History of DOANYS

Paper and its History

The Symbol of Recycling

Recycling in Greece

Paper Processing - Recycling

Waste Paper Merchants

Benefits of Recycling

Contact

PAPER PROCESSING - RECYCLING

The natural resources of timber used for pulpwood come from coniferous trees such as spruce, pine, fir, larch, hemlock, and from deciduous trees such as eucalyptus, aspen and birch.
Paper undergoes a specific processing depending on the intended use. In newsprint (newspapers, magazines), which is produced in a way that combines functionality and economy, mechanical paper pulp is mainly used, as it is intended for transient use and no high resistance to particular conditions is required (humidity, extreme temperatures, mechanical strain, radiation, etc.).
On the other hand, paper used for writing is made with higher specifications with regard to its resistance in time and ambient conditions, and chemical paper pulp is used for this purpose.
The mechanical paper pulp is produced by mechanical grinding and shredding of wood. The fibers are released with the greatest possible yield in paper pulp and low loss of components (some water-soluble extractable components). Yield ranges from 90 to 98%.
The chemical paper pulp is produced by chemical grinding of the fibers, i.e. a combination of woodchips and chemicals in large containers known as digesters, where heat and chemicals break the lignin that holds together the cellulose fibers, but without decompositing them. Yield is considerably reduced because of this process, ranging from 40 to 60%.
It is usually used for materials that must have resistance or, in combination with mechanical pulp, it gives the product different characteristics.
Greater consumption of trees (wood) is required for the manufacture of an equal quantity of paper by chemical paper pulp (printing paper) in relation with the mechanical one. Chemical paper pulp is about 72% of the paper pulp produced from tree wood.
Each of these techniques has different advantages. For this reason, in many cases a combination of these processes is applied in order to produce the best possible products.
In this case, the methodology and processing conditions of the paper pulp are similar to those of the individual processes, but the conditions are milder.
The most common procedures for recycling paper are:

• grinding of old paper.

• a process which combines grinding with purification by chemical and mechanical methods and paper pulp compaction.

• a procedure similar to the previous one except that after purification follows fractionation of fibers, compaction and dispersion.

The paper coming from photocopying machines and printers yields an ash content. The final product, the paper coming from floatation contains filling materials shown as ash.
The difference lies in that during flotation a large quantity of filling material drifts with the wind aside inks, resulting in the foam collected being rich in mineral matter.
So, the recycled paper contains fibers in a high percentage. In the wet sheets water is in a free space between fibers. This does not allow the fibers to form strong hydrogen bonds and be agglutinated to produce a uniform and resistant paper mass.
So, when the paper is dry shows more increased whiteness compared to the wet paper, in which light is refracted and not only the surface but also the inner inks become visible as it enters the mass of paper. The sheet that has undergone compression becomes smoother, thereby appears whiter than the sheet that has not undergone any process.
The first sheet approximates specular reflection while the second approximates diffusion. The amount of reflection depends on the smoothness of the fibers' coating in combination with paper processing.
In papers without processing, fibers act as thousands small mirrors which reflect light, leaving very little to pass under the paper surface.
The most important property contributing to brightness is light diffusion. It derives from a combination of multiple reflections and refractions of light through the cellulose fibers and any additives.
The diffusion of light and its reflection give the total brightness.
The greater the intensity of visible light that returns to our eyes, the greater the brightness.

Resources and old paper collection

Almost every paper can be recycled, used newspapers, cardboard boxes, packaging, stationery, correspondences, magazines, catalogues, cards and main suppliers of old paper are supermarkets with cardboard boxes and packing papers, converters (companies that take rolls of paper and convert them into finished products) with paper residues, printeries with incorrect and useless prints, schools and students with books and workbooks of bygone years, offices with writing papers, catalogues and useless documents, and of course, households with papers from everyday use.
Statistically, the greatest resource of old papers is industry and professionals with 52% rate, which covers losses from processing (shreds, chops) and returns from unsold newspapers and magazines.
About 10% comes from offices and the remaining 38% comes from households. A separate 20% of the recovered paper is "pre-consumption" paper (the one that never reaches consumers), such as incorrect prints from printeries and residues from converting companies.
The old paper collection depends on its resource. The volume of old paper from large industrial and commercial sources is so great that they have their own collecting equipment.
In households, paper for recycling is collected separately from other refuse, as contaminated paper is not suitable for recycling. Contaminated paper may introduce impurities and bacteria in the recycling process.
In certain countries recyclable materials such as paper and cardboard, plastic, aluminum, etc. are collected together.
In other countries, old magazines and newspapers are collected separately from the remaining paper and cardboard.
The most common way of collection is applied with containers, large and small, placed in spots of the city, which bear the symbol of recycling and encourage people to throw in there the paper for recycling. Large containers are outside supermarkets and industries, while small ones are scattered in neighbourhoods.
Big trucks pass by these spots and empty the contents of small containers in their large bodies, while for large containers there are special trucks on which the container is loaded and transferred complete. In turn, these trucks go to the place where the sorting of paper will take place, whether it is the same with the place of recycling, or the warehouses of the old paper traders.

Old paper sorting and baling

DOANYS is included in this course of recovered paper for recycling, since it is one of the companies in Greece preparing paper for recycling, i.e. sorting and baling.
Sorting is necessary because specific qualities of recovered paper are suitable for specific finished recycled paper products.
For example, it is impossible to take newspapers and cardboard boxes and produce white copy paper. The fibers from newspapers and cardboard boxes are more suitable for the production of packing paper and board.
There are various types of recovered paper and board to meet the needs of different producers according to strict specifications.
More than 50 grades of recovered paper are designated in the "European List of Standard Grades of Recovered Paper and Board".
In summary, the grades can be classified as follows:

• Low grades (mixed paper, old corrugated cartons, boards, etc.) constitute the main percentage of recovered paper consumption. These are used for the production of packing paper and board.

• Deinked grades (newspapers and magazines, graphic paper, etc.) are usually considered low grades as well. These are used for graphic and sanitary uses.

• High grades (nuggets, white glues, printing residues) require little or no clearing. They can be used in any product as pulp substitute.

Baling is done when it comes to transferring large quantities of recovered paper from sorting place to recycling place. Once the paper has been divided into categories, it passes through a special baling press and comes out in bales, as they are called. Paper is pressed to occupy less space during transportation to enable the transportation of larger quantity of paper.
If the recovered paper was transferred directly from the collection sites to recycling plants, without interference of the old paper traders, sorting would by more costly and time-consuming, since it would be done manually by the plant's staff with damage to other works, because of the high cost of sorting and lack of baling.

Procedure diagram for old paper recycling




DOANYS   INTERNATIONAL ORGANISATION OF PAPER & PACKAGE RECYCLING
10 IRAS & KASSIMI, TAVROS - 17778   ATHENS - GREECE    • Tel.: +30210 3458265   • Fax: +30210 3470855    info@doanys.gr


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