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Tyco Electronics Corporation
300 Constitutional Drive
Menlo Park, CA 94025 USA
Specification
This Issue:
Date:
Replaces:
RT-1323
Issue 1
August 5, 1986
None
Thermofit® Zerohal™ Polyolefin Molded Components
Halogen-Free, Flame Retarded, Semi-Flexible, Heat-Shrinkable
1. SCOPE
This specification covers the requirements for one type of semi-flexible electrical insulating molded
component whose dimensions will reduce to a predetermined size upon the application of heat in excess of
121°C (250°F).
2. APPLICABLE DOCUMENTS
This specification takes precedence over documents referenced herein. Unless otherwise specified, the latest
issue of referenced documents applies. The following documents form a part of this specification to the
extent specified herein.
2.1 GOVERNMENT-FURNISHED DOCUMENTS
Military
MIL-H-5606 Hydraulic Fluid, Petroleum Base, Aircraft, Missile and Ordnance
MIL-T-5624 Turbine Fuel, Aviation, Grades JP-4 and JP-5
MIL-L-23699 Lubricating Oil, Aircraft Turbine Engine, Synthetic Base
MIL-C-24643 Cable and Cord, Electrical, Low Smoke, for Shipboard Use, General Specification for
2.2 OTHER PUBLICATIONS
American Society for Testing and Materials (ASTM)
D 149 Standard Methods of Test for Dielectric Breakdown Voltage and Dielectric Strength of
Electrical Insulating Materials at Commercial Power Frequencies
D 257 Standard Methods of Test for D-C Resistance or Conductance of Insulating Materials
D 412 Standard Test Method for Rubber Properties in Tension
D 570 Standard Methods of Test for Water Absorption of Plastics
D 635 Standard Methods of Test for Rate of Burning and/or Extent and Time of Burning of Self-
Supporting Plastics in a Horizontal Position
D 792 Standard Methods of Test for Specific Gravity and Density of Plastics by Displacement
D 882 Standard Test Methods for Tensile Properties of Thin Plastic Specimens
D 2671 Standard Methods of Testing Heat-Shrinkable Tubing for Electrical Use
D 2863 Standard Method for Measuring the Minimum Oxygen Concentration to Support Candle-
Like Combustion of Plastics (Oxygen Index)
D 3487 Specification for Mineral Insulating Oil Used in Electrical Apparatus
E 662 Test Method for Specific Optical Density of Smoke Generated by Solid Materials
(Copies of ASTM publications may be obtained from the American Society for Testing and Materials, 1916
Race Street, Philadelphia, Pennsylvania 19103.)
Page 2 SPECIFICATION RT-1323 ISSUE 1
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3. REQUIREMENTS
3.1 MATERIAL
The molded components shall be fabricated from a crosslinked, halogen- free, thermally stabilized, flame-
retarded, modified polyolefin composition. They shall be homogeneous and essentially free from flaws,
defects, pinholes, bubbles, seams, cracks, and inclusions.
3.2 COLOR
The molded components shall be black, unless otherwise specified.
3.3 PROPERTIES
The molded components and the material from which they are fabricated shall meet the requirements of
Table 1.
4. QUALITY ASSURANCE PROVISIONS
4.1 CLASSIFICATION OF TESTS
4.1.1 Qualification Tests
Qualification tests are those performed on molded slabs and components submitted for qualification as
satisfactory products and shall consist of all tests listed in this specification.
4.1.2 Acceptance Tests
Acceptance tests are those performed on molded slabs and components submitted for acceptance under
contract. Acceptance tests shall consist of the following: dimensions, dimensional recovery, tensile strength,
ultimate elongation, secant modulus, specific gravity and dielectric strength.
