Aerospace and cable products shallow

   The basic requirements for aerospace cable is light weight, small diameter, high temperature and wear resistance, and should also be resistant to fuel oil, lubricants and other chemical solvents. China's aerospace cable current national military standard GJB 773A-2000 "aerospace fluoropolymer insulated wire and cable general specification" as the main system, the polyimide composite film wrapped insulation rarely do. This specification applies to fluoropolymer insulated wire and cable products (hereinafter referred to as the aviation cable), including polytetrafluoroethylene (PTFE), Fluorinated ethylene propylene (FEP),

polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene ─ ethylene copolymer (ETFE), crosslinked ethylene-tetrafluoroethylene copolymer ─ (XETFE), tetrafluoroethylene - perfluoroalkyl vinyl ether copolymer (PFA) and other fluoropolymers. These polymers may be used alone, it can also be used in combination with other materials. This section describes some varieties.

1. Conductor materials and structures

   There tinned copper conductor, silver-plated copper, nickel-plated copper, tin-plated copper alloy wire, silver-plated copper alloy wire, nickel-plated copper alloy wire and aluminum wire (JL type). Coating restrict the use of temperature: tin 150 ℃, silver 200 ℃, nickel 250 ℃. Reference GJB 1640-1993 "aerospace grade varieties of wire and cable conductor cross-section series" 

standard, concentric stranded copper conductor cross-section, the structure size and DC resistance at 20 ℃ in , concentric stranded copper alloy conductor cross-section, the structure and size 20 ℃ DC resistance in Table 2, stranded copper conductor cross-section, the structure size and 20 ℃ DC resistance are shown in Table 3, concentrically stranded aluminum conductor cross-section, the structure size and DC resistance are shown in Table 4. Cross-section of the elongation at break of 0.5 mm2 copper conductors should not be less than 6% or less, the cross section 0.5 mm2 and an elongation at break above copper conductors shall be not less than 10%. All sectional specification elongation at break of copper conductor and aluminum alloy conductors shall be not less than 6%. less than 490MPa. The electrical resistivity of not more than 0.02196Ω · mm2 / m. Section Conductor Stranding pitch diameter ratio factor should not be greater than the requirements in Table.

Copper alloy single wire tensile strength not

    On the other hand, it should examine the various surface quality single line, in particular, should pay attention to the silver surface black singlet problem. In addition, it should be noted that when stranded and single-line coating scratch off.

2. insulating materials and their abbreviations

    Polytetrafluoroethylene (PTFE) extruded insulation and wear-resistant filler added with polytetrafluoroethylene (PTFE) extruded insulation (F4).

Fluorinated ethylene propylene (FEP) extruded insulation (F46).

─ ethylene tetrafluoroethylene copolymer (ETFE) extruded insulation (F40).

─ irradiation crosslinked ethylene tetrafluoroethylene copolymer (XETFE) extruded insulation (F40J).

─ ethylene chlorotrifluoroethylene copolymer (ECTFE) extruded insulation (F30).

PTFE film (turning film) wrapped insulation (F42).

Teflon tape around the insulation package (F43).

   Teflon tape / glass fiber coated with polytetrafluoroethylene emulsion / Teflon tape insulation combinations (F44).

   Fluorinated ethylene propylene (FEP) / polyvinylidene fluoride (PVDF) composite insulator (F45).

   PTFE / polyimide / polytetrafluoroethylene (PTFE / PI / PTFE) composite tape and Teflon tape insulation combinations (F47).

   All of the above performance requirements of the fluoropolymer in Table 6 to Table 13.

3. shielding materials and structures

     Shielding materials are round tin-plated copper wire, tinned flat copper wire, round silver-plated copper, silver-plated flat copper wire, round copper nickel-plated, nickel-plated flat copper wire, silver-plated copper alloy round wire, flat silver-plated copper alloy wire , nickel-plated copper alloy wire round and flat nickel-plated copper alloy lines. Shield structure has a round or flat braided conductor conductor braided, tightly wound round the conductor or flat conductor tightly wound. Shielding thickness of flat copper wire is 0.040mm ± 0.010mm, the width of the specification should be detailed provisions choose. Braid shield density should not be less than 85%; or not less than 90%. In addition to the core diameter greater than 7.9mm, braiding angle should not be less than 50 degrees and not more than 72 degrees. Braided copper joints should be trimmed, the shield should be continuity.

4. sheathing materials and structures

     Cable core sheath may be extruded FEP jacket or sheath ETFE or PVDF sheath concentricity should be not less than 70%. Raw material using PTFE tape wrap sheath wrapped corrugated rate should not be less than 25%, the high temperature sintered coating. Using extruded PTFE or PFA jacket sheath concentricity should be not less than 70%. Using dip PTFE fiber braided sheath emulsion composition, weave density should not be less than 98%. Core cable outer diameter of 6 mm or less dip PTFE latex, 6 mm or more wrapped 1-2 layers PTFE with raw material and extruded or PFA. Dip PTFE emulsion or sintered at high temperature should wrap PTFE raw material belt. Fiber braided layer PTFE content should be not less than 15%. Using PI / FEP composite tape wrapping sheath wrapped corrugated rate should be not less than 30%, after the coating coated FEP emulsion or PI varnish and high temperature melting sealing. Sheath thickness shall comply with the detailed specification requirements.

5. Silver-plated copper crosslinked ethylene - tetrafluoroethylene copolymer insulated wire and cable

    From the history of development, the rubber insulation cotton knit lacquer line in the 1950s eliminated PVC insulated nylon jacket line-out in the 1980s, after a variety of fluorine plastic insulated cables for the aviation mainstream varieties, F4 and F46 once dominant. The current mainstream products are silver plated copper conductor cross-linked ethylene - tetrafluoroethylene copolymer insulated wire and cable, including standard and light two series, the product type and name are shown in Table 14, the size of some of the products are shown in Table 15, the rated voltage AC 600 V, rated temperature of 200 ℃, the lowest ambient temperature of -65 ℃. Other varieties of fluorine plastic insulation can be found in detail GJB 773A-2000 standard, but not the amount of use.