Patent ID: 8460588

Claim:
A method of coextruding polymers into an edge laminated film, comprising: supplying a first polymer melt stream at a first temperature to a first inlet of a coextruder body; supplying a second polymer melt stream at a second temperature different than the first temperature to a second inlet of the coextruder body, wherein the temperature differential is at least 25° C. different and is selected such that the viscosities of the first and second melt streams are within 10 percent of one another where outputting the converged output from the body occurs; flowing the first and second melt streams through first and second flow passageways passing through the body to a converged output of the streams, wherein the first flow passageway includes a transverse diverging chamber laterally oriented relative to the second flow passageway at the converged output, wherein the second inlet is arranged relative to the transverse diverging chamber to limit dwell time for the second melt stream in the coextruder body, thereby maintaining a first thermal zone for the first melt stream and a second thermal zone for the second melt stream in the coextruder; wherein the first thermal zone is isolated and different from the second thermal zone; and outputting the converged output from the body to form the edge laminated film continuous across a full width of the film wherein at the converged output the first and second melt streams have a temperature differential relative to one another and wherein the first melt stream includes polyethylene and poly(styrene/ethylene-butylene/styrene) and the second melt stream includes polypropylene, polyethylene, and poly(styrene/ethylene-butylene/styrene).