MICROFICHE REFERENCE LIBRARY A project of Volunteers in Asia The Preparation of Soap by Ir, S-P, Bertram et. al. Published by: Eindhoven University of Technology Committee for International Cooperation Activities (CICA) P.O. Box 513 5600 MB Eindhoven THE NETHERLANDS Available from: Stichting TOOL Entrepotdok 68A/69A 1018 AD Amsterdam THE NETHERLANDS 9 Reproduced by permission. Reproduction of this microfiche document in any form is subject to the same restrictions as those of the original dpcument. Eindhoven University of Technology CICA publication 83-01 Eindhoven University of Technology Committee for International Co-operation Activities Subcommittee for Microprojects Office for Development Co-operation Post Box 513 5600 MB Eindhoven The preparation of soap THE PREPARATION OF SOAP preparedby : fr. S.P. Bertram revised by : A. Oerbmans H. de Boon CICA-publication 83.01 This publication may be obtained through : T0OL foundation 61a Hauritskade 1092 AD Amsterdam The Netherlands Free use may be made of the information in this publication, provided the source is properly indicated. The Eindhoven University of Technology cannot be held responsible for the possible damages resulting from the use of the information contained in this publication. Eindhoven University of Technology, Committee for International Cooperation Activities (CICA) SubcommIttee for Microprojects . P.O. box 513 5600 MB EINDHOVEN, The Netherlands October, 1983 600 copies. COWENTS PAGE 0. 1. 2. 3. 4. 4.1. 4.2. 4.2.1. 4.2.2. 5. 6. 7. 7.1. 7.2. 8. 8.1. 8.2. 8.3. INTRODUCTdbN ................................... 1 DIFEXRENT KINDS OF SOAP ........................ 1 EQtJIPNHNT NEEDED ............................... 1 Fmw MA-s .................................. 2 DISCUSSION OF THE RAW MA‘I'ERIAL ................. 2 The fat and o-it ................................ The lge (h?aOg) ............................... The nieaeuring 8tiCk/tUbB.............~ ......... (Smoking the &e Conoentrcrtion ................. THE MIXING RATIOS OF LYE AND FATS .............. 4 PREPiUtAl’I~ OF THE SOAP ........................ 8 FIJRTIHEH PROCESSING ............................. 8 The pouring out of the BOCZF .................... Making bdtsddoon soap ........................ PREPARATXON OF THE SOAP WITH POTASSIUM LYE ..... 9 &qXZiitiOtZ Of Soft SO~..................e.a .. Making Zye out O~pZ~t-a8heS .................. The bumzing of Ztms ............................ -l- TSEPRSPARATIONOFSOAP 0. INTRDDUCTION Many people want to prspare soap in order to maintain the necessary hygiene. In tropical countries soap is sometimes either difficult to obtain or very expensive even though the raw materials for the preparation of soap are often available. Anybody can make soap at home as long as he follows the instructions mentioned below. Some of these instructions may seem somewhat technical but it is necessary to describe directions in this way as otherwise soap of a bad quality may be obtained. 1. DIPFE3ENT KINDS OF SOAP The soap recipe in this booklet works with caustic soda, which makes hard soap. Soft soap is made by using caustic potash, instead of soda (see chapter g). If you seperate this pure soap from the brine, (as described in 7.2.1, the result will be soft soap. Hard soap can be coloured with pigment, that is, a very fine pcwder which is mixed with the soap mass, but does net dissolve in it. You will have to experiment with locally available pigments, to find out which colour keeps best. In the tropics a testing period of at least 2 months is needed. With colour, you can also givs the soap a scent. This is done by mixing perfume and/or colour with the warm soap massr just before pouring it into the moulds. Special scents for the soap industry are commercially available, but if these are not at hand in your area, you'll have to experiment. Bad results will be easily recognised by a very different odour, after waiting a few days. For preparation of soap we need vessels made of iron or stone. Aluminium should not be brought into contact with warm soap as this affect8 the material. Moreover, a couple of spoons or sticks of the correct size are necessary in order to stir the mixture during the preparation. To achieve the soap's final form the substance can be poured out into bowls, wooden boxes and even in cardboard boxes as long as these are strong enough. Coconut shells can often be used very well to obtain the good form. To prepare good soap the raw materials should be mixed in proper proportions for which a measuring-glass, or something like it, is necessary. For the preparation of soap you will have to melt fats, and thus, some heat source is needed. Because the chemical reactions in the process produce heat, the temperature should not rise over 90°C, if you want to prevent spilling over. Therefore, a well controlled heat suppb~ is recommended. ^, , ‘I s;->,. * 9 -2- 39 TIiJZRAWMATERIALS . As raw material all oils and fats of animal or vegetable origing can be used. Lye, which is often sold on inland markets , and soft water, for which rain- water can be used, are also required. If there is no sufficient rainwater available you can also add some lye to water of different origin.,In doing this it is necessary to stir* well after which you leave the mixture for a couple of days. A sediment will then be formed that settles well. The top-layer of water can then be used for the following recipes. 