Method and apparatus for making reclosable packages having slider-actuated string zippers

A method of making reclosable packages, comprising the following steps:

• (a) providing an elongated web of packaging film having first and second edges that are substantially mutually parallel;
• (b) interlocking first and second flangeless zipper strips with each other;
• (c) joining a back of said first flangeless zipper strip to said web along a first band-shaped zone while said first and second flangeless zipper strips are interlocked, said first band-shaped zone being substantially parallel to said first edge;
• (d) folding said web to form a first folded side and a second folded side interconnected by a folded section, said first and second folded sides being substantially vertical and said folded section being at the bottom;
• (e) joining said first and second folded sides to each other along lines substantially transverse to said first and second flangeless zipper strips and spaced at regular intervals to form cross seals with pockets therebetween;
• (f) loading product into each pocket;
• (g) for each loaded pocket, joining a back of said second flangeless zipper strip to said web along a second band-shaped zone while said first and second flangeless zipper strips are interlocked, said second band-shaped zone being substantially parallel to said second edge;
• and
• (h) inserting sliders at spaced intervals along said first and second flangeless zipper strips, one slider per pocket, said first band-shaped zone being disposed between said first flangeless zipper strip and a first side wall of said slider, and said second band-shaped zone being disposed between said second flangeless zipper strip and a second side wall of said slider.

A method of making reclosable packages, comprising the following steps:

• (a) folding an elongated web of packaging film having first and second edges;
• (b) joining a back of a first flangeless zipper strip to said web along a first band-shaped zone that is substantially parallel to said first edge;
• (c) joining a back of a second flangeless zipper strip to said web along a second band-shaped zone that is substantially parallel to said second edge;
• (d) joining opposing sides of said folded web crosswise along lines that are substantially orthogonal to the fold and spaced at regular intervals to form pockets, one crosswise line of joinder per package width;
• (e) loading product into each pocket after steps (a) through (d) have been performed;
• and
• (f) inserting sliders at spaced intervals along said first and second flangeless zipper strips, one slider per package width, said first band-shaped zone being disposed between said first flangeless zipper strip and a first side wall of said slider, and said second band-shaped zone being disposed between said second flangeless zipper strip and a second side wall of said slider.

A method of manufacturing comprising the following steps:

• (a) extending a web of bag making film of constant width under tension in a machine direction, said web having first and second lateral edges and a medial line parallel to said machine direction;
• (b) joining a first flangeless zipper strip to one side of said web along a first zone of joinder disposed parallel and near to said first lateral edge of said web;
• (c) joining a second flangeless zipper strip to said one side of said web along a second zone of joinder disposed parallel to said first zone of joinder and in a region between said medial line and said first zone of joinder;
• (d) joining a third flangeless zipper strip to said one side of said web along a third zone of joinder disposed parallel and near to said second lateral edge of said web;
• (e) joining a fourth flangeless zipper strip to said one side of said web along a fourth zone of joinder disposed parallel to said third zone of joinder and in a region between said medial line and said third zone of joinder;
• (f) folding said web in first, second and third zones disposed parallel to said medial line, said first folding zone being disposed in a region of said web that would be between said first and second zones of joinder if the web with joined first through fourth flangeless zipper strips were in a planar configuration, said second folding zone being disposed in a region of said web that would be between said second and third zones of joinder if the web with joined zipper strips were in a planar configuration, and said third folding zone being disposed in a region of said web that would be between said third and fourth zones of joinder if the web with joined zipper strips were in a planar configuration, said web after folding having a generally W-shaped profile comprising first through fourth walls;
• (g) joining said first and second walls of said web to each other along lines substantially transverse to said first and second flangeless zipper strips and spaced at regular intervals to form a first set of cross seals with pockets in between, thereby forming a first chain of pockets, each of said first set of cross seals extending from said first folding zone to said first and second flangeless zipper strips;
• (h) joining said third and fourth walls of said web to each other along lines substantially transverse to said third and fourth flangeless zipper strips and spaced at regular intervals to form a second set of cross seals with pockets in between, thereby forming a second chain of pockets, each of said second set of cross seals extending from said third folding zone to said third and fourth flangeless zipper strips;
• (i) loading product into each pocket of said first and second chains;
• (j) severing said first and second chains of pockets from a portion of said web that includes said second folding zone;
• (k) inserting a first set of sliders at spaced intervals along said first and second flangeless zipper strips, one slider per pocket, said first band-shaped zone being disposed between said first flangeless zipper strip and a first side wall of each slider of said first set, and said second band-shaped zone being disposed between said second flangeless zipper strip and a second side wall of each slider of said first set;
• and
• (l) inserting a second set of sliders at spaced intervals along said third and fourth flangeless zipper strips, one slider per pocket, said third band-shaped zone being disposed between said third flangeless zipper strip and a first side wall of each slider of said second set, and said fourth band-shaped zone being disposed between said fourth flangeless zipper strip and a second side wall of each slider of said second set.