9606.21.40.00 - Of acrylic resin, of polyester resin or of both such resins

This HTS category, 9606.21.40.00, specifically classifies plastic buttons that are not covered with textile material and are manufactured from acrylic resin, polyester resin, or a combination of both. These buttons are typically rigid and are used as fasteners or decorative elements on apparel, accessories, and other manufactured goods. The classification hinges on the primary plastic material composition of the button itself.

Distinguishing this category from its siblings is crucial for accurate classification. While all fall under "Buttons: Of plastics, not covered with textile material," this specific subheading isolates buttons made from acrylic or polyester resins. This differentiates them from buttons made of casein (9606.21.20.00), which is a protein-derived plastic. Furthermore, it is separate from the "Other" category (9606.21.60.00), which would encompass plastic buttons of any other composition not already specified.

As this is a leaf node in the HTS classification system, there are no further subcategories. Therefore, practical classification relies on confirming the material composition of the button. Importers and exporters must ensure that the buttons they are declaring are indeed made predominantly from acrylic resin, polyester resin, or a blend of these two specific plastic types to correctly utilize this subheading.