Tyco Electronics Corporation 300 Constitutional Drive Menlo Park, CA 94025 USA Specification This Issue: Date: Replaces: RT-1321 Issue 3 December 1, 1981 Issue 2 THERMOFIT(R) ELASTOMERIC POLYMER BLEND MOLDED COMPONENTS Flame Resistant, 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 175C (347F). 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 2.2 Cleaning Compound, High Pressure (Steam) Cleaner Military MIL-G-3056 Gasoline, Automotive, Combat MIL-H-6083 Hydraulic Fluid, Petroleum Base, for Preservation and Operation MIL-L-7808 Lubricating Oil, Aircraft Turbine Engine, Synthetic Base MIL-F-46172 Fuel, Diesel, Referee Grade MIL-H-46170 Hydraulic Fluid, Rust Inhibited Fire Resistant, Synthetic Hydrocarbon Base MIL-STD-105 Sampling Procedures and Tables for Inspection by Attributes 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 SelfSupporting 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 If this document is printed it becomes uncontrolled. Check for the latest revision. Page 2 SPECIFICATION RT-1321 ISSUE 3 (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-retsistant , modified elastomeric polymer blend. 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. If this document is printed it becomes uncontrolled. Check for the latest revision. SPECIFICATION RT-1321 ISSUE 3 4.3 TEST PROCEDURES 4.3.1 Dimensional Recovery Page 3 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 2C (347 4F) 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 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 5 minutes in a 175 2C (347 4F) 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 5 minutes in a 175 2C (347 4F) 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 x 100 Lo Le - Lr R = L - L x 100 e o Where: 4.3.3 E R Lo Le Lr = = = = = Expansion (percent) Retraction (percent) Original Length [inches (mm)] Extended Length [inches (mm)] Retracted Length [inches (mm)] 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 3/8inch (9.5-mm) mandrel, in a cold chamber at -55 3C (-67 5F) 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 200 5C (392 9F) 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 over a 3/8-inch (9.5-mm) diameter mandrel. The specimens then shall be visually examined for evidence of dripping, flowing or cracking. If this document is printed it becomes uncontrolled. Check for the latest revision. Page 4 4.3.6 SPECIFICATION RT-1321 ISSUE 3 Heat Aging Three specimens, prepared and measured in accordance with 4.3.3 shall be conditioned for 168 hours in a 121 3C (250 9F) 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 3C (73 4F) . 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. If this document is printed it becomes uncontrolled. Check for the latest revision. SPECIFICATION RT-1321 ISSUE 3 Page 5 TABLE 1 Requirements PROPERTY PHYSICAL Dimensions UNIT REQUIREMENTS TEST METHOD Inches (mm) Section 4.3.1 ASTM D 2671 Dimensional Recovery Inches (mm) Elastic Memory Percent Tensile Strength Tensile Stress Ultimate Elongation Specific Gravity Hardness Low Temperature Flexibility 4 hours at -55C (-67F) Heat Shock 4 hours at 200C (392F) Heat Aging 168 hours at 121C (250F) Followed by tests for: Tensile Strength Elongation ELECTRICAL Dielectric Strength psi (MPa) psi (MPa) Percent --Shore A In accordance with applicable specification control drawing In accordance with applicable specification control drawing 200 minimum expansion 90 minimum retraction 1500 minimum (10.3) 1200 maximum(8.3) 300 minimum 1.6 maximum 85 + 10 No cracking Section 4.3.3 Section 4.3.3 ASTM D 412 ASTM D 792 ASTM D 2240 Section 4.3.4 --- No dripping, flowing or cracking Section 4.3.5 --- --- Section 4.3.6 psi (MPa) Percent 1200 minimum (8.3) 250 minimum Section 4.3.3 Volts/mil (kV/mm) ohm-cm 200 minimum (7.9) ASTM D 149 1010 minimum ASTM D 257 Seconds 120 maximum ASTM D 635 Inches (mm) --Percent 1.0 maximum (25) Rating of 1 or less 1.0 maximum ASTM G 21 ASTM D 570 --- --- Section 4.3.7 psi (MPa) percent percent 1000 minimum (6.9) 225 minimum 10 maximum Section 4.3.3 Volume Resistivity CHEMICAL Flammability Average Time of Burning Average Extent of Burning Fungus Resistance Water Absorption 24 hours at 23C (73F) Fluid Resistance 24 hours at 25 3C (77 5F) in: Lubricating Oil (MIL-L-7808) Diesel Oil (MIL-F-46462) Water Followed by tests for: Tensile Strength Ultimate Elongation Weight Increase If this document is printed it becomes uncontrolled. Check for the latest revision. Section 4.3.2 Section 4.3.7 Page 6 SPECIFICATION RT-1321 ISSUE 3 TABLE 1 Requirements CHEMICAL (Continued) Fluid Resistance 24 hours at 25 3C (77 5F) in: Gasoline Automotive (MIL-G-3056) Followed by tests for: Tensile Strength Ultimate Elongation Weight Increase Fluid Resistance 24 hours at 25 3C (77 5F) in: Isopropyl Alcohol Cleaning Fluid (P-C-437) Followed by tests for: Tensile Strength Ultimate Elongation Weight Increase Fluid Resistance 24 hours at 71 3C (160 5F) in: Hydraulic Fluid (MIL-H-6083) Hydraulic Fluid (MIL-H-46170) Followed by tests for: Tensile Strength Ultimate Elongation Weight Increase --- --- Section 4.3.7 psi (MPa) percent percent --- 800 minimum (5.5) 225 minimum 25 maximum --- Section 4.3.3 psi (MPa) percent percent --- 1400 minimum (9.7) 225 minimum 10 maximum --- Section 4.3.3 psi (MPa) percent percent 1000 minimum (6.9) 225 minimum 25 maximum If this document is printed it becomes uncontrolled. Check for the latest revision. Section 4.3.7 Section 4.3.7 Section 4.3.7 Section 4.3.7 Section 4.3.3 Section 4.3.7