207W213-25-01/225-0 (255611-000) - Tyco Electronics

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Tyco Electronics Corporation

300 Constitutional Drive

Menlo Park, CA 94025 USA

Specification

This Issue:

Date:

Replaces:

RT-1325

Issue 6

February 23, 2001

Issue 5

THERMOFIT® ELASTOMERIC MOLDED COMPONENTS

Flame-Retarded, Semi-Rigid, Heat-Shrinkable

1. SCOPE

This specification covers the requirements for one type of flexible, electrical insulating molded component

whose expanded dimensions will reduce to a predetermined size upon the application of heat in excess of

175°C (347°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

Federal

P-C-437 Cleaning Compound, High Pressure (Steam) Cleaner

VV-F-800 Diesel Fuel

Military

MIL-G-3056 Gasoline, Automotive, Combat

MIL-T-5624 Turbine Fuel, Aviation, Grades JP-4 and JP-5

MIL-PRF-6083 Hydraulic Fluid, Petroleum Base, for Preservation and Operation

MIL-A-8243 Anti-Icing and Deicing-Defrosting Fluid

MIL-L-23699 Lubricating Oil, Aircraft Turbine Engines, Synthetic Base

MIL-H-46170 Hydraulic Fluid, Rust Inhibited Fire Resistant, Synthetic Hydrocarbon Base

MIL-STD-105 Sampling Procedures and Tables for Inspection by Attributes

2.2 OTHER PUBLICATIONS

American Society for Testing and Materials (ASTM)

D 149 Standard Methods of Tests 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 Method of Tests 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 2240 Standard Method of Tests for Rubber Property -- Durometer Hardness

D 2671 Standard Methods of Testing Heat Shrinkable Tubing for Electrical Use

G 21 Recommended Practice for Determining Resistance of Synthetic Polymeric Materials to

Fungi

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(Copies of ASTM Publications may be obtained form the American Society for Testing and Materials, 1916

Race Street, Philadelphia, Pennsylvania 19103.)

3. REQUIREMENTS

3.1 MATERIAL

The molded components shall be fabricated from a crosslinked, thermally stabilized, flame-resistant,

modified elastomeric 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.

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, heat shock, and flammability.

4.2 SAMPLING INSTRUCTIONS

4.2.1 Qualification Test Samples

Qualification test samples shall consist of six 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 in accordance with MIL-STD-105,

inspection Level S-2, AQL 6.5 percent. 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.

SPECIFICATION RT-1325 ISSUE 6 Page 3

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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 175 ± 2°C (347 ± 5°F) oven, or equivalent,

cooled to room temperature and re-measured.

4.3.2 Elastic Memory

A 6 x 1/8-inch (152 x 3.2-mm) specimen cut from a molded slab shall be marked with two parallel gauge

lines 1 inch (25 mm) apart in the central portion of the specimen. The distance between gauge lines shall be

recorded as the original length. A 2-inch (51-mm) portion of the specimen including both gauge lines then

shall be heated for 1 minute in a 175 ± 2°C (347 ± 4°F) oven, or equivalent, removed from the oven and

stretched within 10 seconds, until the gauge lines are 4 inches (102 mm) apart. The extended specimen shall

be cooled to room temperature and released from tension. After 24 hours at room temperature, the distance

between the gauge lines shall be measured and recorded as the extended length. The portion of the specimen

including both gauge lines then shall be reheated for 1 minute in a 175 ± 2°C (347 ± 4°F) oven, or

equivalent, and the distance between gauge lines then shall be measured and recorded as the retracted length.

Expansion and retraction shall be calculated as follows:

E = Le - Lo

Lo x 100

R = Le - Lr

Le - Lo x 100

Where: E = Expansion (percent)

R = Retraction (percent)

Lo = Original Length [inches (mm)]

Le = Extended Length [inches (mm)]

Lr = Retracted Length [inches (mm)]

4.3.3 Tensile Strength, Tensile Stress and Ultimate Elongation

Three specimens cut from a molded slab using Die D of ASTM D 412 shall be tested for tensile strength,

tensile stress and ultimate elongation in accordance with ASTM D 412.

4.3.4 Low Temperature Flexibility

Three 6 x 1/4-inch (152 x 6.3-mm) specimens cut from a molded slab shall be conditioned, along with a 3/8-

inch (9.5-mm) mandrel, in a cold chamber at -55 ± 2°C (-67± 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 from 100 to

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200 feet per minute past the specimens. After conditioning, the specimens shall be removed from the oven,

cooled to room temperature, and bent through 360 degrees over a 3/8-inch (9.5-mm) diameter mandrel. The

specimens 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 4.3.3 shall be conditioned for

168 hours in a 150 ± 3°C (302 ± 5°F) mechanical convection oven with an air velocity of 100 to

200 feet per minute past the specimens. 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 4.3.3.

