Waterbased cleaning of mixing vessels
4. Procedure and Methodology
Previous activities under the project "Cleaner Technology in the Lacquer and Paint Industry" form the basis for the present project.
In 1997 Teknos Technology A/S initiated investigations of possibilities for water-based cleaning.
Cleaning techniques and chemistry were screened for feasible solutions, and laboratory as well as full-scale testing has been carried out. To verify reproducibility of the results and to obtain more detailed information it was agreed to perform further laboratory and full-scale testing.
Earlier results provided the basis
The results of laboratory tests and full-scale testing in 1997 as well as experiences made by potential suppliers and operators with implementation and operation of water-based cleaning technologies provided the basis for devising the program and carrying it out within the framework of this study.
Figure 4.1
Procedure and Methodology
Interviews and on-site visits
During the course of the study, several enterprises and suppliers with experience in implementation and operation of water-based cleaning technology were interviewed. Two plants in operation (one water/alkaline-bases and one solvent-based) were visited on-site for completion and verification of information. The collection of experience and ideas was rounded off by a workshop arranged by a supplier in which various actors from the paint and coatings industry participated. The results can be summarized as follows:
 | All enterprises with operating experience of water-based cleaning technology use hot alkalis as cleaning chemicals. Operating experience has been consistently favorable, as long as build-up of hardened encrustations due to lengthy periods of standing is avoided. If cleaning is attempted after the paint residues have been allowed to harden for too long, these adhere firmly to the surface, and subsequent manual cleaning, possibly involving the use of solvents, may become necessary |
| All companies have implemented a trials phase before adopting water-based cleaning processes |
| Suppliers of water-based cleaning technology recommend laboratory and full-scale testing prior to its implementation, so that a cleaning concept matched to the customer-specific technical and economic conditions can be developed. Both manufacturers have available appropriate facilities for conducting laboratory and full-scale tests on their premises |
Because supply and erection of a trials plant would involve relatively high costs and would be time-consuming, for purposes of this study, it was decided to conduct the laboratory and full-scale tests directly in the development centers of potential manufacturers.
These tests were conducted by the companies Renzmann, Germany, and Riobeer, Switzerland.
Full-scale tests at Riobeer were not possible within the timescale of the project.
Laboratory tests and full-scale trials are carried out with Teknos Technology A/S products.