Patent ID: 6755774
Filing Date: 2004-06-29
Classification: B31B

Abstract:
A method of automatically producing bags with openings therein, comprising the steps of:(a) providing a film tube having a width; (b) providing an apparatus for automatically producing bags with openings wherein the apparatus comprises: (i) a pay-off reel for supplying the film tube in a lengthwise direction; (ii) a device for making openings in the film tube; (iii) a floating separator for inserting in the film tube at a position along the lengthwise direction corresponding with the device for making openings, wherein the floating separator is limited from moving in the lengthwise direction and in a direction of a width of the film tube, wherein the floating separator serves as a cradle or block against which the device for making openings makes openings in at least one surface of the film tube, and wherein the floating separator comprises a core member sensitive to magnetism, wherein the core member is selected from the group consisting of one or more mild steel plates and a plastic molded member in which ferrite is disposed; and (iv) an electromagnet disposed to impart magnetic force to the floating separator to reduce pressure on a lower surface of the film tube; (c) imparting magnetic force to the floating separator using the electromagnet to reduce pressure on a lower surface of the film tube; (d) moving the film tube in a lengthwise direction; (e) inserting the floating separator in the film tube; (f) limiting the movement of the floating separator in the direction of width and in the lengthwise direction; (g) intermittently stopping the movement of the film tube; and (h) forming openings in at least one surface of the film tube during the intermittent stopping of movement of the film tube using the device for making openings.