Lab scale production of soap

8/18/2019 Lab scale production of soap

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EXPERIMENT No: 3

LAB SCALE SOAP PRODUCTION

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JAN

2015

1.0 OBJECTIVES

The objectives of this experiment are:

To calculate weights of materials to be used in the formulation of soap

To produce average quality of soap bar using basic formulations from palm oil.

2.0 INTRODUCTION

Soap is a surfactant used in conjunction with water for washing and cleaning. It usually comes in

a solid molded form, termed bars The use of thick liquid soap has also become widespread,

especially from soap dispensers in public washrooms. Applied to a soiled surface, soapy water

effectively holds particles in suspension so the whole of it can be rinsed off with clean water. In

the developed world, synthetic detergents have superseded soap as a laundry aid.

Much soap are mixtures of sodium (soda) or potassium (potash) salts of fatty acids which can be

derived from oils or fats by reacting them with an alkali (such as sodium or potassium

hydroxide) at 80 – l00°C in a process known as saponification. The fats are hydrolyzed by the

base, yielding glycerol and crude soap. Historically, the alkali used was potassium hydroxide

made from the deliberate burning of vegetation such as bracken, or from wood ashes.

Soap is derived from either oils or fats. Sodium tallowate, a common ingredient in many soaps,

is in fact derived from rendered beef fat. Soap can also be made of vegetable oils, such as olive

oil. Soap made entirely from such oils, or nearly so, is called castile soap. The use of the word

"soap" has become such a household name that even cleaning solutions for the body that don't

have soap in the ingredients are referred to as soap.

Cold Process

Cold process is a method of making soap (saponification) which does not require an external

heat source to initiate saponification. (Heat may still by applied in order to melt fats or oils that

are solid at room temperature, and to speed the reaction.) This process is often used by soapers,

or home soapmakers. A Lye solution, either sodium hydroxide or potassium hydroxide and


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water, is mixed with an appropriate amount of fats and/or oils to start the saponification process

that leads to soap.

Once the warmed or melted oils or fats and the lye solution have cooled to about 80-90 degrees

Fahrenheit, the lye solution is poured into the oils and stirred. A stick blender is often used to

speed this process. The two thin, clear substances become cloudy and begin to thicken.

Soapmakers refer to the

thickening process as "tracing". After many minutes of stirring, the mixture turns to the

consistency of a thin pudding.

Essential oils, fragrance oils, herbs, oatmeal or other additives are added at light trace, just as the

mixture starts to thicken. Soap is then typically poured into wooden molds lined with heavy wax

paper, covered and/or insulated with towels or blankets and allowed to continue saponification

for 18-24 hours. During this time, it is normal for the soap to go through a "gel phase" where the

opaque soap will turn somewhat transparent for several hours before turning opaque again. The

soap will continue to give off heat for many hours after trace.

After the insulation period the soap is firm enoughto be removed from the mold and cut into

bars. At this time, it is safe to use the soap since the saponification process is complete.

However, most soapmakers prefer to cure the bars for 2-6 weeks, depending on initial water

content, to allow for the bars to harden significantly before using. For successful cold-process

soap making, one needs to measure the exact amount of lye to be used and know the

saponification values ofthe oils being used in the soap. Excess unreacted lye in the soap will

result in a very high pH and can bum or irritate the skin.

Not enough lye, and the soap is greasy and oily. Most soap makers formulate their recipes with

3-15% excess oil so that all of the lye is reacted and that excess fat is left f( skin conditioning

benefits. Other processes used by soapers are the hot process, and the melt and pour process, and

rebatching.


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Hot Process

Hot process is a traditional method of making soap, still used by some soapmakers. In the hot

process method, fats and oils are boiled in a lye solution (either sodium hydroxide or potassiumhydroxide). After saponification has occurred, the soap is sometimes precipitated from the

solution by adding salt, after

which the liquid component is drained.

Most modem soapmakers add the correct amount of lye and water to the hot oils and stir until

full saponification occurs- either by taste (a quick touch to the tip of the tongue - I has a very

bright and distinct taste which goes away upon saponification) or by eye (m( experienced soap

makers know what gel stage and full saponification looks like). The hot, soft soap is then

spooned into a mold. Hot process soap can be used right away (co process needs to be insulated

so the saponification can finish).

Historically salt has been added to harden the bars- potassium hydroxide (a.k.a potash) makes a

soft soap. Sodium hydroxide (most commercially available lye) makes a quite satisfactorily hard

bar. Although more time consuming than the cold process, the hot process was used in the time

before pure lye was available, as it can use natural lye solutions such as potash. T; main benefit

of hot processing was that the exact concentration of the lye solution did] need to be known to

perform the process with adequate success. Today's hot process soap makers do use accurate

amounts of lye thereby taking the guesswork out of soap making. Other processes or techniques

used by soapers are the cold process, the melt and

pour process, and rebatching.

