China Rope & Line Group Ltd

MADE IN CHINA ROPE

Synthetic Winch Rope Information, Analysis and Summary

Synthetic Winch Rope Information, Analysis and Summary

Trade names

Strength of 3/8" (lbs.)

Elong. at break

Crit. Temp.

Melting Point

Chafe Res.

UV Res.

Misc.

Kevlar

12,000

1.5 - 4.5%

400° F

930° F

Fair

Fair

Strong, very low-stretch, no creep; very fatigue-prone when worked

Technora Aramid

18,500

1.5 - 4.5%

350° F

930° F

Good

Fair/Good

Strong, very low-stretch, no creep

Dyneema, Spectra

19,000

2.3 - 3.9%

150° F

290° F

Very Good

Fair/Good

Strong, very low-stretch Creeps; Integrity degredation above 150°F.

Vectran

20,000

4 - 5%

300° F

625° F

Very Good

Poor

Strong, low-stretch, no creep, UV-sensitive.

Polypropylene

4,100

18 - 22%

200° F

 

Fair

 

Low cost - Never use Polypropylene for winch rope.

Summary:

Winch rope is a compromise. We can only choose the best combination of the previously listed atributes.

The ultimate winch rope would have: Strength of Vectran - Stretch of Technora - Heat Resistance of Kevlar - Abrasion Resistance of Stainless Steel - UV Resistance of Stainless Steel and Cost of Polypropelene. This given lets look at what we need in a good winch line.

UV Resistance - Coatings that are applied to the rope after the weaving process protect the fibers of the rope from the damage that would otherwise be caused by the Sun's harmfull UV rays. Any of these fibers can be treated and this becomes a non-issue.

Abrasion resistance. All of the above fibers are pron to damage from abrasion. Steel wire rope is far and away a superior product in this catagory. Any high quality winch rope should come with a chafe guard. This is a tube that can slide along the lenght of the rope. This provides a good form of protection from abrasion and this becomes a non-issue

Strength - A recommended strength is three times your vehicle weight. In the 3/8" catagory this eliminates Kevlar and PolyPropylene as a synthetic fiber for light weight truck and Jeep recovery.

Critical Temp - There is a great amount of heat pruduced by the brake on a planetary winch. This eliminates Dyneem / Spectra.

What's left? Technora.

Conclusion: Technora, though a bit more expensive than the more commonly used Dyneema seems to fit our purpose the best. High strength, good abrasion and high heat resistance make Technora the best winch line available. There's good reason that Ramsey Winch Company offers Technora winch lines. The prices are steep though. We at JeepSWAG have decided to manufacture winch rope assemblies ourselves. As with all the products we offer, you'll be able to buy them at deeply discounted, factory direct prices. Check back soon for price and availability.

Some additional technical informatio about synthetic fibers:

Dyneema fibers derive their strength from the extreme length of each individual molecule. The fibre can attain a parallel orientation greater than 95% and a level of crystallinity of up to 85%. Its melting point is around 175 degrees and DSM (the fiber manuacturer), it is not advisable to use Dyneema at temperatures exceeding 175 to 210 degrees.

Kevlar derives its strength from strong bonding between relatively short molecules. Its melting point is around 600 degrees.

Technora, like Kevlar, is an aramid, but with vastly improved fatigue properties. It shares Kevlar's high tensile strength and high melting point.

Spectra:
Spectra is a very high molecular density form of polyethylene - the same thing used to make grocery bags, six-pack carriers and milk jugs. The manufacturing process aligns the molecules, which vastly increases the strength of the material. It is twice as strong as hardened steel (per unit area) and one-tenth the density. Spectra has several difficult issues. The melting point is very low, 290 degrees, not much warmer than boiling water. The material is unbelievably slippery, which makes it difficult for manufacturers to form into a workable rope. And, while the modulus of the fibers is comparable to steel, they slowly elongate under a continuous load. This process is called "creep." It is mostly irrelevant to climbers, but annoying to sailors. Spectra/Nylon is also known as Dyneema (a trade name of Beal Ropes) in Europe.

Vectran:
Vectran is a liquid crystal polymer - its properties are between those of crystalline solids and liquids. It has similar strength to Spectra, but without the creep problems. It has poor UV resistance, even when covered.