Evaluation of Accelerated Ageing Tests for Metallic and Non-Metallic Graffiti Paints Applied to Stone

Coatings

卷:7

Patricia Sanmartín¹  Francesca Cappitelli² 

[1] Departamento de Edafoloxía e Química Agrícola, Facultade de Farmacia, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain;

[2] Dipartimento di Scienze per gli Alimenti, la Nutrizione e l’Ambiente-DeFENS, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy;

关键词: accelerated ageing tests;    graffiti;    coating;    stone protection;    gravimetric analysis;    colour measurements;    infrared spectroscopy;   

DOI  :  10.3390/coatings7110180

来源: DOAJ

【 摘 要 】

Graffiti are increasingly observed on urban and peri-urban buildings and their removal requires a huge financial outlay by local governments and agencies. Graffiti are not usually removed immediately, but rather over the passage of time, viz. months or even years. In this study, which forms part of a wider research project on graffiti removal, different methods (gravimetric analysis, examination of digital images, colour and infrared measurements) were used to evaluate the performance of accelerated ageing tests (involving exposure to humidity, freeze-thawing cycles and NaCl and Na2SO4 salts) for graffiti painted on stone. Silver (metallic) and black (non-metallic) graffiti spray paints were applied to two types of igneous rock (granite and rhyolitic ignimbrite) and one sedimentary rock (fossiliferous limestone, i.e., biocalcarenite). The metallic and non-metallic graffiti spray paints acted differently on the stone surfaces, both chemically and physically. Older graffiti were found to be more vulnerable to weathering agents. The ageing test with NaCl and particularly Na2SO4, both applied to granite, proved the most severe on the paints, yielding more detrimental and faster artificial ageing of the type of material under study.

【 授权许可】

Unknown