In situ temperature‐controlled rotational molding for self‐building ribs in <scp>PA6</scp> liner for type <scp>IV</scp> hydrogen storage tanks

Abstract Type IV hydrogen storage tank liners must exhibit optimal appearance, stiffness, and lightweight construction to maximize hydrogen storage density while also serving as a platform for carbon fiber winding. However, the inherent weakness in stiffness, particularly in larger structures, necessitates the incorporation of localized reinforcements. Internal rib reinforcement is a key strategy for addressing this challenge. This study analyzes the effect of circumferential ribs on the performance of PA6‐based liners, demonstrating a significant increase in the critical buckling load by up to 15.2%. Furthermore, the study introduces a novel in situ, temperature‐controlled rotational molding (ITRM) platform that enables the one‐step creation of local inner reinforcements. By precisely controlling both the temperature and heating rates, we successfully manufactured a PA6 liner with stainless‐steel inserts and three reinforcing ribs, achieving a volume exceeding 600 L. The ITRM platform represents a significant advancement in addressing the weak stiffness of large‐capacity liners and offers promising potential for further innovation in liner development. Highlights Development of in situ temperature‐controlled rotational molding equipment Analysis of the impact of the position and number of ribs on the structural stiffness Proposed inner circumferential ribs design method in liners to enhance stiffness Manufactured large‐diameter and thin‐walled PA6 liner with stainless‐steel insert