Balance sheet parameters

The balance sheet parameters in detail

The following illustration shows an example of the importance of the balance sheet parameters and their contribution to CO₂ emissions during print production. The relation of CO₂ emissions, especially between the material and production, can differ depending on the print job run length. For long print runs the balance sheet is determined by the paper. The smaller the print run, the more the prepress operations, additives and utilities contribute to the CO₂ emissions.

Material

Paper
The paper is an important balance sheet parameter. The CO₂ emissions which result from the paper are determined by a variety of influencing factors. Not only the paper grade and the production process are crucial. Of importance is the type and generation process of the required production energy. Working provisionally with CO₂ equivalents for paper categories is useful. The present manufacturer’s description of paper grades of production sites still requires a harmonized calculation basis. The volume of paper that is required for a print job is calculated in a practical manner by a calculation module of the CO₂-calculator.

Ink
Ink is an important material component of print production. With the offset printing process just a thin ink film is transferred to the paper (the thickness may vary depending on the paper grade and the printing process) which makes a low contribution to the CO₂ quantity. As important raw materials for the manufacture of printing inks (e.g. pigments) are ordered from the Far East, the identification of manufacturing-related reference values for the typification of printing inks according to their CO₂ volume is very difficult. The formula of the calculator for determining the ink consumption is extracted from imported cost and performance fundamentals used in the printing industry.

Damping solution
The conventional offset process requires the use of damping solutions. The main ingredients are mostly water and additives to minimize surface tension and ensure process stability. One important additive is isopropyl alcohol. Isopropyl alcohol is highly volatile and has, besides the production-inherent CO₂ emissions, also a greenhouse effect. The Global Warming Potential in the balance parameter of isopropyl alcohol is taken into account by the calculator. Other damping solution additives such as glycols, tensides, acids, etc. are displayed by the CO₂ over a reference value for the production of organic chemicals. Generic, industry-based data on the consumption amount of the principal components of damping solution in relation to the ink are shown in the CO₂-calculator.

Cleaning agents
Low-emission hydrocarbon cleaning agents or a mixture of long-chain Aliphatics and vegetable oil esters are used almost exclusively to clean the inking and printing units of offset printing presses. The evaporation rate of the latter-mentioned agents in practical use is almost zero. With low-emission hydrocarbon cleaning agents or a mixture of long-chain Aliphatics, the evaporation rate is far below 20 percent for automatic cleaning and far below 30 percent for manual cleaning. The Global Warming Potential of this theoretically assumable evaporation rate is considered in the balance sheet. The cleaning agent quantity which is allocated to a print job is generated out of data from the annual industry analysis.

Offset Printing Plates
The difficult offset printing process, based on interfacial physics, requires offset printing plates made from primary raw material. The production of the base raw material, namely aluminium sheets and polyester foils, are therefore energy-intensive processes. Thus offset printing plates are indirectly a significant emission source of a print job. The high CO₂ equivalents of both production processes of aluminium sheets or polyester foils made from primary raw materials as well as the photosensitive coating of offset printing plates are considered in the calculation. Type, number, size and thickness of the printing plates are considered as additional balance sheet parameters by the CO₂-calculator.

 

Production

Prepress
The steps before actual printing, including imaging of offset printing plates, are allocated to prepress. Altogether these are steps like typesetting, reproduction, assembly and platemaking. The operation of these devices and machines used in prepress are CO₂ effective because of their electric power consumption. The electric power consumption is based on the estimated manufacturing time (makeready and production time) and the nominal power values of the machinery needed for a print job. Since the real electric power consumption of the production machinery is much lower than the nominal power values, practical correction factors are integrated and used. The nominal power values and correction factors of the categories of machines are continually updated in consultation with the machinery manufacturers.

