The effect of adhesive concentration, reactivation time, and pressure on the peel strength of heat and solvent-reactivated
| Main Authors: | , |
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| Format: | Book Chapter |
| Language: | English Slovak |
| ISBN: | ISBN 1-84407-253-3 |
| Online Access: | http://www.viks.sk/chk/14tmh_89.doc |
| Abstract: | SUMMARIES. The peel strength of fabric specimens adhered with Lascaux 360/498 HV and prepared using acetone, IMS, and heat reactivation under varying conditions of adhesive concentration, reactivation time, pressure, and temperature was compared. Acetone reactivation gave stronger bonds than IMS or heat at constant time and pressure. IMS produced stronger bonds than heat at times over 5 min. Increasing reactivation time, pressure or temperature increased peel strength. If levels were too high, the bond was very strong and adhesive was transferred to the artifact fabric on peeling. Tests using a continuous film of adhesive are recommended for determining optimum reactivation time, pressure and temperature. Clipon weights can be used to classify the peel strength of mock-up specimens. CONCLUSIONS. By comparing the peel strength of specimens reactivated using acetone, IMS, and heat under varying conditions of adhesive concentration, reactivation time, pressure, and temperature, this study has shown that conservators can manipulate these variables to achieve bonds with Lascaux 360/498 HV that range from very weak to very strong. Increasing adhesive solution concentration to form a continuous film of adhesive as opposed to a coating over the yarns increased the peel strength substantially owing to greater bonding area. With increased reactivation time, bonds became so strong that adhesive was stripped from the support fabric when specimens were peeled. The time at which this occurs was specific to the reactivation agent and technique, occurring in a few minutes with acetone, as compared to 20 min with IMS or heat (115 °C). Increasing the pressure applied during reactivation also increased peel strength. Very strong bonds were achieved more rapidly at higher pressures. Increasing the temperature of heat reactivation increased peel strength, although some of the difference was due to pockets of delamination in specimens heat-sealed at lower temperatures and pressures. Because bond strength depends on fabric weave and stiffness, adhesive type and thickness, and specimen size, as well as the materials and techniques used for reactivation, which often vary from studio to studio, this research does not replace the need for mock-up tests. These results suggest that tests using continuous films of adhesive would facilitate determination of the appropriate reactivation times, pressures, and temperatures for specific reactivation materials and techniques. The resulting reactivation techniques could then be used to determine the appropriate adhesive solution concentration. This study also illustrates the usefulness of a simple method, the clip peel test, for quantifying the results of mock-up peel tests. Such quantification would better permit comparison of treatment techniques from project to project and studio to studio. |
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| ISBN: | ISBN 1-84407-253-3 |
