Take you to understand the characteristics of pulp molding

2022-09-24 16:56:32

Take you to understand the characteristics of pulp molding

Pulp molding is a three-dimensional papermaking technology. It uses waste paper as raw material, and uses special molds on a molding machine to form paper products with a certain shape. Pulp molding has four advantages: the raw material is waste paper, including cardboard, waste Box paper, waste white edge paper, etc. come from a wide range of sources; the manufacturing process is completed by pulping, adsorption molding, drying and shaping, which is harmless to the environment. It can be recycled; its volume is smaller than that of foamed plastic, it can be stacked, and it is convenient to transport. Pulp molding, in addition to being used as lunch boxes and tableware, is more used as industrial buffer packaging, and it is developing rapidly.

What are the characteristics of pulp molding? Let's take a brief look at it together.

Including egg boxes, egg trays, fruit trays, flower pots, disposable medical bedpans, etc. It uses waste paper as raw material, adds some moisture-proofing agent (aluminum sulfate) or waterproofing agent, and then makes various shapes according to different purposes. product. Used as packing liner for eggs, fruits, precision instruments, fragile glass, ceramic products, handicrafts, etc. Pulp molding has good cushioning and protective properties. Pulp molding technology and equipment have developed rapidly, and the basic processes are pulping, molding, drying and shaping. In China, it is mainly semi-automatic equipment, while in foreign countries, it is almost all fully automatic and high-energy-consumption assembly lines.

What is the molding process of pulp molding products? There are two kinds of pulp molding equipment: vacuum forming method and injection molding method.

1. Vacuum suction forming method. This is a popular method for paper and plastic products. Depending on the structure, there are three ways: drum type, flip type, and reciprocating lift type.

Rotary drum type: continuous rotary production, high production efficiency, large mold investment, high mold processing accuracy, high technical requirements for equipment processing accuracy, one set of concave dies and eight sets of punch dies, requiring CNC center to process molds, long processing cycle, large investment . Because it is continuous production, it is suitable for mass production of molded products, such as plates, dinner plates, wine trays, egg trays, etc. For industrial molding production, it is not applicable due to non-standard, small quantity and batch, and large mold investment.

Rotation type: Rotary production is less efficient than drum production, suitable for medium batch and non-standard production of industrial molding. However, because it is a set of concave dies and two sets of punch dies, a CNC center is required to process the dies, which requires a large investment and a long cycle.

Lifting type to the rice: The production efficiency is lower than that of the drum type, and it is not much different from the reverse rotation type. It is the equipment commonly used in normal wind at present.

This equipment only needs a set of concave molds and a set of punches, and does not require CNC center processing. It is especially suitable for non-standard, small batch, and fast-cycle industrial packaging products (the production cycle of industrial packaging products molds is usually within 10 days).

2. Grouting method. The injection molding method is to calculate the required amount of pulp (material) according to different pulp packaging products, and quantitatively inject it into the molding cavity for adsorption molding. This molding method is suitable for standard products with little change and stereotypes. It is often used in tableware molding For products, this molding method is not used for non-standard paper-plastic packaging (industrial packaging) due to the difficulty of mastering the calculation of stereotypes.