Paper had an important role on spreading and developing the science and culture, and it was the beginning of the first money logic, monetary issues like buying something and exchanging.. The ease of writing, carrying and keeping ensured the science and knowledge anywhere to be spread all over the world easily, thereby it was one of the major means for reaching today’s civilization. In today’s world, paper is one of the leading industry products and one of the required items in daily life. Paper is used in scientific studies, education and training institutions, all sorts of media, publication activities as well as printing money, packaging business, kitchen and many other places.
As paper manufacturing was limited in the past, it was treasured all over the world. After the manufacturing got wide and became widespread, it lost its old reputation. However, it becomes more valuable day after day because of the raw materials used in making paper tending to exhaust, increasing costs and other reasons.
It is not known exactly who discovered paper. However, it is accepted that a court servant named Ts’ai Lun in China in 105 AD made the first model of the paper obtained by today’s pulp. Ts'ai Lun took the inner barks of trees, cloth pieces and other fibrous materials, pounded them until they became dense and soft pulp, then mixed this pulp with water in a large water tank and obtained the first mechanical wood pulp. He then poured this mixture onto a flat piece of coarsely woven cloth and let the water drain through, leaving only the fibers on the cloth.
Once this sheet taken from the mold was dried and then calendared primitively by handmade cylinders, it became ready for use. It has been 2000 years since its discovery up until now. In the studies and digs made in Middle East, it was found that the papers used between the third and seventh centuries were made from the inner barks of mulberry tree, cannabis, hemp and cotton.
Paper was passed along to Iran from China. After the battle of Talas in 751, paper making was learnt from the captives taken from China.
In Near East, paper making center was first founded in Baghdad in 754, in the time of Abbasid emperor Haroon Rasheed. World of West learned the presence of paper by Muslims after a long while like 400 years. After that, paper mills were founded in Damascus, Tripoli, Yergen and Egypt.
After the Muslims captured North Africa and then passed to Spain, the paper mills were also moved there. These mills are very important as they were founded by Muslims and as they were the first paper mills of Europe.
So, the paper, which was manufactured thousand years ago in China, was manufactured with new methods by time and the first paper machine was built in France in the 18th century. There had been continuous changes to paper machines in parallel with technological developments, and so today’s automatic paper machines with multi-engine driven system that keep the characteristics of pulp such as density, temperature, pH, weight in grams and moisture under control were shaped.
Paper Manufacturing In Turkey
Paper industry in Turkey also developed continuously in parallel with the developments in world. Ottomans supplied their paper requirements directly. In Evliya Çelebi’s book named Seyahatname, it was learnt that there had been a paper mill in Kağıthane remaining from Byzantine time. In the time of Third Sultan, Selim Han, there was a small paper mill, however it was closed because the manufacturing costs were high.
The first paper mill was founded in Yalova in 1744. The decision of founding a paper mill in Yalova was made to supply the paper requirement that was increased after İbrahim Müteferrika established the first Turkish printing house. Various types of paper was manufactured in this mill. Sultan First Mahmut Han was very pleased about this mill. He wanted other paper mills to be established in order to reproduce Quran and other Islamic books. However, because of the water shortage, disrupted water supplies and competitive European papers, the paper mill in Yalova was closed. The long-lasting paper mill established in Ottoman Empire time was Beykoz Paper Mill. It was intended to make paper in the same quality of British and Dutch papers in this paper mill put in commission in 1804. Later on, it was more economical to bring paper from abroad, and foreign countries sabotaged the paper industry by selling their paper at less than cost. Consequently, the mill in Bykoz was also closed.
İzmir Paper Mill was established in 1844. It was decided to run the mill by steam power. This mill met the paper requirement of the government for a while. Again as a result of several tricks of Europe, it was closed.
Hamidiye Paper Mill was our last paper mill established in the time of Ottoman Empire. Sultan Second Abdülhamid Han charged Mr. Serkarın Osman with the duty to establish Hamidiye Paper Mill. Kır Mevkii and Hünkar Port in Beykoz were chosen for the location of the mill. It was enlarged by taking the land of 420 thousand squares belonging to Mr. Ali Cevat, son of Mr. Osman. This mill was managed by Hamidiye Paper Mill having branch offices in Istanbul and London, and the company established with the name Ottoman Paper Manufacturing Company Limited. The stocks issued by this company were not sold. Masson Scott company ran this mill for some time. The company (Hamidiye Paper Mill) was transferred to Masson Scott company by decree of court when it didn’t acquit its debt. Later on, this company issued its stocks in 1912. Hamidiye acquired this company again. However, British employees returned their home with the eruption of First World War at that time. The victorious governments dissolved the paper mill after the Ottoman Empire was defeated in the war.
