Artcare - Auckland Art Gallery

PlasticTemperature—as heat will accelerate deteriorationprocesses, a stable temperature that is not allowed toexceed 20°C is recommended. High temperatures shouldbe avoided because they cause many plastics to soften oreven melt.Stress—such as that imposed by stretching andbending can increase the rate of deterioration. Crackswill tend to appear as a result of the applied stress as iscommonly seen along a fold and tearing can result fromstretching.Dirt—thermoplastic materials remain soft and soare particularly prone to permanent soiling from dirtbecoming ingrained in their surfaces.HandlingWear gloves when handling plastics. Provide adequatesupport for the entire object and avoid creasing orstretching.Display and StorageCertain plastics emit gaseous degradation productswhich may affect other parts of the object, or objects inthe vicinity. For example, cellulosic materials andpolyvinyl chloride emit acid degradation products whichaccelerate deterioration and can initiate corrosion ofmetals. Ventilation of these materials is very important,and in some cases isolation may also be necessary toprevent damage to other materials.Plastics should be displayed in display cases (withadequate ventilation) and covered in storage to protectthem from dust.Plastic objects should be displayed in a way thatsupports their correct shapes and prevents stress.Plastic surfaces should not be left in contact with oneanother or with other surfaces as they can becomesticky.Light levels for display should be kept below 150 luxand ultraviolet light should be screened out.In general, plastic objects should be stored in cold,dark, dry conditions. Oxygen-free storage is recommendedfor particularly valuable objects. This is possible throughthe use of oxygen scavengers such as Ageless. The object isplaced in an airtight bag with sufficient Ageless packets toreduce the oxygen level and thereby slow oxidation. Pleaseconsult a conservator about this method.Otherwise most plastic materials will benefit fromstorage in a frost-free deep freezer or cold room whichwill slow the natural processes of deterioration. In thiscase, the objects should be placed in sealed glass or airtightplastic with colour-indicating silica gel.52