The development of the rich mineral paper industry has been disputed. On the one hand, its main components are Calcium Carbonate, Titanium dioxide and Talcum powder. These inorganic powders are widely distributed and can be recycled and free from the dependence of paper on wood resources. It has reduced the consumption of forest resources and water resources in the traditional papermaking process. On the other hand, the inorganic mineral powder needs a large amount of synthetic resin as a connecting carrier to form a flexible sheet. The substance is a highly filled modified plastic material. The disposal of chemicals in the production process and the final waste department will cause some damage to the environment. It is also true that although rich mineral paper had appeared in the 60s of last century, it was not applied to some products until 80s. The cost is high due to the addition of the dosage of resin. Meanwhile, compared with the traditional fiber paper, it has many disadvantages such as high density, poor stiffness and poor handwriting, so it has not been well developed.
In the 21st century, the research project of rich mineral paper has been strongly supported by the state. The production technology has been greatly improved, the quality of the products is further improved, the amount of the inorganic stone powder is increased to more than 80%, and the application of the degradable resin makes the final product waste completely degraded. The whole production process basically achieves no "three wastes" emissions, which conforms to the concept of low breaking, energy saving and sustainable development. As a kind of environmental protection product that can replace fiber paper, rich mineral paper has attracted more and more attention and recognition. The following introduces the new progress of the technology through the newly published rich mineral paper patent in China.
The patent application under the notice number cN202742735 introduces a kind of food-grade rich mineral paper, which is composed of two layers of material. The first layer is made of 80% calcium carbonate (food grade calcium carbonate powders over 1,250 meshes), 15% high density polyethylene and 5% composite modifiers (including toughening agents and compatibilizers). The second layer is low density polyethylene compounded on the first layer. The first layer of material is used as packaging paper to directly contact the product, which can be used not only for packaging candy and cooked food, but also for packaging milk and vegetable juice.
The invention patent application with the publication number cN102205550A introduces a kind of stone corrugated paper board. The stone paper surface and the stone paper core are combined with high temperature hot melt instantly and then pass through the high temperature preheating roller, so that the adhesive surface reaches the molten state, and then under the pressure of the composite roller compound into corrugated paper board. Compared with the traditional corrugated paper board, the stone corrugated paper board can be used in the environment with high humidity for a long time and has good anti-puncture performance.
For example, rich mineral paper products with the public number cn102678900a. Its components include: superfine CaC03 with 55 ~ 70, 10~20 parts of biodegradant with, polypropylene 10~25, 5~7 parts of maleic anhydride graft polyethylene material, 10 parts of low molecular weight hydrocarbon, 9 parts of thermal oxidation accelerator, 2 parts of epoxy soybean oil, 0.1 parts of catalyst. After 6-9 months in the natural environment, the product can be completely degraded into basic strength free fragments and even pulverized wood, which meets the standard of the national GB/T 93451988 " definition mark and degradation performance requirements of degradable plastics".