54280563 Small Scale Soap Making a Handbook 1986

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MlCFlOFlCHEREFERENCELIBRARYA project of Volunteers in Asia

Small-S& Soapmakim HandbookBy: Peter Donkor

Published by: Intermediate TechnoFogyPublications103/l 05 Scuthampton RowLondon WCIB 4HHU.K.


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SnKALL-SCALE SOAPMAKINGA handbook

Peter Donkor


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ContentsPREFACEACKNOWLEDGEMENTSCHAPTER 1: INTRODUCTION1.1 Brief History of Soapmaking1.1.1 The Development of Soapmaking n Europe1 1.2 The Development of Soapmaking n Ghana1.1.3 Lqe-scale SoapProduction in Ghana1.1.4 The Roie of Research nstitutions in Ghana1.2 Definition and Properties of Soap1.3 Hydrolysis of Soap

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CHAPTER 3: THE CHOICE OF SUITABLEOILS AND FATS FOR SOAPMAKING3.1 Saponification Value3.2 Iodine Number3.3 INS Factor3.3.1 Prtictical Application of INS Factor3.4 Lathering and Solubility Properties of SoapCHAPTER 4: PLANT AND EQUIPMENT FORSOAPMAKING4.1 Equipment and Plant for Laundry Soapmaking4.1.1 SoapBoiling Tanks4.1.2 CausticSodaStorageTanks4.1.3 SoapMoulding Boxes4.1.4 SoapCutting Tables4. f .5 SoapStamping Machines4.2 Equipment and Plant for Toilet Soapmaking4.2.1 Mixing Machines4.2.2 Milling Machines4.2.3 Plodders4.3 Other Equipment and ToolsCHAPTER 5: PRE-TREATMENT OF FATS ANDOILS FOR SOAPMaKING5.1 Refining of Oils and Fats51.1 Alkali Refining5.1.2 Another Clarification Method5.1.3 Bleaching of Oils and Fats

2121232324262727272929293131313233343636363738


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CHAPTER 7: SMALL-SCALE PRODUCTIONOF TOILET SOAP7.1 Cold Process7.2 Milled Toilet Soapmaking7.2.1 Drying of SoapBase7.2.2 Mixing of Perfume and Dye7.2.3 Milling7.2.4 Compressing7.25 Cutting and Stamping7.3 Remelted SoapsCHAPTER 8: NON-EDIBLE OILS FORSOAPMAKING8.1 Neem Oil8.1-l Soapmakingproperties8.2 Castor Oil8.2.1 SoapmakingProperties8.3 PhysicOil8.3. f SoapmakingProperties8.4 Process f SoapmakingCHAPTER 9: GHANA STANDARDSSPECIFICATIONS FOR SOAPS9.1 Filled Hard SoapSpecifications9.2 Genuine Hard Soap Specifications9.3 Filled Carbolic Soap Specifications9.4 Toilet SoapSpecifications

52525353535454545455555758595959616363646444


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PrefaceIn April and May 1985, I visited Ghana to gather data for abook on the work of the Technology Consultancy Centre atKumasis University of Science and Technology. TCC wasfounded in 1972, n an effort to adapt and transfer to ordinaryGhanaians some of the knowledge that is often held captivewithin university walls. It was soon discovered, however, thatthe development of appropriate technologies was not the samething as he transfer of technology, and it becameclear that theCentre would have to involve itself not only in projects thatwere relevant to the cultural and economic environment of thecommunity, it would have to become involved in thecommunity itself. This, in turn, led to an appreciation thateven a basic technology like soapmaking cannot becompartmentalized. Thus, making soap became a bit like


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palm oil became aimost totally unavailable during the droughtand the economic crisis of 1983, TCC began a search or non-edible oil substitutes, conducting successfulexperiments withboth neem and castor oil. Perfume was developed from lemongrass. A measure rf the successof such experiments is therecent adoption of some of TCCs techniques and findings bythe large iever Brothers soap plant in Accra.Peter Donkors book modestly avoids discussionof the greatpains that he and others put into the development of thetechnology he describes, and of the success hat has beenachieved n having the process adopted on a widespread scalein Ghana, by small urban and rural entrepreneurs, by v illageco-operatives and by development organizations. A furthermeasureof success as been the number of requests rom othercountries in Africa for assistance n establishing the process.Peter Donkor has travelled to Guinea Bissau. Mali, Togo,Sierra Leone and Mozambique to help set up smallsoapmaking enterprises. We s therefore uniquely equipped towrite about a processwhich ha,s een tried and tested, not onlyin the sterile laboratories of the Ghana StandardsBoard, but inthe bustling shops and stalls of the Ghanaian market place.Ian SmillieLondon, 1986


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AcknowledgementsThere is no doubt about the fact that a lot of people havecontributed in one way or another to the success f this book.My special thanks go to Dr. J.W. Powell, Director of TCC,whose encouragement and editing as well as contact with theIntermediate Technology Publications made the publication ofthis book possible. My sincere thanks also go to theIntermediate Technology Development Group in the UK,for funding the printing of the first edition of this book.I will also like to expressmy heartfelt thanks to the followingpeople and companies: Miss Esther Akom and her assistantsMiss Grace Dery and Angelina Pamford, all of TCC, whotyped the draft of this book, Mr. W.A. Osekre, the Universityphotographer who printed some of the pictures used in thebook, the Obegam Soap Enterprise, Kumasi, and KwamotechLtd, Kwamo, who allowed some pictures of their workshops obe taken for this book.

Last and not the least, my special gratitude goes to Mr.Smillie who agreed to write the preface of this book. Mr.Smillie paid a visit to TCC (when this book was being written)


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Chapter 1Introduction

1.1 Brief History of SoapmakingThe need for soap, a cleansing agent, has been felt ever sinceman became aware of the necessity to clean his body andenvironment in the primitive ages.Soap has therefore acquiredthe status of a basic necessity in the modern civilized world.Soapmaking is one of the oldest industries in the world; mostauthorities claim that it originated on the sacrificial altars ofearly primitive people, when fat from animals killed on altarsdripped over wood ashes, hereby combining with the potashin the ashes o form crude soap.1.1.1 The Development of Soapmalcing in EuropeIt is recorded that the Gauls were the first to produce soap bymixing goat fat (tallow) with potash from beechwood ashes,and were followed by the Romans who learnt the art after the


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production as a result of two discoveries. Nicholas Leblancdiscovered a process for the chemical production of causticsoda from common salt in 1787, and a few years ater MichaelEugene Chevreul carried out a successful research into theconstitution of fats and oils, and demonstrated thatsoapmaking was a chemical process involving the initialsplitting of fatty acids and glycerol. These findings gave thesoapmaker an unlimited supply of one of his basic rawmaterials - caustic soda. They also placed the soap industryon a scientific basis as soapmakerswere now in a position toknow the nature of the chemical reaction involved insoapmaking.The history of many modern soapmaking companies inEngland can be traced back to the eighteenth and nineteenthcenturies, although their growth at the time was hampered byhigh taxation. However, following the scientific breakthrough,soap axation was abolished in England, resulting in the rise ofthe demand and supply for soap. During this period, W .G.Lever became a dominating figure in the soap trade inEngland. In 1884, he introduced sunlight soap for the firsttime. Gradually, other soap manufacturers began developingdifferent kinds of soap for cleaning different articles, and moreattention was also given to the form in which the soap waspresented. Lux flakes, for example, were first marketed in1900,and were a big success.Lever also introduced the use oftropical vegetable fats and oils like palm oil, coconut oil, palmkernel oil, etc, for the making of soap at a time when the


