Why is maintaining a FIFO inventory system critical for powdered materials in SLS?

Maintaining a FIFO (First-In, First-Out) inventory system is critical for powdered materials in SLS (Selective Laser Sintering) because these materials can degrade over time, even under proper storage conditions. Factors such as exposure to humidity, temperature fluctuations, and even the material's inherent chemical instability can lead to changes in its flowability, particle size distribution, and sintering behavior. Using older powder that has been sitting in storage for an extended period increases the risk of printing defects, inconsistent part properties, and machine malfunctions. A FIFO system ensures that the oldest powder is used first, minimizing the chance of using degraded material and maintaining consistent print quality. This is especially important for materials with a limited shelf life or those that are particularly sensitive to environmental conditions. Consistently using material in order of receipt helps guarantee the stability of the material throughout the printing process.