General Conclusions
| Author | European Union Publications Office, 2006 |
| Pages | 147-157 |
Page 147
Regarding the understanding of the nature and processes of aesthetic damage (fingerprint, mar, scratch) of stainless and conventional colour pre-painted steels, various methodologies have been studied and test methods have been set up. Although evaluation modes were often different among partner, similar ranking resulted in the round robin tests.
As concerns the enhancement of stainless and pre-painted steel sheets by means of clear coatings, it has been found that good performance can be obtained with different varnishes, thermal or UV curable. In the course of the project a big evolution has been observed in the field of clear coatings for coil coating applications. In particular big improvements in adhesion and ductility have been observed with UV-curable varnishes. As these coatings have big potentialities - due to their low environmental impact (they are solventless) and to the high speed of their curing process - we think that the UV-technology can have in the next future positive developments in the field of pre-coated steel sheets for appliances, architectonic, automotive sectors.
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pre-painted steel sheets for automotive industry, home appliance, building sector clear coats for coil coating applications UV-curable varnishes
[1] Jeanne L. Courte, E.A. Kamenetzky: "Micro-and nano-indentation and scratching for evaluating the mar resistance of automotive clearcoats", ECJ 7-8/99 (presented at the Nürnberg Congress).
[2] Jeanne L. Courte: "Mar Resistance of Automotive Clearcoats: I. Relationship to Coating Mechanical Properties", Journal of Coatings Technology 69, 75-63 (1997).
[3] BASF: Automotive OEM Coatings WV Techworkshop - 31/03/00
[4] Loren W. Hill, "Cure of Thermoset Industrial Coatings", Solutia Inc. Resins Division, Presented at the Proceedings of the 2nd Pacific Coatings Forum, Suzhou, China, November 1-3, 1997
[5] G. Wagner and M. Osterhold: "Comparison of different test methods for determining the mar resistance of clearcoats", Mat.-wiss. u. Werkstofftech. 30, 617-622 (1999).
[6] H.-U. Meier-Westhues et al: "Polyurethan-Klarlacke mit optimierter Kratz- und Chemikalienbeständigkeit", JOT 1999/9, 52 - 58.
[7] Hans Schellekens, Leoni C.A. Somers und Henk J.C.M. van der Wegen: "Polyurethanpolyole gegen Säure und Kratzer", Farbe & Lack, 107. Jhg, 8/2001, (28 - 37).
[8] L. Kahl, R. Halpaap und Ch. Wamprecht: "Umweltresistente 2K-UPR-Klarlacke für die Automobilerstlackierung", I-Lack 1/93, 61. Jhg., 30 - 34.
[9] E. Klinke, C.D. Eisenbach: "Scratch Resistance of Organic Coatings as Evaluated by a Single Scratch Test and Relation to Bulk Mechanical Properties", 6th Nürnberg Coating Congress 2001.
[10] Vincent Jardret, B.N. Lucas, and Warren Oliver: "Scratch Durability of Automotive clear Coatings: A Quantitative, Reliable and Robust Methodology", Journal of Coatings Technology Vol. 72, No. 907, Aug. 2000, pp. 79-88.
[11] Jeanne L. Courte, E.A. Kamenetzky: "Micro- and nano-indentation and scratching for evaluating the mar resistance of automotive clearcoats", ECJ 7-8/99 (presented at the Nürnberg Congress).
[12] Y. Hara, T. Mori, T. Fujitani: "Relationship between visco-elasticity and scratch morphology of coating films", Prog. Org. Coat. 40, 39-47 (2000).
[13] Mong, G., Ramotowski, R, The analysis of latent print residue of children and adults, Proc. of the 1st Int. Conf. on Forensic Human Identification in The Millennium, 1999 London, UK
[14] Buchanan, M.V., Asano, K,.Bohanon, A., Chemical characterization of fingerprints from adults and children, Proc. SPIE 2941, 89 (1997).
[15] Standard guide for testing high performance interior architectural wall coatings, ASTM D3730-94
[16] MIL-C-15074E Corrosion preventive, fingerprint remover, 1991
[17] Blondeau, J.P., et al., Solready: Sollac's answer to customer requirements for on line surface pretreated steel sheets, Galvatech '95, Conference proceedings, I, p. 225
[18] Hyung-Joon Kim, Characteristics of the one coat/one bake type antifinger printed electogalvanised sheet, Galvatech '92, Conference proceedings, p. 422
[19] Tajiri, Y., et al., Effect of chromate coating structure on surface characteristics of electrogalvanised steel sheet, Galvatech '92 conference proceedings, p. 501
[20] DIN EN ISO 2409, Lacke und Anstrichstoffe - Gitterschnittprüfung, 10/1994
[21] DIN EN 13523-6:2002, Bandbeschichtete Metalle - Prüfverfahren; Teil 6: Haftfestigkeit nach Eindrücken (Tiefungsprüfung)
[22] DIN EN 13523-7:2001, Bandbeschichtete Metalle - Prüfverfahren; Teil 7: Widerstandsfähigkeit gegen Rissbildung beim Biegen (T-Biegeprüfung)
Page 151
Annex 1 - FTIR spectra of reference materials
[ FIGURE ARE NOT INCLUDED ]
Page 152
Annex 2 - Roll-coating pilot construction
This pilot allows us to make the deposition by our own to study the effect of roll coating parameters. We could make A3 samples. Several varnish suppliers has been contacted and asked for varnishes. Valspar answered to our demand and sent us a sample of varnish. We would like to compare different coatings applied in the same conditions and on the same substrate. And then we could have the possibility to adapt and optimise the coating conditions.
Principle
The roll coating pilot is composed of three rolls : the inker roll (steel ; - = 50mm) the applicator roll (rub ; - = 110mm) the carrying roll (rub ; - = 180mm) and of two guiding tables which lead the samples during the application.
[ FIGURE ARE NOT INCLUDED ]
The strip thickness must be comprised between 0,38 and 3mm and the coating thickness can be from 1 to 25 um.
All the rolls are able to turn in the two directions so we can make direct rotation application or reverse rotation application.
Conception
The roll coating pilot is a homemade pilot. On the following picture, is presented the frame with the 3 rolls on it.
[ FIGURE ARE NOT INCLUDED ]
Then the pilot has been covered and finished with the set-up of the inkpot, the guiding tables and a plastic protection to avoid projections of varnish and vapour emanations (the pilot will be linked to an extractor hood during experiments).
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[ FIGURE ARE NOT INCLUDED ]
Below is presented a global view of the roll coating pilot with the control board on which are placed the roll controls: each roll can turn at a speed between 10 and 60m/min and in the two directions.
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Annex 3 - FTIR spectra of new coatings
[ FIGURE ARE NOT INCLUDED ]
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Annex 4 - GDOES of new coatings
[ FIGURE ARE NOT INCLUDED ]
