Control questions

1. Which kinds of surface-active substances are used in cake soaps? Their content.

2. Structure and properties of cake soap.

3. A purpose of introduction of lanolin and lecithin in cake soap structure.

4. Basic stages of cake synthetic detergent production by forming method.

5. Explain the technological scheme of production of cake synthetic detergents by forming method.

6. Basic stages of cake synthetic detergent production by pressing method.

7. Explain the technological scheme of production of cake synthetic detergents by pressing method.

4.7 Manufacture of paste and liquid detergents

The share of synthetic detergents, which are released in industry as pastes and liquids, is insignificant in comparison with powder synthetic detergents, but last years there is a tendency to their growth. Interest to release of paste-like and liquid detergents is caused by the following factors: low energy inputs at manufacture and application of paste-like and liquid detergents, absence of dusting at washing, occurrence of fabrics of new structures. The economy of energy resources in industrial production is carried out due to reduction of release of washing powders by method of spray drying and increases of share of paste-like and liquid detergents. Decrease of energy inputs in a life is possible by creation of effective detergents and transition to washing of products in cold water.

4.8 Compositions and production technology of paste-like synthetic detergents

Basic paste-like synthetic detergents are the means for washing of products from cotton, linen, woolen, silk and synthetic fabrics; also exist paste-like synthetic detergents of universal action, which are used for washing of products from any kinds of fabrics.

Last years the paste-like synthetic detergents with enzymes, disinfectant and antistatic additives are issued. The most known compositions of released paste-like SD are submitted in table.

Table 6. Paste synthetic detergents’ compositions.

Name of components	SD for cotton and linen fabrics	SD for woolen, silk and synthetic fabrics	SD of universal purpose	SD with antistatic action
1. SAS (on 100 % of a basic substance): - alkyl sulphates of primary spirits - sintanol DS-10 - soap of synthetic fat acids - alkyl sulphonates - oxy-ethylative acids - mono ethanol amides of synthetic fat acids - synthetic amide-5 2. Sodium threepolyphosphate 3. Liquid glass (in recalculation on SiO2) 4. Carboxylmethilcellulose 5. Sodium sulfate 6. Sodium chloride 7. Soda ash 8. Ammonium chloride 9. Optical bleach 10. Aromatic substances 11. Water	20 - 3 4 13 - - - 25 2 1 0-5 4 3 - 0,2 0,2 up to 100	17 4 - - 13 - - - 10 - 1 0-5 1-3 3 4 0,2 0,2 up to 100	18 - 5 2 9 - 2 - 30 2 1 0-5 3-6 - - 0,3 0,2 up to 100	23 - 9 - - 7 3 4 25 - 1 4 6 - - 0,3 0,2 up to 100

Basic parameters of paste-like synthetic detergents are washing ability, color, smell, stability at storage, viscosity, fluidity. Viscosity and fluidity give the representation about adaptability of paste and its behavior at the basic stages of process, especially at packaging. Optimum fluidity and adaptability of paste are achieved at viscosity corresponding to beginning of its flow. The increase in viscosity complicates processes of swapping and packaging of product.

On viscosity of composition the big influence the following factors are rendered 1) a relation of SAS included in compoundings of synthetic detergents in quantity 20-23 %; 2) a presence of such additives, as carboxylmethilcellulose, sodium silicate; they are contained in small amounts - 0,2-0,3 %. Even little change of additives content in composition allows defining necessary fluidity and uniformity of paste, to prevent it from hardening.

The technology of production of paste-like and liquid synthetic detergents consists of the following stages:

- Preparation of loose and liquid raw material;

- Weighing of raw material in reactor in the certain sequence;

- Dissolution and mixing of components;

- Homogenization of paste;

- Packaging in polymeric container.

Production process is carried out in periodic mode (fig.4.5).

The paste-like raw material (various kinds of SAS) is melted in melting chambers at temperature up to 80⁰С and pumped in account reservoir 1. The loose raw material (sodium threepolyphosphate, sodium sulfate) is loaded into account bunkers 2. The loose substances, which have slumped at storage, are preliminary passed through hammer crusher, sieved on sieves, and then fed on preparation of paste.

Some components of raw material (carboxylmethylcellulose, monoethanolamines) are preliminary dissolved in water, and solution is pumped in account reservoir. Dissolution of carboxylmethylcellulose is carried out in reactor with gate-impeller mixer and jacket at temperature 50-60⁰С within 1,5-2 hours for preparation of homogeneous mass. The solution of monoethanolamines is similarly prepared.

Preparation is carried out in the steel or enameled reactors-mixers, equipped with jackets for heating and mixers. Liquid raw material in certain sequence through weighers 3 is loaded into reactors 6, where from account bunkers 2 through weigher 4 with help of screw feeders 5 the loose raw material is fed. Duration of preparation of paste-like synthetic detergents depends on a compounding, a capacity of reactor, a kind of raw material and productivity of the equipment. Ready paste from reactor is taken away by pump 7, pumped over through pump-homogenizer 8 and loaded into collections 10 with mixers and heating, whence the paste by gravity is given to packaging automatic devices 11. Liquid synthetic detergent before collections 10 is filtered on the filter 9.