Soap and Detergent Operation

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SOAP AND DETERGENT OPERATION

LITERATURE REVIEW

Detergent is a material used to assist cleaning. The term ‘detergent’ is sometimes intended to differentiate between the soap and other surfactants used for cleaning. Surfactant is an abbreviation for surface active agent, which literally means active at surface (Jonsson , 1998). The function of these surfactants is to break down the interface between water and oils or dirt. The surfactants are classified based on the head part charge (hydrophilic group). They are anionic, nonionic, cationic and amphoteric. This project, the preparation of dishwashing liquid detergent used a different raw materials that are mostly based on different kinds of surfactants. The quality of dishwashing liquid detergent was defined in qualitative (foaming condition, appearance, cleaning performance) and quantitative (pH, viscosity, specific gravity). The surfactants used in this project are linear alkyl benzene sulfonates (LABSA), sodium xylene sulfonate (SXS), sodium carbonate, sodium lauryl ether sulphate (SLES), Coconut diethanolamide (CDE)

Sodium carbonate is a white, odorless powder, has an alkaline taste, and forms a strongly alkaline water solution. It is also known as, soda ash (Na2CO3), the water-soluble sodium salt. The purpose of sodium carbonate in detergent is as a stabilizer for the pH (for neutralization). Coconut diethanolamide (CDE) is prepared by reacting the mixture of fatty acids from coconut oils with diethanolamine. It is a viscous yellowish liquid and used as a foaming agent. CDE act as foam boasting and foam stabilizer to other surfactant system (SALAGER, 2002). 

Sodium Xylene Sulfonate (SXS) in a detergent acts as a wetting agent that helps a formula spread more easily and ensures efficient cleansing. It is a solid and white powdery crystal.  It is classified as a hydrotropic, or an organic compound that increases the ability of water to dissolve other molecules (SALAGER, 2002). SLES is a white to yellowish paste, odorous and an anionic surfactant. SLES is an inexpensive and very effective foaming agent (SALAGER, 2002). In addition, the function of SLES is to reduce the surface tension and separate molecules in order to allow better interaction between the detergent and dirt.

 LABSA is liquid, brown, clear and non-volatile compound produced by sulfonation. An alkyl benzene sulfonate can be produced from natural oil and fat origin at a low cost by sulfonation and neutralization, which is much lower than soap (SALAGER, 2002). The LABSA in detergent acts as a main active matter, emulsifier and coupling agent. It has a good decontamination and foaming property, and it is stable in acidic, alkali and some oxide solution (SALAGER, 2002) (Bayly, 2008) . CMC is a chemical compound derived from cellulose. It is a hydrophilic white powder in pure form and dissolves in cold (but not in hot) water, forming a clear viscous solution or gel. The uses of CMC in detergent is as a thicken agent (Agarwal, 2012) . It makes a washing liquid more viscous and the effect of washing more stable. It also acts as anti-re-deposition agent that prevents the dirt from settling back to the plate during washing process.

In conclusion, the recommended product for this project based on the aforementioned raw materials includes the following formula: Sodium carbonate (9.0 g), SLES (15.0 g), LABSA (40.0 g), CMC (9.0 g) and CDE (3.0 g).

INTRODUCTION

The UMP Green Technology Sdn Bhd (UMPGT) is wholly owned by the Universiti Malaysia Pahang (UMP) and was registered in April 2010. It is a spin-off technology based company originated from two technology-funded projects entitled ‘Recycling of Base oil from Spent Lubricant’ and ‘Ultrasonic Solvent Extraction of Oil from Spent Adsorbents’ and headed by Prof Dato’ Dr. Rosli Bin Mohd Yunus. The company strives to continuously upgrade its pool of management and engineering professionals, in line with its nation-building objective of optimizing ‘Waste to Wealth’. The current project that was conducted in this company is the manufacturing of soap and detergent. The main product is the dishwashing liquid detergent (premium grade). Currently, the company has already developed a range of formulations for this product based on the packaging size.

The raw materials used in the preparation of dishwashing liquid detergent are mostly based on different kinds of surfactants. The function of these surfactants is to break down the interface between water and oils or dirt. In addition, it also holds and removes these oils and dirt in suspension until it can be rinsed away. The surfactants are able to act in this way because of their molecular structure that contains a hydrophilic and hydrophobic group. The hydrophilic group (water loving) is a head part that usually dissolves in water. The hydrophobic group (water hating) is a tail part that dissolves in oil or dirt.

Generally, water has a property called surface tension. Surface tension causes the water to bead up on surface (crockery), which reduces the wetting of the surface and inhibits the cleaning process. In the cleaning process, the surface tension must be reduced so water can spread and wet the surfaces thus will enhance the cleaning process. In order to reduce the surface tension of water, a surfactant in a detergent is a must.

In cleaning process, the hydrophilic part of surfactant is attracted to the water molecules while the hydrophobic part is repelled by water but was attracted to the oil. These opposing forces loosen the oil and suspend it in the water. The surfactant molecules remain surrounding the oil when they are removed, preventing them to re-deposition onto the cleaned surface.

The surfactants are classified based on the head part charge (hydrophilic group). They are anionic, nonionic, cationic and amphoteric. In anionic surfactant the hydrophilic group is negatively charged. It is widely used in detergent because of the low cost compared to others. These surfactants are also excellent foaming and wetting agent.  The examples of anionic surfactants are linear alkyl benzene sulfonates (LABSA), sodium xylene sulfonate (SXS), sodium carbonate and sodium lauryl ether sulphate (SLES).

The nonionic surfactant has no charge on their hydrophilic part, which make it a superior oil emulsifier. It is often used together with anionic surfactant. The advantage is that the nonionic surfactant does not interact with calcium and magnesium ions in hard water thus make it more efficient in removing oily and organic dirt than anionic surfactant. Although they do not contain the ionic group, but they have a presence number of oxygen atoms in one part of the molecule which are capable to form hydrogen bonds with water molecules. Some nonionic surfactants are high foaming agent (like anionic) but they are in form of thick liquid or syrup (unlike anionic). The example of nonionic surfactant is coconut diethanolamide (CDE).