-3, transverse reinforcing bands 77 are fed in between webs W-2 and 5 and pasted in between them, the bands being spaced at bag length intervals along the length of the web W-3. The bands 77 are severed from a continuous web 79 of band material drawn from a supply roll (not known). This material is preferably paper, but it may be any other suitable reinforcing material such as cloth. As shown in Fig. l, the width and lateral register of the web 79 is the same as that of web 65. The web 79 is drawn from its supply roll at a speed less than the speed of webs 1, 3 and 5 and the same as the speed of web 65 by a pair of draw rolls 81. It travels from its supply roll between webs 3 and 5 to a guide roll 83, thence up to the draw rolls 81. It is fed upward by the draw rolls through a cutter and between the converging webs W-2 and 5 into the bite B of these webs. The cutter, as shown, may comprise an anvil roll 87 and a rotary blade 89, and is adapted to sever the web into bands 77 which are of the same dimension in the longitudinal direction of the webs as bands 63. The line on which the cutter 85 cuts web 79 is preferably spaced from the bite B of webs W-2 and 5 a distance corresponding generally to the desired longitudinal dimension for each band 77. The timing of the cutter 85 is such that it severs the web 79 to form a band 77 substantially at the instant that the end of the web 79 is caught in the bite of webs W-Z and 5, and the severed band 77 is thereupon drawn in between the webs W-2 and 5 at the speed at which webs W-2 and 5 are travelling. The band is pulled away from the freshly cut end of web 79 since web 79 is fed by the draw rolls 81 at a speed lower than the speed of the webs W-2 and 5, and the bands drawn in between the webs W-2 and 5 are spaced along the length of the web W-3 at equal intervals. The speed of web 79 in relation to the speed of webs W-2 and 5 is such that the spacing of the bands corresponds to the desired length of the bags to be manufactured.

The timing of the band cutters 71 and 85 relative to one another is such that the bands 63 of the series of bands fed in between webs 1 and 3 are out of phase with respect to the bands 77 of the series of bands fed in between web W-2 and web 5 to the extent that the bands of one series are longitudinally spaced from and lie on opposite sides of the groups of lines of cuts and perforations in the web W-3 from the bands of the other series. More particularly, as shown in Fig. 2, the bands 63 are stepped forward of the lines 35, 37 and 39, and the bands 77 are stepped back from the lines 55, 57 and 39.

As the web 1 travels from the roll 13 to the roll 15, three transverse rows of paste spots 91a, 93a and 95 are applied to the inside face of the web by means of a spot paster such as indicated at 97 in Fig. 1. As the web 3 travels from the roll 19 to the combining roll 7, three rows of paste spots 91b, 93b and 95a are applied to the face of the web 3 which is opposed to the inside face of the web 1 by a spot paster such as indicated at 99 in Fig. 1. When the webs 1 and 3 come together, rows 91a and 91b come into register on opposite faces of bands 63 and paste the forward edge of the band 63 to both the webs 5 1 and 3, rows 93a and 93b come into register on opposite faces of bands 63 and paste the rearward edge of the band 63 to both the webs 1 and 3, row 95 pastes the webs 1 and 3 together immediately rearward of the rearward edge of the band 63, and row 95a pastes the webs 1 and 3 tgether rearward of row 95.

As the web W-2 travels from the roll 7 to the roll 9, three transverse rows of paste spots 101, 103a and 105a are applied to the inside face of the web W-2 by means of a spot paster such as indicated at 107 in Fig. 1. As the web travels from the roll 23 to the combining roll 9, three rows of paste spots 101a, 103b and 1051) are ap plied to the face of the web 5 which is opposed to the inside face of the web W-2 by a spot p aster such as indicated at 109 in Fig. 1. When the webs 5 and W-2 come together, row 101 pastes the Webs 5 and W-2 together immediately forward of the forward edge of the band 77, row 101a pastes the webs 5 and W-2 together forward of row 101, and rows 103a and 103b come into register on opposite faces of bands 77 and paste the forward edge of the band 77 to the webs 5 and W-2, and rows 105a and 105b come into register on opposite faces of the bands 77 and paste the rearward edge of the band 77 to the webs 5 and W-2.

The composite three-ply web W-3 is folded on lines L1 and LZ to form the tube T illustrated in Fig. 3 in a manner which is conventional and well known in the art, the web 1 becoming the inner ply of the tube, the web 3 the intermediate ply, and the web- 5 the outer ply. The longitudinal ply seams of the tube are indicated at 111, 113 and 115. The folds on lines L1 and L-2 are the side edges of the tube. In the tube, at each bag length interval, there is a group of slits and lines of perforations as follows: longitudinal slits 27 and 29 through all the plies adjacent edge L1 with slit 27 in the seamed wall of the tube and slit 29 in the unseamed wall; longitudinal slits 33 and 31 through all the plies adjacent edge L-2 with slit 33 in the seamed wall and slit 31 in the unseamed wall; a line of perforations 41 through all the plies in both walls extending from edge L1 to the slits 27, 29; a line of perforations 43 through all the plies in both walls extending from edge L2 to the slits 31, 33; a line of perforations 5557 in the seamed wall of the outer tube ply 5 extending between'slits 27 and 33 and stepped back from lines 41 and 43; a line of perforations 4749 in the seamed Wall of the intermediate tube ply 3 extending between slits 27 and 33 and aligned with lines 41 and 43; a line of perforations 3537 in the seamed wall of the inner ply 1 extending between slits 27 and 33 and stepped forward of lines 41 and 43; a line of perforations 59 in the unseamed wall of outer ply 5 extending between slits 29 and 31, stepped forward of lines 41 and 43 and registering with lines 35-37; a line of perforations 51 in the unseamed wall of ply 3 aligned with lines 41 and 43; and a line of perforations 39 in the unseamed wall of inner ply I stepped back from the lines 41 and 43 and registering with lines 5557.

The tube T is segmented into individual bag tubes 117 by tearing it apart on the lines of perforations 41, 43, 5557, 4749, 3537, 59, 51 and 39, as illustrated at the left of Fig. 3. A bag tube 117 thus produced is illustrated in Figs. 4 and 5, Fig. 4 showing the seamed wall of the tube, and Fig. 5 showing the unseamed Wall. It will be observed that at one end of the tube (the upper end as shown in Figs. 4 and 5), the intermediate ply has a straight end edge constituted by line 46. The outer ply 5 has an inner stepped-end edge portion in the seamed wall constituted by lines 5557 at the inner edge of a recess 121 in the seamed wall and an outer stepped-end edge portion in the unseamed wall constituted by line 59 at the outer edge of an extension 123 which projects beyond the edge 46 of the intermediate rply. The inner ply 1 has an inner stepped-end edge portion in the unseamed wall constituted by line 39 at the inner edge of a recess 125 and an outer steppedend edge portion in the seamed wall constituted by 3537 at the outer edge of an extension 127 which projects beyond edge 46 of the intermediate ply.

Similarly, it will be observed that at the other end of the tube (the lower end as shown in Figs. 4 and 5), the intermediate ply has a straight end edge constituted by line 46. The outer ply 5 has an inner stepped-end edge: portion in the unseamed wall constituted by line 59 at the inner edge of a recess 131 and an outer stepped-end edge portion in the seamed wall constituted by lines 5557 at the outer edge of an extension 133 which projects beyond the edge 46 of the intermediate ply. The inner ply 1 has an inner stepped-end edge portion in the seamed wall constituted by lines 3537 at the inner edge of a recess 135 and an outer stepped-end edge portion in the unseamed wall constituted by line 39 at the outer edge of an extension 137 which projects beyond edge 46 of the intermediate ply.

