Abstract: This invention provides an apparatus for removing wrinkles in a thin flexible moving web such as paper or textiles. The web is passed over a bar curved to effect a shear force on the web and/or a tensile force on the web in a direction perpendicular to the direction of movement of the web. The bar is oscillated resonantly or nonresonantly with one component of the oscillation being in a direction normal to the web surface so that its intermittent contact with the web causes any wrinkles therein to collapse. Gas, under super-atmospheric pressure can be passed through ports in the bar surface and into contact with the web to assist in collapsing wrinkles. SPREFERENCE TO RELATED APPLICATIONSThis application is a continuation-in-part of Application Ser. No. 521,179, filed Nov. 6, 1974, now abandoned, which is a continuation-in-part of now-abandoned Ser. No. 436,838, filed Jan. 28, 1974, which in turn is a continuation-in-part of now-abandoned Ser. No. 331,199, filed Feb. 9, 1973 .