4.3.7 Fluid Resistance

Six specimens prepared and measured in accordance with 4.3.3 shall be completely immersed in each of the

test fluids listed in Table 1 for 24 hours at the temperature specified. 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 then

air-dried for 30 to 60 minutes at 23 ± 2°C (73 ± 4°F) . The three specimens intended for the tensile strength

and elongation tests shall then be tested for tensile strength and ultimate elongation in accordance with 4.3.3.

The other three specimens shall be weighed before and after immersion and the weight change calculated as

a percent.

4.4 REJECTION AND RETEST

Failure of any sample 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 them 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

Packaging of molded components shall be in accordance with good commercial practice. The 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 manufacturing

name or symbol, the manufacturer’s part number, lot number, date of manufacture, and use before date.

SPECIFICATION RT-1325 ISSUE 6 Page 5

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TABLE 1

Requirements

PROPERTY UNIT REQUIREMENTS TEST METHOD

PHYSICAL

Dimensions

Inches (mm)

In accordance with applicable

specification control drawing

Section 4.3.1

ASTM D 2671

Dimensional Recovery Inches (mm) In accordance with applicable

specification control drawing

Elastic Memory Percent 200 minimum expansion

90 minimum retraction Section 4.3.2

Tensile Strength psi (MPa) 1500 minimum (10.3) Section 4.3.3

Tensile Stress @100% Elongation psi (MPa) 1500 maximum (10.3)

Ultimate Elongation Percent 350 minimum ASTM D 412

Specific Gravity --- 1.40 maximum ASTM D 792

Hardness Shore D 45 + 10 ASTM D 2240

Low Temperature Flexibility

4 hours at -55°C (-67°F) No cracking Section 4.3.4

Heat Shock

4 hours at 225°C (437°F) --- No dripping, flowing or cracking Section 4.3.5

Heat Aging

168 hours at 150°C (302°F)

Followed by tests for:

--- --- Section 4.3.6

Tensile Strength psi (MPa) 1200 minimum (8.3) Section 4.3.3

Elongation Percent 300 minimum

ELECTRICAL

Dielectric Strength

Volts/mil

(kV/mm)

300 minimum (11.8)

ASTM D 149

Volume Resistivity ohm-cm 1012 minimum ASTM D 257

CHEMICAL

Corrosive Effect

16 hours at 150°C (302°F)

---

Noncorrosive

Section 4.3.7

ASTM D 2671

Procedure A

Flammability

Average Time of Burning

Seconds

120 maximum

ASTM D 635

Average Extent of Burning Inches (mm) 1.0 maximum (25)

Fungus Resistance --- Rating of 1 or less ASTM G 21

Fluid Resistance

24 hours at 25 ± 3°C (77 ± 5°F) in:

JP-4 Fuel (MIL-T-5624)

Hydraulic Fluid (MIL-H-5606)

Defrosting Fluid (MIL-A-8243)

Lubricating Oil (MIL-L-23699)

Cleaning Compound (P-C-437)

--- --- Section 4.3.8

Water

Followed by tests for:

Tensile Strength psi (MPa) 1000 minimum (6.9) Section 4.3.3

Ultimate Elongation percent 200 minimum

Weight Increase percent 8 maximum Section 4.3.8

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TABLE 1

Requirements

CHEMICAL (Continued)

Fluid Resistance

24 hours at 50 ± 3°C (122 ± 5°F) in:

DF-2 (VV-F-800)

JP-4 Fuel (MIL-T-5624)

Followed by tests for:

--- --- Section 4.3.8

Tensile Strength psi (MPa) 1000 minimum (6.9) Section 4.3.3

Ultimate Elongation percent 200 minimum

Weight Increase percent 15 maximum Section 4.3.8

Fluid Resistance

24 hours at 71 ± 3°C (160 ± 5°F) in:

Hydraulic Fluid (MIL-PRF-6083)

Hydraulic Fluid (MIL-H-46170)

--- --- Section 4.3.8

Followed by tests for:

Tensile Strength psi (MPa) 1000 minimum (6.9) Section 4.3.3

Ultimate Elongation percent 200 minimum

Weight Increase percent 25 maximum Section 4.3.8