Friday, 17 October 2014

Thinking about the Box: Storage of Plastics

My favourite part of my job is coming up with new creative ways of storing the modern objects found in the HIV/AIDS collections. It’s not just a case of sticking them into a box and hoping they will be alright; you have to think about what the item is made from, how it will deteriorate, in what way it will be used in the future and how frequently it will be consulted.

Conservation Scientist, Anita Quye, recently visited the LHSA studio to give advice on how to identify different plastics and how to store them. One top tip she described when identifying plastics, is to think about how the item was used originally. For example, balloons need to be flexible to be blown up; therefore they are likely to contain a lot of plasticisers. This means that as they degrade and lose their plasticisers, they are likely to become very brittle. Plastic banners made for use outdoors, on the other hand, need to be lightfast (not discolour in light) and as such, are suitable for exhibition, where they are subject to light for a long period of time.

Once the type of plastic has been identified and the potential conservation risks considered, it’s time to think about the storage of the object. Storage can depend on the conservation needs of the particular object. We have a large collection of balloons in the HIV/AIDS collections, that were used in health promotion campaigns. Since balloons are likely to become brittle over time, it is a good idea to create storage that will reduce flexing of the balloons as much as possible. Balloon samples were previously housed wrapped in tissue paper, inside the original envelope which recorded the type and colour the balloons it contained. This was not ideal as the balloons needed to be handled a lot to view them, and in some cases the balloons had become stuck to the tissue paper. To store these, I made shallow trays from box board and created a frame from mount board to hold the balloons and envelope in place. I also lined the boxed with an activated charcoal cloth to absorb any acidic gases released from the balloons and slow down deterioration.  
GD22 - Balloon samples, before treatment. Balloons are wrapped in tissue paper and stored inside a paper envelope.
GD22 - Balloon samples, after treatment. Balloons are inserted into a polyester sleeve and stored in a shallow clam shell box with frame.
There is also a plastic banner in the HIV/AIDS collection which has a strong ‘plastic’ smell, suggesting it is deteriorating rapidly and likely to become brittle as it ages. To avoid excessive handling of this object, I created a ‘concertina’ folder which could display three flags only and leave the rest untouched. Since the “Take Care” logo is repeated on each flag, it is not necessary to view the entire length of the bunting.  This way, the general design of the bunting can be viewed and the condition of the item can be monitored without touching it at all.
GD22- Plastic bunting, before treatment. Object is wrapped in tissue paper.
GD22 - Plastic Bunting, after treatment. Object is stored in a 'concertina' folder.
If an object is at high risk of deterioration and needs to be monitored regularly, it may be best to store it so that it can be viewed easily, without excessive handling. For example, a collection of vulnerable plastic watches were previously stored wrapped up in tissue paper, again making the items difficult to view and hard to wrap up neatly once the package had been opened. To aid monitoring of these items, I made a box using mount board with a clear polyester window on top. As plastics degrade, they release acidic vapours. If these are trapped inside a box, they can speed up the deterioration process of the object. Therefore, ventilation holes were made at the corners of the box to ensure these vapours can escape, whilst still protecting the object.

GD22 - Watches, before treatment. Watches are wrapped in tissue paper.
GD22 - Watches, after treatment. Watches are stored in box with clear polyester window.

Thoughtful storage can ensure the longevity of the object. I hope these items will survive for many years to come!

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