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ash colour, it is very mild and has some bleaching property onthe skin, which has made the use of the soap very popularamong women who prefer to be fair in complexion. Apart fromits bleaching property, it is also used for dermatologicalpurposes. Its use in the treatment for ringworm, and prickleheat rashes s well known.The sort of nature of potash soap, and its short-shelf lifecoupled with the difficulty in the preparation of caustic potash(prepared from the ashesof cocoa pods, plaintain peels, etcjand/or the scarcity of potash at the local market, has limitedthe production of this soap to some extent. It was no surprisethat when the country was colonized the indigenoussoapmakersswiftly switched over from the production of thetraditional soap to the laundry soap ntroduced by the colonialmasters, which involved the use of ready-made importedcaustic soda.1.1.3 Large-scale Soap Production in GhanaSince the first Portuguese stepped on the shores of the land,laundry soapmaking has steadily been carried out on a smallscale by local soapmakersalong with the dwindling volume ofpotassium soap production. In 1963, Lever Brothers set up asoap complex in Tema to start large-scale production oflaundry, toilet and powder soaps o boost the local productionof soap. More recently, two other soap complexes have beenestablished n Kumasi and Cape Coast.


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and to offer free training to local soapmakers on thetechnology of good quality soap production. The Centre stilloffers this training and produces soapmaking equipment forsale to local soapmakers.The Centres current soap training programme is gearedtowards the production of laundry soap but some attempts arealso being made to improve the colour and hardness of thetraditional potash soap.1.2 Definition of PropertiesThe definition of soap is generally restricted to thecombination of fatty acids and alkalis obtained by reactingvarious animal and vegetable fats and oils with caustic soda orpotash, the former giving hard soap and the latter soft soap.Both soaps are readily soluble in hot water or alcohol.However, they dissolve very slowly in cold water forming aturbid solution owing to slight decomposition. Sodium soaps(made from caustic soda) are found to be insoluble in verystrong caustic solutions, and for the most part in strongsolutions of brine; hence the addition of strong solutions ofbrine to a solution of sodium soap causes he soap to separateout and rise to the surface of the caustic or salt so!ution. Thisseparation (also referred to as graining) of soap s employed incommercial soap production. On the other hand, addition ofbrine to a solution of potassium (potash) soap merely results indouble decomposition giving rise to sodium soap andpotassium chloride.


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2 Cl7 Hs5 COONa -t Hz0 = N&X-I + HNa (C,7H35COO),(Soap)+(Water)=(Caustic Soda)+(Acid Salt)1.4 Detergent ActionMany theories have been proposed to explain the detergentaction of soap - the property possessedby soap to removedirt. However, the commonest explanation is that the alkaliliberated in the processof hydrolysis attacks any greasy matteron the surface being cleam=d, and as fat is dissolved, theparticles of dirt are loosened and easily washed off.Another theory suggests that the alkali set free by thehydrolysis of soap serves as a lubricant, making dirt lessadhesive, and thus promoting its removal.Yet another theory states that the alkali tends to lower thesurface tension of the water, and thus permits theemulsification of fat-bearing dirt particles on the surface of thematerial being cleansed.


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Chapter 2Raw Materials forSoapmakingThe raw materials for the making of soap cover a wide range ofsubstances which may be classified under the followingheadings:I. Fat and oils2. Alkalis3. Filling agents4. Water5. Salth. Perfumes7. Colours or dyesHowever. fats and oils constitute approximately 00% of thesoapmakers raw materials. and ;I dctaiicd treatment of fatsand oils is made in this chapter.2.1 Fats and Oils


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oils being liquid and the fats solid or pasty.Fats and oils are divided into three classes, namely, fixedoils, mineral oils and essential oils. However, fixed oils formthe main raw materials for soapmaking as they decompose ntofatty acids and glycerol when strongly heated, and are easilysaponified by alkali. Fixed oils and fats, which include bothanimal and vegetable fats and oils, are further classifiedaccording to their physical properties as follows:a) Nut oils: These oils are characterized by a largeproportion of fatty acids with low molecular weight, especialylauric acid. Examples of these oils are coconut oil and palmkernel oil. These oils (especially cuconut oil),when used intoilet soaps are the chief suds-producing ngredients.They saponify easily with strong alkali solution (30-35Be).Once these oils begin to saponify the processproceeds apidlywith the evolution of heat. They also require large quantities ofstrong brine (1648Be) to grain their soaps, and the grainedsoaps end to carry more salt than other soaps. These oils aremore suitable for the making of cold processsoaps.b) Hard Fats: The hard fats contain appreciable quantities ofpalmatic and stearic acids. Examples of these fats are palm oil,animal tallow and hydrogenated oils. These oils or fats produceslow-lathering soaps but the lather produced is more stableover long periods of time than the nut oils. In soapmaking,they are first saponified with weak alkali (10~lSB@),and inthe final stageswith stronger alkali solutions.


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All fats and oils used in soapmaking consist of a mixture ofcompoundsof glycerol with fatty acid which occur in nature inthe form of triglycerides.The most important of theseacids romthe soapmakerspoint of view are stearin, palmitin, olein andlaurin. The presenceof stearin and palmitin, which are solidsat room temperature, gives firmness to fats and oils. Thegreater the percentagepresent the harder the oil or fat, and thehigher its melting point. Where olein, which is liquid atordinary temperature, is the chief constituent, the oil or fat issoft.The soapmaking properties of fats and oils can bedetermined by the molecular weights of their fatty acids. Withincreasing molecular weight in the case of naturally occurringsaturated fatty acids in fat or oil, the following properties arefound:1. The boiling point of the oil rises,2. The melting point of the oil/fat rises,3. The saponification value of the oil/fat decreases.Also, the properties of their corresponding sodium soapsvary as follows with increasing molecular weight:1. The solubility increases,2. The lathering properties improve up to lauric acid anddeteriorate from lauric aoid upwards,


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3. The stability of the lather increases,4. The detergent action decreases,5. The soapshave milder skin action as the series progresses,6. The property of holding filling solutions such as sodiumsilicate decreases.This explains the reason why nut oil (such as coconut oil)soaps lather readily and profusely but not stably. They alsohave a firm texture and are hard but dissolve more readily inwater than do soaps rom the hard oils. They can also retain agood amount of water, and take up fairly !arge quantities offillers like sodium carbonate.Naturally occurring saturated fatty acids(The C,Hz,Oz Scrica)

No. of Meltingclmn1on ClJrboni- Chefk.w l ~Molix+rrlar PointName SiJtbtJS F0~~rltllU Weight (C) Orcws InButyric 4 cg-i,COOH 88.1 -8 Milk fatCaproic 6 CSH 1 COOH 116.16 - 2 Milk fatCaprylic 8 CTH &OOH 144.21 16.0 Milk fatCapric 10 C,H ,&OOH 172.26 31.3 CoconutLaurie 12 C, ,H$OOH 200.31 43.6 CoconutMy&tic 14 CllHz&OOH 228.37 54.0 Animal fatPalmitic 16 W-hCOOH 256.42 63.0 Animal/vcgctablcfatStcaric 1x C,7H3SC00H 284.47 69.6 AnimaiivcgctablcfiatArachidic 20 C,pHa>COOH 312.52 75.3 Groundnut