4. DISCDSSION OF TIE RAW MATDRIAL 4.1. !Fhe fat and oi2 All fats and oils at your disposal can be used for the preparation of soap, Even fat-leftovers and polluted fat can be used provided that the mixture of fats, from which the soap is to be prqpared, is melted as a whole. When the fat-mixture stinks it must be washed with hot water and filtered through a fine-woven cloth in order to remove any dirt. To obtain a good soap it is advisable to use in any case some coconut fat, palmkernel fat and/or butter fat. These last mentioned fats make a well-foaming soap. 4.2. The &J&2 It often is not known how strong lye is which is bought on the market. For the preparation of hard soap only caustic soda can be used. The quantities of lye and fat to be used should be adjusted very carefully to obtain a good quality of soap. If there is any weighing-device present, it is advisable to weigh the required amounts, according to table 1 ( see page 4 1. For this method however it is necessary to use fresh, dry and pure caustic soda. This will only be so if the caustic soda is packed in a aealed unopened container.If you are not sure about the quality of the caustic soda, you shall have to measure the density of the solution by means of an aerometer , a device costing about 5 f sterling. The density of the solution should be 1.22 for a 18 w% solution and 1.37 for a 27 ti solution. If no aerometer can be obtained, a battery-acid meter will suffice. You can also try to apply the following trick as described : the measuring stick/tube. 4.2.2. The meas~ng stick/tube : First a saturated rock salt (sodium chloride) solution is prepared. - dissolve a fair amount of salt in water, stir well - let stand until next day. If no solid salt is left on the bottom, add morer until some is left. Your solution is now saturated. -3- - take a small stick of solid wood, tie something heavy to one end '( a pebble, or piece of iron 1 - stick this into your salt solution. The stick should stand straight up and a small part of it should stick out of the liquid. If not, adjust its weight. - mark the stick where it is touched by the surface of the liquid - you now have a measure for lye concentration, which can be used time and again. mark salt Fig. 1 The gauging of the stick or tube As by drying out, or by water absorption, the weight of the stick may change, it is necessary to check the stick occasionally. It should dip up to it's mark in the saturated salt solution. The salt solution for checking the stick can be used as long as solid salt remafns in the solution. An alternative for the measuring-stick is the measuring-tube. This tube consists of a small lenght of plastic (PVC-) tubing, that has been squeezed shut at the bottom so that a piece of stone or iron can be put into it. This tube can be used in exactly the same way as the measuring-stick; it does not dry out or absorb water however, so that it is more convenient. If necessary, the tubs can be shut above the stone alsos to prevent it from falling out. -4- 4.2.2. mecking the lye cacentratim - put your stick into the lye solution, the mark will be above the liquid surface - add slowly water, stirring well, until the stick floats into the liquid exactly up to its mark. Now your solution has the right concentration. It contains about l8w% of lye, This lye can be used for the preparation of soap. It is also possible to make lye of the correct density by comparing the weight of a certain volume of lye to that of the same volume of saturated rock-salt solution (without crystals). These weights should be equal. The above mentioned tricks are only suitable for the preparation of an 19 w% solution. There are no such methods available to prepared a 2f w% solution ; this should always be done by use of an aerometer or battery-acid meter. 