AbstractThe leakproof sealing of paperboard trays depends on factors such as the quality of the sealed tray and the parameters of the sealing process. Leakproof sealing is critical when food products are packed, as poor sealing can result in leakage and cause a reduction in the microbiological quality and sensory shelf life of packed food products. In this paper, factors affecting the leakproof sealing of paperboard trays, such as sealing pressure and the geometry of creases in the trays, were investigated. Trays were sealed with varied sealing pressure and temperature, and the sealed trays were inspected using a coloring solution test, oxygen content measurements, and microscopic analysis. The results show that the sealing pressure is a critical parameter in the sealing process. The minimum sealing pressure that resulted in leakproof within the materials investigated was 1.8 N/mm2. The depth of crease that can be sealed in a leakproof manner was found to be up to 150 µm.