Adjacent the upper end of the bag tube 117 is a band 77 (see Figs. 4 and 6). The band 77 is located between the outer ply 5 and the intermediate ply 3. It extends girthwise of the bag from near one side of the seamed region of the tube to near the other side of this region. It is pasted to the ply 5 by rows of paste spots 103b and 105b and pasted to ply 3 by rows of paste spots 103a and 105a. The outer edge 139 of the band 77 is located inward of the innermost stepped-end edge portions 39 and 5557 (the inner edges of recesses 121 and 125). Between the outer edge 139 of the band 77 and the edge portions 39 and 5557 is the row of paste spots 101 which pastes together the plies 5 and 3. The plies 1 and 3 are pasted together at the upper end of the tube by the row of paste spots 95a.

Adjacent the lower end of the bag tube 117 is a band 63'. The band 63 is located between the inner ply 1 and the intermediate ply 3. It extends girthwise of the bag from near one side of the seamed region of the tube to near the other side of this region. It is pasted to the ply 1 by rows of paste spots 91a and 93a and pasted to .ply 3 by rows of paste spots 91b and 93b. The outer edge 141 of the band 63 is located inw-ard of the innermost stepped-end edge pontions 59 and 3537 (the inner edges of recesses 131 and 135). Between the outer edge 141 of the band 63 and the edge portions 59 and 3537 is the row of paste spots 95 which pastes together the plies 1 and 3. The plies 3 and 5 are pasted together at the lower end of the tube by the row of paste spots 101a.

The bag tube 117 is formed with folded and pasted top and bottom closures 143 and 145 as illustrated in Figs. 7 and 8. These closures are similarly formed, except that a different paste pattern is used in the top closure to provide 'a valve. As to the top closure, the slits 2729 and 31-33 define end flaps 147 and 149 and side flaps 151 and 153. The side flap 153 is folded back upon the tube on a main fold line 155 extending transversely with respect to the length of the tube. This operation effects turning in of the end flaps 147 and 149, the end flaps folding in on lines indicated at 157 extending from the side edges of the tube to the inner ends of the slits. Paste is applied to the flaps in an L-shaped pat-tern such as indicated at P-1 in Fig. 7. The flap 151 is folded over on a transverse crease line 159 to over-lie the end flaps, then the side flap 153 is folded over on a transverse crease line 161 to overlie the side flap 151. The inner and outer folded-over side flaps 151 and 153 thus become pasted together and pasted to the end flaps. In the top closure, a valve is provided at the upper right corner as shown in Fig. 8 in view of the L-shape of the paste pattern in the top closure, as will be readily understood in the art.

In the top closure, the extension 123 of the outer ply 5 is included in the outer side flap 153 and the extension 127 of the inner ply 1 is included in the inner side flap 151. The portion of the inner ply 1 in the outer side flap 153 becomes pasted to the outside of extension 127 of the inner ply, the portion of the intermediate ply 3 exposed by recess 125 becomes pasted to the portion of the intermediate ply exposed by recess 121, and the extension 123 of the outer ply becomes pasted to the outside of a portion of the outer ply in the inner side flap 151.

As to the bottom closure, the slits 2729 and 3133 define end flaps 167 and 169 and side flaps 171 and 173. The side flap 171 is folded back upon the tube on a main fold line 175 extending transversely with respect to the length of the tube. This operation effects turning in of the end flaps 167 and 169, the end flaps folding in on lines indicated at 177 extending from the side edges of the tube to the inner ends of the slits. Paste is applied to the flaps at the bottom in a U-shaped pattern such as indicated at P-2 in Fig. 7. The flap 171 is folded over on a transverse crease line 179 to overlie the end flaps, then the side flap 173 is folded over on a transverse crease line 181 to overlie the side flap 171. The inner and outer folded-over side flaps 171 and 173 thus become pasted together and pasted to the end flaps.

In the bottom closure, the extension 133 of the outer ply 5 is included in the outer side flap 173 and the extension 137 of the inner ply 1 is included in the inner side flap 171. The portion of the inner ply 1 in the outer side flap 173 becomes pasted to the outside of extension 137 of the inner ply, the portion of the intermediate ply 3 exposed by recess 135 becomes pasted to the portion of the intermediate ply exposed by recess 131, and the extension 133 of the outer ply becomes pasted to the outside of a portion of the outer ply in the inner side flap 171.

