As a member of the paper packaging family, pulp molded products play an increasingly important role in commodity packaging with the continuous improvement of its production technology, continuous improvement of product performance, continuous expansion of production scale, and continuous expansion of the scope of use.more fully revealed.Pulp molding is a new type of papermaking technology developed on the basis of paper and cardboard production technology.The raw materials, processes and equipment used in the production process of pulp molding products are closely related to the papermaking process.
(1) The production raw materials are basically the same.
Both pulp molding production and paper and board production can use the basic raw materials of papermaking, such as reed Reed, bagasse, wheat straw, bamboo and other herbaceous plant fiber pulp or recycled pulp from waste paper products.The chemical additives used in the production process are basically the same, such as retention aids, drainage aids, wet strength agents, dry strength agents, water repellents, oil repellents, dyes, and brighteners.However, pulp molding has different requirements on the performance of raw materials than papermaking. For example, the raw materials are required to have stiffness after molding, and are not easy to deform.For example, the paper made from bagasse pulp is brittle, which is not a good papermaking raw material, but it is used for pulp molding.Molding is very suitable, and the same situation applies to raw materials such as straw.With the rapid development of the pulp molding industry and the expansion of market demand, raw materials such as straw, bamboo, and bagasse are less used in the paper industry.It will also shine in the pulp molding industry.
(2) The raw material treatment process and equipment are basically the same.
For example, the use of waste paper raw materials to produce cardboard must go through waste paper sorting, hydropulper crushing, beating machine or refiner refining, pulp sizing, pulping and other processes, and then pumped to the paper machine through paper Page forming, press dehydration, drying cylinder drying and other processes become paper products.Pulp molding production uses grass pulp or waste paper raw materials, and also After hydropulper disintegration, beating machine or refiner refining, pulp sizing, pulping and other processes, it is then transported to the paper mold forming machine for forming, extrusion dehydration, drying and shaping, etc., to become qualified pulp. Molded finished product. The raw material handling equipment in the two production processes can even be used in common, but the molding and drying equipment are different.
(3) The molding principle is similar, but the molding form and equipment are completely different.
Pulp molding production and paper and cardboard production are formed by wet forming, and then dehydrated and dried to become finished products.The difference between the pulp molding production process and the traditional paper production process is that the paper or cardboard is “sprayed” (fourdrinier paper machine) or “fished” (rotary net paper machine) at the wet end of the paper machine.Dehydration is formed on the forming net (metal net or plastic net), and the wet paper sheet and the dried finished product are continuous flat strips and rolled into rolls.Pulp molded products are dehydrated and molded in the forming machine on the forming net mold (wire mesh is attached to the mold), and wet paper blanks are mostly intermittent single-piece output, and the finished product is a three-dimensional material or container.
(4) The forming and drying equipment is different.
The paper machine for paper or cardboard is generally a relatively large device that integrates forming and drying.equipment, while the pulp molding machine and dryer can be set up separately and produced individually or in combination.
In summary, it can be considered that pulp molding is a three-dimensional papermaking technology developed on the basis of traditional papermaking technology.With the development of the economy and the advancement of science and technology, this three-dimensional papermaking technology is also gradually developing and improving.