Developing an Automatic Compression Machine with Multi-level Pressing Distance Adjustment for the Formation of Curd from Milk

The objectives of this study were (1) to develop an automatic compression machine with multi-level pressing distance adjustment for the formation of curd from fresh milk, (2) to investigate three critical parameters: pressing distance, pressing time, and curd weight, for their effect on the curd formation to find an optimal parameter setting, and (3) to study the impact of the optimized condition for pressing efficiency of the automatic compression machine. The structural simulation method and software were used to create the data set for the optimization process. In this study, the four-level automatic compression machine prototype was developed, and its pressing distance was controlled by the Arduino board to test and investigate the effect of pressing height, pressing time, and curd weight, for their effect on the efficiency of the curd formation. A structure of the machine was made of food-grade stainless steel. The automatic compression machine could be adjusted for the pressing distance within four levels: 20 mm (level 1 control), 30 mm (level 2 control), 40 mm (level 3 control), and 50 mm (level 4 control) by using 100 W brushless DC motor. In this study, the researchers investigated the efficiency of the curd formation by an optimal parameter setting for the machine with 90 mm diameter of circle molding, the impact of pressing distance (20 mm, 30 mm, 40 mm, and 50 mm), pressing time (10 s, 20 s, and 30 s), and curd weight (200 g, 250 g, 300 g, and 350 g). The results showed the optimal settings for these factors: 48 mm for pressing distance (at level 4 control), 30 s for pressing time, and 350 g for curd weight. Therefore, when compared to the manual curd formation, the machine developed in this study was able to reduce the pressing time by approximately 50 percent.