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hydraulic presses, and at the small-scale level using hand-operated screw presses. However, traditional extractiontechniques cater for about 30% of the total palm oil producedin the country. The oil forms about 5040% of the total oils andfats used in Ghana for soapmaking.Palm oil usually produces a crumbling soap which canot bereadily milled for toilet soap production, but with 20-25%coconut oil blend, it produces satisfactory toilet soap.ii. Coconut oilThe oil is produced from copra mostly in the Western Region,by the Esiama vegetableoil mill, using oil expellers. However,traditional extraction methods are used widely in the WesternRegion and other areas of southern Ghana. The oil isextensively used to blend other oils like shea butter, palm oiland cotton seed oil for soapmaking becauseof its property toproduce hard and lathering soaps. It also finds application inthe production of liquid soaps because its potassium soapremains clear at low temperatures.Because of its high saponification number, it requires astrong caustic solution (known as ye) for its saponification. Itssoap is usually white, firm and soluble with rapid forminglather which is not very stable.iii. Palm Kernel OilThis oil is produced mostly in Ghana using traditionaltechniquesand is used nterchangeably with coconut oil in bothlaundry and traditional potassium soapmaking. Its soap has


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is the chief fat used n the north for soapmaking, since most ofthe other oils mentioned are not found in the north.v. Gutton Seed OilCotton seed oil is not widely produced in Ghana. The CrystalOil Company in Accra is the main producer of cotton seed oilsoap stock for soapmaking.The crude oil saponifieswith easebet the soap s difficult tograin. It produces soap of soft consistency, f used alone, andhas a bad odour.2.2 fiudisThe two alkalis popularly used in the making of soaps arecaustic soda and caustic potash.26.1 Caustic SodaCommercial caustic soda is creamy in appearanceand fibrousin structure. It readily absorbsmoisture and carbonic acid fromthe air to form sodium carbonate. Due to its hygroscopicproperty of absorbing moisture, it must not be exposed o theair. Caustic soda is also very corrosive to the skin andaluminium containers, and as such must be handled with greatcare. It is available on the market in various forms, namelyflakes, powder, sticks and blocks. The powder and the flakesare very convenient to handle but are costlier than the solid orblock caustic soda, and are normally used when the volume ofsoap production is very small. For large soap production units,


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P1.A TE 3: Using hydrometer to &ermine the strength of caustic sodasohr ion.Lanrl Production (Using Precipito tiorr Rextim)In Ghana. the Technology ConsusltancyCentre (TCC) of the


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ICI (Ghana) Ltd., Tema, or the open market in 50kg bags;b) slaked ime - a by-product of the manufacture of acetylenefrom calcium carbide and water by LAir Liquide.Presently, the lime is a waste material for the company, andis collected by soapmakers ree of charge.Eqrupmen :The equipment for the manufacture of the chemical is acylindrical tank reactor (Plate 5) made from galvanized steelsheet with a diameter and heigh; of 120cm 4ft). The reactor isequipped with four baffles which extend from top to bottom at90 to the walls of the tank. Their purpose is to promote agood agitation of the slaked lime suspension during thereaction. .An agitator, axially positioned in the tank, consistsofa shaft and a 4-bladed axial flow turbine which is 1705cm 7in)above the bottom of the reactor. The width of each blade is4cm (Min), the length is 1605cm (&42in), and the pitch of theblade is 45.The shaft of the agitator is directly rotated by a lhpelectric motor at a rotational speedof 950rpm. The agitator andthe baffles have been designed o keep the lime in suspensionduring the reaction.45cm (18in) from the bottom of the tank., along the walls ofthe reactor is a swivelling decanting pipe with 31.25mm (1 Xin)valve through which the clear solution of caustic soda isdecanted, and at rhe centre of the bottom of the reactor is a1Ocm (4in) valve through which the sludge of calcium


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switched on, and 150kg of sodium carbonate introduced intothe water for absolute dissolution. When the carbonate iscompletely dissolved 182kg of dry slaked lime is introducedinto the reactor, and the reaction allowed to take place forthree hours to completion with continuous agitation. Afterthree hours, the heating is stopped and the calcium carbonatesuspension is then allowed to settle after which the clearsolution of caustic soda s decanted. The solution has a causticconcentration of 103g/litre and sodium carbonateconcentration (i.e. unreacted carbonate) of 2lg/litre. Whenused for soapmaking, this carbonate goes into the soap as afiller.2.2.3 Caustic PotashCaustic potash possesses hemical propcrtics similar to thoseof caustic soda. It is, however, much stronger in chemicalreaction than soda. It produces soap of soft consistency andhigher solubility in water than sodium soaps, and is thereforegeneraily used for the making of liquid soaps, shampoos andsoft soaps.Commercial ProductionCommercial production of caustic potash involves the sametwo methods as already described n the production of causticsoda, namely precipitation reaction method and theelectrolysis method.In the precipitation reaction, slaked lime is reacted with


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2.2.4 Description of Process for Local ProductionThe process involves burning any one of the raw materialsmentioned above into white ashes. It must be noted that theraw material must be very dry before being burnt at hightemperature to ensure complete combustion and theproduction of fine white ashes.A kiln has been designedby theEngineering Faculty of the University of Science andTechnology (UST) for the production of white ashes.Some ofthese kilns are being used n the southern part of Ghana for theproduction of white ashes or caustic potash manufacture.


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the ashes o absorb as much water as possible before addingmore water. After the ashes have absorbed enough water,brown lye (caustic potash solution) begins to drop slowly fromthe bottom of the basket into the tray or drum under it? asmore water is put on the ashes. The dripping must be sEowenough to allow maximum dissolution of the caustic potash inthe ashes in the water put in the basket. When no moresolution drops, the lye obtained is put back in the basket torepeat the leaching process.This second eaching ncreases hestrength of the lye.A suitable strength for soapmaking can be checked crudelyby dipping a chicken feather or putting a fresh egg into thesolution. A stronger solution will dissolve the feather, orsupport an egg. A hydrometer can also be used to determinethe density of the solution, if available. If the solution is foundto be weak, boiling will concentrate he solution to the requiredstrength.2.3 Other Raw MaterialsIn addition to fats, oils and alkalis, a lot of other chemicalsareused in comparatively small quantities to give variouscharacteristics to soaps. These chemicals include builders,fillers and various other additives.BuildersBuilding agents are essentially used to build up, i.e. increasethe detergent power of soaps. Their use in soaps has enabled


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Chapter 3The Choice of Suitable Oilsand Fats for SoapmakingWhether soap production is done on a small or large scale, thequality and properties of the soap to be produced depend to alarge extent on the type of oil used; hence the choice of asuitable oil is very necessary or the production of good soap.Many small-scalesoapmakers n Ghana seem to be ignorant ofthis important fact, and therefore produce soaps of poorquality. Though a lot of technical and economic factersdetermine the choice of oil by the soapmaker, e.g. availabilityof the particular oil needed, and the type of equipment andmachinery as well as the process of manufacture being used,certain specific constants of the oil or fat determine thehardness, lathering properties and w&ing efficiency of thesoap to bc produced. Knowlcdgc of these constants. if usedproperly. is a big asset o the boapmakcr. They help to forecastthe quality of soap to be cxpcctcd from the choice of a


