A material, such as plastic, paper or metal, that is impermeable to gas or liquid. Modern barrier materials are usually made from lightweight transparent plastic sheets whose goal is to reach the barrier properties of a metal or glass. Metal sheets, such as aluminum foil have good barrier properties. They are often laminated with polyethylene and/or nylon to provide tear and corrosion resistance. Some plastics work well as vapor barriers (polyvinylidene chloride, polyester, rigid polyvinyl chloride, nylon, polychlorotrifluoroethylene, polyvinyl fluoride) while other are best for moisture (polyvinyl chloride, regenerated cellulose, polyethylene, polypropylene, polymethyl methacrylate (Hatchfield 2002). Multiple materials are laminated for optimized barrier properties. For anoxia treatments, films with low oxygen permeability are best. Some examples of films with minimal oxygen transmission are: Filmpak 1193 = 0.1 cc/m2/day ( mil thick); Aclar® =14 cc/m2/day( 4.5 mil thick) ; Marvelseal® 360 = 0.01 cc/m2/day; EVOH/nylon barrier film = 2.3 cc/m2/day (3 mil thick).
Synonyms and Related Terms
barrier plastic; barrier film; barrier board; vapor barrier; vapour barrier; air barrier; air infiltration barrier; Marvelseal® 360; Marvelseal® 470; Aclar® [AlliedSignal]; Filmpak 1193; Film O-Rap [Bell Fibre]; ESCAL; EVOH/nylon; Sperrschichtmaterial (Deut.); matériau barrière (Fr.); barreira (Port.)
° P.Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002.
° J.Burke, "Vapor Barrier Films" WAAC Newsletter, Vol 14, No. 2, 199, 13-17.
Sources Checked for Data in Record
- Boise Cascade Paper Group, The Paper Handbook, Boise Cascade, Portland OR, 1989
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 578
- Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002
- Conservation Support Systems, Catalog, 1997
- Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988
- Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000