Design and Development of a Community-Scale Charcoal Briquette Mixing and Compaction Machine Using Quality Function Deployment

Abstract

This research aimed to design and develop a community-scale charcoal briquette mixing and compaction machine using Quality Function Deployment (QFD), to evaluate its performance, and to assess user satisfaction. The machine design was based on the requirements of 20 community charcoal briquette producers. Data were collected through interviews, questionnaires, observation of the existing production process, and House of Quality analysis to translate user requirements into engineering specifications. The prototype consisted of a raw material mixing tank, stirring shaft and blades, power transmission system, material conveying chute, horizontal briquette compaction unit, and supporting frame. Machine performance was tested using three raw materials: chopstick charcoal powder, coconut shell charcoal powder, and briquette made from dried spent coffee grounds. The mixing time was fixed at 5 minutes for all formulations. The results showed that the machine achieved an average production capacity of 45.71 kg/h, an average compaction efficiency of 92.21%, an average coefficient of variation (CV) of the mixture of 5.27%, and an average breakage rate of 5.62%. The coconut shell charcoal briquette had the highest heating value of 5,535.36 cal/g, followed by chopstick charcoal briquette at 5,354.76 cal/g and dried spent coffee grounds briquette at 4,680.91 cal/g. The overall user satisfaction was at the highest level, with a mean score of 4.53 and a standard deviation of 0.51. These findings indicate that the developed machine is suitable for community-scale charcoal briquette production, particularly when coconut shell charcoal powder and chopstick charcoal powder are used as the main raw materials.