Industrial Chemistry Part V Soap & Detergent Manufacture 2011

Soap & Detergent Manufactureing Process

Hot Process Soap (Natural) Home MadeIndustrial Manufacturing Cold Process Batch Process Continuous Process

Cold Process Cold process soap is soap made using no external heat source to speed up the saponification process. Fatty acids and the alkali is not complete for 4-6 weeks. Fragrance oil or an essential oil is normally an oil base and it is therefore effected by the saponification process. Limitation Hot Process Hot process soap is soap made using external heat source to speed up the saponification process.

Trace stage Both methods use the same recipes. The difference between the two methods is the addition of heat to 'cook' the soap in the hot method after the trace stage Trace is the so-called "point of no return" in soap making. It is the point where the oils or the fats in your soap have successfully mixed with your lye solution. More appropriately, this is the point where your oils and your lye turn into soap. In the hot process methods all additives are added after the saponification process finished. WHY?

Factors that Affect Trace One major factor that affects the speed in which your soap achieves trace is the heaviness of the fat used. The heavier the fat or oil used, the faster trace occurs. For animals fats such as tallow or lard, you can expect to wait for about half an hour to one hour. For lighter fats or oils, such as vegetable oils you can expect to wait several hours to even days before your soap reaches trace. Another factor which affects the speed in which your soap mixture reaches trace is your method of mixing. With traditional hand mixing, it can take a very long time for your mixture to get to trace stage.

False Trace False trace usually happens when you use fats that are solid at room temperature such as tallow or lard. Your mixture, at room temperature will seem to thicken up faster than it should and you may be mislead to thinking that you've achieved trace. But it's not trace; it's your fats solidifying again. This is not good since if your soap will develop pockets of lye afterwards, which will cause danger to those who use it. To prevent this from happening, make sure that as you mix your soap, the temperature of your mixture stays above the melting temperature of your fats. For instance, tallow melts at temperatures between 42 to 45 degrees Celsius but it stays liquid until its temperature falls to 33 to 34 degrees

Batch Process & Continuous Process Saponification Lye separation Soap washing Lye separation Neutralisation Drying