Preventing chill mark formation by stamp stretching with supporting air
During the thermoforming process, material costs can account for up to 90 % of total production costs. Since products are typically designed for minimum wall thickness, areas with higher wall thickness often lead to over-dimensioning and, consequently, increased material consumption. To address this challenge, a novel air-support system was successfully designed and integrated into the thermoforming process within the “Thermoforming with supporting air” project.
By applying controlled air pressure to the stamp-assist, chill mark formation could be completely prevented, and a more uniform wall thickness distribution was achieved. Compared to the conventional process, the use of air-assisted stamps resulted in an improvement in wall thickness distribution of approximately 26 %. Investigations using different stamp variants demonstrated that a stable and consistent air cushion can form between the stamp and the sheet, effectively preventing direct contact. This reduces thermo-mechanical stress on the sheet and significantly enhances product quality.
While transferring the developed approach to other material systems such as PET and rPET requires further adaptation of process parameters, the results already demonstrate strong potential for industrial implementation, particularly in the production of material-efficient packaging solutions.
© IKVProject data and funding
We would like to thank the BMWE for funding the IGF project (funding code 22994 N) and the project partners for their cooperation.
Project duration: 01.09.2023 – 31.08.2025
Promotion:
