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. 
== Barrier Film Comparison==
Single layer barrier films, such as used for short term applications include cling wrap (polyvinylidene) shrink wrap (polyethylene) and nylon (polyamide) films. Double-layer films made by thermoforming one material to another provide a better balance of impermeability to both moisture and oxygen, thus providing protection for longer durations. Multi-layer films provide the best protection and usually include combinations of the following: Ethylene-Vinyl alcohol (EVOH), aluminum foil, metallized polyester, nylon, and polyvinylidene chloride. Polyethylene and/or polypropylene are often used to adhere layers together. Some commercial brands form barrier films include:
Tradenames 	DescriptionComposition layers 	Thickness (mils)	Water-vapor transmission gm/m2 per 24 hours	Oxygen transmissioncc/m2 per 24 hours	Recorded testsBrand name: number (dates)See note below.	Data sheet link
Marvelseal 360 	Superior tear and puncture resistance from air, light, and moisture; approved for direct food contactnylon\PE\Foil\PE\LLDPE 	4.6 - 5.2 Mils 	0.0006 - 0.009 (90% RH, 100°F) 	0.009 (@ 0 RH, 73°F) 	* Marvelseal 360: 1 (2018) 	Data sheet 1Data Sheet 2
FR 2175 formerly Marvelseal 470	Superior tear and puncture resistance as well as protection from air, light, and moisture vaporPP\PE\Foil\PE\LLDPE 	5.0 - 5.6 Mils 	0.0005 - 0.009 (90% RH, 100°F) 	0.009 (0 RH, 73°F) 	* Marvelseal 470: 1 (2019) 	Data sheet
Cadpak N 	Strong foil barrier material for very low oxygen and moisture levelsBiax Nylon/PE/Foil/PE 	4.2 Mils 	0.0005 (90% RH, 40°C) 	0.0005 	* Cad Pak N: 1 (2019) 	Cadpak-N
Cadpak HD-100 	Heavy Duty barrier packaging: water-vapor proof, grease proof, flexible, heat-sealableBiax Nylon/PE/Foil/PE/Heavy Duty Coex 	7.3 - 7.9 Mils 	0.0005 (90% RH, 40°C) 	0.0005 	* Cadpak Hd100: 1 (2018)* Cepac Hd100: 3 (2015) 	HD-100
Cadpak HD-200 	Super heavy Duty barrier packaging: water-vapor proof, grease proof, flexible, heat-sealableBiax Nylon/PE/Cross-lam PE/PE/Foil/Heavy Duty Coex	10.3 Mils 	0.0005 (90% RH, 40°C) 	0.0005 	* Cadpak Hd200: 1 (2018) 	HD-200
Aclar UltRx 6000 	polychlorotrifluoroethylene 	6.0 Mils 	0.0047 	27.9 	* n/a 	
Peralux 	PVC\Aclar 	6.0 Mils 	0.03 (90% RH, 100°F) 	14.8 	* n/a 	
kp (Pentapharm) 	PVC\Aclar\PVdC\PVC 	3.0 Mils 	0.35 (90%RH, 38°C) 	0.18 	* n/a 	
Filmpak 1193 	Polyester\PE\Aclar\PE 	4.9 Mils 	0.03 (90% RH, 100°F) 	0.05 	* n/a 	
ESCAL 	PP\Silica deposited polyvinyl alcohol\LLDPE 	114 microns 	0.01 (25°C 60%RH) 	0.05 (25°C 60%RH) 	* n/a 	
EVOH/nylon barrier film 	EVOH/nylon 	3.0 Mils 	 	2.3 	* n/a 	
Note: The AIC Materials Testing Results page provides information on Oddy tests that were completed on these materials. Access their database, then use the search box to locate materials of interest.
== 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 ==
* M.Elkhial, N.El Hadidi, 'Assessing the suitability of new film laminates for sustainable insect eradiation by modified atmosphere in museums', Heritage Science, 10:28, 2022.
* 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
* Mid-South Packaging: Data sheets
Category:Materials databaseCategory: MWGCategory: Sheet/Film, CompositeCategory: LaminatesCategory: Comparisons