Gasket types, generic

Gasket types: 1. o ring, 2. fiber washer, 3. paper gaskets, 4. cylinder head gasket
Credit: Sonett72, Wikipedia

Description

For further information, please see AIC wiki Gaskets for Exhibit Cases

Gasket types
Credit: National Park Service

A compressible material used in an interface to reduce gaps and create tighter fitting joints. Gaskets are held under pressure to reduce leakage, transmission, and or vibration. As such, in museums, gaskets can be used to minimize air exchange between sealed cases and museums, to compensate for alignment irregularities between two edges, and to reduce potential for the transfer of dust, dirt, pollutants and pests. In the past, Natural rubber, Paper, Metal, Felt, Asbestos, and Cork were used for gaskets. More recently, synthetic options, called elastomers have become available.

Examples of some elastomers include:

• Silicone rubber (dimethyl silicone): most stable of all elastomers, silicone is resistant to high and low temperature ranges, fatigue, most chemicals, oils, oxygen, and ozone.
• Cellular silicone sponge (poly-dimethyl siloxane also referred to as PDMS): silicone rubber that has been foamed into a uniform unicellular structure. It has the same characteristics as silicone rubber and is shaped by either extrusion or cutting.
• Ethylene propylene diene monomer (EPDM): resistant to ultraviolet light, ozone, oxidants, heat, compression set and resists the swelling effects of polar chemicals.
• Ethylene vinyl acetate closed-cell elastomeric seal (EVA): similar to other elastomers in flexibility and softness, EVA has relatively low resistance to heat and solvents but excellent ozone resistance.
• Nitrile rubber:
• Teflon (Polytetrafluoroethylene-PTFE):