Literature

Saponification is the hydrolysis of an ester under basic conditions to form an alcohol and the salt

of a carboxylic acid. Saponification is commonly used to refer to the reaction of a metallic alkali

(base) with a fat or oil to form soap. Saponifiable substances are those can be converted into

soap. The reaction

is stated below:


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The lye used is a form of sodium hydroxide (NaOH) which is a caustic base. If NaOH was used,

a hard soap will be formed, whereas a soft soap is formed when potassium hydroxide (KOH) is

used. Vegetable oils and animal fats are fatty esters in the form of triglycerides. The alkali breaksthe ester bond and

releases the fatty acid and glycerol. The soap is salted out by precipitating it with saturated

sodium chloride

3.0 METHODOLOGY

3.1 Preparation of ingredients

The ingredients required for this experiment are listed below:

Refined Bleached Deodorized Palm Oil (RBDPO)

Sunflower oil

Sodium Hydroxide (NaOH)

Sodium Chloride (NaCl)

Ethylene diamine tetra acetatic acid (EDTA) 0.1%

Water

Fragrance

The students have to calculate the weight of each ingredients required based on 1000g of

blended oil used (RBDPO and Sunflower oil). The sample of calculation is provided in the

appendix. The calculations have to be prepared before the experiment and must be included in

the report.


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3.2 Experimental Procedure

1. Melt the blended oil in a water bath at 70 – 80oC until homogeneous.

2.

Switch on reactor or mixer machine and warming up the machine for 5 minutes.

3. Add in the blended oil into the mixer and start the mixer for 10 minutes.

4. Slowly, add in half of NaOH solution into mixer for neutralization taking place.

5. After 10 minutes, add in half of NaCI solution into the mixer.

6. Then, add in half of EDTA into the mixer.

7. Add in the remaining of NaOH, NaCl and EDTA solution into the mixer and let

the reaction take place for 20 minutes

8.

After that, take all the materials in the mixer and put it in flat plate. Let thematerial under aircond condition for 5 minutes or until it become semi solid.

9. Cut the material into piece and cover it with tissue, after that stamp it with

stamper to produce shape and company name to the soap.

4.0 ANALYSIS

4.1 pH Value

Check the pH value of soap bar using pH paper and record the value in the table.

4.2 Saponification Value

Theory

The saponification value is a measure of the alkali reactive groups in industrial oil and

derivatives and is expressed as the mg of potassium hydroxide which react with 1 g of

test sample.

The saponification value (SV) can be calculated by the equation below:

SV =56.×(−)

Where,


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M is molarity of standardized HCl solution

V0 is volume of titrant of blank (mL)

Vt is volume of titrant of test sample (mL)

m is mass of test portion (g)

Apparatus:

Conical flaks

Reflux condenser

Water bath or hot plate

Burette, 50mL capacity

Pipette, 25mL capacity

Solutions

1. Hydrochloric acid, 0.5M

2. Potassium hydroxide (KOH), 0.5M solution in 95% (v/v) ethanol.

This solution shall be colorless or straw yellow. A stable colourless solution can

be prepared by either of the following procedures.

(a)

Reflux 1L of ethanol with 8g of potassium hydroxide and 5g aluminium pellets for 1hr, then distill immediately. Dissolve the required amount of

potassium hydroxide in the distilled ethanol. Allow to stand for several days,

and then decant the clear supernatant liquid from the potassium carbonate

deposit.

(b) Add 4g of aluminium tert-butylate to 1L of ethanol and allow the mixture to

stand for several days. Decant the supernatant liquid and dissolve in it the

required amount of potassium hydroxide. Allow to stand for several dayds and

then decant the clear supernatant liquid from the potassium carbonate

deposited.

Store this solution in a brown or yellow bottle fitted with a rubber stopper. Do not

use a glass stopper. Decant the solution before use.

3. Phenolphthalein indicator solution

10g/L solution in 95% (v/v) ethanol or alkali blue 6B, 20g/L solution in 95% (v/v)

ethanol.


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4.3 Moisture Content

Theory:

The moisture content can be calculated by the equation below:

% Moisture and volatile matter =

− × 100%

Where,

m is the mass of the dish (g)

m b is the mass of the dish and test sample (g)

md is the mass of the dish and test sample after drying (g)

Apparatus:

Air oven

Analytical balance

Petri dishes

Desiccator

Experimental procedures:

1. Dry cleaned petri dishes in the oven at 103oC for at least 15 min and allow

cooling in desiccators. Weigh the dish to the nearest 0.001g.

2. Weigh approximately 10g of the molten oil (test sample) to the nearest 0.001g

into the dish. Return to the desiccators until the oil has thoroughly cooled. Weigh

the dish plus the oil to the nearest 0.001g and place the dish in the middle shelf of

the oven at 103oC for exactly 2.5h.

3. Remove the dish and allow it to cool to room temperature in the desiccators (30 to

45 min) before reweighing to the nearest 0.001g.

4. If the moisture exceeds 0.3%, continued drying (at 30 min interval) to constant

weight is recommended. In this case, the difference between two successive

weighing should not exceed 0.002g. Carry out two determinations of test portions

taken from the same test sample.


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Table of Data:

Table 1: Formulation of soap bar

Material Weight (g)

RBDPO

Sunflower oil

NaOH

NaCl

EDTA

Water

Fragrance

Table 2: Result of analysis

Analysis Sample 1 Sample 2 Sample 3 Average

pH value

Saponification value

Moisture content

(%)


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Lab scale production of soap

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