As to the top closure 143, it is most advantageous that the band 77 extends inward (downward) past the main transverse fold line 155 and that the rows of paste spots 105a and 105b be located inward of this fold line. As to the bottom closure 145, it is most advantageous that the band 63 extends inward (upward) past the main transverse fold line 175 and that the rows of paste spots 91a and 9111 be located inward of this fold line. From this it will be clear that the appropriate dimension for each of the bands 63 and 77 in the longitudinal direction of the plies is that which is sufficient for this purpose. With the band of each closure extending from near the innermost of the stepped-end edge portions of the plies inward of the main fold line of the closure, the band spans both the main fold line and the crease lines on which the side flaps of the closure are folded in, and thereby reinforces the bag at all folds and creases made in forming the closure, and particularly at points of in tersection of folds and creases which, without the band, would be especially weak points. With the bands, the three-ply bag is as strong as a four-ply bag, and, of course, includes less paper. While the bands, as shown herein, do not extend into the seamed region of the bag, they are not needed in this region since there is an extra thickness of paper in each seam due to the seam overlap. However, the bands may, if desired, extend into the seamed region.

It will be understood that band 63 or 77, instead of being pasted to both of the plies between which it lies, may be pasted only to one of these plies. It will also be understood that the band 63 or 77 need not have its outer edge set back from the innermost of the steppedend edge portions of the plies, but may have its outer edge coincident with the innermost of the stepped-end edge portions of the plies. In such case, each band should be pasted to both of the plies between which it lies to accomplish securement of these plies one to another. However, no band should have its outer edge farther outward than the innermost of the stepped-end edge portions of the plies.

In view of the above, it will be seen that the several 8 objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above methods without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. The method of manufacturing reinforced multiply paper bags comprising combining at least three paper webs, feeding in between two of the webs a first series of transverse reinforcing bands spaced at bag length intervals, feeding in between another two of the webs a second series of transverse reinforcing bands also spaced at bag length intervals but out of phase with the first series to the extent that the bands of the two series are longitudinally spaced, forming the resultant multi-ply web with the bands therein into a tube, segmenting the tube on lines between the bands of the first series and the bands of the second series to form individual bag tubes, each of which has a band from one series at one end and a band from the other series at the other end, and forming each individual bag tube with end closures including the bands.

2. The method of manufacturing reinforced multiply stepped-end paper bags comprising the steps of perforating at least three paper webs on lines for forming stepped-end closures, combining the webs, feeding in between two of the webs a first series of transverse reinforcing bands spaced at bag length intervals, feeding in between another two of the webs a second series of transverse reinforcing bands also spaced at bag length intervals but out of phase with the first series to the extent that the bands of the first series are longitudinally spaced from and lie on opposite sides of said lines from the bands of the second series, forming the resultant multi-ply web with the bands therein into a tube, segmenting the tube on said lines between the bands of the first series and the bands of the second series to form individual bag tubes, each of which has a band from one series at one end and a band from the other series at the other end, and forming each individual bag tube with stepped-end closures including the bands.

3. The method of manufacturing reinforced multiply paper bags comprising continuously feeding at least three paper webs in predetermined paths and combining the webs to form a multi-ply web, continuously feeding a first strip of reinforcing material in a path between a first and a second of said three webs, continuously feeding a second strip of reinforcing material in a path between the second and third of said three webs, segmenting the strips of reinforcing material transversely into pieces, accelerating and feeding the pieces segmented from the first strip in between the first and second of said webs so that they lie in a first series spaced at bag length intervals along the length of the multi-ply web, accelerating and feeding the pieces segmented from the second strlp in between the second and third webs so that they lie in a second series spaced at bag length intervals along the length of the multi-ply web out of phase with the first series to the extent that the pieces of the two series are longitudinally spaced, adhering said pieces between the webs, continuously forming the resultant multiply web with the pieces therein into a tube, segmenting the tube on lines between the pieces of the first series and the pieces of the second series to form individual bag tubes, each of which has a piece from one series at one end and a piece from the other series at the other end, and forming each individual bag tube with end closures including the pieces.

