Barrier material
Description
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 film to provide tear and corrosion resistance. Some plastics also work well as vapor barriers (Polyvinylidene chloride, Polyester, rigid Polyvinyl chloride, Polychlorotrifluoroethylene, Polyvinyl fluoride) while others 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).
Examples of some barrier films include:
| Tradenames | Composition | Thickness (micron) | Adhesion | Water-vapor transmission | Oxygen transmission |
|---|---|---|---|---|---|
| Marvelseal 360 | Nylon, Polyethylene, Aluminum foil, Polyethylene, LLDPE | 5.2 Mils | Heat-seal at 350F | 0.009 gms/meter2 (0.0006 gms/1002 inches.) per 24hrs @ 90% RH, 100°F | 0.009 cc/meter2 (0.0006 cc/1002 inches.) per 24 hrs @ 0 RH, 73°F |
| Marvelseal 470 | Polypropylene, Polyethylene, Aluminum foil, Polyethylene, LLDPE | 5.0 Mils | Heat-seal at 350F | 0.009 gms/meter2 (0.0006 gms/1002 inches.) per 24hrs @ 90% RH, 100°F | 0.009 cc/meter2 (0.0006 cc/1002 inches.) per 24 hrs @ 0 RH, 73°F |
| Aclar | Polychlorotrifluoroethylene and Polyester sandwiched between two layers of Polyethylene | 2 | Heat-seal | Thermoformable; clear or opaque options | |
| Filmpak 1193 | Multi-layer: Polyester, Polyethylene, Aclar, Polyethylene | 4.9 Mils | Heat-seal 350F | 0.03g/100in2 per 24hr @ 90% RH, 100°F | 0.05cc/m2 per 24hr. |
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.)
Resources and Citations
- 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.
- 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
- Conservation Support Systems, Catalog, 1997 Barrier films
- Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988
- Art and Architecture Thesaurus Online, https://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000