4. Contents :
1. Chemistry of soap
2. Manufacturing of soap by continuous process
3. Colgate palmolive process
4. Lever rexona process
5. Batch process
6. Cleansing action of soap
5. Chemistry of soap
• Soap:
• Soaps are the sodium and potassium salts of several combinations
of fatty acid and cleansing action in combination with water.
• Examples:
• Sodium stearate(C17H35COO-Na+)
• Sodium palmitate(C15H31COO-Na+)
• Sodium oleate (C17H33COO-Na+)
6. Raw Material:
• Soaps consist of two primary raw material:
• Alkali
• Fats
• Alkali is most commonly used material and is also called as sodium
hydroxide.
7. Structure of Soap :
• A soap molecule is a sodium or potassium salt of long chain fatty
acids.Thus Soaps has two parts :
• Hydrophobic tail:
• This part of soap is water repellent in nature and dissolves in oil.It is
ionic in nature.
• Hydrophilic head:
• This part of soap is water loving and dissolves in water. It is made up
of long chain of hydrocarbons.
8. Manufacturing of soap:
• Both fats and oils are needed to make soaps and they are extracted from
plant and animals.The common alkali that are used to make soaps are
sodium hydroxide(caustic soda) and potassium hydroxide(caustic potash).
• The manufacturing process of soaps consist of following different methods:
• Saponification:
• Common methods used to make soaps.Soap is made by heating animal fats
or vegetable oil with concentrated sodium hydroxide(NaOH).
• Fat or Oil + NaOH Soap + Glycerol
9. Neutralization:
• Fats and oils get hydrolyzed in the presence of high pressurized steam
for getting crude fatty acids along with glycerine. These fatty acids are
then purified by the process of ditillation and nuetralized through an
alkali to give a soap.
10. Continuous process :
• Definition:
• A process that operates on the basis of continuous flow, as opposed
to batch, intermittent, or sequenced operations.
• Types of continuous process :
• . Colgate palmolive process
• . Lever rexona process
11. Colgate palmolive process:
• There are following steps involved in the production of soap.
• 1. Saponoficatipn
• 2. Lye separation
• 3. Soap washing
• 4. Lye separation
• 5. Neutralisation
• 6. Drying
13. 1. Saponification
• The raw materials is fed into the reactor. Its fixed proportion of 80:20.
Tallow, coconut oil with 50% Naoh forming wet soap and glycerin and
excess amount of Lye is recovered from saponoficatipn vessels.
14. 2. Lye separation
• The wet soap is pumped to a “static separator” – a settling vessel
which does not use anymechanical action. The soap / lye mix is
pumped into the tank where it separates out on the basis of weight.
The spent lye settles to the bottom from where it is piped off to the
glycerinerecovery unit, while the soap rises to the top and is piped
away for further processing.
15. 3. Soap washing
• The soap still contains most of its glycerine at this stage, and this is
removed with fresh lye ina washing column. The column has rings
fixed on its inside surface. The soap solution is added near the
bottom of the column and the lye near the top. As the lye flows down
in the Washing column ring and keep washing until remove the
glycerine during this soap With lye and need to separate next.
16. 4. Lye separation
• The lye is added at top of washing column and The soap removed
from the colum as overflow . As the Lye is added near the Overflow
pipe the washed soaps is about 20% fresh lye The soap and lye must
be ses fresh lye.
• The removed Lye is used as fresh lye.
17. 5. Neutralization
• Although the caustic levels are quite low, they are still
unacceptably high for toilet and laundry soap. The NaOH is
removed by reaction with a weak acid such as coconut oil
(which contains significant levels of free fatty acids),
coconut oil fatty acids, citric acid or phosphoric acid, with
the choice of acid being made largely on economic grounds.
• Some preservative is also added at this stage.
18. 6. Drying
• Finally, the water level must be reduced down to about 12% .
• This is done by heating the soaps to about 125⁰c(to prevent the
water from boiling off while the soap is still in the Pipe) then
spraying it in evacuated chamber at 40nm then it solidifies onto
the chamber walls. soap chips are scraped off the wall and
“Plodded”(Squeezed together ) by the screw known as “ plodder
worm” to form soap noodles. The soap is now known as soap
Chips and can be converted into the variety of different soap in
the finishing stage.
20. Lever roxona process
• Following steps involved in the production of face soap.
• 1. Oil preparation
• 2. Saponification
• 3. Washing
• 4. Fitting
• 5. Drying
• 6. Packaging
21. Oil preparation
• Coconut oil (525.9kg/hr) and tallow (132. 5kg/hr)
• . Blended together and vacuum dried
• . Bleaching earth drawn into chamber by vacuum
• . Spent earth is landfilled
• . Oil stored for saponification
22. Saponification :
• Mixture of bleached oils mixed with spent lye.
