3901.20 - Polyethylene having a specific gravity of 0.94 or more:

This HTS category, 3901.20, covers polyethylene resins that possess a specific gravity of 0.94 or greater. These are typically high-density polyethylene (HDPE) grades, characterized by their more rigid structure and higher molecular weight compared to lower-density counterparts. Examples of products classified here include resins used in the manufacture of bottles, pipes, films, and containers where stiffness and tensile strength are critical performance requirements.

It is crucial to distinguish this category from its sibling, 3901.10, which specifically covers polyethylene with a specific gravity *less than* 0.94, often referred to as low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE). Furthermore, while 3901.30 and 3901.40.00.00 deal with copolymers (ethylene-vinyl acetate and ethylene-alpha-olefin respectively), this sub-heading is for homopolymer polyethylene meeting the specified density criterion. The "Other" category, 3901.90, would encompass any polymers of ethylene not otherwise specified.

Within this classification, two subcategories further refine the classification based on specific technical properties. The first, 3901.20.10.00, applies to polyethylene with a relative viscosity of 1.44 or more, indicating a higher molecular weight and potentially enhanced processing characteristics. The second, 3901.20.50.00, is for all other polyethylene resins that meet the specific gravity requirement of 0.94 or more but do not fall under the higher relative viscosity criteria.