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value if given must always be multiplied by a factor (O-7) toobtain its value in terms of caustic soda.Let us see the practical use of this value in soapmaking, byassuming hat a soapmakerhas 3kg of palm oil for soapmaking,and he is told that the saponification value of the oil is 202.How can he estimate the quantity of caustic soda required tosaponify the oil? This can be worked out as follows:If the saponification value of the oil is 202, then the quantityof caustic soda required to saponify lg of the oil is 202x0.7mg(ie 202~0*7~10 g). Hence the quantity of caustic sodarequired to saponify 3OOOg 3kg) of the oil will be202x0-7x10~3x3000g, or 424*2g. Thus from the givensaponification value, the soapmaker knows that he requires424g of caustic soda to process he 3kg of oil into soap.Saponification Value and Iwline Numbers for Some Common SoapmakingOils and Fats

Oil/ FurPalm OilCoconut OilPalm Kernel OilShea ButterCatton Seed OilAnimal TallowVegetable TallowLardNccmGroundnutSunflower

Supponigicntion V&w200-20s251-264248178-189193-195190-199192-195195186-204186-194189-194

hhre mrmber49-598-101 l-1556-65

108-I 1035-464059-6369.090- I03126


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Since it has a saponfication value of 248, the quantity of sodarequired will be 2%8~0~7~1O-~~lOOOg,.e. 1736g. That forthe 3kg palm oil is found to be 424-28. Therefore 538g ofcaustic soda wil? be needed o saponify an oil blend of 3kg palmoil and 1kg palm kernel oil.It must be noted, however, that the saponification value is ofsignificance while making soap using the cold or semi-boilingprocess, but in the full boiling process it is of little or nosignificance since any strength of caustic soda solution can beused and grained. The averagesaponification value for most ofthe soapmaking oils (excluding the nut oils) is 190.3.2 Iodine NumberThis constant is defined as the number of centigrams of iodineabsorbed by lg sample of the oil. The number, in fact,indicates the presenceof unsaturated acids n the oil or fat. Thehigher the number for an oil, the greater the percentage ofthese acids, and thus the softer the soap produced from the oil.The soft oils (like cotton seed oil and groundnut oil) have highiodine numbers and are readily oxidized. The iodine numberthus indicates the hardnessof the soap, the lower the number,the harder the soap produced. Cotton seed oil has an iodinenumber of 109 while coconut oil has an iodine number of 9.This explains why coconut oil produces hard soaps.The use of this number in determining the hardnessof soapproduced from a blend of oils is not very reliable since it does

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INS Factors of Common Oils and Fats wed in SoapmakingName of OillFat INS FactorCoconut Oil 250Palm Kernel Oil 235Vcgctablc tallow (mafura ) 165Mutton tallow 155Beef tallow 150Palm Oil 146Lard I37Olive Oil 108Cotton Seed Oil 85Soya Bean Oil 54Linseed Oil I53.3.1 Practical Application of INS Factor

oils. This factor ranges rom 15 to 250 for soapmaking oils andfats. The liquid oils with high proportions of unsaturated fattyacids have low factors while the hard fats and nut oils with lowmolecular weight saturated acids have high factors.Generally, with increasing INS factor, the followingobservations are found:1. the oils vary from liquid to solid and produce harder soap;2. the detergent and lathering properties as well as thesolubility of the soap decreases except the nut oils) withimproved colour, and capability to hold more filling agents;3. the soap or oil diminishes in its tendency to go rancid onageing.


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-1ils on the other hand have the dual purpose of increasing thelathering properties of the soap as well as softening the soap,the degree of softening depending on the quantity used for theblend. It is therefore necessary o increase the hardness byadding a certain proportion of a nut oil (e.g. coconut oil) to theblend. This will further increase he lathering properties of thesoap. Therefore a good oil blend must be made up of a nut oil(coconut oil), soft oil (ground nut oil) and hard oil (palm oil).It is interesting to note that the nut oils are unique oils forblends since hey have the property of increasingboth hardnessand solubility of soapswhile all other oils capable of hardeningsoap (e.g. tallow, palm oil) have the disadvantageof reducingsolubility.The question now confronting the soapmaker is: whatquantities of these three oils (soft oil, hard oil and nut oil)should be suitable for a good oil blend to produce the requiredquality of soap?Let us consider how the INS factor can be used practicallyto resolve this issue.Let us assume hat a soapmaker has to make a blend of palmoil, coconut oil and cotton seedoil such hat the blend will havean INS factor of 146 (which corresponds o that of palm oil andlies in the INS range for soap oils) and constitute 50% of palmoil. We therefore need to determine the percentagesof cottonseed oil (say, X) and coconut oil (50-X) which must beadded to the palm oil to form the blend.


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lot of local soapmakersbut if followed carefully they help thesoapmaker to form a suitable blend, with the quantities of oilsat his disposal, since a blend of the salve INS factor producessoap of the same hardness rrespective of the component partsof the blend.Lathering and Solability Properties of SoapThe lathering and solubility properties of soap is found to bedependent on the INS factor of the oil or oil blend used n themaking of the soap. Oils and fat with an INS of 130-160areindividually unsuitable for soapmaking on account of lowlathering. Though the low INS factor oils reduces he hardnessof soap, they tend to increase the solubilitv, but the rate ofsoftening is greater than the rate of solubility increase. Thusthe presenceof coconut or palm kernel oil (high INS oils) inthese soapsare essentialsince they have marked effect on bothhardnessand solubility.However, the following observations must be noted as theuse of some of these oils is subject to limitations:a) Palm kernel oil, which serves as a good substitute forcoconut oil in soapmaking, should not be used n toilet soapsas the odour of the oil is likely to develop in the soap withtime. Also any oils with high levels of unsaturated fatty acids

(cotton seed oil) are not suitable for toilet soapmaking onthe grounds of rancidity.b)Generally, any quality of tallow, and bleached palm oil can


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Chapter 4Plant and Equipment forSoapmakingPlant and equipment required for small-scalesoap productionunits vary in design from one place to another. Generally, theyinclude soap-boiling pans for soap boiling, wooden or metalsoap frames to hold liquid soap for solidification, a cuttingtable to cut solid soap blocks into slabs, bars and tablets, a footor hand operated stamping machine, hydrometers to measurethe strength of caustic soda and common salt solutions. Causticsoda mixing tanks, and other items like rubber gloves,weighing scales, buckets, and polythene sheets for framelining.4.1 Equipment and Plant for Laundry Soapmaking4.1.1 Soap-boiling TanksThese pans may vary in size and material depending on themaximum volume of soap to be boiled and the processbeing


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steel pipe with a matching gate valve through which the boiledsoap is discharged nto the soap frames. The tank is mountedon a one metre high ring frame support, made of 2Scm ironrod, surrounded by burnt bricks and clay with an entrance anda chimney to form a hearth for firewood heating.In some developing countries like India, the wood-firedboiling tanks are gradually being replaced by tanks equippedwith closed and open coils through which steam at about 45psiflows (from a boiler) for the boiling of the soap.In the rural areas of Ghana, soapmaking at the village levelis done using a 200 litre oil drum for the boiling of the soap.4.1.2 Caustic Soda Storage TanksThis is a tank in which caustic soda solution of the requiredstrength is prepared and stored for use when needed. The tankmay be rectangular or cylindrical in shape, but made of astrong and thick material to withstand attack from causticsoda.4.1.3 Soap Moulding BoxesThese are wooden or metal frames into which the boiled soapis run for cooling. The boxes are rectangular in shape and thenumber of boxes used by a soapmaker depends on the volumeof soap normally produced in the unit. The sides of the framescan be made to be taken apart for easy removal of the driedsoap, or can be permanently nailed. If the latter is usedpolythene sheets are used to line the box before the boiledsoap is run into them.