4.2 SAMPLING INSTRUCTIONS
4.2.1 Qualification Test Samples
Qualification test samples shall consist of molded slabs, 6 x 6 x 0.075 ± 0.010 inches
(152 x 152 x 1.9 ± .25 mm) and the number of molded components specified. The molded slabs shall be
fabricated from the same lot of material and shall be subjected to the same degree of crosslinking as the
molded components.
4.2.2 Acceptance Test Samples
Acceptance test samples shall consist of specimens cut from a molded slab,
6 x 6 x 0.075 ± 0.010 inches (152 x 152 x 1.9 ± .25 mm), and molded components selected at random. The
molded slab shall be fabricated from the same lot of material and shall be subjected to the same degree of
crosslinking as the molded components.
A lot of components shall consist of all molded components from the same lot of material, from the same
production run, and offered for inspection at the same time.
4.3 TEST PROCEDURES
4.3.1 Dimensional Recovery
Samples of molded components, as supplied, shall be measured for dimensions in accordance with ASTM D
2671. The samples then shall be conditioned for 10 minutes in a 150 ± 2°C (302 ± 4°F) oven or equivalent,
cooled to room temperature, and remeasured.
4.3.2 Tensile Strength and Ultimate Elongation
Three specimens cut from a molded slab using die D of ASTM D 412 shall be tested for tensile strength and
ultimate elongation in accordance with ASTM D 412.
4.3.3 Secant Modulus
Five specimens, 6 x 3/4 x 0.075 inches (150 x 19 x 1.9 mm) cut from a molded slab shall be tested for secant
modulus at two percent strain in accordance with ASTM D 882. Use an initial jaw separation of 4 inches
(100 mm) and a crosshead speed of 0.4 inches (10 mm) per minute.
SPECIFICATION RT-1323 ISSUE 1 Page 3
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4.3.4 Low Temperature Flexibility
Three 6 x 1/4 inch (152 x 6.3 mm) specimens cut from a slab shall be conditioned, along with a
3-inch (75-mm) mandrel, in a cold chamber at -20 ± 2°C (-4 ± 4°F) for 4 hours. After completion of the
conditioning, and while still in the cold chamber, each specimen shall be bent around the mandrel through not
less than 360 degrees within 10 ± 2 seconds. The specimens then shall be visually examined for cracks.
4.3.5 Heat Shock
Three 6 x 1/4 inch (152 x 6.3 mm) specimens cut from a molded slab shall be conditioned for 4 hours in a 225
± 5°C (437 ± 9°F) mechanical convection oven with an air velocity of 100 to 200 feet
(30 to 60 m) per minute past the specimens. After conditioning, the specimens shall be removed from the
oven, cooled to room temperature, and then shall be visually examined for evidence of dripping, flowing, or
cracking.
4.3.6 Heat Aging
Three specimens prepared and measured in accordance with 4.3.2, shall be conditioned for
168 hours in a 150 ± 3°C (302 ± 5°F) mechanical convection oven in which air passes the specimens at a
velocity of 100 to 200 feet (30 to 60 m) per minute. After conditioning, the specimens shall be removed from
the oven, cooled to room temperature, and tested for tensile strength and ultimate elongation in accordance
with 4.3.2.
4.3.7 Fluid Resistance
Three specimens prepared in accordance with 4.3.2, shall be completely immersed in each of the fluids listed
in the applicable section of Table 1 for 24 hours at the specified temperature. The volume of the fluid shall
be not less than 20 times that of the specimens. After conditioning, the specimens shall be lightly wiped and
air dried for 30 to 60 minutes at room temperature. The specimens then shall be tested for tensile strength
and ultimate elongation in accordance with 4.3.2.
4.3.8 Oxygen Index at Elevated Temperature
Determine the oxygen index using the apparatus described in ASTM D 2863 with the exception of a special
double wall glass chimney replacing the standard chimney. This chimney must be equipped with a heating
element and temperature controller capable of maintaining the temperature of the gas atmosphere in the
chimney to ± 2°C (± 4°F).