5. TFIE MIXING RATIOS OF LYE AND FATS In table 1 two concentrations of lye are given, 18 weight percent caustic soda in water ( 18 0w 1 and 27 weight percent ( 27 %w 1 . The 27 %w solution is only suitable for low temperature saponification6 meaningothat lye is to be added to a fat tixture with a temperature of 60 C ( 140 F 1. The 18 %w solution is suitable for boiling saponification. The solutions can be weighed as follows : 18 %w 27 %w water 1000 gr (31 L) 1000 gr caustic soda (NaOH) 220 gr 370 gr caustic soda (NaOH) 1000 gr 1000 gr water 4545 gr 2703 gr Table 1 i The weightratios of the lye solutions Per 1000 grams of water the indicated weight of caustic soda should be dissolved. The caustic soda should be fresh, dry and pure. The lye has to be used imediately because it is not stable on contact with air. It is also necessary to use all the available caustic soda for the preparation of soap, in other wxds : to adjust the production of soap to the available quantity of caustic soda. Caustic soda in an opened container is not stable on contact with air. WARNING As lye is an agressive material it can affect the skin and eyes very badly. rf by any chance your skin or eyes come in contact with the lye it is advisable to wash with plenty of water. Your skin, not your eyes, can eventually be treated with diluted vinegar. In any case one must be very cautious with the eyes, since lye may irreparable damage; if possible wear goggles or glasses while working with lye. If somebcdy has swallowed lye, let him drink as much water as he can and let him/her have lemonjuice , rhubarb, citrus-fruit or vinegar. Always keep the lye away from children. In table 2 ( see page 6 1 the mixing ratio of a number of fats and oils with lye is given. For solid caustic soda the weights are given, viz. the number of kilogrammes fat or oil to be saponufied with one kilogramme of solid, .pure caustic soda. For the solutions volume-ratios are given ( litres oil or fat per litre lye 1 as well as weight-ratios ( kilogrammes of oil or fat per kilograme of lye I. While working with solutions one should use the ready-made solutions as mentioned ahove. Babassu fat Cacao fat castor oil c!o#onseed oil Wut fat Linseed oil Nustard oil old-ve oil Palm oil Palmkernel oil Peanut oil l?apese!edoil Saffloser oil Sesaw oil Shea butter soya oil sunflower oil saponificatfonvalue 18 w% NaOH 16 %w FiaOH 27 %w NaOH 27 %w NaOH kg fat/kg NaOE kg fathg'soln 1 f&/l soln kg fat/kg scln 1 fat/l soln 5.62 + 0.13 1.01 1.32 1.52 2.14 7.25 + 0.16 1.31 1.61 1.96 2.62 7.75 2 0.17 1.39 1.74 2.09 2.82 7.25 + 0.10 1.31 1.70 1.96 2.75 5.46 + 0.15 0.98 1.27 1.47 2.07 7.35 + 0.16 1.32 1.69 1.98 2.74 8.00 2 0.25 1.45 1.89 2.17 2.82 7.35 + 0.16 1.32 1.73 1.98 2.80 7.09 + 0.10 1.27 1.65 1.91 2.67 5.65 + 0.13 i 1.02 1.31 1.53 2.12 7.30 + 0.16 1.31 1.72 1.97 2.79 7.94 + 0.19 1.43 1.87 2.15 3.03 I 0 7.35 + 0.16 1.33 1.72 1.99 2.79 I 7.35 2 0.16 1.33 1.72 1.99 2.79 7.58 + 0.23 1.38 1.80 2.07 2.92 7.35 + 0.10 1.32 1.71 1.98 2.77 7.41 + 0.16 1.33 1.73 2.00 2.80 ~&le 2. The saponification of fats and oils with .NaOH ( caustic soda 1 -7- A nuz&er of fats and oils that have not been included in table 2 can be compared quite good to fats and oils that are included. These fats and oils can be divided into two groupn : Group 1 butter foot oil chicken fat horse fat hog grease ( pig fat 1 beef suet mutton fat Group 2 maize oil hempseed oil tea oil tung oil walnut oil comparable to : palmkernel oil comparable to : olive oil If the fat that you are using is not included in this list, it can be compared best to olive oil. With this table and list you can now calculate how much oil or fat you will need for the available quantity of caustic soda. Example: If you have 10 kg of fresh, pure caustic soda, you can prepare 10 x 4545 = 45450 grames = 45.5 litrsa of lye. ( 18 w% 1 With this solution you can saponify various amounts of fats and oils, e.g. : 10 litres of lye for 10 x 1.27 - 12.7 litres of coconut fat 12.5 litres of lye for 12.5 x 1.73 - 21.6 litres of olive oil 12.5 litres of lye for 12.5 x 1.65 - 20.6 litres of beef suet 10.5 litres of lye for 10.5 x 1.73 - 18.2 litres of maize oil - 8- 6. PREPARATION OF = SOAP melt the fat until completely liguid add eventual soap rests of earlier preparations add very carefully one cup of lye. Keep stirring well. The mixture should become thick and heavy to stir. If not, add a little water. Let the mixture come to boil softly, take care of possible spray. when adding more lye, the mass might boil over, pour on a little cold water keep stirring, gradually pour in remaining lye. If the mass thins out, stop adding lye, let mixture become thick again. If this would not happen, add a little more water. when all lye has been added, let boil for one hour. Keep on stirring, to avoid burning. 7. FURL'XER PlVXESSING Now you can either : pour the soap directly ( 7.1. 1 Eepare boiled down soap ( 7.2. 