4. The method of manufacturing reinforced multiply paper bags comprising continuously feeding at least three paper webs in predetermined paths and combining the webs to form a multi-ply web, continuously feeding a first strip of reinforcing material in a path between a first and a second of said three webs, continuously feeding a second strip of reinforcing material in a path between the second and third of said three webs, segmenting the strips of reinforcing material transversely into pieces, applying paste for pasting said pieces in between the webs, said pieces being fed in between the webs extending transversely thereof, the speed of the webs being greater than that of said strips an amount such that the pieces segmented from the first strip and fed in between the first and second of said webs lie in a first series spaced at bag length intervals along the length of the multiply web, and the pieces segmented from the second strip and fed in between the second and third webs lie in a second series spaced at bag length intervals along the length of the multi-ply web, the feeding of the pieces of the second series being out of phase with respect to the feeding of the pieces of the first series to the extent that the pieces of the two series are longitudinally spaced, continuously forming the resultant multi-ply web with the pieces therein into a tube, segmenting the tube on lines between the pieces of the first series and the pieces of the second series to form individual bag tubes, each of which has a piece from one series at one end and a piece from the other series at the other end, and forming each individual bag tube with end closures including the pleces.

5. The method of manufacturing reinforced multi-ply stepped-end paper bags comprising continuously feeding at least three paper webs in predetermined paths, perforating the webs on lines for forming stepped-end closures, combining the webs to form a multi-ply web, continuously feeding a first strip of reinforcing material in a path between a first and a second of said three webs, continuously feeding a second strip of reinforcing material in a path between the second and third of said three webs, segmenting the strips of reinforcing material transversely into pieces, accelerating and feeding the pieces segmented from the first strip in between the first and second of said webs so that they lie in a first series spaced at bag length intervals along the length of the multi-ply Web with each piece lying on one side of a respective one of said lines, accelerating and feeding the pieces segmented from the second strip in between the second and third webs so that they lie in a second series spaced at bag length intervals along the length of the multi-ply web out of phase with the first series to the extent that the pieces of the two series are longitudinally spaced with each piece of the second series lying on the other side of the respective one of said lines, adhering said pieces between the Webs, continuously forming the resultant multi-ply web with the pieces therein into a tube, segmenting the tube on said lines between the pieces of the first series and the pieces of the second series to form individual bag tubes, each of which has a piece from one series at one end and a piece from the other series at the other end, and forming each individual bag tube with stepped-end closures including the pieces.

6. The method of manufacturing reinforced multi-ply stepped-end paper bags comprising continuously feeding at least three paper webs in predetermined paths, perforating the webs on lines for forming stepped-end closures, combining the webs to form a multi-ply web, continuously feeding a first strip of reinforcing material in a path between a first and a second of said three webs, continuously feeding a second strip of reinforcing material in a path between the second and third of said three webs, segmenting the strips of reinforcing material transversely into pieces, applying paste for pasting said pieces in between the webs, said pieces being fed in between the webs extending transversely thereof, the speed of the webs being greater than that of said strips an amount such that the pieces segmented from the first strip and fed in between the first and second of said webs lie in a first series spaced at bag length intervals along the length of the multi-ply web with each piece lying on one side of a respective one of said lines and the pieces segmented from the second strip and fed in between the second and third webs lie in a second series spaced at bag length intervals along the length of the multi-ply web, the feeding of the pieces of the second series being out of phase with respect to the feeding of the pieces of the first series to the extent that the pieces of the two series are longitudinally spaced with each piece of the second series lying on the other side of the respective one of said lines, continuously forming the resultant multi-ply web with the pieces therein into a tube, segmenting the tube on said lines between the pieces of the first series and the pieces of the second series to form individual bag tubes, each of which has a piece from one series at one end and a piece from the other series at the other end, and forming each individual bag tube with stepped-end closures including the pieces.

References Cited in the file of this patent UNITED STATES PATENTS

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