What is "what does leave film on tray?

The phrase "leave film on tray" likely refers to the residue or coating that remains on surfaces after certain cleaning processes, food preparation, or cooking activities. This can pertain to various contexts, such as:

1. Dishwashing Residue: In dishwashing, particularly with automatic dishwashers, a film can be left on dishes or trays if the dishwasher detergent doesn't dissolve properly, the rinse aid isn't used, or if there’s hard water.

2. Food Residue: When cooking or baking, certain ingredients can leave a film or residue on baking trays or cookware. For example, oils, sugars, or proteins can create a baked-on film that may require thorough cleaning to remove.

3. Chemical Coating: In industrial or laboratory settings, a film might refer to a thin layer of chemicals left on a tray or surface after a process. This could be intentional or a byproduct needing removal.

4. Cleaning Product Residue: Some cleaning products may leave a film if not rinsed properly, affecting surfaces like trays, countertops, or other kitchenware, and can make them appear cloudy or dirty.

Failures in rinsing, improper use of cleaning products, or buildup from repeated use can all contribute to this issue. Correcting it often involves ensuring thorough rinsing, selecting appropriate cleaning agents, or addressing water quality issues like hardness.