A rate of drying curve is a graphical representation of the rate at which moisture is removed from a material during a drying process. The curve typically shows the rate of drying on the y-axis and time on the x-axis.

   At the beginning of the drying process, the rate of moisture removal is high, as there is a lot of moisture to be removed. As the drying process continues, the rate of moisture removal slows down as the material becomes drier and the moisture content decreases. The rate of drying curve typically shows a downward-sloping curve, with the rate of drying decreasing over time until it levels off at a constant rate.

   The shape of the curve can vary depending on a variety of factors, including the material being dried, the temperature and humidity of the drying environment, and the airflow rate. Understanding the rate of drying curve can be useful in optimizing drying processes to ensure efficient and effective moisture removal.