The scientific term for the process of kalai (or kalaiwaa) of utensils is "Tinning." Tinning is a traditional process used to coat metal utensils or containers, typically made of copper or iron, with a layer of tin to prevent corrosion and improve their durability. This process has been used for centuries to create a protective barrier on the surface of the utensils, making them safe for cooking and storage of food.
During tinning, the surface of the utensil is cleaned and prepared to ensure proper adhesion of the tin. The tin is then melted and spread over the surface of the utensil, creating a uniform layer. This layer of tin helps to prevent the metal from coming into direct contact with the food and reactive substances, reducing the risk of metal leaching into the food and potential health hazards.
Tinning is particularly common in traditional cookware and containers in some regions, but with modern advancements in kitchenware manufacturing, the need for tinning has reduced significantly. Instead, many modern cookware items are coated with non-stick or other protective materials to achieve similar effects without the use of tin.