초록 ▼

A plastic or other film bag is formed from a continuous extruded tube. The tube is flattened and sealed across its width at intervals to form bag bottoms. The bags are joined to one another at a perforation line and folded in thirds lengthwise prior to being rolled into a compact roll, either with o

A plastic or other film bag is formed from a continuous extruded tube. The tube is flattened and sealed across its width at intervals to form bag bottoms. The bags are joined to one another at a perforation line and folded in thirds lengthwise prior to being rolled into a compact roll, either with or without supporting core. After folding the bags may be chisel cut through the center of the perforation line to assist in dispensing of the bags. The chisel cut will extend through all layers of the bag when folded, resulting in three chisel cuts in the bag. The bags may be gusseted for part or as much as all of their width. The bags may also be corona treated and printed on their outer surfaces. The bags may be formed from partially recycled materials and various combinations of linear low density, medium and high density polyethylene.

대표청구항 ▼

1. An apparatus for making a roll of tri-fold bottom seamed bags, comprising: a supply of either of plastic and other extrudable film material;an extruder, said extruder forming a seamless continuous tube of thin film from said material;a tubing flattener, said flattener flattening said continuous t

1. An apparatus for making a roll of tri-fold bottom seamed bags, comprising: a supply of either of plastic and other extrudable film material;an extruder, said extruder forming a seamless continuous tube of thin film from said material;a tubing flattener, said flattener flattening said continuous tube into a flattened tube, said flattened tube having first and second side edges and upper and lower interior surfaces disposed adjacent one another;a sealer, said sealer forming a series of seals in said flattened tube perpendicular to a long axis of said tube said seals forming bottom seams for bags of said roll of tri-fold bottom seamed bags;a folder, said folder comprising: first and second curved guide bars, said curved guide bars guiding said first and second side edges of said flattened tube under and over each other to form a continuous, compact Z-folded flattened tube;each of said curved guide bars having an outer side and an inner side, an end closer to said extruder and an end further from said extruder, said first curved guide bar having a wide horizontal platen at said closer end and a first curved portion at said outer side, said first curved portion extending under said platen;said second curved guide bar having a second curved portion at said closer end and a narrow supporting ledge;said second curved guide bar being spaced from a first side edge of said first curved guide bar with said narrow supporting ledge disposed below said first side edge of said first curved guide bar;said second curved guide bar transitioning to a wider, upper C-shape between said closer end and said further end, said upper C-shape having an upper portion and a lower portion;said first curved guide bar transitioning to a narrower, lower C-shape between said closer end and said further end, said narrower, lower C-shape having an upper portion and a lower portion;said first and second side edges of said flattened tube being disposed between said wider, upper C-shape of said second curved guide bar and said narrower, lower C-shape of said first curved guide bar;said first and second curved guide bars forming a Z-shaped configuration at said further ends;said upper portion of said second curved guide bar disposed above said upper portion of said first curved guide bar;said upper portion of said first curved guide bar disposed above said lower portion of said second curved guide bar;said lower portion of said second curved guide bar disposed above said lower portion of said first curved guide bar;said flattened tube disposed below a lower surface of said platen and above said narrow supporting ledge at said closer ends of said first and second curved guide bars and formed into a Z-folded flattened tube at said further ends of said first and second curved guide bars;a perforator, said perforator perforating said compact, Z-folded flattened tube through six film layers and forming a perforation line; anda bag roller, said bag roller rolling said perforated compact flattened tube into a compact roll. 2. The apparatus for making a roll of tri-fold bottom seamed bags, as described in claim 1, further comprising at least one creasing roller, said creasing roller disposed downstream from said folder and bearing against said Z-folded flattened tube to reinforce folds in said flattened tube. 3. The apparatus for making a roll of tri-fold bottom seamed bags, as described in claim 1, further comprising a chisel cutter, said chisel cutter forming a chisel cut through said six film layers at a center point of said perforation line. 4. The apparatus for making a roll of tri-fold bottom seamed bags, as described in claim 1, further comprising a supply of cores, said compact bag web being wound around said core to form said compact bag roll. 5. The apparatus for making a roll of tri-fold bottom seamed bags, as described in claim 1, further comprising a gusseter, said gusseter forming at least one side gusset in said continuous tube prior to flattening. 6. The apparatus for making a roll of tri-fold bottom seamed bags, described in claim 1, further comprising a corona treater, said corona treater corona treating at least one upper and lower surface of said continuous bag web prior to folding. 7. The apparatus for making a roll of tri-fold bottom seamed bags, as described in claim 6, further comprising a printer, said printer printing on at least one of said upper and lower surfaces of said continuous bag web after corona treatment. 8. The apparatus for making a roll of tri-fold bottom seamed bags, as described in claim 1, wherein said folder divides said continuous flattened tube into a first side portion, a center portion and a last side portion and folds said first side portion over said center portion and said last side portion under said center portion, thereby forming a Z-fold bag web and Z-fold bags.