Analysis of equilibration time for cased cut tobacco based on digital temperature and humidity sensing

In order to determine the appropriate equilibrium time of cased cut tobacco after changes in storage conditions, so as to enable rapid deployment and improve production efficiency, balance experiments were conducted on cut tobacco under different storage environments, and the heat transfer characteristics of different types of cut tobacco were compared and analyzed. Extreme temperature scenarios in winter and summer were simulated using a low-temperature freezer and a high-temperature, high-humidity chamber. Multi-point real-time monitoring of temperature and humidity inside sealed boxes of cut tobacco was achieved based on digital sensor technology, thereby obtaining the variation patterns of temperature and humidity under different conditions. The results showed that: 1) For leaf strips, expanded stem strips, and expanded leaf strips equilibrated in a low-temperature environment (approximately ‒20 ℃, relative humidity about 55%), the time required to reach temperature equilibrium after being transferred to a constant temperature and humidity storage room (approximately 26 ℃, relative humidity about 60%) was 51.5, 38.25, and 46.25 h, respectively. For those equilibrated in a high-temperature environment (approximately 42 ℃, relative humidity 75%), the corresponding times were 31.5 h, 24.0 h, and 28.75 h, respectively. 2) During the equilibrium process of boxed cut tobacco, uneven distribution of temperature and humidity was observed, with the surface layer reaching equilibrium faster. Compared with temperature, humidity reached equilibrium more quickly under low-temperature conditions. Leaf strips required relatively more time to warm up, while expanded stem strips and expanded leaf strips required relatively less. 3) The physical indicators of cut tobacco, such as filling value, whole strip ratio, broken strip ratio, and moisture content, showed only minor changes before and after temperature equilibrium. This study provides a theoretical reference for the stable quality control of cut tobacco supplied from different locations.