Using run data to determine pet food freeze dryer cycle endpoint — Ligman explains how the high cost of freeze drying often stems from the uncertainty that the process cycle is complete and the product is sufficiently dried, thereby causing most manufacturers to add an arbitrary amount of time to their freeze-drying cycle. By using multiple data points, the end of the cycle can be much more accurately predicted, making product cycles faster, more repeatable and risking less waste. Most commercial freeze driers already include data tracking in their control software, so using this data to determine end point is merely a matter of ensuring that, using the correct parameters, the data is properly analyzed in concert with monitoring product quality and final water activity. Ligman proposes several methods of determining end point along with the scientific underpinnings that support the methods.
Gene Ligman is an independent engineer, retired from a career in vacuum equipment and applications. He has deep domain knowledge in the science and technology of freeze drying, approaching it using the fundamentals of physics and the practical nuts and bolts of commercial operations. Ligman focuses on helping freeze-drying clients operate their current systems better to raise production and reduce down time. Affiliated with a major OEM of freeze-drying technology, he understands the challenges and has key insights into recipe development, cycle time reduction, end point detection and selective upgrades to systems to correct problems or reduce bottlenecks.