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give the dimensions of the soap slab when cut. Similar sets ofsuspensionwires are arranged on the other side of the table tocut the slabs nto bars or tablets.The soap block is cut into slabs by manually pushing theblock against the suspensionwires.4.1.5 Stamping MachinesTo give a commercial finish to the cut soap tablet, the soap ismoulded into a precise shape and an inscription or trademarkof the manufacturer put on one or both surfaces of the soapusing a stamping machine. The foot or hand operated machinehas a vertical treadle motion and gives a direct blow to thesoap. Two dies are normally required for both surfacesof thesoap are stamped. The dies are made of hard brass or a betterfinish. The bottom die normally rests in the box which holdsthe soap while the top die is fixed to the plunger. To stamp thetablet, it is put in the soap holder and the hand or foot leveroperated. The two dies, with the trademark engravings onthem, move vertically in opposite directions against the soap,which is thus stamped on both sides. The stamped soap isautomatically released on the return stroke.4.2 Plant and Equipment for Small-scale ToiletSoapmakingThe preparation of toilet soap on a small-scale nvolves variousoperations of soap base preparation, chipping of soap base,

-


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use by village and cottage soap industries has a materialhandling capacity of 20kgIhour.


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suitably arranged screws, the pressure of the rollers on oneanother can be adjusted to give the issuing soap ribbons anyrequired thickness.


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emerges through the nozzle to which an attached cutter ofsuitable shape cuts the extruding polished and neat soap barinto the required length. The nozzle is equipped with acartridge electric heater providing temperatures between 50-55C to allow the soap to be easily forced out. Thetemperature is automatically controlled through a thermostatprovided at the top of the heating chamber to avoid the soapbecoming blistered if the nozzle s too hot, or being of poor anddull appearance f the temperature is low.The Indian model has a material handling capacity of20kg/hour.


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bodily contact with caustic soda* solutions; enamelled,galvanized or plastic buckets or containers to hold caustic sodasolution, water and oil; a plastic sheet for lining the soapmoulding box; and a stirrer if stirring soap is to be donemanually during the boiling process.


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Chapter 5Pre-Treatment of Fats andOils for SoapmakingIn Chaper 3 the raw materials required for the making of soapwere discussed. Notable among these materials are fats andoils. Depending on the characteristics of the fats or oils theymay be subjected to various pre-treatments like clarifying,bleaching and deodorizing. The sort of treatment to be applieddependson the oil type and its purity, as well as he type of soapto be produced with the oil.5.1 Refining of Oils and FatsOil refining comprises various processes f clarification of oilsand fats to rid them of impurities and free fatty acids, and anyunwanted odour, and the bleaching of the oil to removeobjectionable colour.5.1.1 Alkali RefiningIrrespective of the process used in the extraction of oils, the


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refining. During the process, he free fatty acids n the oil reactwith the weak caustic soda solution to form soap stock whichalso absorbs some colour, odour and impurities from the oil,thus rendering the oil clean.It is always advisable to determine, as a first step in therefining process, he content of free fatty acids n the oil sample(by titrating the oil with standard alkali) to enable thesoapmaker o calculate the amount of caustic soda required forthe refining. For example, if it is found that the free fatty acidspresent n an oil sample s 0=6%, then 1OOkg f the oil contains006kgof free fatty acids to be neutralized. A 20Be solution(of relative density l* 16) of caustic soda is normally used forrefining. Such a solution contains 14*3% of pure caustic soda.It is also known that 14% (by weight of fatty acid) of purecaustic soda is required to neutralize a given weight of fattyacid.Thus O*bxO*14kg,or 0=084kgof 100% caustic soda will berequired to refine 1OOkg f the oil. Using a 20Be solution (of14.3% strength) 0@$4/0*143 r 0059kgof the solution will berequired to refine 1OOkg f the oil. In practice, however, Osl-005% more solution is used.The process of alkali refining involves heating the oil in asuitable tank to around 32C and while stirring the correctquantity of 20Be caustic solution is evenly sprinkled on thesurface. After several minutes of the addition of the solution,brownish or dark clots, which are saponified acids and


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on the top of the water is then siphoned from the tank whilethe water with the settled impurities from the oil is drained offfrom the bottom of the tank.6.1.3 Bleaching of Oils and FatsThree bleaching methods are generally employed in thebleaching of oils and fats, namely earth bleaching, airbleaching and chemical bleaching.Earth BleachingIn this process he clarified oil to be bleached is heated to 90-lOOC, and 4% of Fullers Earth and a small quantity ofactivated charcoal are added to the oil and slowly agitated for15-20 minutes to keep the bleach in suspension. The oil andbleach are then filtered in a filter press, or the oil is allowed tocool for a night and decanted, when the bleaching agentssettledown to the bottom of the tank.Air BleachingThis process is widely used in rural soapmaking for thebleaching of palm oil. In this process, clarified palm oil isheated to 200-250C n an open tank for 4-6 hours dependingon the quantity of o il treated. In the course of the heating theoil is oxidized and the red colour of the oil soon vanishes. Insome caseswhere the bleaching is done in a steam jacketedtank with an open (perforated) coil, air is blown continuouslythrough the oil by means of the coil when the oil is heated to1OO*c.


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----Ibichromate and 20-27kg of dilute sulphuric acid is used. Caremust be taken so that the bleaching temperature of 52C ofthe oil is not exceeded or else the resultant oil onsaponification will yield a soap of reddish-brown colour.


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Chapter 6The Processes ofSoapmakingVarious attempts have been made to produce soap by firstdecomposing the fat or oil into fatty acids and glycerin, andthen converting the acids into soap by treatment with sodiumor potassium carbonate. However, three conventionalmethods of soapmaking are generally used in both large- andsmall-scale soap production units. These methods includesemi-boiling, full-boiling and cold processes, and will bediscussed n this chapter.6.1 Semi-boiling ProcessThe process,although not suitable for the production of toiletsoaps,can be used o produce laundry and all types of soft andliquid soaps.The processdoes not permit the removal of wastelye which contains the glycerin produced in the soapmakingprocess, and hence the glycerin, which tends to decrease he


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caustic soda required for the saponification of the oil. Thisweight of caustic soda is dissolved in ten times its weight ofwater to obtain a 9% solution. When the caustic solution is runinto the oil, saponification starts when an emulsion is formedas the soap is stirred. More caustic solution is then run in toprevent the mass hickening. After sufficient solution is addedbit by bit to complete the saponification, boiling of the masscontinues until the soap is clear.During the boiling processmoderate heat is maintained andeach addition of caustic soda solution must be allowed to reactwith the oil before the next addition is made. A hasty additionof the lye in the initial stages of the process may retard thesaponification, or at the final stagesof the saponification mayresult in the graining of the soap, while judicious addition willkeep the mass n a form of smooth homogeneousemulsion. Ifthe soap shows any signs of separation or graining, furtherwater or oil is added to bring the mass o a homogeneousstate.


