Method and apparatus for manufacturing plastic film with integral interlocking closure members incorporating shape conforming cooling shoes after extrusion

A method of manufacturing a plastic film for forming reclosable bags comprising the steps of:

• simultaneously extruding through a contiguous die opening, a thin plastic film and integral closure member extending from one side of said plastic film, and,
• cooling said plastic film and integral closure member by passing said plastic film over a rotatably driven chill roll and by placing a cooling shoe, which forms a heat sink and which conforms in shape to said closure member as originally extruded, in engagement with said closure member one the closure member side of said plastic film and drawing heat from said closure member.

The method of claim 30 wherein said integrally extruded closure member comprises a female closure member with two upstanding walls and said step of placing further comprises the step of inserting an extension of said cooling shoe between said two upstanding walls for separating said two upstanding walls and drawing heat therefrom.

An apparatus for manufacturing a plastic film for forming reclosable bags comprising:

• an extrusion die having an elongate generally longitudinal and thin slot contiguous with a closure member channel;
• and,
• a cooling means for cooling an extruded plastic film and integral closure member extending from one side of said plastic film and extruded from said die, said cooling means comprising a rotatably driven chill roll having a longitudinal axis generally parallel to said thin slot adapted for passing the plastic film and integral closure member thereover, and a cooling shoe, which forms a heat sink and which, placed in engagement with the extruded integral closure member on the closure member side of said plastic film conforms in shape to said closure member as originally extruded.

an apparatus for manufacturing a plastic film for forming reclosable bags comprising:

• an extrusion die having an elongate generally longitudinal and thin slot continguous with a closure member channel;
• and,
• a coling means for cooling an extruded plastic film and integral closure member extending from one side of said plastic film and extruded from said die, said cooling means including a cooling shoe, which forms a heat sink and which conforms in shape to said closure member as originally extruded, placed in engagement with the extruded integral closure member on the closure member side of said plastic film.