purposes. Uncontrolled disposal of cooking oil waste will cause environmental pollution. Environmental pollution that is not curbed will lead to the destruction of the ecosystem, which also negatively impacts human life. The main purpose of this project is to produce a Mini Soaper Machine model that is capable of mixing and forming bar soap from used cooking oil. The mixing motor speed of the Mini Soaper Machine is set at 150 rpm which is capable of mixing used cooking oil, water and Sodium Hydroxide (NaOH) with a ratio of 3:2:1 in just 10 minutes. The mixed mixture is then transferred through the pipeline into the heater. The heating process of mixed ingredients occurs in two processes, namely cooking and warming. Each has a different temperature which is 100°C and 60°C. The cooking heating process will operate for 1 hour and be kept warm for another 1 hour 30 minutes. After the heating process, this mixture will freeze and form into a soap bar. The study shows that this machine is able to increase the productivity of soap production compared to the traditional method because the process of hardening the mixture using a heater is better than the traditional method. Bar soap products can also be used directly compared to the traditional method which requires 24 hours for the purpose of hardening and needs to go through a curing process for one month before the soap products can be used. The Mini Soaper machine can save as much as 67% of the time compared to using an egg beater and as much as 50% compared to an automatic mixer. The use of this machine can also encourage the practice of recycling used cooking oil
Noor et al. (Mon,) studied this question.