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The end of the process s easily recognized by an experiencedsoapmaker. However, crude tests can be made to determinewhen saponification is completed. The ribbon test involvestaking a small sample of the soap from the pan and cooling it.When a little quantity of the cooled soap is pressed betweenthe thumb and forefinger, the soap should come out in the formof firm shiny ribbons with slight opaque ends and be clearwhen held against the light. If the cooled sample draws out inthreads, there is an excess water present in the soap, andfurther boiling is required to evaporate more water. If theopaque ends appear and vanish, the soap is oily and requiresmore caustic, while if the soap is grainy, or turbid andsomewhat white, it indicates a high level of unreacted caustic,and requires more oil. A physical test - the taste test - canalso be done to determine the level of caustic. This testinvolves cooling a small quantity of the soap, and tasting withthe tip of the tongue. A very sharp bite indicates too muchcaustic n the soap, while no bite at all indicates a high level ofunsaponified fat or oil. A good soap should give a faint bite onthe tongue.After the completion of the boiling process, the fire iswithdrawn, and the soap allowed to cool in the boiling pan withoccasional stirring. At this point, perfume and colour can bestirred into the soap, if required, and the final soap poured intosoap moulding boxes. It is then allowed to stay for 24-36hoursto harden, after which the moulds are emptied and the solidsoap block cut into the required sizes and stamped.


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Phte 13: Soap-boiling ruing a KC-designed boiling tank capable ofproducing 500 bars of soap a day6.2.1 Saponification ProcessThe process s started by putting the melted oil into the boilingtank and running a weak (9.10%) caustic soda solution into the


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saponification is completed, the soap becomes firm and drywith a permanent faint caustic taste on the tongue whencooled. The soap, which now consists of imperfect soaptogether with water in which is dissolvedglycerin and any slightexcessof caustic soda, is then ready for graining out.6.2.2 Graiuiug OutThe object of this is to separate the waste lye (which is amixture of glycerin produced during the soap boiling processand excess austic soda solution) from the soap. This is broughtabout by the use of common salt in the dry form or as brine.The term graining is used here becauseafter the introductionof the salt, the homogeneous soap has the appearance ofgrains. During the graining process, brine of relative density1.2 is added to the boiling soap and boiling is continued. Toomuch brine must not be added at a time. Usually the total saltused s 840% by weight of the oil used, depending on the typeof oil. Less salt is required for tallow and palm oil while moresalt is needed for coconut and palm kernel oils. As the salt isadded and the soap allowed to boil and stirred, the soap isgradually thrown out of the solution, and loses ts transparentand homogeneous appearance, becoming opaque and grainy.The graining is comp!ete when the soap s practically free fromfoam and floats as neat soap on the lye. At this stage, a sampleof soap taken from the tank consistsof distinct grains of soapand a liquid portion which will easily separate. The boiling isthen stopped and the excess ye allowed to settle for severalhours or overnight.


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moulds. When the soap is sufficiently cooled in the soapmoulding box, it is taken from the mould, cut into the requiredsizes and stamped ready for use.6.2.3 Clear Boiling and FittingThe object of clear boiling and fitting is to obtain a pure soapsuitable for the making of toilet soaps, by removing the lasttraces of impurities from the grained soap. In the clear boiling,complete saponification is attained and the soap is hardened.During the process, he bottom layer of the soap s drained outafter the graining. The content of the boiling tank is thenboiled with strong caustic solution of 25-30"Bk (relativedensity 1.21 to 1.26). More solution is added as it is absorbeduntil the soap is again grained, and is then allowed to boilsteadily. As the boiling continues, complete saponificationtakes place, and the boiling is stopped. The grained soap is leftfor some hours to allow the settling of the excess ye which isthen drained off.The soap s then boiled with a little water to make it smoothand homogeneous. This boiling process is called fitting.During the fitting operation, samples of the soap are takenfrom time to time to determine the quality of the soap and theend of the operation. If the soap s good, a small quantity takenon a trowel should slip off from it without adhering to its sides.If the soap adheres, too much heat was used for the fitting,and a little lye must therefore be carefully added to the soapand boiled again until the desired condition is attained, and the


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second ayer of good soap s then drained nto another pan (i-e.cleansed) and treated to obtain the final product. In thecleansingprocess,care is taken to avoid the presence of any ofthe low grade soap forming the third layer. The temperature atwhich the soap is cleanseddepends on the soap type - soapsto be liquored should not be cleansed oo hot or separationwill take place during the liquoring; a temperature of 66C isan ideal temperature for this. Cleansing emperatures of 7476C are suitable for firm unliquored soaps.After the cleansing, the soap is stirred, or clutched, until asufficiently low temperature is attained.6.3.1 LiquoringThis involves the addition of various alkali solutions to thecleansed soap to produce soaps of different qualities.Liquoring can be done during the stirring (clutching). Amongthe alkalis most frequently used are sodium silicate and sodiumcarbonate. The latter may be used n *ihe orm of soda crystalscontaining 63% of water dissolved in its own water ofcrystallization on heating, and in that manner added, giving itfirmness and increasing ts detergentroperties. It can also beadded to soap as a solution of soda ash, either concentrated (ofrelative density l-31) or of various strengths of relative densityl-125 upwards) at a temperature of 60C o stiffen and hardenthe soap.In the choice of the solutions, care must be taken as strongsoda ash solution in firm soaps results in a brittle product,


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Plate 14: Draining semi-boiled soap from the boiling tank to themodding box lined with polythene sheet6.3.3 FramingHaving cleansed, clutched, liquored and filled the soap, the


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Plate 15: Removing soap from the soap moulding box for cutting


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Plate I?: Arrcrrtgirlg j%slred sorry bars ONshelv~~.sor drying

resulting in shrinkage and distortion. The dry soap is thenstamped by means of a stamping machine. If necessary, thesoap is transferred to racks after the stamping to expose it to


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Coconut oil is the chief oil employed but sometimes allow,palm oil lard, cotton seedoil, or even castor oil can be blendedwith coconut or palm kernel oil to make the soap, with slighttemperature change to render the blend liquid. Soaps madewith these blends resemble, in appearance,milled toilet soaps.In this process, it is very necessary o use high grade rawmaterials. Oils and fats should be free from excess aciditybecause austicsoda rapidly neutralizes ree fatty acids orminggranules of soap which grain out in the presence of strongcausticsolution, and since he grainy soap s difficult to removewithout heat increase, the soap tends to become thick andgritty and sometimes discolours. The caustic soda being usedmust also be pure, i.e. must contain as little carbonate aspossible, and the water must be soft and all other materialscarefully freed from particles of dirt.The process nvolves stirring into the milled fat or oil in atank, half its weight of caustic soda solution of 40B6 of(relative density l&37) at a temperature of 24C for coconutand 38C to 49C for the blends. The running of the causticsolution into the oil must be done slowly and continuously.When the solution is being run into the oil the mixture must bestirred in one direction. When all the caustic soda solution hasbeen run into the oil and the mixture stirred for 30-45minutes,chemical reaction takes place with the generation of heat,finally resulting in the saponification of the oil. The content ofthe tank looks thin at first, but after some ew hours it becomes


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Some Advantages and Disadvantages of Cold Process over Bo!!ing ProcessAdvantages

Cold Process Hot Processi. Requires inexpensive equipment Equipment and capital investmentand hence small capital can be very expensive.investment.ii. Less skilled labour. and simpleprocessing technique. More skilled and experienced labourrequired. Processing technique morecomplex.iii. Glycerin produced during the Glycerin removed (except for semi-soap making process is retained boiling process).

in the soap, preventing thecracking of the soap on keeping,and incrtzasing its emollientproper-tics.iv. Soap produced easily dissolves in The soap is not readily solublewater with abundant iathcr. except when certain pcrcentagcs ofSoft oils ilrC uSCd.v. Soap has whiter colour, and

hence the process is used toproduce some special types ofsoap.

