Energy and Material Flow Management at an Offset Printing Works

This report describes, how Umberto was used in an offset printing plant. The company wishes to remain undisclosed.

Objective of the investigation

The objective of the project is to introduce material flow and energy management in a large offset printing works.

Potentials for ecological and economic improvements are to be pointed up and the transparency and trackability of the material flows are to be assured.

The following requirements and demands are made of the material flow model:

•  

• the in-firm data already available are to be used,
• it must be possible to draw up periodic, process-related material flow analyses,
• it must be possible to draw up order-specific (or product-specific) material flow analyses,
• ease of updating periodic and order-related models must be assured.

Implementation

• The printing works forms the boundary of the material flow model. The energy-providing processes outside the printing works (power station, gas supply) are modelled in addition because of the essential environmental impacts they involve. (Fig 1)
• The model is drawn up by analogy with the plant structure of the firm. The individual machines, which are run as separate cost centres within the firm, are shown as transitions with the relevant cost centre designation in the material flow model. The model must be able to reproduce all possible ways of producing a product. (Fig 2) For instance, a product may be folded at folding machine 1, at folding machine 2, or not at all. It must be possible to represent and assess each of these options in the material flow model.
• The printing processes at the printing machines represent a special feature. Within the company these are only covered as one cost centre, but they can be split up into a number of individual processes. At the highest hierarchical level, printing processes are therefore represented as sub-networks which front for the more detailed processes. (Fig 3 + Fig 4)
• It is conspicuous when modelling material flows in the printing branch that in many cases the information connected with the inputs of a process is not sufficient to be able to make quantitative statements about the process output. Thus a printing plate that enters the printing process as an input can in the worst case be used to print just one page, and in the best case to print several million pages. This is why additional information is always needed in the individual transitions. All the items of information needed in the material flow model are therefore run as parameters. (Fig 5)
• These parameters are managed in the Input Monitor. Here the parameters are filed in a number of thematically ordered lists. (each "list" is represented by an Input vector.) The lists reflect the data structure of the firm. Some data are surveyed annually, while other data are collected within the firm for each individual order. The parameters are labelled in accordance with their normal in-house designations (e.g. the in-house designation of the electricity meters, or the in-house numbers of the individual inks used for printing). (Fig 6)
• In order to ensure order-related calculations, all the data surveyed periodically are converted so as to apply to the individual order with the aid of reference values.

Results

• The model permits representation and transparency of all ecologically relevant material flows. This forms the basis for a better understanding of the process and for building up an environmental management system in accordance with the EMAS Regulation as desired in the printing works under review here. (Fig 7)
  Picture caption: Transparency regarding the electricity flows in the printing works makes it clear that the infrastructure (compressors, lighting) accounts for the highest electricity consumption. Potentials for savings in these areas are currently being investigated.
• With the aid of an indicator system it is possible to carry out a periodic calculation of (environmental) indicators in Umberto?. This forms the precondition for periodic in-firm comparisons and monitoring, as well as for a comparison with indicators of similar firms (benchmarking). (Fig 8)
• A first calculation of the solvent flows shows the "status quo" in the firm. The main sources of solvent discharge can be traced. A comparison of the solvent discharge with the requirements of the EU VOC-Directive valid as of 2007 reveals that it is important to aim for improvements. (Fig 9)
• With the aid of the hazardous materials labelling ("material properties") it is possible to point up essential ecological potentials for improvement and substitution where hazardous materials are used. According to an initiative of the printing industry, use of agents with a low temperature of flame acccording to the "ordinance of combustible liquids" is to be minimised. However the printing works under review still uses large quantities of these cleaning agents.
• Apparently the largest and fastest printing machine is also the one that produces the highest waste paper quota of 12.9 %. A point of approach for economic improvements is seen here. Reduction of the waste paper quota by 1 % on this printing machine alone comprises a savings potential of approx. 180 000 DM. Potentials for improvement exist above all in the overprinting sector, which should be exploited in full in future. (Fig 10)
• The calculation of orders and hence a comparison of the ecological and economic parameters of similar products is planned for the future on the basis of the existing model. It is expected that potentials for economic and ecological improvements will be identified here too.