A.17.17. Sheldahl 146383 (previously G400900)
PRODUCT
Type			Thermal-control plastic film.
Chemical Composition			Fluorocarbon (FEP), Aluminised.
Manufacturer	Sheldahl 1150 Sheldahl Rd. Northfield, MN 55057 USA				Tel: +1 507 663 8000 Fax: +1 507 663 8545 Email: sheldahl.info@sheldahl.com www.sheldahl.com
EXPERIENCE & AVAILABILITY
Development Status			Special Commercial Product
Cost Range			High
Lot Reproducibility			Good
Space Experience			Good
GENERAL PROPERTIES (Physical, Mechanical, Thermal, Electrical, Optical)
Nature			Typical Value				Remarks
Specific Gravity				2.15			DuPont’s Data
Thickness				127 mm			Manufacturer’s Data
Tensile Strength				21 MPa			DuPont’s Data
Thermal Expansion Coefficient				83 x 10^-6 °C^-1			-70°C to +70°C
Thermal Conductivity				0.194 W m^-1 °C^-1			DuPont’s Data
Specific Heat				1.17 J g^-1 °C^-1			DuPont’s Data
Dielectric Strength (of FEP film)				138 kV/mm			25°C, 60Hz
Surface Resistance				10^16 W £			ASTM D257-61
Volume Resistivity				10^16 W m			ASTM D257-61
Solar Absorbtance				0.13			ECSS-Q-70-09
Thermal Emittance				0.77			ECSS-Q-70-09
Standard Width				122 cm			Manufacturer’s Data
PROPERTIES RELEVANT TO SPACE USE
Nature		Typical Value				Type of Test
Temperature Range		-185 to +150°C				Long term
Outgassing		RML = 0.05% CVCM = 0.01%				ECSS-Q-70-02
UV/Particle Radiation		Das = 0.18				OTS Spec. 7 years.
Moisture Absorption		< 0.01%				DuPont’s Data
Oxygen Index		95				ECSS-Q-70-21
Toxicity/Offgassing		Pass				NASA NHB 8060-1A
SPECIAL RECOMMENDATIONS
· There exist thinner films of the same material: 50mm 146377 (G.400500), 25mm 146416 (G402000) and also thicker; 254mm 146434 (G403800). Other widths than standard can be obtained. · There exist similar films with incorporated adhesive, either acrylic pressure sensitive, suitable for space, or silicones of which the suitability is doubtful. It is anyway preferable to fasten the film on a separately applied double-sided adhesive tape in order to avoid crazing in the metal layer due to the peeling off of the liner. · The nomenclature of the Sheldahl company can be confusing and identification of films must be known very precisely for each type used. · Depending on the adhesive used, Sheldahl aluminised FEP may be damaged by thermal cycling according to ECSS-Q-70-04. · Perforated versions of the film are available. Perforation is recommended for space use · Electrically conductive versions are also made by Sheldahl (front layer ITO deposit). However, conductivity is not maintained during wide temperature band of thermal cycling and ITO layer is degraded by long-term exposure to RH > 60%. · Protective overlay is available.