Products soaps of varying colours.

vi. The process is quicker andrcquircs incxptnsive perfumesfor scenting.Bisacivan rages

The process is long, sometimestaking weeks (full boiling) tocomplete.

Cola Processi. Bad soaps produced cannot bereclaimed using the sameHot ProcessBad soaps produced can bcreclaimed using the same process.


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Chapter 7Small-scale Production ofToilet SoapsBy definition, a toilet soap s a soap specially adapted for toiletuse due to its good detergent and lathering properties, as wellas its freedom from caustic alkali and any other ingredientlikely to cause rritation to the skin.Toilet soaps can be classified according to their method ofmanufacture into the following classes:a) cold processsoap,b) milled soap,c) remelted soap.The processes or the manufacturing of these three types ofsoapsare described below.7.1 Cold ProcessIn practice, good toilet soaps are produced using the milling


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stirring until the oil is completely saponified and the massbegins to thicken. Finally the thickened mass s drained intosoap moulding boxes and allowed to harden slowly.The quantities of raw materials to be used depend on thetype of soap to be produced. For simple white toilet soaps orexample, a blend of oils consisting of 20kg of coconut oil,27.3kg of tallow (or palm oil) and 1 8kg of castor oif is treatedwith 25kg of 4OBecaustic soda solution.

7.2 Milled Toilet SoapmakingAlmost all the high class soaps used on the market passthrough the milling process which consists briefly of thefollowing operations: drying of soap base, mixing of perfumeand dye, milling, compressing,cutting and stamping.7.2.1 Drying of Soap BaseThe final soap obtained after the treatment of the settled soapalready described in Section 6.3 servesas a soap ase for themilled soap. After the solidification in soap frames, this soapcontains 28-30% of water, and this quantity has to be reducedby half before any satisfactory milling can be done. Drying isbest done by chipping the soap into smaller sizesand exposingthe chips in trays to a current of hot air at 35-40C.There areseveral orms of drying chambers n which the chips n the traysare placed upon a series of racks, one above the other andwarm air circulated through.It is very important that the correct amount of moisture

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to mix thoroughly at toom temperature.The quantity of perfume to be added varies considerablywith the perfume type. For cheap grade soapsO-6 o l-7% (byweight of soap) are used, while for costly soaps 2-3% aresometimes used.7.2.3 MilliugFrom the amalgamator, the soap is put into the millingmachine or the chips to be milled into more homogeneous hinsoapribbons. Prolonged milling does not improve the quality ofthe soap but only gives a semi-transparent appearance o it.7.2.4 CompressingThis follows the milling process. The operation tends to bindthe soap ribbons into a solid bar suitable for cutting andstamping. In this process, the milled soap is fed into thecompressor (or plodder), and as the compression takes placethe soap extrudes through the nozzle of the compressor as along polished solid bar.7.24 Cutting and StampingIn cutting the extruded soap into the required sizes forstamping, the cutter should shape it somewhat similar to therequired finished tablets. An ordinary cutting table can beemployed. Stamping of the cut pieces can be done with eitherfoot or hand operated stamping machines.7.3 Remelted Soaps


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Chapter 8Non-edible Oils forSoapmakingTraditionally, soapmaking in Ghana and many other Africancountries involves the use of various types of edible oils andfats. However, over the years there has been a very rapidincrease in the demand for edible oils and fats for bothconsumption and industrial purposes. This has resulted in theincrease in the price of such edible oils like palm, coconut,palm kernel and shea butter which are extensively used inGhana for soapmaking. The large increase in the prices ofedible oils has in turn rendered soapmaking relativelyunprofitable. It has therefore become imperative to search orother alternative sourcesof raw materials which could providesuitable substitutes for the edible oils traditionally employed insoapmaking.In Ghana some research on the use of non-edible oils forsoapmaking, carried out by the Technology Consultancy


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and an unpleasant garlic odour. The oil is extensively used toblend other oils in the making of both laundry and toilet soapsin India. Analysis of locally extracted oil gave the followingproperties.Physical PropertiesColourOdourTasteSolubilityDensityRefractive IndexChemical Properties

greenish yellowrepulsive garlicvery bitterinsoluble in water0.905gkC1.47

Saponification Value 194.78Iodine Value 65Unsaponifiable matter 2.5%8.1 .l Soapmaking PropertiesThe oil saponifies readily and gives a hard-grained soap withgood and very stable lather. When used alone for the makingof soap it is very necessary o grain the soap as this helps toremove most of the disagreeable odour and colour. On theother hand, if it is used to make soap with other oils, it isadvisable o first make neem oil soap. After the soap has beengrained, the other oils are stirred into the soap and therequired amount of caustic soda solution added to start thesaponification again. Neem oil soap is used for both laundryand antiseptic purposes.


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Castor oil is obtained from the seeds of the castor plant(Abonkruma in Fanti). In Ghana, the oil has no economicvalue as no oil is extracted from the seeds. Apart from usingthe plant to give shade to young seedlingsof oil palm, cocoa,coffee and coconut at nurseries of the Ministry of Agriculture,the plants are normally seen growing wild, especially at theoutskirts of towns and villages in both savannaand forest zonesof Ghana.


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Soapmaking PropertiesCastor oil consists mainly of ricinoeic acid and smallerpercentagesof stearic and palmitic acids. The oil has the samebehaviour as coconut oil as regards to saponification, beingreadily saponified with strong caustic lye. The oil produceshard, white, and transparent soap. Below are the analyzedproperties of soap made from locally extracted castor oil.

