In mechanical dishwashers, what is the function of the prewash step?

The prewash step in mechanical dishwashers is designed to loosen food particles from dishes before the main wash cycle begins. This process is crucial because it helps to ensure that the dishes are adequately cleaned in subsequent cycles. By loosening food residue, it prevents clogging and ensures that the more vigorous cleaning in the main wash can be more effective. If food particles are not adequately loosened, they may remain on the dishes or get redistributed, leading to less satisfactory cleaning results.

The prewash step often involves a brief rinse with water that helps to remove larger particles and prepares the dishes for the more intensive cleaning that follows, thus enhancing the overall efficiency of the dishwasher.