The diagram illustrates the major steps of soap manufacturing before and nowadays.
Overall, in the past soap was made by an individual by mixing and heating two ingredients. However, these days the process of producing soap contains 6 stages and the soap is made with the help of machinery at factories.
Looking at the details, to make soap plant ashes were added to previously stored animal fat. Then the mixture was mixed and heated.
By contrast, these days soap is manufactured at factories. The first stage is that molten fat is added to a high column. Then water at about 130 degrees is introduced to break down the fat molecules into fatty acid and glycerin. The next stage is that the fatty acid is transported to a large mixing tank and alkali is added. Before the mixture is left to cool, it is moulded. Then the soap is milled by huge rollers and perfume is added. The last stage is that the finished soap is stamped and wrapped.
