Patent ID: 7455802

Claim:
A stress/strain relief process for a flexible, multilayered web stock comprising: providing a multilayered web stock including at least one layer to be treated, the at least one layer to be treated having a coefficient of thermal expansion significantly differing from a coefficient of thermal expansion of another layer; passing the multilayered web stock at a continuous speed over and in contact with a first concave or reversed-crown wrinkle-reducing roller that spontaneously creates transverse tension stress in the at least one layer to be treated; passing the multilayered web stock at a continuous speed over and in contact with a processing tube, wherein at least one heat source heats the at least one layer to be treated above a glass transition temperature T g of the at least one layer to be treated to thereby create a heated portion of the at least one layer to be treated, a portion of the web stock in proximity to the heated portion of the at least one layer to be treated thereby becoming a heated portion of the web stock; inducing curvature in the heated portion of the web stock; and cooling the heated portion of the web stock at said curvature by directing a cooling stream at the heated portion of the web stock, wherein the first wrinkle-reducing roller has a center diameter from about 1 to about 4 inches and a differential diameter between ends of the roller and a center of the roller of from about 0.002 to about 0.1 inch, wherein the first wrinkle-reducing roller offsets and suppresses web stock micro ripple formation induced by the processing tube.