Stone paper is also called environmentally friendly paper. It uses calcium carbonate, the most abundant mineral resource in the earth’s crust, as its main raw material. It uses polymer materials and a variety of inorganic substances as auxiliary raw materials. It uses polymer interface chemistry and filling modification technology. A new type of recyclable paper with modern technical characteristics. At the 2010 National “Two Sessions”, the meeting notices, schedules, sticky notes and other materials used by the delegates and members of the meeting were all stone paper. This technology is not new, but in the context of the global call for energy saving and emission reduction, this "fashionable" environmental protection concept has been valued again by people.
Stone paper has many advantages:
1. Energy saving and environmental protection of production technology
According to statistics, traditional papermaking technology uses 3.7 tons of wood chips to produce 1 ton of paper, which is equivalent to cutting 20 large trees with a growth period of 20-40 years. At the same time, it uses 200 tons of fresh water, consumes 1.8 tons of standard coal, and consumes 600 kilowatts of electricity. At the same time, a large amount of waste water and more than 300 types of hazardous waste gas have been identified. The stone paper breaks through the papermaking technology that has been used for more than 2000 years with wood pulp and straw pulp as raw materials. The production technology is energy-saving and environmentally friendly. The production process does not require water, acid and alkali, bleaching, and no waste gas, waste water or other harmful waste. The unit energy consumption is only 2/3 of the traditional papermaking technology.
2. Superior performance
(1) Superior physical properties. The physical properties of stone paper, such as tensile strength, tearing resistance, bursting resistance and folding resistance, are larger than those of plant fiber paper. The surface is not easy to fluff, it is durable and has stable dimensions.
(2) Outstanding chemical performance. Stone paper has good antibacterial and insect resistance, outstanding water resistance, oil resistance and chemical resistance, and is not easy to change color.
(3) Good safety performance. The main raw material of stone paper is calcium carbonate and other inorganic substances. The resin and various additives are also non-toxic and have no adverse effects on the objects in contact. At the same time, stone paper does not absorb water, and it is difficult for molds to adhere to the surface of the paper, and the disposal of waste paper is also safe and will not cause soil pollution.
(4) Good printability. ①Stone paper is to coat nano-scale stone powder slurry mixed with a small amount of auxiliary materials on the substrate. After molding, many tiny particles make the surface of the paper have countless small holes, which promotes the adhesion of pigments more firmly, and is used in various types of inkjet printers. It will not be corroded during the printing process, and it is well waterproof and oil-proof. ②Because stone paper is not made of wood fiber, the paper surface is flat and smooth, and there is no ink halo phenomenon. Therefore, compared with traditional plant fiber paper, stone paper saves more ink or pigment in printing under the same conditions, and has higher definition. ③The calcium carbonate on the surface of the stone paper will not chemically react with the ink, which avoids the occurrence of color cast and decolorization of the printed product.
It can be seen that the emergence of stone paper not only guarantees high-definition, high-precision printing quality, but also brings about the "devaluation" of the printing accuracy of traditional plant fiber paper. In addition, because most pigments contain a large amount of heavy metals and toxic organics, the reduction of printing pigments not only saves resources and reduces costs, but also reduces environmental pollution caused by the production, use, recycling and processing of printed materials.
3. Wide range of uses
Stone paper has a wide range of applications due to its excellent performance. Excellent water resistance makes it especially suitable for outdoor advertising. Because it does not produce dust and does not shed hair, it can be used in clean rooms. Table 2 shows the scope of application of stone paper.