Hetron-Ashland Resins

ELECTRICAL PROPERTIES
The cured resins have high dielectric constants and low
dissipation factors. Dielectric constant is the ratio of
the capacitance of a weakly conducting material to
that of air. Dissipation factor is the loss of energy resulting
when a polymeric material experiences molecular
motion in an alternating electric field. See Table 6 for
electrical properties of standard resin castings.
TABLE 6
ELECTRICAL PROPERTIES OF CLEAR CASTINGS
(TYPICAL VALUES PER ASTM D150)
Average
Dielectric Dissipation dielectric
Resin constant1 factor constant2 HETRON 942/35 3.45 0.0050 3.38
HETRON 922 3.34 0.0123 3.39
HETRON FR992 3.29 0.0128 3.21
HETRON 980 3.44 0.0055 3.34
HETRON 197-3 3.04 0.0156 2.94
AROPOL 7334 3.49 0.0106 3.37
HETRON 800 5.35 0.0253 4.94
HETRON 92FR 3.37 0.0201 3.27
HETRON 99P 3.39 - 3.28
HETRON 700 2.94 0.0147 2.88
1 = KHz 2 = Average of 1KHz 10KHz 100KHz and 1MHz
10
FLAME RESISTANCE
Many HETRON polyester and epoxy vinyl ester resins
are based on halogenated intermediates. These unique
chemical structures account for their excellent corrosion
resistance and also make these HETRON resin
composites inherently flame resistant. For increased
flame resistance, antimony oxide can be added to
many of these resins during fabrication. Antimony
oxide is not effective when added to non-halogenated
resins. ASTM E84 “Standard Method of Test for Surface
Burning Characteristics of Building Materials’’ is
commonly referred to as the “Tunnel Test.’’ This tunnel
test is the accepted standard for determining flame
spread values.
Current industry practice requires materials of
construction for ducts, hoods, and other fume handling
equipment to have a flame spread rating of 25 or less
(commonly referred to as Class I). See Table 7 for
specific flame spread values.
Several other tests commonly used for classifying
smoke and flame retardant properties of FRP equipment
include ASTM E162 “Standard Test Method for
Surface Flammability of Materials Using a Radiant
Heat Energy Source (Radiant Panel Test),’’ ASTM E662
“Standard Test Method for Specific Optical Density
of Smoke Generated by Solid Materials (Smoke
Chamber),’’ UL94 “Standard for Tests for Flammability
of Plastic Materials for Parts in Devices and
Appliances.’’
For more specific information on these and other
flame resistance test results (UL94, oxygen index, cone
calorimeter), contact your sales or technical service
representative. Please consult HETRON Technical
Service for low smoke alternatives.
TABLE 7
FLAME SPREAD VALUES OF COMPOSITES1 (TYPICAL VALUES PER ASTM E84)
Resin type Flame spread Class2 CONTROL:
Asbestos/Cement
0 I
HETRON FR998/35
(no antimony trioxide required)