The first process involves weighing the raw materials in ratios prescribed in the master formula. The weigh-up coincides with the amount needed by the customer order and also the capacity of the premixing vessel. Typical production batches require a number of premix charges to achieve the targeted quantity. Multiples of weigh-up charges are therefore necessary.
Batch size influences yield. Relatively small batches , generate smaller yields than larger batches. A well run process will operate at an efficiency level between 95 and 99%. The yield of smaller batches typically runs between 90 and 95%. Experience dictates the capability of the process and guides the formulator in determining how much excess raw material to use.