With the continuous progress of its production technology, the continuous improvement of product performance, the continuous expansion of production scale, the continuous expansion of the scope of use, molded pulp products, as a member of the paper packaging products family, play an important role in the commodity packaging more and more fully displayed. Pulp molding is a new paper-making technology developed on the basis of the paper and cardboard production process. The raw materials, technology and equipment used in the production process of molded pulp products are closely related to the production process of papermaking.
(1) Raw material processing technology and equipment are basically the same. For example, using waste paper raw material to produce paperboard, waste paper sorting, water pulp shredding, pulp beater or grinder grinding, pulp sizing, mixing and other processes, and then pump to the paper copying machine through the paper industry molding, press dehydration, drying and other processes into paper products. The paper pulp molding production uses grass pulp or waste paper raw materials, but also through the hydraulic pulp shredder, pulp beater or grinder grinding pulp, pulp sizing, blending and other processes, and then transported to the paper film molding machine for molding, extrusion dehydration, drying and shaping process, become qualified molded pulp products. The raw material processing equipment in the two production processes can even be common, except for the molding and drying equipment.
(2) The forming principle is similar, but the form of forming and equipment is completely different. Molded pulp production and paper and board production are formed by wet forming method, and then dehydrated and dried into finished products. Pulp molding production process and the traditional paper production process without the point is: paper or paperboard is in writing machine wet ministry of pulp “into” (long net paper machine), or “to” (mould machine) forming network (metal mesh or plastic mesh) on dehydration, dry wet sheet and finished product are continuous flat ribbon, and rolled into the drum shape form, as shown in figure 1-1; The paper pulp molding products are dehydrated and formed on the forming mesh mold (metal mesh is attached to the mold) “picked up” in the molding machine. The wet paper billet is mostly intermittent single output, and the finished product is a three-dimensional material or container, as shown in Figure 1-2.
(3) Forming drying equipment is different. Paper or cardboard paper machine is generally relatively large, forming and drying into one of the equipment. And pulp molding machine and dryer can be set up separately, alone or in combination for production.
To sum up, it can be considered that pulp molding is a three-dimensional papermaking technology developed on the basis of the traditional papermaking process, with the development of the economy and scientific progress. This kind of three-dimensional paper-making technology is also developing and perfected step by step.