PRACTICAL ASPECTS ON THE TESTING AND USE OF ADHESIVES ON POLYSTYRENE
BY THEA WINTHER
This presentation will focus on experience derived from adhesive joining of polystyrene objects. In 2012 seven adhesives were tested for their effect on polystyrene before and after light ageing. The impact of adhesives for treating general purpose and high impact polystyrene in the museum environment were investigated studying such factors as stability, impact on test material, working properties, aesthetics, ageing of the adhesive join and the question of reversibility. Based on a survey among conservators, the adhesives included were acrylates (Paraloid B72 in acetone:ethanol 1:1, or only ethanol, Paraloid B67 in isopropanol, Primal AC-35, Acrifix 116), epoxies (Hxtal NYL-1, Araldite 2020) and one cyanoacrylate (Loctite Super Attak Precision). Adhesives were tested on extruded sheets of transparent, general purpose polystyrene and white HIPS applied on joined edges and as an open layer. Methods applied before and after light ageing were visual assessment, colour measurement, ATR-FTIR, SEM-imaging, tensile testing, assessment of working properties, type of break and hardness testing.
Based on the outcome from this project some of the adhesives were chosen to be tested on real objects. The results enabled conservators to choose an adhesive to be applied in the conservation work of the 1970’s sculpture Trappan by Kjartan Slettemark in the collection of Moderna Museet, Stockholm, with several parts in polystyrene. The experience derived from the joining of the polystyrene objects will be presented and the suitability of the methods used for testing and ageing of the adhesive joins will be discussed. The project provides information on adhesives for the repair of polystyrene objects in collections today.