5501 - Synthetic filament tow:

Category 5501 encompasses synthetic filament tow, which refers to a large, untwisted bundle of continuous synthetic filaments. These are essentially the raw material from which synthetic staple fibers or spun yarns are produced. Filament tow is characterized by its length and the large number of individual filaments, which are not separated into individual strands at this stage.

Unlike its siblings at the root level of the HTS, which cover a diverse range of live animals and other commodity groups, category 5501 is specifically focused on man-made textile raw materials within Section XI. It differentiates itself from other textile chapters by dealing with continuous filaments in a tow form, rather than processed staple fibers (Chapter 55), yarns (Chapter 50-54), or woven/knitted fabrics.

The subcategories within 5501 break down filament tow based on the type of synthetic polymer from which it is made. This distinction is crucial for customs purposes, as different synthetic materials have varying properties and trade flows. For instance, filament tow of polyesters (5501.20) is classified separately from that of acrylic or modacrylic fibers (5501.30), and similarly, polypropylene tow (5501.40) is distinguished from nylon or other polyamide tows (under 5501.10). This granular classification allows for accurate statistical tracking and the application of relevant trade regulations.