Method for making tri-fold side seamed plastic produce bag

Abstract

A trifold side seamed film produce bag includes a front wall and a back wall, first and second side edges sealed together and a seamless bag bottom. The bag is joined at the side edges to additional bags by a perforation. The bag is corona treated on at least one wall and promotional material is printed on the treated surface. The bags are folded to one third of their height to fit compact bag roll dispensers. The bags are folded in a Z-fold or C-fold configuration. The method includes manufacturing the bags and winding them onto cores or forming the bags into coreless rolls. An apparatus for forming the side seamed bags includes an extruder, a tubing flattener, a perforator, a sealer, a corona treater, a printer and a slitter. The treated, printed bags may be stored on rolls for later slitting into two bag streams and folding into thirds.

Claims

1. A method of making tri-fold side-seamed plastic produce bags, comprising the steps of: extruding a continuous tube of plastic film; flattening said tube, said tube having an upper surface, a lower surface, first and second side edges; forming a perforation perpendicular to said first and second side edges across an entire width of said tube; sealing said tube at a first side seam spaced from and parallel to said perforation; sealing said tube at a second side seam, said second side seam being spaced from and parallel to said first side seam; cutting said upper surface and said lower surface to form two facing bag streams, each of said bag streams having a first predetermined width; and folding each of said bag streams to one third of said first predetermined width.

2. The method of making tri-fold side-seamed plastic produce bags as described in claim 1, further comprising the step of corona treating at least one of said upper surface and said lower surface of said flattened tube.

3. The method of making tri-fold side-seamed plastic produce bags as described in claim 2, further comprising the step of printing either of advertising and informational material on at least one of said corona treated surfaces of said flattened tube.

4. The method of making tri-fold side-seamed plastic produce bags as described in claim 1, further comprising the step of rolling each of said bag streams to form a bag roll.

5. The method of making tri-fold side-seamed plastic produce bags as described in claim 1, further comprising the step of rolling each of said bag streams about a cylindrical core to form a bag roll.

6. The method of making tri-fold side-seamed plastic produce bags as described in claim 1, wherein each of said bag streams is folded in a Z-fold configuration.

7. The method of making tri-fold side-seamed plastic produce bags as described in claim 1, wherein each of said bag streams is folded in a C-fold configuration.

8. A method of making tri-fold side-seamed plastic produce bags, comprising the steps of: extruding a continuous tube of plastic film; flattening said tube, said tube having an upper surface, a lower surface, first and second side edges; corona treating at least one of said upper surface and said lower surface of said flattened tube; printing either of advertising and informational material on at least one of said corona treated surfaces of said flattened tube; forming a perforation perpendicular to said first and second side edges across an entire width of said tube; sealing said tube at a first side seam spaced from and parallel to said perforation; sealing said tube at a second side seam, said second side seam being spaced from and parallel to said first side seam; winding said tube onto a core for later cutting of said upper surface and said lower surface to form two facing bag streams, each of said bag streams having a first predetermined width; and folding each of said bag streams to one third of said first predetermined width.

9. The method of making tri-fold side-seamed plastic produce bags as described in claim 8, further comprising the step of rolling each of said bag streams to form a bag roll.

10. The method of making tri-fold side-seamed plastic produce bags as described in claim 8, further comprising the step of rolling each of said bag streams about a cylindrical core to form a bag roll.

11. The method of making tri-fold side-seamed plastic produce bags as described in claim 8, wherein each of said bag streams is folded in a Z-fold configuration.

