202D153-4/86-0 (005087-000) - Tyco Electronics

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Tyco Electronics Corporation

300 Constitutional Drive

Menlo Park, CA 94025 USA

Specification

This Issue:

Date:

Replaces:

RT-1304

Issue 3

April 17, 1995

Issue 2

Thermofit® Polyolefin Molded Components

Flame-Retarded. Flexible, 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

100°C (212°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-G-5572 Gasoline, Aviation, Grades 80/87, 100/130, 115/145

MIL-H-5606 Hydraulic Fluid, Petroleum Base, Aircraft, Missile and Ordnance

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

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 Material.

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 747 Standard Methods of Test for Stiffness of Plastics by Means of a Cantilever Beam

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

(Copies of ASTM Publications may be obtained from 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 polyolefin composition. They shall be homogeneous and essentially free from flaws, defects,

pinholes, bubbles, seams, cracks, and inclusions.

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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: 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

+ .25mm) 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.

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 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 gage

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

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

shall be heated for 1 minute in a 150 + 2°C (302 + 4°F) oven, or equivalent, removed from the oven and

stretched within 10 seconds, until the gage 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 gage lines shall be measured and recorded as the extended length. The portion of the

specimen including both gage lines then shall be reheated for 1 minute in a 150 + 2 °C (302 + 4°F) oven,

or equivalent, and the distance between gage lines then shall be measured and recorded as the retracted

length.

SPECIFICATION RT-1304 ISSUE 3 Page 3

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Expansion and retraction shall be calculated as follows:

L e- Lo

E = Lo x 100

L e - Lr

R = 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 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.

4.3.4 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 tess than 360 degrees (6.28 rads) 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 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 (6.38 rads) 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

175 + 5 °C (347 + 9°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 Corrosive Effect

Three 1 x 1/4-inch (25.4 x 6.3-mm) specimens cut from a molded slab shall be tested for corrosive effect in

accordance with ASTM D 2671, Procedure A. The specimens shall be conditioned for 16 hours at 175 +

3°C (347 + 5°F).

4.3.8 Fluid Resistance

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

the test fluids listed in Table I for 24 hours at 25 + 3 °C (77 + 5 °F). 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 room temperature. The specimens then shall be tested for tensile strength

and ultimate elongation in accordance with 4.3 .3.

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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 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

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 with the manufacturing name or symbol and the

manufacturers part number.

SPECIFICATION RT-1304 ISSUE 3 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 275 minimum expansion

93 minimum retraction

Section 4.3.2

Tensile Strength psi (MPa) 1200 minimum (8.27) Section 4.3.3

Ultimate Elongation Percent 250 minimum ASTM D 412

Stiffness psi (MPa) 10,000 maximum (68.9) ASTM D 747

Specific Gravity --- 1.40 maximum ASTM D 792

Hardness Shore D 40 ± 5 ASTM D 2240

Low Temperature Flexibility

4 hours at -55ºC (-67ºF)

--- No cracking Section 4.3.4

Heat Shock

4 hours at 225ºC (437ºF)

--- No dripping, flowing o cracking. Section 4.3.5

Heat Aging

168hours at 175ºC (347ºF)

Followed by tests for:

--- --- Section 4.3.6

Tensile Strength psi (MPa) 1000 minimum (6.89) Section 4.3.3

Ultimate Elongation Percent 200 minimum

ELECTRICAL

Dielectric Strength

Volts/mil

(kV/mm)

225 minimum (8.9)

ASTM D 149

Volume Resistivity ohm-cm 1012 minimum ASTM D 257

CHEMICAL

Corrosive Effect

16 hours at 175ºC (347ºF)

---

Non corrosive

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 maximum (25)

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

Water Absorption

24 hours at 23ºC (73ºF)

Percent

0.5 maximum

ASTM D 570

Fluid Resistance

24 hours at 23ºC (73ºF) in:

JP-4 Fuel (MIL-T-5624)

Skydrol* 500

Hydraulic Fluid (MIL-H-5606)

Aviation Gasoline (100/130)

(MIL-G-5572)

Water

Followed by tests for:

--- --- Section 4.3.8

Tensile Strength psi (MPa) 750 minimum (5.22) Section 4.3.3

Ultimate Elongation Percent 200 minimum

*Trademark of the Monsanto Company.