An injection molding method and a deformable molding unit are provided. The method includes the following steps. First, a mold positioning step is performed to define a mold cavity. The step includes: providing a deformable molding unit on a first axis, the deformable molding unit having a deformable cavity and including a bottom portion and a first elastic portion being elastically deformable with respect to the bottom portion; and applying a first compression force to the first elastic portion by a first drive module along a second axis, reducing the size of the deformable cavity to a reduced dimension. Next, plastic is injected into the mold cavity including the deformable cavity with the reduced dimension to form a workpiece. Then, the first compression force is released, allowing the deformable cavity to return to its original dimension. Afterward, the deformable molding unit is retracted along the first axis.

Disclosed is a cap configured for removable attachment a medical device. The cap has a body with an opening, a bottom, and a chamber defined between the opening and the bottom. The cap has a wall of the chamber comprising a thread originating proximate the opening and extending into the chamber by a height. The height of the thread increases as a function of increasing distance from the opening. A liquid disinfectant is contained within the chamber.

A mold structure includes a fixed mold and a movable mold, and a first insert and a second insert disposed in the movable mold. A molded product includes a plate-shaped body, a side wall, and a wrapped portion. The side wall has a basal end region that is curved and connected to the body. The first insert is located at a position corresponding to the side wall inside the molded product. The second insert is located at a position corresponding to the body inside the molded product. The second insert has a contact surface for the molded product. When the mold structure is clamped, an edge of the contact surface is located closer to a distal end of the side wall than a position where the basal end region of the side wall is connected to the body.