As tapes became commercially available in the late 1920s, they quickly integrated into our lives due to their ease of purchase, convenience, and quick attachment, and became a common tool used in museums, record institutes, and libraries for identific...
As tapes became commercially available in the late 1920s, they quickly integrated into our lives due to their ease of purchase, convenience, and quick attachment, and became a common tool used in museums, record institutes, and libraries for identification and repair of artifacts. However, tape can be the cause of problems over time. Among the tapes attached to modern and contemporary records, rubber-based tapes oxidize over time and leave yellow stains. Stains caused by degradation impair the original shape, value, and readability of the artifact. Existing solvents and tools commonly used for tape removal are not able to remove adhesives perfectly due to the sensitivity of paper, inks and pigments used thereon. Their effects are also minimal, thus new removal methods are needed.
This study examined the degradation characteristics of rubber-based tapes depending on the stage and conducted comparative experiments using existing solvents and new preservation materials and solvents to determine the best removal method for each stage of degradation.
First, four types of rubber-based tapes purchased on the market were divided into backing and adhesive, and eight parts of them were analyzed using infrared spectroscopy (FT-IR). Results showed that three types of substrates were polypropylene, cellulose, and polyethylene, and that the adhesive surface was identified as synthetic rubber and natural rubber.
Artificial degradation was performed to observe the changes of the adhesive according to the degradation stage. Four types of rubber-based tapes were attached to A4 size 80g/㎡ paper, and experimental samples were divided into 4 types according to the removal method and degradation period. The experiment was conducted under 105℃ dry heat conditions for 20 days, and the time frame was divided by 5 days.
Based on Robert L. Feller's study, artificially degraded rubber-based tapes were divided into three stages of degradation, and visual observation, microscopy, chromaticity measurements, and infrared spectroscopy (FT-IR) were performed to examine the degradation characteristics of each period. The tapes A and B in the day 5 sample were in an induction stage of degradation which is there is little change in shape and the adhesive is soft and can be removed relatively easily. Tapes C and D of day 5 sample and day 10 sample showed the condition of oxidized stage, which is the second stage of degradation where the adhesive begins to penetrate into the paper and part of it remains on the surface. The sample on days 15 to 20 showed a three-step crosslinked stage in which the substrate hardens and is easy to fall off, and the adhesive is absorbed into the paper, leaving stains and losing adhesion. These results indicated that the type of substrate and the type of adhesive affect the degradation status.
Four methods were conducted to find appropriate removal measures for each stage of degradation of rubber-based tape. Four types of chemicals used: Toluene+Acetone (1:1) and Microemulsion (EAPC) which are mixed solvents, and Alcohol and Acetone which are single solvents. Regarding methods, a cotton swab with the mixed solvent was used to remove the samples, and the compatible solvent was mixed with of three Gels (Gellan Gum, Agar Gel, Hydrogel) in the Sol-Gel process or loaded into the gel.
After visual observation, chromaticity measurement, microscopy, and FT-IR analysis, the results showed that the mixed solvent of Toluene + Acetone (1:1) was the most effective on removing samples in the induction stage and the oxidized stage, and for the crosslinked stage the Hydrogel loaded on the solvent was the most effective.
This study demonstrated that rubber-based tapes had different degradation characteristics depending on the type of substrate, the components of adhesive, and the duration of degradation. In addition, it showed that an appropriate removal method that matches the characteristics of the degradation stage should be used to remove tape, given the experiment showing that various gels newly suggested in this study were more effective than Toluene + Acetone (1:1), commonly used mixed solvent, in the third stage of degradation. As the number of modern and contemporary records is increasing and its value is changing, research on the new ways of preservation and treatment for modern and contemporary records will be necessary.