- Categories:Stone plastic paper technology
- Time of issue:2020-07-31 00:00:00
Inorganic fillers (calcium carbonate, talc, wollastonite, titanium dioxide, etc.) in synthetic paper account for about 60% to 80% of the total mass of synthetic paper. According to different uses of synthetic paper, resins such as PP and PE and various chemicals are added. Additives are produced into special master batches through blending, modification and extrusion processes.
At present, synthetic paper at home and abroad is mainly divided into calendering method, casting method, blown film method, biaxial stretching method and non-woven paper method. According to the structure and use requirements, it is divided into single-layer synthetic paper, three-layer synthetic paper, and five-layer Synthetic paper and multilayer synthetic paper, etc.
1. Synthetic paper-calendering production method
Calendering process: dosing, blending, banburying, extrusion to produce special masterbatch, and then through extrusion, calendering, stretching, cooling, surface treatment, slitting, coating, it is synthetic paper. Some of this technological process adopts special masterbatch and calendering segmented production, and some foreign advanced production equipment also adopts continuous one-shot molding process.
The calendering method has high production efficiency, good product quality and smooth paper surface. It is suitable for printing high-end picture albums and book covers. Its disadvantages are that the process is complex, the product proportion is relatively large, and the equipment is relatively expensive.
2. Synthetic paper-casting production method
The production process of the casting method is basically similar to the calendaring method. The characteristic of the casting method is that there is a certain speed difference between the extrusion speed of the die and the rotation of the casting roll, and a stretch is formed between the meniscus extruded by the die and the cooling roll. According to different product requirements, the synthetic paper The thickness can be adjusted. Many products use PP as the matrix resin, which has the advantages of good rigidity, high toughness, and good tensile strength. Due to the production process, the molecular structure distribution of the product is unidirectional, and the longitudinal and transverse physical properties of synthetic paper have certain differences.
Polypropylene resin is used to produce shopping bags, packaging boxes, airplanes and food packaging boxes for shopping malls, with exquisite appearance and natural degradation.
3. Synthetic paper-blowing film production method
The base material used in the production of synthetic paper by the blown film method is mostly PE, mainly three-layer co-extrusion blow molding, and some use single-layer, five-layer, and multi-layer production processes. According to the product use, the inside and outside of the synthetic paper The resin content of the layer is appropriately increased, and the inorganic powder content of the inner layer is large, and the materials used for each layer are different. The vertical and horizontal stretching of the product can be adjusted within a certain range, so that the thickness of the synthetic paper product is uniform and the physical properties are stable.
This process is characterized by high output, simple process, uniform product thickness, and small equipment investment. However, due to the high resin content, the width of the paper is limited.
The film blowing method is divided into up blowing method and down blowing method:
4. Synthetic paper-uniaxial stretching production method
The uniaxial stretching method adopts an extrusion process similar to calendering and casting, and is equipped with a unidirectional stretching system. After longitudinal stretching, the resin molecular chains are uniformly distributed, and the longitudinal physical properties of synthetic paper are basically similar. In the process of uniaxial stretching, due to the difference in material properties and interface compatibility between synthetic resin and inorganic powder, small gaps that are difficult to observe will occur, commonly known as "sea island phenomenon". These phenomena can reduce the specific gravity and production cost of synthetic paper, and also significantly improve the physical properties, appearance, colorability, and moisture absorption of synthetic paper. Especially after stretching, a certain pearlescent effect will be formed, which makes paper printing have a gorgeous and exquisite effect, which is suitable for advertising inkjet and exquisite picture albums. The uniaxial stretching process equipment is complicated, the investment is large, and the production technology is superb. It will be restricted by various factors in the initial stage of popularization and promotion of synthetic paper. However, with excellent product performance, low production cost, and wide range of uses, this process will be the development direction of synthetic paper and is also an advanced processing technology currently applied internationally.
5. Synthetic paper-non-woven paper production method
DuPont of the United States applies its non-woven fabric production process to the synthetic paper production process, using mainly polypropylene as the base material to produce "non-woven synthetic paper." After the raw and auxiliary materials are melted, extremely fine thread-like fibers are extruded and rolled into non-woven synthetic paper.
The product has the characteristics of paper, light specific gravity, strong permeability, good physical and mechanical properties, high color strength, and low product deformation. This product can be widely used in furniture decoration, product packaging, interior decoration wallpaper, etc. However, this process has high production costs and complex processing equipment.
At present, many domestic manufacturers are trying to produce synthetic paper, and many companies have also carried out various innovative researches on raw materials, equipment, processes, etc., such as: heavy/light calcium blending, PP/PE compounding, blending/extrusion One-step production process and so on.
To learn more about the production technology and equipment of the "Synthetic Paper/Stone Paper" project, Nanjing Juli Chemical Machinery Co., Ltd. welcomes you to call, write to us or visit our company to discuss and exchange information on the production technology of "Synthetic Paper/Stone Paper". Equipment matters!
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