PropertyColourHardnessLather stabilityWashing efficiencyTotal fatty matterFree caustic alkaliMoisture

s

Analysis result of soap (Hot process)palevery hardmuch lather but very unstable - lather vanishesafter few secondslow67%0.0%20.5%

8.3 Physic OilThe physic oil is obtained from the seedsof the physic nut (orJatropha) plant, locally called Aduadze in Fanti or Nktandua inTwi. The plant is often grown for hedges and fences butcommonly found growing wild around the Afram plains,central region around Cape Coast, and the Axim area. Theseed contains about 52% oil. The oil has been used along with


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8.4 Process of SoapmakhgDue to the complexity of the full boiling process, t is generallynot used in small and village scale soapmaking. However, thesemi-boiling and the cold processnormally used by the small-scale soapmakersare not suitable for use with non-edible oilsdue to the fact that majority of these oils have deep colour andbad odour. Instead, a combination of the full-boiling andsemi-boiling process s used.In the combined process, he deep coloured and bad smellingnon-edible oils to be purified are first saponified, and thengrained to remove the colour and odour. The grained soapobtained is used in soapmaking together with other palecoloured oils, using the semi-boiled process.A typical formulation and process nvolving the use of neem,castor and physic nut oils is described as follows:Rm MrrttviulsNccm oil 6wPhysic nut oil 3,5kgCastor oil wCaustic soda l4kgSodium Carbonate 2SkgCommon Salt Bkg

The neem oil is clarified by boiling with an equal volume ofwater and draining the water out after settling, with the dirt


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It must be noted that since non-edible oils havecomparatively large proportions of free fatty acids, retardationof the saponification sometimes occurs because he free fattyacids sometimes form granular soap and accumulate aconsiderable quantity of caustic soda, thus preventing freecontact between the oil and the caustic. When retardationoccurs some water should be added to the soap and boiled withstirring.The melted neem soap can be drained into soap mouldingboxes to harden and keep for future use, or when a continuousprocess is being done, the neem soap is melted with somewater. Meanwhile the remaining 606kg of caustic soda isdissolved in 1608kgof water. Some of the caustic solution isadded to the melted soap and the physic nut and castor oilsadded and stirred. The remaning caustic solution is added tothe soap in bits until it is all used up to complete thesaponification process. The sodium carbonate (or 25kg of4OBesodium silicate solution) can be introduced at this stageand stirred for about an hour. Colour and perfume may beadded and the soap drained into moulding boxes. Thetemperature at the time of moulding, in the caseof pure soap,should not exceed 70C.


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.

Chapter 9Ghana StandardsSpecifications for SoapThere are certain international quality standards to whichsoaps,whether for laundry, toilet or medical purposes,have toconform before they are sent to the market. As a check onthese standards it is necessary hat samples of soap batchescoming to the market from the manufacturer are physically andchemically analyzed.

In Ghana, the National Standard Board has promulgatedcertain standards for different types of soap (based on theBritish and Indian standards for soaps). Soaps producedcommercially at both the large- and small-scale evels shouldsatisfy these standards before they can be marketed under theGhana Standard Board Certificate for soaps.9.1 Filled Hard Soap SpecificationsThese soaps are defined as hard soapscontaining fillers. Theymay be white or coloured, and should be well saponified, and in


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9.2 Genuine Hard Soap SpecificationThis is defined as hard soap of a firm texture without theaddition of any filler.Physical RequirementsThe soap should consist principally of the alkali salts of fattyacids, and be free from objectionable odour, and with goodlathering properties. It should be in the form of a neat bar,ball, or tablet.Chemical RequirementsIt should be in addition to the above physical requirementshave the following composition.Total fatty matter Not less than 59%Free caustic alkali Not more than 0.05%Total caustic alkali Not mow than 0.2%Total free alkali Not mow than 0.25%Moisurc Not more than 28X9.3 Filled Carbolic Soap SpecificationsThis is defined as hard soap containing fillers and phenolicsubstances ike cresylic acid. Physically, the soap should be offirm texture, free from objectionable odour, and possess oodlathering properties. The ingredient of the soap should benon-toxic. It may be in a form of a bar, tablet or ball.Chemical RequirementsTotal fatty matter Not loss than 46%


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possessgood lathering properties. The ingredient of the soapshould be non-toxic.Chemical RequirementIn addition to the above physical requirements, the soapshould have the following chemical properties:Total fatty matter Not less than 75.6%Free caustic alkali Not more than 0.05%Total free alkali Not more than 0.22%Moisture Not more than 14%

9.5 Medicated SoapThis is defined as any soap other than carbolic soap for whichtherapeutic claims are made. The level of active ingredientmust be indicated and must comply with the requirement of thecode of good manufacturing practice for the Cosmetic andToiletry Industry in Ghana.The soap should consist principally of the alkali salts of fattyacids, be of firm texture, and free from objectionable odour. Itshould possessgood lathering properties, and its ingredientsshould be non-toxic.Chemical Requirements % by mass of soapTotal fatty matter Not less than 63Free caustic alkali Not more than 0.05Total free alkali Not more than 0.25Total free fat Not more than 0.2Matter insoluble in ethanol Not more than 2.0


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f) Ghana Standard (GS) numberg) Ghana Standard Board Certificate Markh) In the case of medicated soap, there should be a conspicuouswarning of the following nature0 that use of the soap he discontinued immediately skinirritations or any other adverse reaction appears.ii) that prolonged use may be dangerous.

In addition, for medicated soaps containing mercuric oxidethe product should not be used on damaged skins, e.g. cut oropen skin. This warning must appear on the outer cover of thecontainer.


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Appendix 1Some typical formulationsfor soaps1. Laundry soap - using semi-boiling process

Palm oil 150kgCoconut oil 30kgCaustic soda 28kgKaolin 15kg

2. Soft potassium soap (indigenous soap) - wingsemi-boiling processPalm oil 22SkgCaustic potash 4.5kg (dissolved in11.25kg of water)Salt 4%


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5. Laundry soap - using cold processa. Palm oil 16.4kgCoconut oil 2.2kg

Caustic soda 3kg (dissolved in 7kg of water)b. Palm oil 4.5kgPalm kernel oil 1.3kgCaustic soda lkg (dissolved in 4.5kg of water)6. Toilet soap - using cold processa. Coconut oil 42.7kg

Castor oil 3.7kgCaustic lye (38Be) 23kgb Coconut oil 22.7kgTallow (or Palm oil) 22.7kgCaustic lye (37Be) 22.7kg7. Transparent soap - using semi-boiling processa. Coconut oil 1.8kgCaustic soda 1.2kg (dissolved in water to obtaina 20Be solution)Note: The method involves the production of soap stock using theabove raw materials. The stock is then dried to 30-35C. The nextoperation involves dissolving 50 parts of the dried soap in 50 parts ofthe industrial methylated spirit on moderate heat, and cooling inframes. It must be noted that the transparency of the soap is foundafter it has been exposed to dry air for a considerable period.


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Formula88-92% soap chips 5.45kgWater 32.7kgMineral oil or lanolin 2.2kgN-Brand Sodium Silicate 4.45kg

MethodThe soap is dissolved in hot water. The silicate is added and the massis mixed and cooled. The mineral oil and 112gm of perfume areadmixed, with stirring until uniform. The product may be filled intocans.


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Appendix 2Properties of soaps from different oils/fatsi Texture 1Latherinn Provertv1 fairly soft 1More and stablelather

Coconut very hard Plenty and fairly4c=, stable latherTallow hard More and stablelathePalm oil hard More and stableZEpShea butter latherfairly hard Fairly good latherCocoa butter hard Good lather

Cleaning PropertyGoodvery goodvery goodvery goodgoodvery goodgoodgood

Effect on Skin 1 UsesAntiseptic washing, bathingand medicinalNo effect 1washing, bathing1and shaving1washing, bathing1and shaving1washing andNo effectNo effect

,:::::

1bathing

54280563 Small Scale Soap Making a Handbook 1986

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