• . Mix is heated and separated
• . The glycerine rich neutral lye is extracted
• . Caustic liquor is introduced
• . Mix is reheated
23. Washing
• Crude soap is pumped to a divided pan unit.
• . Lye comprises of a fresh brine solution and nigre lye.
• . Washed soap emitted from divided pan unit.
• . Lye pumped back into the saponoficatipn pans.
24. Fitting :
• Unwanted glycerin removed via boiling water, Nacl and Naoh.
• . Soap and water separate into two layers.
• . Top layer is neat wet soap and bottom layer is nigre layer.
• . Soap crust forms over a lower of nigre lye.
• . Soap remains in pan while nigre lye pumped back into divided pan
unit.
25. Drying :
• Water levels are reduced to 12 percent.
• . Soap solidifies onto walls of chamber.
• . Soap Chips are scrapped off to form soap noodles.
• . Evaporated moisture transported to barometric condenser.
• . Soap dust is removed by cyclones.
26. Packaging :
• One easy way to package your soap is to drop it in an appropriately
sized box. Many companies sell soapboxes, and you can just add your
own label and/or graphics to it. You can also use a custom box with a
die-cut cutout in it. It looks professional and gives a little window
onto the soap so that you can see its color.
28. Batch process :
• There are following steps involved in the production of soap by batch
process.
• 1. Heating
• 2.Purification
• 3.Mixture heating
• 4.Saponification
• 5. Addition of Nac
• 6.Addition of additives
• 7.Moulding
29. Heating :
• Fats and alkali are melted in a kettle, which is a steel tank that can
stand three stories high and hold several thousand pounds of
material. Steam coils within the kettle heat the batch and bring it to a
boil. After boiling, the mass thickens as the fat reacts with the alkali,
producing soap and glycerin.
30. Purification :
• In batch method purification, wash and elution fractions are
separated from the resin after centrifuging to pellet the resin beads.
The liquid cannot be removed completely because some of it is
contained within the volume of porous bead pellet.
31. Mixture heating :
• Batch heating or cooling systems are found in many places in modern
industry (process, food, pharmaceutical etc). In these systems, a
vessel is filled with content and needs to be heated or cooled in a
predefined time period.
32. Saponification:
• In this type of saponification plant, the reaction is done at about 90°C.
Filtered vegetable oils or animal fats are pumped into the
Saponification Crutcher by means of, then the caustic soda solution is
pumped gradually through a distributor ring installed on the top of
the crutcher.
33. Addition of Nacl :
• Function of sodium chloride in soap making is to provide a balance of
hardness and softness. The sodium chloride in soap making is
responsible for the solid consistency of soap and for making soapy
molecules adhere to one another, forming an insoluble mass.
34. Addition of additives :
• Additives are chemicals added to the base polymer to improve
processability, prolong the life span, and/or achieve the desired
physical or chemical properties in the final product. While the content
of additives is typically only a few percent, their impact on polymer
performance and stability is significant.
35. Moulding :
• The injection molding process is a process of batch processing, in
which the entry of molten material into a cavity is forced under
pressure, and the part just take its shape by cooling. The injection
molding machine becomes material in pellet form moldings by fusion,
injection, compaction and final cooling cycle .
37. Cleansing action of soap
• Most of the dirt is oily in nature and oil does not dissolve in water. The molecule of soap constitutes sodium
or potassium salts of long-chain carboxylic acids. In the case of soaps, the carbon chain dissolves in oil and
the ionic end dissolves in water. Thus, the soap molecules form structures called micelles. In micelles, one
end is towards the oil droplet and the other end which is the ionic faces outside. Therefore, it forms an
emulsion in water and helps in dissolving the dirt when we wash our clothes.
• Soap is a kind of molecule in which both the ends have different properties.
• Hydrophilic end
• Hydrophobic end
• The first one is the hydrophilic end which dissolves water and is attracted to it whereas the second one is the
hydrophobic end that is dissolved in hydrocarbons and is water repulsive in nature. If on the surface of the
water, soap is present then the hydrophobic tail which is not soluble in water will align along the water
surface.
39. In water, the soap molecule is uniquely oriented which
helps to keep the hydrocarbon part outside the water.
When the clusters of molecules are formed then
hydrophobic tail comes at the interior of the cluster and the
ionic end comes at the surface of the cluster and this
formation is called a micelle. When the soap is in the form
of micelles then it has the ability to clean the oily dirt which
gets accumulated at the centre. These micelles remain as
colloidal solutions. Therefore, the dirt from the cloth is
easily washed away. The soap solution appears cloudy as it
forms a colloidal solution which scatters light.