12. The method of making tri-fold side-seamed plastic produce bags as described in claim 8, wherein each of said bag streams is folded in a C-fold configuration.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of the preferred embodiment of the invention, a trifold side seamed produce bag as formed in FIG. 1A;

(2) FIG. 1A is a perspective view of the FIG. 1 embodiment of the invention as the bags are formed, illustrating two facing streams of side seamed plastic produce bags attached with perforations;

(3) FIG. 1B is a perspective view of the FIG. 1 embodiment after folding in thirds;

(4) FIG. 2 is a perspective view of a first method of making the invention illustrating the flattening and slitting of the tube, perforating the tube, sealing the bag side edges, cutting the two facing bag streams apart, folding them in thirds and winding them on rolls;

(5) FIG. 3 is a perspective view of the FIG. 2 embodiment further illustrating corona treatment and printing of the tube prior to slitting;

(6) FIG. 4 is a perspective view of a coreless roll of the FIG. 1 bags;

(7) FIG. 5 is a perspective view of a cored roll of the FIG. 1 bags;

(8) FIG. 6 is a perspective view of the FIG. 1 bag folded into a Z-fold configuration;

(9) FIG. 7 is a perspective view of the FIG. 1 bag folded into a C-fold configuration;

(10) FIG. 8 is a perspective view of a process for forming a flattened plastic tube and rolling same onto a core for later processing;

(11) FIG. 9 is a perspective view of a second portion of the FIG. 8 process in which the printed tube is slit, perforated, sealed and cut into two facing bag streams;

(12) FIG. 10 is a perspective view of another method of making the FIG. 1 bags by corona treating, slitting, printing, perforating and sealing the tube and winding the tube onto a core for later separation into two facing bag streams;

(13) FIG. 11 is a perspective view of a second portion of the FIG. 10 process in which the printed tube, slit, perforated and sealed tube is cut into two facing bag streams;

(14) FIG. 12 is a perspective view of still another method of making the FIG. 1 bags by corona treating, printing, slitting, perforating and sealing the tube and winding the tube onto a core for later separation into two facing bag streams;

(15) FIG. 13 is a perspective view of a second portion of the FIG. 12 process in which the printed tube, slit, perforated and sealed tube is cut into two facing bag streams;

(16) FIG. 14 is a detailed perspective view of a plastic film slitting mechanism removing a central strip from the tube;

(17) FIG. 15 is a detailed perspective view of a bag folding mechanism capable of folding a bag stream into thirds;

(18) FIG. 16 is a detailed perspective view of the bag folding mechanism operating on a stream of trifold side seamed bags;

(19) FIG. 17 is a perspective view of the preferred embodiment of the invention, a trifold side seamed produce bag as formed in FIG. 17A;

(20) FIG. 17A is a perspective view of the FIG. 17 embodiment of the invention as the bags are formed, illustrating two facing streams of side seamed plastic produce bags attached with perforations;

(21) FIG. 17B is a perspective view of the FIG. 17 embodiment after folding in thirds;

(22) FIG. 18 is a perspective view of a first method of making the invention illustrating the flattening and slitting of the tube, perforating the tube, sealing the bag side edges, cutting the two facing bag streams apart, folding them in thirds and winding them on rolls;

(23) FIG. 19 is a perspective view of the FIG. 18 embodiment further illustrating corona treatment and printing of the tube prior to slitting;

(24) FIG. 20 is a perspective view of a coreless roll of the FIG. 17 bags;

(25) FIG. 21 is a perspective view of a cored roll of the FIG. 17 bags;

(26) FIG. 22 is a perspective view of the FIG. 17 bag folded into a Z-fold configuration;

(27) FIG. 23 is a perspective view of the FIG. 17 bag folded into a C-fold configuration;

(28) FIG. 24 is a perspective view of another method of making the FIG. 1 bags by corona treating, printing, perforating and sealing the tube and winding the tube onto a core for later separation into two facing bag streams;

(29) FIG. 25 is a perspective view of a second portion of the FIG. 24 process in which the printed tube, perforated and sealed tube is cut into two facing bag streams;

(30) FIG. 26 is a detailed perspective view of a bag folding mechanism capable of folding a bag stream into thirds; and

