Along with the increase of the industry production and the population’s living standard, there is more and more waste. However, thanks to the awareness of some environmentalists people have recognized that waste can be used as a raw material for industry which less pollutes. At the same time, the raw material is cheaper and less energy is used during processing . With the growth of the population, the amount of waste will rise. But people have the opportunity to avoid further pollution and fully exhaustion of raw material sources. This opportunity is recycling. Among materials that can be again used in order to decrease the consumption of precious resources, to reduce water and energy consumption as well as to reduce air pollution is paper. It can be recycled, which includes collecting, processing and making again usable material. Paper is a product that is composed of interwoven cellulose fibers, but in the paper industry in addition to cellulose, other raw materials also can be used (mainly of mineral origin), depending on what kind of paper has to be made. Paper is the basic raw material in the graphic industry, where various types of paints and finishing are used. Colors are produced on the base of organic compounds (polymerised nylon) or inorganic compounds (metals, nonmetals and their compounds).
Paper can be divided into:
-stationery (office) paper
-other types of paper
Recycling of office and other types of paper is an efficient way of saving forests which represent national wealth for each country. In the process of recycling paper is first required to be separated from other waste,
then sorted by quality. Office paper then goes on flotation, in which the colours are removed from paper fibers.
Waste paper passes through several of stages. Types of devices and the order in which they are used depends on the quality of waste paper, on the kinds of unwanted impurities and on the required quality of the final product.
Generally, paper recycling can be described through the following phases:
1. Collecting waste paper through the use of special containers for paper.
2. If paper is not possible to sort out in the stage of collecting waste in containers, then it is separated from other waste in centers for waste sorting. The collected paper is sorted by quality and pressed into bales.
3. Sorted bales of paper are carried to a recycling center of paper.
4. The quality of waste paper is assessed in the center of recycling in order to determine the price.
5. Residual, large pieces of waste, such as plastic, wood, metal, textile an so on are separated from paper.
6. The paper is chopped (in cylindrical crusher), then water is added and pulp is created.
7. The process of cleansing from fine particles of residual waste, such as plastics, rubber bands, glue, latex, and other
impurities is continued.
8. Flotation. One of the biggest challenges in paper recycling is removal of harmful impurities. Some of the most problematic detrimental contamination are polymer inks and coatings. Toner used in laser and xerographic copy machines are attached through heat with the surface of the printed page. These are nylon-based polymers that can not be easily separated from the paper fiber. It is unfavorable, because office paper is produced from previously strongly bleached paper pulp. During flotation fatty acids are used as collectors. With removing paint from paper fibers, raw material is practically ready for further treatment at a paper factory.
9. Depending on your needs, additional washing of paper fibers is sometimes necessary to remove fillers and coatings.
10. Stage of bleaching and other operations that follow in a paper factory.