1 ff the first time the soap feels to "slippery" on your skin, use next time somewhst less lye. 7.1. The pcmrhg out of the SOQ? The prepared substance should be poured into the moulds when it is still warm. For larger quantities you can use a wooden chest, lined with paper on the inside. This paper prevents the warm soap from loaking through the seams and sticking to the wood. Small quantities of soa,p can be poured in bowls, coconut shells etc. when you have cardboard boxes at your disposal you can use these too, provided that all seams are carefully closed ( adhesive tape 1 and the sides of the boxes are well supported, otherwise the warm soap will distort the box. The poured-out soap must remain in the mould for at least 24 hours, after which time the soap blocks so obtained can be cut into pieces and left to : dry in the air, if necessary. The best way to cut the soap is to use a piece of thread on which a piece of wood is fixed on both ends, to have a good hold. : -9 - 7.2. Making bti.Zed down soap You can make so-called boiled-down soap by adding salt. This makes the mixture divide into two layers, i.e. an upper soap layer and a lower brine layer. This treatment should be done when the liquid mixture is still hot. The top layer of the soap must first be ladled into the mould. See to it that the bottom layer is not taken along. Also the dirt and colouring-matter that often settles between the two layers , should not be taken along with the soap. It does not matter when some soap is lost as this soap can be used again for the next soap preparation. You can simply add this material to the fat mixture, as mentioned in 3.1. Take into account that no extra lye will be necessary for the added soap I Boiled down soap makes hard soapcakes, which last longer, are more economical in use than softer soap. 8. PREPARATION OF SOAP WITH POTASSIUM LYE 8.1. Fm3paratim of soft soap Beside the preparation of soap with caustic soda you can also make soap by using caustic potash. This process will always yield soft soap. For the preparation of soft soap you need a 24 %w solution of caustic potash. This solution is prepared by dissolving 316 grams of caustic potash in one liter of water. The density of the solution should be 1.3 ; check this with an aerometer. The caustic potash must be dry, pure and fresh. The quantities needed can be measured according to table 3 on page 10 . Fats and oils not mentioned can be compared in the same way as done with the caustic soda. The preparation of the soft soap is done in exactly the same way as has been told in chapter 6. The soap will not solidify but will remain a paste ; therefore, it is no use to pour the soap into molds. You can let it cool off and scoop it from the vessel. WARNING As lye is an agressive material it can affect the skin and eyes very badly. If by any chance your skin or eyes come in contact with the lye it is advisable te wash with plenty of water. Your skin, not your eyes, can eventually be treated with diluted vinegar. In any case one must be very cautious with the eyes, since lye may irreparable damage; if possible wear goggles or glasses while working with lye. If somebody has swallowed lye, let him drink as much water as he can and let him/her have lemonjuice, rhubarb, citrus-fruit or vinegar. Always keep the lye away from children. - lo- Babassu fat Cacao fat Castor oil Cottonseed oil Coconut fat Linseed oil Mustard oil Olive oil Palm oil Palmkernel oil Peanut oil Kapeseed oil Safflower oil Sesame oil Shea butter Soya oil Sunflower oil Saponification value kg fat/kg KOH 4.01 + 0.10 5.18 + 0.11. 5.54 + 0.12 5.18 + 0.07 3.90 + 0.11 5.25 + 0.11 5.71 + 0.18 5.25 + 0.11 5.06 + 0.07 4.04 + 0.10 5.21 + 0.11 5.67 + 0.14 5.25 + 0.11 5.25 + 0.11 5.41 + 0.16 5.25 + 0.07 5.29 2 0.11 24 w% KOH 24 w% KOH kg fat/kg soln 3 fat/l soln 0.96 1.24 1.33 1.24 0.94 1.26 1.37 1.26 1.21 0.97 1.25 1.36 1.26 1.26 1.30 1.26 1.27 1.35 1.69 1.82 1.78 1.33 1.77 1.93 1.81 1.74 1.38 1.80 1.92 1.84 1.80 1.88 1.79 1.81 Table 3 : Saponification of oils and fats with KOH ( caustic potash ) - ll- 8.2. Making hje out o? plant-ashes Ash from plants exists of anorganic materials that are partly soluble in water, partly not. In the soluble -part you will find potassium carbonate together with other salts like potassium sulphate, phosphate, etc. Plants growh on saltish oil will give ash that may contain a substantial amount of salt ( NaCl 1. It is not possible to remove that salt. That is why you better not use ash coming from plants that have grown on saltish soil. It is also no good to use ash coming from brown coal or pit-coal. Stir the white-burned ash with water ( 1 kg ash in 1 litre water 1. The specific gravity has to be 1.23 now. You can determine that with an aerometer. If the specific gravity is too high, you may add some water. If it is too low, you may add more ash. In the latter case, when you cannot reach the specific gravity of 1.23, the ash contains an insufficient percentage of potassium-carbonate and you will have to try another kind of plant, or you can drain off the liquid and evaporate some water. Once you have the good specific gravity, let the solution settle down one night. After that night, you may pour it off. Take care to pour it off without shaking. It is not so bad if some sediment goes with, provided it is just a little bit. One possible way to do this, is to place the pot on a small bench before letting the solution settle down ( see figure 2).Next day you can easily pour it off. The thus obtained carbonate solution is stable and may be obtained unlimited, provided no rain-water falls in it. Figure 2. The pouring off of the clear solution