5801.37 - Warp pile fabrics:

This HTS category, 5801.37, specifically covers warp pile fabrics that are composed of man-made fibers. Warp pile fabrics are characterized by the presence of raised loops or cut threads (pile) that are formed by extra warp yarns woven into the fabric structure. These yarns are either allowed to remain as loops or are cut to create a soft, plush surface. The key differentiating factor here is that the pile is created by the warp yarns, as opposed to weft yarns.

Within the broader group of "Of man-made fibers" (5801.3), this heading distinguishes itself from sibling categories by its pile construction. Unlike 5801.31 (uncut weft pile fabrics), 5801.32 (cut corduroy), and 5801.33 (other weft pile fabrics) which are defined by weft-wise pile formation or specific structures like corduroy, 5801.37 is exclusively for warp pile fabrics. It also differs from 5801.36 (chenille fabrics), which have a distinct looped or fuzzy appearance created by a special weaving process, not necessarily warp pile formation.

The subcategories within 5801.37 further refine the classification based on the treatment of the pile. The distinction between 5801.37.10 (epinglé, uncut) and 5801.37.50 (cut) lies in whether the warp pile loops are intact or have been severed. Epinglé, often characterized by raised, uncut loops forming a distinct rib effect, falls under the uncut category. All other warp pile fabrics of man-made fibers where the pile has been cut would be classified under the cut designation.