Aim
The aim of these case studies is to provide examples of objects that are made of different plastics and have degraded in different ways to help people understand the typical degradation of particular plastics and what can be done to slow the degradation process down. You can match an object of concern in your collection to one of the case studies and find out what treatments are suitable and how best to care for it. Any treatments or storage solutions proposed are of a realistic kind that any museum should be capable of achieving without excessive cost or impact on existing storage.
Plastics identification
Being sure of which particular plastic the object of concern is made is key to its care as different plastics have different requirements. Identification has been done by infrared (IR) spectroscopy. In this technique, IR radiation is passed through a sample. Some of this radiation is absorbed by the sample and some of it is passed through (transmitted). The resulting spectrum (graph) represents the molecular absorption and transmission, creating a molecular fingerprint of the sample. Each plastic produces its own IR spectrum. No two specific plastics produce the same infrared spectrum. This makes infrared spectroscopy extremely useful for the analysis of plastics.
Content of each case study
Each case study contains:
- the featured material's IR spectrum.
- images of the object including close-ups of any degradation. New images will be provided on a six month basis to show any changes in condition.
- enlargements of the IR spectrum and images in a pdf accessed just below the images of degradation.
- source of the object.
- any history of the object that is known that could impact on its condition.
- a description of the degradation.
- what could have contributed to its degradation.
- any degradation typical of the material not visible in the particular example.
- preventive, palliative and interventive treatments.
- display and storage options for the object.