Slot-cast intergrated interlocking film closure structure
AssigneeThe Dow Chemical Company
InventorsHerbert B. Geiger, Donald L. Kain, Jr.
Life of this patent
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Abstract
A method and apparatus is disclosed for producing a reclosable bag film. The bag film is produced by extruding a bag film web having a relatively thinner first portion and relatively thicker second portions which are formed unitarily with the first portion. Closure members preferably in the form of male and female fastener profiles, are formed separately from the web portion and joined to the thicker second portions before the thicker second portions have become cooled to an ambient temperature.
Claims11
A method for forming plastic bag film for reclosable plastic bags comprising
- extruding a bag film web including a relatively thinner first portion having relatively lesser heat retention properties and a relatively thicker second portion having relatively greater heat retention properties,
- extruding a closure member,
- joining said closure member to said thicker second portion before said thicker second portion has cooled to an ambient temperature, and
- cooling said closure member and bag film.
An apparatus for producing an integrated bag film having a closure member comprising:
- a first extrusion means including a generally continuous extrusion slot having a relatively thinner first portion and a relatively thicker second portion for extruding a bag film web having a relatively thinner first portion and a relatively thicker second portion,
- a second extrusion means including an extrusion slot for extruding a closure member, and
- joining means positioned for joining said closure member to said second portion of said bag film web before said second portion has become cooled to an ambient temperature.
A method for forming plastic bag film for reclosable plastic bags comprising the steps of,
- extruding a bag film web having at least one portion thereof which is thicker than the remainder of said web and having relatively greater heat retention properties than the remainder of said web,
- applying a closure member to said thicker portion of said web before said thicker portion has cooled to an ambient temperature, and
- cooling said closure member and bag film.
An apparatus for producing an integrated bag film having a closure member joined thereto comprising:
- a first extrusion die, including a generally continuous extrusion slot having at least one portion thereof with a cross-section wider than the remainder of said extrusion slot for extruding a bag film web having at least one portion thereof thicker than the remainder of said web, and
- joining means positioned for joining a closure member to said thicker portion of said bag film web before said thicker portion has cooled to an ambient temperature.
Dependencies are inferred from the claim text.