First paper mills in the Republic Period
The first paper mill of Republic Period was established on the 14th August, 1934 and it was commissioned in 1936. This mill was followed by a second paper cellulose mill in 1944 and Chlorine Alkali Mill in 1945. Third paper mill was established in 1954. In 1957, old machines were replaced. In 1960 the fourth and in 1961 the fifth paper mill were established. After working with the name “Sümerbank Kağıt ve Karton Fabrikası” till 1955, it is given the name İzmit Selüloz Sanayii Müessesesi. Later on, it became an economic government facility with the name Türkiye Selüloz ve Kağıt Fabrikaları İşletmesi Genel Müdürlüğü (SEKA) by emerging from Sümerbank with the law issued in 1955.
SEKA
In Izmit, there are Mechanical Wood Pulp, Corrugated Cardboard, Wood Cellulose Mill, Straw Cellulose Factory, Chlorine Alkaline Factory, power plant, water facilities and factories as well as seven paper and cardboard mills affiliated to SEKA.
Zonguldak-Çaycuma institution of SEKA was commissioned in 1970. Craft –cellulose, craft paper and semi-chemical paper had been manufactured here. The facility for mechanical wood pulp and news print in Giresun-Aksu and the facilities opened in 1971, in Muğla-Dalaman are also affiliated to SEKA. In the facility in Dalaman, sulfate and viscose cellulose, and of course paper and cardboard are manufactured.
The other facilities and enterprises affiliated to SEKA are Afyon Beyaz Saman Selülozu Tesisi, Balıkesir Selüloz Kağıt Tesisleri, Antalya Kraft Selülozu ve Kraft Kağıdı Tesisleri, Akdeniz (İçel), Kastamonu, Bolu enterprises commissioned after 1975. Our paper manufacturing which was 10.000 tons in 1936, reached 932.000 tons in 1992. Half of this quantity is manufactured by SEKA, and the other half of it is manufactured by private industry.
Paper types
Being used in every periods of life for wide range of purposes, the paper can be divided into various classes according to the weight (in grams), the type of pulp being used, thereby the tearing and bursting strength and other similar characteristics. However, it is possible to classify in general terms as follows:
» Tab papers (High-grade, 2nd grade and 3rd grade pulp papers, offset paper, tracing paper, etc.),
» Wrapping papers,
» Craft bag or cement bag paper,
» Cleaning papers and hygienic papers, tissue papers,
» Special thin papers (such as cigarette paper, etc.),
» Corrugated cardboard papers (craft liner, waste paper craft liner, corrugated solid paper),
» Cardboards.
Another classification can be:
» Cultural papers,
» Industrial papers.
Raw materials of paper
The major raw material of the paper is wood. The quality of wood for paper is lower than the wood used in furniture manufacturing and higher than used as fuel. This wood is also obtained from coniferous trees (soft such as pine trees) or leafy trees (hard such as oak).
Paper industry is in the third order, following forest products industry and fuel, and when we consider the long time required for the growth of forests, only paper industry can even exhaust the forest resources of a country in a short period, if required importance is not given to forestry. Therefore, the paper industry worldwide turns to sources other than wood. Among these, stems of straw, bamboo, cannabis-hemp and tobacco, sunflower, etc, which are known as yearly plants, can be listed. Among these wide ranges of plants, only straw, bamboo and cannabis reached the level of economic use till now.
Recycling of papers
Another raw material is old paper. Although old and waste papers seem to be low-priced raw materials, depending on the printing ink and the structure of the paper being used, removal of ink constitutes the most important problem especially in the making of tab paper. Grey cardboard manufacturing, which is still used extensively, is made from this kind of old paper without removal of ink.
Auxiliary raw materials
These can be examined in three groups as filling materials, dyestuffs and adhesive materials for paper:
Filling materials are used on the wavy paper surface consisting of fibers in order to give a smoother shape by filling the gaps between fibers. Furthermore, they make the ink to be absorbed better by preventing it to disperse. They increase the brightness of paper and they also have positive effect on the softness of paper.
On the other hand, they lower the breaking, tearing, double folding and bursting strength of the paper as they weaken the connection between the fibers. When delivering the pulp to paper machine, as they hold on more to the upper side of pulp flowing over drain, they cause two-sides on paper. They have negative effect on the adherence of paper. If they hold on weakly on the paper, they cause stain, dirt and wear during deletion.
