Okka Adiyanto
@ie.uad.ac.id
Industrial Engineering
Universitas Ahmad Dahlan
RESEARCH INTERESTS
Product Design, Ergonomic, Tribology, Material
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Muhammad Faishal, Effendi Mohamad, Hayati Mukti Asih, Azrul Azwan Abdul Rahman, Astaman Zul Ibrahim, and Okka Adiyanto
Malque Publishing
Lean Six Sigma is a systematic and scientific operations management methodology aimed to improve the performance of their manufacturing processes through the elimination of waste. The objective of this paper is to analyses the problem of increasing demand of briquettes in BriqCo (Briquettes Coconut shell Charcoal) company. in this case, the company has a waste problem due to defective products amounting to 10.2% of the total production of 169.298 kg. The high defects cause the company to suffer losses profits due to the re-production process of defects and a decrease in selling because the unsuitable quality. This study uses the Lean Six Sigma – Define, Measure, Analyze, Improve, Control (DMAIC) method. The define stages use the SIPOC diagram to determine the elements involved in the production process and Value Stream Mapping. Measure stages to determine the level of sigma based on production results. The analyze uses a fishbone diagram to determine the root cause problems. In improve, the application of the 5S Method and Standard Operating Procedures (SOP) proposed for a work improvement process that aims to improve the production process. In Control stage, the application of new SOP conducted to improve the production process in order to reduce defects. Based on the results, the initial sigma level reached 3.19. The causes of defects in briquette products consist of human, material, machine, method and environmental factors. With the application of 5S through SOP, it is expected that the level of disability will decrease by 50%.
Okka Adiyanto, Effendi Mohamad, Irianto, Rosidah Jaafar, Muhammad Faishal, and Muhammad Izzudin Rasyid
MDPI AG
Brick is a common building material that is used in society for constructing buildings. A viable environmental strategy to lessen the amount of plastic waste involves the inclusion of plastic trash in building materials. Globally, there is a severe issue with the disposal of plastic garbage in landfills. The primary and secondary carbon bonds that are formed in plastic packaging wastes can severely contaminate the environment. Hence, managing plastic waste to generate new and useful items is essential. One of the most practical ways to safeguard the environment is to manufacture eco-bricks from PET waste and epoxy resin. Additionally, as there is no combustion involved in the production of this eco-brick; it does not harm the environment. Eco-brick can be defined as a novel concept and approach to waste management and recycling. Eco-bricks have many advantages, such as easy availability and being environmentally friendly. This study aimed to improve the composition of the eco-brick using a mixture of epoxy resin and PET particles. In this study, a mathematical modelling technique called the Response Surface Method (RSM) was designed using the Central Composite Design (CCD). Variable input factors were used to develop eco-bricks such as mixture ratio (10–90%), particle size (1–5 mm), and drying time (1–7 days), whereas the variable response included the compressive strength. The complete experimental design was developed using Design Expert 11 software, and simulation experiments with 17 sets of parameters were generated. The microstructural characteristics of the eco-brick were examined using SEM. The results of the experiments indicated that the most optimised parameters that could be used for eco-brick application were: a PET particle size of 1.1 mm, a mixing ratio of 89.9%, and a curing time of 6.9 days. Earlier research that was conducted regarding the production of eco-bricks using a PET particle and epoxy resin mixture showed that these materials had a high potential to boost compressive strength. The quadratic model was used as the basis for the regression analysis for generating the response equations. Since the difference between the experimental and anticipated values was less than 5%, it was concluded that the results of the experimental and predictive tests showed good agreement. The model used in this study yielded noteworthy outcomes. As a result, the suggested statistical model can offer a clear understanding of designing experiments and variables that affect the production of eco-brick using a blend of PET particles and epoxy resin.
Okka Adiyanto, Effendi Mohamad, Rosidah Jaafar, and Muhammad Faishal
Nepal Journals Online (JOL)
Introduction: Plastic waste is considered one of the common vital waste problems in developing countries such as Indonesia. One proposed alternative way to reduce plastic waste is by reusing and recycling it into bricks. Eco-bricks are a form of recycled plastic waste that can be used as an alternative building construction material. Unfortunately, manufacturing workers do not ergonomically perform this work during their working hours. Therefore, it causes inappropriate body postures and leads to musculoskeletal disorders easily. This study intends to identify the posture of workers in the manufacture of eco-bricks in Indonesia Methods: A cross-sectional study was done with purposively selected 32 eco-bricks workers from 10 waste bank communities in Central Java and Yogyakarta. Sampling was done by snowball method. This research was conducted by interviewing and collecting data on body complaints using a Nordic Body Map (NBM) questionnaire. Results: All respondents (100%) experienced musculoskeletal disorder complaints while producing eco-bricks. Based on the results gained from the Nordic Body Map Questionnaire, the common complaints perceived by eco-bricks workers are upper neck, lower neck, back, waist, buttock, and bottom. In addition, workers also perceived complaints on the right side of the body, particularly the right shoulder, right upper arm, right elbow, right lower arm, right wrist, and right hand Conclusion: Working postures that are not well-organized in terms of ergonomics during the production process of eco-bricks will provoke complaints on the limbs caused by the continuous load on the muscles on the right side of the body.
Okka Adiyanto, Pandu Sandi Pratama, and Wonsik Choi
Emerald
Purpose This paper aims to examine the friction coefficient and wear rate characteristics of SCM 440 bearing steel used in the cylinder block of a tractor engine with gas lubrication and oil lubrication. Design/methodology/approach Friction tests were performed using a pin-on-disc tester with loads of 2 to 10 N and sliding velocities of 0.06 to 0.34 m/s. The experiment was done with and without nitrogen, and paraffin oil lubricant was used to prevent wear during process. Findings The nondimensional characteristic number from the Stribeck curves indicated that the lubrication regime is hydrodynamic. As the velocity and load increased, the friction coefficient of the SCM 440 increased and greater applied load resulted in a smaller friction coefficient. The range of the friction coefficient was 0.017001 to 0.092904 with paraffin oil lubrication and 0.01614 to 0.4555 with nitrogen lubrication. Nitrogen is effective in reducing the friction coefficient of materials that are in contact and subjected to a load and velocity. Originality/value The experiments confirm that nitrogen is effective for reducing the friction coefficient of SCM 440 materials that are in contact with each other and subjected to a load and velocity.