Using hydraulic pressing techniques with appropriate heating levels, a group of Da Nang students successfully created a machine to shape dishes from areca leaves, with a capacity of 60 products per hour.
The product was made by Le Van Tuan, Dang Huu Tai, Mai Xuan Son, Phan Tan Sang, Ho Van Ly, students of the mechanical department, University of Technical Education – University of Da Nang.
Le Van Tuan, group leader, said that the group wants to create cups and plates from nature, replacing those made of disposable foam, which affect human health and pollute the environment. Therefore, the materials chosen are areca leaves, bamboo shoots, coconut fiber shells, and leaves that are abundant in nature and have high cellulose content, so when pressed into shape, they have high durability and usability.
During four months, the group of students designed, processed and manufactured the press. The machine has a rectangular shape made of steel pipes joined together, 1.2 m high, nearly 70 cm wide, and weighs about 150 kg.
The machine has a hydraulic cylinder piston press, a mold to shape dishes, controls and a cleaning system… When you press the button on the control panel, the heating system begins to operate to increase the temperature. into the mold at about 120 – 180 degrees Celsius for 60 – 90 seconds. When putting raw materials into the injection mold, the user presses the button on the control panel to power the hydraulic machine. The piston performs the journey of pressing and shaping the product and then returns it to the cylinder, ending the process.
Introducing the operating principle of the group’s dish making machine from areca leaves. Video: NVCC
Before being pressed, the areca wood is cleaned with high-pressure compressed air to blow dirt out, increasing the cleanliness of the material surface. After successfully shaping, the dishes are cleaned with UV light in the machine’s tray. During operation, when there is an emergency, the user will press the button to turn off the power and the parts will stop working.
The team’s testing showed that in one press, depending on the heating time for different materials, the machine productivity is different. With areca leaves and bamboo shoots, pressing time for one minute produces one product, meaning the machine can create 60 products in one hour. With all kinds of leaves, the pressing time per hour is about 120 products. For each different material, the appropriate temperature will be adjusted to create the best product quality.
The disc is pressed from areca leaves, leaves such as banana leaves, lotus leaves, and almond leaves of the group. Image: NVCC
After being shaped, the dishes and dishes can be used to hold fast foods such as sticky rice, sausages, cakes, fruit pickles… According to Tuan, with ingredients such as areca leaves and bamboo shoots with a cellulose fiber structure With a strong connection, it can completely contain liquid foods without damaging the surface of dishes. The group does not use any additives or adhesives in the process of shaping dishes. The reason is that if additives are used when pressing the heating time at high temperatures, it will cause chemical reactions that create toxic substances that affect human health when using the product.
“In the coming time, the group will combine teachers from the chemistry department to research natural bio-glue products that are friendly to human health to create adhesion and shine for products with beautiful, quality designs that are suitable for everyone. more user tastes,” Tuan said. The team also set a goal to improve the mold to create more material shapes and more diverse types of pressing materials. This is the basis for the group to introduce the machine to businesses and farmers producing disposable plastic products.
3D design of the machine. Image: NVCC
Dr. Bui He Thong, Lecturer in the Department of Mechanical Engineering, University of Technical Education – University of Da Nang, assessed that the group’s products have great potential for practical application in the direction of green economic development. However, he said that the machine’s capacity is currently quite low, and the mechanical system is not highly complete. Therefore, the group needs to research increasing engine capacity, improving the pressing system and molds to diversify product types.