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Material Guide - Paper

    Manufacturing of paper and cardboard

     

    Paper consists of a net of cellulose fibers. Cellulose fibers are made by treating wood which consists largely of cellulose and lignin. Several different factors can affect the properties of the paper such as length of fibers, filling additives (for example, clay or chalk) or different fiber pre-treatment. By doing so, many different types of paper can be produced.

    To make paper pulp, you start by barking the wood and then working it to expose its fibers. There are different methods to do this and the method is adapted to the paper you wish to produce. Read more below about the process!

    Stock preparation

     

    Paper pulp in the form of mass or bales is dissolved with water. Different types of pulp can be mixed together to get the desired properties of the paper as different pulp varies in how good it is at bonding to a net - abrasive pulp contains short fibers which give low strength to the paper but good printing properties while soft pulp with long fibers gives a strong paper but has poor printing properties. The pulp is ground to make the fibers more water-absorbing and willing to attach to each other and form nets. The grinding is adapted to the type of mass and the desired properties of the paper.
    Mechanical pulp and recycled fibers usually do not need to be ground because they already have the right properties. At this stage, pH-adjusting chemicals and fillers are added.

    Next, adhesives are added that reduce the water-absorbing ability of the fibers again. Alum is added to facilitate the adhesive attachment to the fibers. Starch is added to increase the strength and stiffness of the paper. Color, antifoam and retention agents (which cause the mixture to stay on the wire in the following process steps) are also added.

    De-watering

    The pulp is then diluted with even more water and rinsed out over a permeable cloth. On the cloth, the water runs off and a sheet of paper begins to form. 

    Pressing

    The sheet is taken through a machine that extracts more water by pressing it in several steps. It has then reached a dryness of 30-50%.

    Drying

     

    A final dryness of 95% is reached by taking the sheet through heated drying cylinders. Moist air is ventilated out and the heat is made into energy. 

    Finalization

    The last stage is to finalize the paper, which is done through different processes depending on the nature and area of use of the final product. The surface can also be treated to be for example shinier, lighter or stronger. When it is then finished it is rolled up on large rolls and sold.

    Use

    and quality

    The advantage of cardboard material is that it comes from a renewable raw material. At the same time, the recycling system for paper and cardboard is well developed and the recycling rate is high. The use of recycled material is also widespread. Cardboard is also biodegradable and is not as problematic as other materials if it gets into nature. Disadvantages are that paper production is water-intensive and energy-intensive, and can give rise to chemical emissions. The use of chemicals is high.

    Take sustainable paper decisions!
    • Minimize the use of material. A lighter carton gives less emissions. But the carton still has to fulfill the function of protecting the products since the products generally have a higher environmental impact than the carton itself.
    • Use recycled material. Recycled material saves resources.
    • Evaluate the suppliers. CO2 emissions vary widely between different suppliers.
    • Encourage consumers to reuse if possible, and if not, to recycle the carton.
    • Avoid mixing materials.
    • Avoid using gold paint to facilitate recycling.
    Paper packaging

    and their sustainability foot print

    Paper packaging is cellulose-based and renewable. However, the climate impact of the carton is strongly linked to the energy mix used in manufacturing. One Swedish manufacturer estimated the climate impact at 0.24 Kg CO2 equivalents per kilogram of false board, while the European average was 1.3 Kg CO2 equivalents per kilogram of false cardboard, according to the Swedish Food Agency's report.

    Corrugated cardboard gives rise to 0.44 Kg CO2 equivalents / kg corrugated cardboard calculated on corrugated cardboard of 18% virgin raw material and 82% recycled raw material and European electricity mix (almost only fossil energy).

    An easy way to make a big difference

    Recycling

     

    In 2018, 82% of the paper, cardboard, and corrugated cardboard were recycled on the market in Sweden (Statistics Sweden). Material recycling of paper packaging is advantageous because it saves the earth's resources - a ton of recycled paper corresponds to 14 trees and it only takes 1/3 of the energy to produce the paper from recycled material compared to virgin material. 37% of the carbon dioxide emissions made in the production of virgin cardboard will be saved if the raw material comes from recycled material.

    When the paper packaging has become waste, they are collected and transported to sorting facilities where they are separated from foreign objects and pressed together into large bales. The bales are driven to the recycler, in Sweden almost always to the Fiskeby Board. They analyze the bales to see what type of paper they consist of (corrugated cardboard, other paper packaging, other paper or other material). Then the cardboard is inserted into a large rotating drum together with large amounts of water.

    The drum functions much like a washing machine and in it the packages are dissolved in fibers that are separated from other materials, such as plastic layers. The fiber material is rinsed out over a special cloth with holes in it. The water runs off and the fiber pulp can then continue into the paper machine where it is pressed together in several layers into cardboard. The cardboard is dried and treated with chalk, clay and binder to obtain the selected final quality. The cardboard is rolled up and sold to packaging manufacturers and printing companies.

    The residual material is sorted away from the process and used for energy recovery. The paper fibers can be used 6-7 times as they wear out and become shorter for each recycling cycle. When they are obsolete, they can be used for energy. The corrugated cardboard and paper recycling process is a durable process. An important factor to think about in order to make recycling easier is to not mix materials, such as having a plastic window in the carton, and avoiding gold paint if the carton is to be lacquered because gold color has historically created problems in the process.

     

    In 2018, 82% of the paper, cardboard, and corrugated cardboard were recycled on the market in Sweden (Statistics Sweden). Material recycling of paper packaging is advantageous because it saves the earth's resources - a ton of recycled paper corresponds to 14 trees and it only takes 1/3 of the energy to produce the paper from recycled material compared to virgin material. 37% of the carbon dioxide emissions made in the production of virgin cardboard will be saved if the raw material comes from recycled material.

    When the paper packaging has become waste, they are collected and transported to sorting facilities where they are separated from foreign objects and pressed together into large bales. The bales are driven to the recycler, in Sweden almost always to the Fiskeby Board. They analyze the bales to see what type of paper they consist of (corrugated cardboard, other paper packaging, other paper or other material). Then the cardboard is inserted into a large rotating drum together with large amounts of water.

    The drum functions much like a washing machine and in it the packages are dissolved in fibers that are separated from other materials, such as plastic layers. The fiber material is rinsed out over a special cloth with holes in it. The water runs off and the fiber pulp can then continue into the paper machine where it is pressed together in several layers into cardboard. The cardboard is dried and treated with chalk, clay and binder to obtain the selected final quality. The cardboard is rolled up and sold to packaging manufacturers and printing companies.

    The residual material is sorted away from the process and used for energy recovery. The paper fibers can be used 6-7 times as they wear out and become shorter for each recycling cycle. When they are obsolete, they can be used for energy. The corrugated cardboard and paper recycling process is a durable process. An important factor to think about in order to make recycling easier is to not mix materials, such as having a plastic window in the carton, and avoiding gold paint if the carton is to be lacquered because gold color has historically created problems in the process.