Drogue Parachute Material

MaterialDescription
Nylon

  • 6-6 → primary parachute material (Source 2)

  • MIL-C-7020 Type III (nylon, ~1.6 oz/yd2 and 100–160 CFM/ft2) (Source 1)

  • F-111 (nylon, 3–5 CFM/ft2)   → from wiki, recovery materials (Source 1)

    • Polyamide - F-111 brand, lightweight and airtight, easily dyeable, typical parachute nylon fabric.

  • Polyamide resin (synthetic) → high tenacity = 6.6  (Source 2)

    • Stress @ break (psi) = 12,800 * specific gravity * tenacity = 128000 * 1.14 * 6.6 = 96psi

    • Minimum elongation specified as 20%, actual elongation 30-40% at break

  • Sensitive to UV light (Source 2)

  • Melts at 480F (Source 2), does not burn (Source 4)

Kevlar (Source 3, unless specified)

  • Kevlar - 29 → a para-aramid fiber produced by E. I. DuPont de Nemours & Co

  • less than one half the weight and one-third the bulk of nylon materials with the same ultimate tensile strength

  • More resistant to strength degradation at elevated temperatures

    • Nylon fails around 290C, but kevlar retains half of its strength

  • Kevlar stretches by only 5% of its original length before failing, whereas nylon stretches by approximately 25%.

  • High tenacity → 2.5-3 times stronger than nylon (Source 4)

  • May be much more expensive than nylon (Source 4)

  • Chinese finger splicing is possible with Kevlar lines; however, the length of the insert should be equal to 15 times the line diameter, instead of 10 times the line diameter as on nylon. (Source 4)

  • The canopy is a continuous-ribbon design rather than a cut-gore construction; again, this design maximizes strength and minimizes weight by reducing the number of ribbon splices and eliminating material overlap at each radial.

Dacron

  • Polyester based, similar to nylon, but requires more treatment for good stability (Source 4)

  • Lower elongation than nylon (Source 4)

  • More temp resistant than nylon (Source 2)

  • Less weight and volume for comparable strength to nylon (Source 2)

Rayon (Source 4)

  • Loses 40% strength when wet

  • Burns easily without melting, decomposes at 450F

  • Used for cargo parachutes in WW2, not really used today

Thread Material

  • same as what being sewn → nylon thread for nylon chute (Source 2)

  • Nylon threads may melt in a sewing machine

Deployment Bags

MaterialDescription
PTFE → Teflon (Source 2, unless specified)

  • Used for deployment bag liners

  • Very expensive

  • Low friction

  • Also can be buffer material

  • Fluorocarbon fiber (Source 4)

  • Used as deployment bag liner and as buffer material where high-speed contact between two nylon components of parachute assembly may cause friction burns (Source 4)

  • Kevlar (Source 3)

  • high strength-to-weight ratio and low ultimate elongation are particularly desirable in the construction of deployment bags for high density packs 

Suspension Lines

  • Kevlar (Source 3)

    • Using kevlar suspension lines on existing parachutes can enable the designer to utilize a proven canopy design while reducing the overall parachute system weight and volume.

    • Can double with nylon lines without increasing weight/volume

    • Attached near skirt

    • Some designers have been reluctant to use Kevlar suspension lines in parachutes for fear that snatch loads might be significantly higher than for nylon suspension lines because Kevlar's ultimate elongation is so much lower than nylon's. Nylon lines are able to store more energy than Kevlar lines of the same strength when equal loads are applied.

What Fruity Chutes Uses (https://fruitychutes.com/): 

  •  Parachute
    • Classical Elliptical Chutes from Fruity Chutes
      • Lightweight 1.1oz Mil-spec calendared Ripstop nylon
      • HP Chutes feature heavy duty tubular nylon bridal and swivel sized to your parachute
    • Iris Chutes from Fruity Chutes
      • Same material
      • Nylon IIIa Paraline shroud lines for strength at lower cost
    • Iris Compact Chutes
      • Same parachute material
      • Spectra shroud lines. Standard is our custom 400# Spectra Nanoline. Optional 725# flat Spectra Nanoline

  • Shock cords

  • Common are nylon, spectra, and kevlar

SOURCES

  1. Wiki (Parachute Design & Fabrication, Recovery Materials (Fabrics, Webbings, and More!))

  2. WPP-263 - 14 Parachute Materials and Stress Analysis, Wolf → from Recovery Zotero

  3. Application of Kevlar to parachute system design → from Recovery Zotero

  4. Parachute Recovery Systems Design Manual, Section 6.6 Designing and Fabricating in Textiles(*) → from Recovery Zotero

(*) Source 4, pg. 6-82 to 6-84 and 6-91 have specific cloth names, ex: MIL-C-7020 Type III


Tables from Source 4, comparing materials

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