In the early years, molded pulp products generally used waste paper as the base material, and used special equipment and molds to perform three-dimensional modeling through a unique process to produce packaging products and objects of various shapes. Molded pulp products start from being applied to transportation packages of agricultural and sideline products such as eggs and fruits, and gradually expand the scope of application research. At present, high-quality molded pulp products using reeds, straw husks, sugarcane, wheat straw, bamboo, wood, etc. as raw materials are also more and more widely used. There are protective packaging for industrial products, such as: electronic products, household appliances, meters, glass ceramics products, and small machinery. There are also retail packaging of high-quality paper and plastic products in the consumer durable category.
Reeds, straw husks, sugarcane, wheat straw, bamboo, wood, recycled paper are used as raw materials, through pulping, refining and other processes to turn them into fibers, which are suspended in water to form a puree. According to the characteristics of the final product, in the process of pulping process, you can control the length of the original pulp fiber, the concentration of the original pulp. With a series of auxiliary operations such as adding functional additives (brightening agents, waterproofing agents, etc.), dyes, the pulp meeting the production requirements can be finally formed.
2. Molding process
The molding process of molded pulp products is mainly through a series of methods such as vacuum molding method and grouting molding method, so that the raw pulp fiber is molded into the shape designed by the mold; the vacuum molding method is the most commonly used and most efficient method.
3. Drying process
The drying process is mainly that the dryer uses fuel, oil, gas, electricity or steam, heat transfer oil or other media as the heat source, heats the air, and dries the molded pulp molded products in hot air, and uses a fan to draw out the moisture that the products evaporate, to achieve the effect of rapid drying.
4. Shaping and trimming process
After the pulp product is shaped and dried, it has been basically shaped, and then the heating plate is heated by electric heating or other heating medium (such as heat transfer oil) to make the pulp product mold have a higher temperature (150~250℃). And then with air pressure or hydraulic pressure, press the paper support product under high temperature and high pressure, make it neat and beautiful, achieve better toughness, and have better shock resistance.
The final products produced through a series of processes are inspected, packaged, and stored. According to the characteristics of different products, manual packing or automatic packing machine can be used for counting and packing.