Press / Printing
The electric power consumption of the printing presses, including the additional components (dryers, compressors, etc.) is considered in the CO₂ balance sheet. Again, the electric power consumption for a print job is based on the production time and on the practical correction factors for the required machinery. In addition, evaporation losses of usual additives used for the offset printing process like isopropanol and cleaning agents are quantified. The CO₂ emissions caused during the printing process result from the electric power consumption and from the CO₂-equivalents under German energy mix deposited in the CO₂-calculator. Companies can also use the specific CO₂ value of electric power consumption by their own energy supply company for the calculation. Depending on the energy mix of the energy supply company it has an influence on the CO₂ balance sheet. In addition, VOC emissions of cleaning agents and isopropanol, which are released through evaporation, are quantified and their Global Warming Potential (GWP 100a – Effect horizon 100 years) as CO₂ volume is added to the offset printing area.

Postpress
The estimated CO₂ emissions from the postpress and enhancement processes are also here determined by the power consumption of the machinery used. A possible contribution of CO₂ emission from adhesives is negligible. However, it is being considered to calculate these values for the sake of completeness.

The postpress calculation operations of the BVDM (Printing and Media Industries Federations) CO₂-calculator are analog to prepress and press/printing. The next expansion stage of The BVDM (Printing and Media Industries Federations) CO₂-calculator will show special materials for print enhancement which at present must be excluded because of the very difficult data-recall process. This will increase the mapping accuracy of print production. But the influence on the balance sheet result will be rather low.

Shipping
Shipping print products to the customers generates CO₂ emissions. The transport weight and the kind of transportation are included in the calculation. The transport weight is determined by the planned gross volume of paper for the job and is not defined in more detail. This cannot achieve higher accuracy, as compared calculations have shown. In advance it cannot be excluded that the print run of the ordered job may be shorter or longer. Moreover, the actual weight of the packaging cannot be precisely determined in advance, etc. The applied calculation method is reasonable and if anything errs on the safe side.

Disposal of Production Waste
The disposal refers to production residues and waste materials. The disposal of print products after their use is not included. The discussions on the balance sheet calculation of such complex and difficult evaluating procedures are not yet complete. This relates to some questions about recycling other waste materials such as old cleaning agents. Aluminium offset printing plates, consisting of primary aluminium, provide a high-grade waste material. They are invariably all recycled, and so a CO₂ reduction in the manufacture of products from waste aluminium is achieved. Under the assumption that primary aluminium is currently recycled around 2.3 times, it is given a credit for CO₂ saving of 4.92 CO₂ eq/kg when it is disposed of as recycling material. This may result in a negative value in the calculation of the CO₂ source for the disposal of production residues. The waste materials that are disposed of by incineration are burdened per kilogram with the released biogenic CO₂ volume.

Employee Traffic
The employees are a factor of production. Their daily trips to work generate CO₂ emissions. The resulting share of employees involved in the print job is not only difficult to define. The employees working in administration who are not directly assignable to the print job must also be considered. The average traveling distance and the kind of transportation the employees use must be determined and the CO₂ emissions assigned as a proportional surcharge to the hours worked by the production departments. The data must be updated when the number of employees changes.

Field Staff Traffic
The annual kilometers of field staff travel is determined according to the kind of transportation used and the CO₂ emissions assigned to each print job as a proportional surcharge to the hours worked by the production departments such as prepress, press and postpress.

Energy Infrastructure
In addition to the electric power consumption of production machines, a further source of CO₂ emissions is the annual volume of energy a company uses for communication, lighting, air conditioning, heating and possibly exhaust air purification. This applies to the technical area as well as administration.

Whereas the energy consumed by a company in the form of district heating, heating oil and gas can be clearly assigned to the infrastructure fields such as heating and air conditioning, the splitting of power consumption into infrastructure and production has to be done by an estimated calculation. In print and media companies the measurement of power consumption according to cost centers or consumer is not common. Therefore, from the annual power consumption, the amount of power needed to maintain the infrastructure is estimated by a rule of thumb method. Experience shows that, depending on the operating situation, the proportion of electric power needed for the infrastructure is between 20 and 40 percent.