Abstract: A support structure of a bra cup contains: a bra cup body and an underwire channel. The bra cup body includes a concave face and a convex face, and the concave face has an imaginary point defined on a central position thereof. The underwire channel is hollow and is in an arcuate strap shape, and the underwire channel is mounted on a peripheral side of a bottom of the bra cup body. The underwire channel includes an external layer, an internal layer, and a hollow portion. The hollow portion has an opening arranged on one end thereof and configured to accommodate an underwire. The underwire channel further includes a flexible mesh sheet arranged on one surface thereof facing the bra cup body. The flexible mesh sheet has a reinforcement section extending outwardly from the underwire channel to the imaginary point of the concave face of the bra cup body.

Abstract: A method of forming an underwire channel of a bra cup contains the steps of: A. providing a first cup layer, a second cup layer, and a channel forming rib; B. stacking a first thermoformed layer of the first cup layer and a second thermoformed layer of the second cup layer together; C. providing a forming mold which includes a first part and a second part each having a cavity; D. heating the forming mold with the first cup layer, the second cup layer, and the channel forming rib stacked together in the cavity; E. opening the forming mold to form a cup portion and a semifinished part of an arcuate underwire channel; F. removing the channel forming rib out of the underwire channel by pulling the extension; G. trimming the semifinished part to form a finished cup; and H. finishing a bra cup.