Using Quality Function Deployment for the Rubber Sheet Machine Design

The purpose of this research was to improve the process and production process of flat rubber sheets by using the Quality Function Deployment technique (QFD) since the traditional rubber sheet production process is human-intensive causing fatigue and delays. The customer needs were identified by groups of rubber farmers in Sakon Nakhon, Nakhon Phanom, Mukdahan, and Bueng Kan Provinces in Thailand. The house of quality (HoQ) of QFD was then applied to translate the customer needs into design targets. The Theory of Inventive Problem Solving (TRIZ) was applied to minimize conflicts between technical requirements. An experiment was designed to determine the optimum speed and distance between the rolls. The results showed that the optimal motor speed was 400 rpm and the optimal distance between the rollers in rubber sheet extrusion was 3.0 millimeters. The average measurements in terms of width, length, and thickness were 448, 849, and 3.82 millimeters, respectively, which conformed to raw rubber sheets standard 2 with the thickness of the rubber sheet not exceeding 4 millimeters and the weight not exceeding 1,200 grams. The production process was reduced from 19 to 14 steps. The product movement distance was reduced from 16.90 meters to 10.25 meters. The production process was reduced from 263 minutes to 187 minutes for 60 sheets. The developed rubber sheet machine has reduced the production time by 76 minutes for 60 sheets, with a high customer satisfaction level (Mean 4.63, S.D. = 0.49).