Method for manufacturing flexible packages having slide closures

A method of making a flexible package for food products, comprising the steps of:

• providing a supply of web material defining a serial succession of wall portions;
• paying out the first portion of the web material;
• providing a supply of mated fastener tracks;
• paying out the first portion of the mated fastener tracks;
• crushing a serial succession of spaced apart portions of said mated fastener tracks to form a serial succession of spaced apart back-to-back slider stop portions which are spaced apart by the same preselected package width in the payout direction;
• providing a vertical forming collar having a throat;
• drawing the web material over the vertical forming collar in a vertical machine direction to fold the web material to form a serial succession of package portions, each package portion having the same preselected package width and overlapping wall portions with overlying free ends and shroud portions at the free ends, and intermediate portions spaced from the shroud portions;
• sensing the position of each of said package portions with a sensor located at or adjacent the throat of said vertical forming collar, said sensor sending sensor signals indicative of the positions of said package portions;
• aligning the mated fastener tracks in-line with the intermediate portions;
• aligning the package portions of said web material in the payout direction with the back-to-back slider stop portions of said mated fastener tracks in response to said sensor signal to register said first portion of the mated fastener tracks with said first portion of web material;
• providing a supply of sliders;
• dispensing the sliders one at a time;
• inserting the sliders on the mated fastener tracks between the back-to-back slider stop portions;
• joining at least a part of the mated fastener tracks to the intermediate portions of the web material;
• forming a peel seal adjacent the intermediate portions;
• forming a transverse, leading, side seal in said overlapping portions to cooperate with said peel seal and said overlapping portions to form a pouch with an upper side seal opening;
• advancing the joinder of the web material and the mated fastener tracks in the vertical machine direction;
• filling the pouch with product through the upper side seal opening;
• forming a transverse trailing side seal between said overlapping portions to seal the contents of the pouch;
• and
• severing the pouch from the web material and mated fastener tracks to form a separate flexible package.