(31) FIG. 27 is a detailed perspective view of the bag folding mechanism operating on a stream of trifold side seamed bags.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(32) (1) A method of making trifold side-seamed plastic produce bags 10, as illustrated in FIGS. 18 and 19 comprises the steps of: extruding a continuous tube 105 of thermoplastic film 75 and flattening the tube 105. The tube 105 has an upper surface 110, a lower surface 115, first 120 and second 125 side edges. Forming a perforation 90 perpendicular to the first 120 and second 125 side edges across an entire width 150 of the tube 105. Sealing the tube 105 at a first side seam 80. The first side seam 80 is spaced from and parallel to the perforation 90. Sealing the tube 105 at a second side seam 85. The second side seam 85 is spaced from and parallel to the first side seam 80. Cutting the upper surface 110 and the lower surface 115 to form two facing bag streams 160, 165, each of said bag streams 160, 165 having a first predetermined width 21. Folding each of the bag streams 160, 165 to approximately one third of the first predetermined width 21.

(33) (2) In a variant of the method of making trifold side-seamed plastic produce bags 10, as illustrated in FIG. 19, the method includes the further step of corona treating 170 at least one of the upper surface 110 and the lower 115 surface of the flattened tube 105.

(34) (3) In a further variant of the method, also illustrated in FIG. 19, the method includes the further step of printing advertising or informational material 175 on at least one of the corona treated 170 surfaces 110, 115 of the flattened tube 105.

(35) (4) In still a further variant of the method, as illustrated in FIGS. 18 and 20, the method includes the further step of rolling each of the bag streams 160, 165 to form a bag roll 180.

(36) (5) In yet a further variant of the method, as illustrated in FIG. 21, the method includes the further step of rolling each of the bag streams 160, 165 about a cylindrical core 185 to form a bag roll 190.

(37) (6) In another variant of the method, as illustrated in FIG. 22, each of the bag streams 160, 165 is folded in a Z-fold configuration 23.

(38) (7) In still another variant of the method, as illustrated in FIG. 23, each of the bag streams is folded in a C-fold configuration 27.

(39) (8) In yet another variant of the method of making trifold side-seamed plastic produce bags 10, as illustrated in FIGS. 24 and 25, the method includes the steps of: Extruding a continuous tube 105 of plastic film 75 and flattening the tube 105. The tube 105 has an upper surface 110, a lower surface 115, first 120 and second 125 side edges. Corona treating 170 at least one of the upper surface 110 and the lower surface 115 of the flattened tube 105. Printing either advertising or informational material 175 on at least one of the corona treated 170 surfaces 110, 115 of the flattened tube 105. Forming a perforation 90 perpendicular to the first 120 and second 125 side edges across an entire width 150 of the tube 105. Sealing the tube 105 at a first side seam 80 spaced from and parallel to the perforation 90. Sealing the tube 105 at a second side seam 85. The second side seam 85 is spaced from and parallel to the first side seam 80. Winding the tube 105 onto a core 185 for later cutting of the upper surface 110 and the lower surface 115 to form two facing bag streams 160, 165, each of said bag streams 160, 165 having a first predetermined width 21. Folding each of the bag streams 160, 165 to approximately one third of the first predetermined width 21, as illustrated in FIG. 18.

(40) (9) In still a further variant of the method, as illustrated in FIG. 20, the method includes the further step of rolling each of the bag streams 160, 165 to form a bag roll 180.

(41) (10) In yet a further variant of the method, as illustrated in FIG. 21, the method includes the further step of rolling each of the bag streams 160, 165 about a cylindrical core 185 to form a bag roll 190.

(42) (11) In another variant of the method, as illustrated in FIG. 22, each of the bag streams 160, 165 is folded in a Z-fold configuration 23.

(43) (12) In still another variant of the method, as illustrated in FIG. 23, each of the bag streams is folded in a C-fold configuration 27.

(44) The Method for Making Tri-fold Side Seamed Produce Bag has been described with reference to particular embodiments. Other modifications and enhancements can be made without departing from the spirit and scope of the claims that follow.