Even if the mold is made precisely, the quality of the finished product cannot be guaranteed if the injection molding conditions are not met. Taeyoung Cap Co., Ltd., the injection division of Taeyoung Industrial Co., Ltd., has summarized three key factors that determine quality at the cap mass production site.

1. Resin selection and drying

caps are mainly molded with HDPE·PP series resin. Since rigidity, flexibility, and chemical resistance vary depending on the application, selecting a resin that meets the product specifications is a priority. Additionally, if hygroscopic resin is not sufficiently dried before molding, it may cause surface defects such as silver streaks and bubbles.

2. Molding conditions: Temperature, pressure, cooling

Resin temperature, injection pressure/speed, holding pressure, and cooling time are interconnected to determine quality. If the pressure is insufficient, a short shot will occur, and if the pressure is too much, a burr (flash) will occur. In particular, the cap is thin and has a uniform thickness, so the balance between holding pressure and cooling determines dimensional stability.

3. Dimensional stability and inspection

In mass production, the same quality must be maintained from the first product to the last product. Regularly inspecting cavity-specific deviations, thread tightening torque, and sealing performance, and recording and managing changes in conditions are the basics of stable mass production.

Taeyoung Industrial Co., Ltd. handles everything from mold production to injection molding and assembly, ensuring that the design intent continues through to the finished product.