They seem to be cutting the cost of paper due to their high-percentage of use from the point of business managers, however a certain amount of filling material can be added to pulp by taking the listed disadvantages into account.
Among the filling materials such as barium sulfate, calcium sulfate (CaSO4), etc., kaolin (a kind of clay) is used extensively.
In order to give desired color to the paper, sufficient amount of dyestuff (synthetic dyes or pigments) is used.
Various papers (especially such as print, money and map papers) are required to resist to liquid materials such as water and ink. For this purpose, while the fibers are in suspended condition, a certain amount of cellophane is added into pulp in order to provide inner of adherence of paper. Then, to make the cellophane precipate on fibers alum is added. The resin obtained from pine trees contains approximately 80% percent of cellophane.
Paper manufacturing
It is possible to separate the factories carrying out paper manufacturing as pulp factories, which are also known as cellulose factories today, and the paper factories. However, today paper factories are established as integrated facilities carrying out both paper and pulp manufacturing.
In pulp manufacturing section, the pulp is manufactured from raw materials in question with various methods. The manufactured pulp is given directly to the paper machine with suitable mixtures as pulp or as diluted or stocked as intensified by taking the water.
The main pulp (cellulose) manufacturing methods
Mechanical pulp
The trees other than some leafed trees generally such as oak are cut with lengths of 1-1.5 m are cut and fiber water mixture suspension is obtained by separating these into fibers in a machine called stony fibering after dampening if required. After passing them through various sieves to separate the substances that would cause contamination and big splinters, they are delivered to paper machine pulp preparation section or stored at special pools by increasing the concentration.
According to the sections that the logs are given to the machine, it can be separated as chain or piston. Among the pistons, designs such as single pocket and multi-pocket are available. The log is pressed on to a rotating stone by applying pressure and the stone is an artificial stone with a diameter of approximately 1.5 m.
Although the procedure is very simple, the difficulty of keeping the quality of the outputted pulp under control constitutes the greatest disadvantage of the procedure. In order to manufacture one ton of mechanical pulp, 2.33m3 peeled wood (yield 98%), 10-15 m3 clean water and 800-1500 kWh electrical energy are needed. It is also not possible to manufacture all kinds of paper with this pulp. It is mostly used in the making of paper types where the color and the physical resistance are less important and bulkiness is important.
Refiner mechanical pulp
Chemical materials are not also used in this method and the pulp manufacturing is carried out by separating the tree chips into fibers in disc refiners. The wood comes to the factory as log and chipped or comes as shavings of lumber factories and given to the refiners.
The quality of the pulp is better than the stone mechanical pulp (50%-100%) and this advantage is provided by consuming 50% more electrical energy (1200-2200 kWh per ton). However, very cheap wood raw materials such as saw shavings can be used.
Thermomechanical pulp
Being different from the refiner mechanical pulp, it is the softening of the wood chips by applying a preliminary procedure before entering the refiner. Consequently, the fibers get less damaged during the fibering process and a better quality pulp can be obtained.
Chemical pulp (cellulose)
They are semi-chemical pulp manufacturing methods and there are also many chemical pulp manufacturing methods. Most used ones among these is the sulfate (craft) method.
Any kind of chip prepared in sulfate process is cooked for 2-2 hours at 160-170°C within alkali and sodium sulfate solution.
The solution is recycled by using recycling units established to use it again. Although the process is suitable for strong pulp manufacturing, it can cause problems in countries which do not have sufficient technology level and having difficulties in supplying chemical material.
Although the newspaper papers can be made from 100% mechanical refiner, thermomechanical or chemical thermomechanical pulp, it is considered suitable to add some amount of cellulose manufactured with sulfate process (around 10-20%) for some purposes. In magazine papers, the mechanical pulp is used as 60% - 100%. The high quality print papers are manufactured from 100% chemical pulp (1st grade pulp). In corrugated cardboard and cement bags, usually sulfate pulp with high resistance is used.
The pulp (cellulose) obtained from the explained methods from the raw materials mentioned in previous parts is given to the paper machine after being processed in the pulp preparation section and adding additives such as filling, pigment etc. The pulp given with a very low concentration (around 1-1.5%) to the paper machine passes through various steps, its water is taken away. There are shaping, pressing, drying and smoothening or coating with surface pressure steps if required. The manufactured paper is wrapped to a roll called buffer with the width of the machine. This paper is cut and becomes coil or layer and submitted for use.