Investigation of the effects of mechanical action and temperature on the cleaning activity of detergent ingredients

In this thesis, the cleaning activity of the detergent ingredients playing an active role to remove stains having different cleaning mechanism is examined. In the scope of the experimental design, the effects of mechanical action percentage and temperature with different washing time on cleaning performance are analyzed. At the first section of thesis, history of washing and the aim of this study are mentioned. The second part of thesis involves main theoretic information about washing process. Laundry washing which is one of the fundamental requirements of social life has been carried out by people with different methods throughout history. This process is carried out using advanced technology washing machines and detergents in the modern world. Washing process can be defined as removal of soil and stains from textile surface with several chemical and physical interactions. The main elements of the washing process are water, soil-stains, textile, cleaning equipment and detergent. Water plays an important role as both a solvent and a transport medium. Soil particles which are removed by surfactants are moved into the washing solution by the effect of water flow. Water amount, hardness, conductivity are the factors affecting the cleaning ability of the detergent. Cleaning mechanism of stains are different because stains have different physical and chemical characteristic. Surfactants, bleaching agents and enzymes in the detergent composition are main groups for the removal of different type of stains. For example, oil based stains are removed by surfactants. Tea and coffee stains are bleachable stains. Enzymes help to surfactant to remove stains by cracking big oil, starch and protein molecules. Textiles can be simple classified as natural and synthetic. Natural textiles are cotton and linens, which are based on cellulose. Synthetic textiles are produced by polymer fibers such as polyester and polyamide. Textiles have different color, brightness, strength, water suction and stain interaction characteristic. Washing equipments which are simple classified as front-loader and top-loader are being used in different regions of the world. Washing program parameters such as water amount, mechanical action percentage and temperature should be optimized to achieve the best cleaning performance. xxii Detergent is a chemical mixture of numerous components. Main function of detergent is to remove stains from the textile surface and to keep them inside the washing solution. Laundry detergent composition can be classified as surfactants, builders, bleaching agents and additives. Surfactants and bleaching agents play active roles for cleaning. Builders are the chemicals that are used for enhancing the cleaning performance of detergents by removing water hardness ions and preventing soil redeposition. Additives are other chemicals to improve the result of washing process such as enzymes, foam regulators, optical brighteners and parfumes. The third section of thesis involves literature search for chemical and mechanical actions of washing machines, cleaning mechanisms of different type of detergents, cleaning effects of detergent ingredients such as surfactants, bleaching agents and consumer habits about laundry washing. At the fourth section of thesis, experimental design studies are explained. Experiments are planned to determine the effects of mechanical action percentage, temperature and time on the cleaning performance. 10 different stains are used in order to determine cleaning performance of the main detergents ingredients. There are 5 different stain types sensitive to different detergent ingredients. 2 stains are available for each group which are surfactants, protease enzyme, amylase enzyme, mannanase enzyme and bleaching agent. Level of mechanical action percentage, temperature and time factors are determined as 3, 4 and 7, respectively. Test procedures and test materials such as loads, stains and detergent are prepared carefully to minimize deviation of test results and prevent mistakes during performance tests. Washing machine program parameters are adjusted for performance tests. Spectrophotometer is used to measure tristimulus Y values of stains. Using these data, cleaning performance are calculated. The results are analyzed by Minitab statistic program. Models are determined for each stain type. The best and optimum conditions to achieve the best cleaning performance are determined regarding life time of a washing machine, textile damage and energy consumption. At the fifth section of thesis, test results for each stain are discussed, respectively. According to Minitab analysis of test results; There is not a significant difference between test repetitions for all stains. The best conditions for the stain 1 and 6 that are sensitive to surfactant are 60 °C, %95 and 7; 40 °C, %95 and 7, respectively. Optimum conditions are 50 °C, %50 and 7; 40 °C, %80 and 7, respectively. The best conditions for the stain 2 and 7 that are sensitive to protease enzyme are 60 °C, %95 and 7; 50 °C, %95 and 7, respectively. Optimum conditions are 50 °C, %50 and 7; 50 °C, %80 and 7, respectively. The best conditions for the stain 3 and 8 that are sensitive to amylase enzyme are 50 °C, %95 and 7; 60 °C, %95 and 7, respectively. Optimum conditions are 40 °C, %50 and 7; 50 °C, %50 and 7, respectively. The best conditions for the stain 4 and 9 that are sensitive to mannanase enzyme are 60 °C, %80 and 7; 50 °C, %95 and 7, respectively. Optimum conditions are 50 °C, %80 and 7; 30 °C, %80 and 7, respectively. xxiii The best conditions for the stain 5 and 10 that are sensitive to bleaching agent are 60 °C, %95 and 7; 60 °C, %80 and 7, respectively. Optimum conditions are 60 °C, %50 and 7; 60 °C, %50 and 7, respectively. The mean and standard deviation values of energy consumption for the time of 7 are calculated for each temperature to estimate energy saving potential. At the sixth section of thesis, overall results for each stain group are mentioned. After the obtained information from this study, suggestions are given to understand cleaning mechanism of detergents deeply for future studies. The best cleaning performance values for almost all stains are achieved at the temperature of 50 °C and more, the mechanical action percentage of %95 and the longest time parameter of 7. These are the best values but optimum values are different. The more mechanical action is applied, the less lifetime washing machine components have. When mechanical action percentage and temperature increase, textile damage increases. A significant reduction for cleaning performance is not observed when temperature is decreased from 60 °C and 50 °C. Energy saving rate is calculated as %19,7 when 50 °C temperature is selected instead of 60 °C. The summary of test result is given below. It is determined that time is an important parameter for all stains. The mechanical action of %80 is suggested for the stains which are sensitive to surfactant and enzymes. %50 can be used for the stains which are sensitive to bleaching agent. The most important parameter for the stains, which are sensitive to bleaching agent, is temperature. The effect of temperature on cleaning performance decreases at higher than 40 °C for other stains. For the future studies, the parameters of water amount, detergent amount and textile types can be taken into account to determine effects on cleaning performance. Beside of cleaning performance, textile damage effect can be measured at future studies.