With the gas supply regulated to 21% oxygen content, determine the temperature, within 10°C (18°F), at
which the specimen will burn 3 minutes or 2 inches (50 mm), whichever occurs first, using the endpoint
criteria of ASTM D 2863. Report this temperature as the oxygen index at elevated temperature.
4.4 REJECTION AND RETEST
Failure of any samples to comply with any one of the requirements of this specification shall be cause for
rejection of the lot represented. Material which has been rejected may be replaced or reworked to correct the
defect and then resubmitted for acceptance. Before resubmitting, full particulars concerning the rejection and
the action taken to correct the defect shall be furnished to the inspector.
5. PREPARATION FOR DELIVERY
5.1 PACKAGING
If not specified, packaging of molded components shall be in accordance with good commercial practice.
The exterior shipping container shall be not less than 125 pound-test fiberboard.
5.2 MARKING
Each molded component shall be distinctly identified on the part and/or package with the manufacturer's
name or symbol, the manufacturer's part number, and lot number.
Page 4 SPECIFICATION RT-1323 ISSUE 1
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TABLE 1
Requirements
PROPERTY UNIT REQUIREMENT TEST METHOD
PHYSICAL
Dimensions
in (mm)
In accordance with applicable
specification control drawing.
Sec. 4.3.1
Dimensional Recovery in (mm) In accordance with applicable
specification control drawing.
Tensile Strength, min. psi (MPa) 1000 minimum (7) Sec. 4.3.2
Ultimate Elongation, min. Percent 250 minimum ASTM D 412
Secant Modulus at 2% Strain psi (MPa) 7250-17400 (50-120) Sec. 4.3.3
ASTM D 882
Specific Gravity --- 1.5 maximum ASTM D 792
Low Temperature Flexibility
4 hours at -20°C (-4°F)
--- No cracking Sec. 4.3.4
Heat Shock
4 hours at 225°C (437°F)
--- No dripping, flowing or cracking Sec. 4.3.5
Heat Aging
168 hr. at 150°C (302°F)
Followed by tests for:
--- --- Sec. 4.3.6
Tensile Strength psi (MPa) 1000 minimum (7)
Ultimate Elongation Percent 100 minimum
ELECTRICAL
Dielectric Strength
V/mil (kV/mm)
380 minimum (15)
ASTM D 149
Short time test
Volume Resistivity ohm-cm 1012 minimum ASTM D 257
CHEMICAL
Water Absorption
24 hours at 23°C (73°F)
24 hours at 70°C (158°F)
Percent
0.5 maximum
1.5 maximum
ASTM D 570
Limiting Oxygen Index Percent 30 minimum ASTM D 2863
Oxygen Index
at Elevated Temperature
°C 250minimum Sec. 4.3.8
Flammability
Average Time of Burning
Average.Extent of Burning
seconds
in (mm)
100 maximum
1 maximum (25)
ASTM D 635
Smoke Density, Ds
4 minutes, flaming mode
--- 60 maximum ASTM E 662
Acid Gas Generation
HCl Equivalent
Percent 1.5 maximum MIL-C-24643
SPECIFICATION RT-1323 ISSUE 1 Page 5
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TABLE 1
Requirements
PROPERTY UNIT REQUIREMENT TEST METHOD
CHEMICAL (continued)
Fluid Resistance
24 hours at 23°C (73°F)
Hydraulic Fluid (MIL-H-5606)
JP-4 Fuel (MIL-T-5624)
*Skydrol 500
Hydraulic Fluid
ASTM Fuel B
Water
---
---
Sec. 4.3.7
24 hours at 50°C (122°F)
Lube Oil (MIL-L-23699)
Insulating Oil (ASTM D 3487)
24 hours at 100°C (212°F)
ASTM #2 Oil
Followed by tests for:
Tensile Strength psi (MPa) 725 minimum (5)
Ultimate Elongation Percent 150 minimum
*TM Monsanto Co.