Determination of Dry CoatingEffectiveness Against Water impregnation.

An examination of various testing methods. 

William J. (Bill) Fronzaglia P.E.Director of Engineering

New England Ropes, Inc.848 Airport Road

Fall River, MA 02720

USA

Phone: 508-678-8200 / 800-333-6679

Fax: 508-679-2363 / 800-647-6731

www.neropes.com

UIAA Journal 2/2001 Pg. 25

Available at WWW.UIAA.CH

Definition

dry (dri) adj. Etymology: Middle English, from Old English dryge; akin to Old High German truckan dry, Old English drEahnian to drainDate: before 12th century

1 a : free or relatively free from a liquid and especially water b : not being in or under water <dry land>

c : lacking precipitation or humidity <dry climate>

• Fact: By Definition: Reduced water impregnation will reduce weight gain.

• Assumption: Keeping water out will keep performance up 

• Proper care and handling to reduce unnecessary water exposure is best 1st choice.

Behavior of Nylon when Wet.

• Weight Gain

• Decrease of tensile strength by 10% - 15%

• Decreased resistance to Yarn on Yarn Abrasion.

• Reduced Elongation

• Increased Impact force

• Decreases number of drops sustained.

• Increased diameter

• Increased risk!

Yarn Finish/Coating Technology

• Spin Finishes

• Marine Overlay Finishes

• Wax Emulsions

• Mineral Oil based products

• Silicone

• Multi part polymer coatings

• Proprietary coatings

Dying process removes beneficial finishes

• Benefits of coating• Improved Hydrophobic properties

• Improved Yarn on Yarn Abrasion Resistance

• Improved Yarn on Metal Abrasion Resistance

• Decreased Internal Yarn on Yarn Friction

• Reduction of dirt impregnation

• Increased Life? 

Manufacturer Claim

Manufacturer Claim

Manufacturer Claim

Manufacturer Claim

Manufacturer Claim

Manufacturer Claim

Manufacturer Claim

Manufacturer Claim

Alternate Test Methods• Water Droplet Test

• Flotation / Buoyancy Test.

• Shower Test – Mammut

• German Military Standard– Test TL 4020-0015 (BWB) Dynamic Ropes.

Method AMethod B (72 Hour Immersion)

• U.S. Fed. Test Method Std. No. 191A – Method 4500

– Method 6011 (24 Hour Immersion)

• 1, 2, 4, 24, 48, 72 Hour Immersion

Test ParametersU.S. FED-STD-191A

(6011)German TL 4020-0015 -

Method BImmersion Test Shower Test

Sample Preparation Length of sample 15" 200mm 200mm 200mm

Sealing of ends No Yes Yes Yes

Water Specifications (Store Bought Distilled Water was used for all tests)Ph 7 7 7 7Hardness 0 0 0 0Temperature 21°C - 70°F 21°C - 70°F 21°C - 70°F 21°C - 70°F

MethodologyWetting Method 9" submerged in loop Placed in 75mm H20 Placed in 75mm H20 18 l/m showerTest Duration (Hours) 24 Hours 72 Hours 1, 2, 4, 24, 48, 72 Hours 2.5 Min.

Drainage Method 1.5 Hours (Rack) 500g weight-3 Min. 3 Min. (Rack)Shake excess/weigh

immediatelyWeighing of Sample Nearest 0.001g Nearest 0.001g Nearest 0.001g Nearest 0.001g

Results of testing.Water Absorption

0.00

0.10

0.20

0.30

0.40

0.50

0.60

Shower Test 1 Hour 2 Hour 4 Hour 24 Hour 48 Hour 72 Hour

A

B

C

D

E

F

G

H

I

J

K

L

M

Results of testing.Water Absorption

0.00

0.10

0.20

0.30

0.40

0.50

0.60

FED-STD-191A (6011) 24 Hour Immersion

A

B

C

D

E

F

G

H

I

J

K

L

M

Results of testing.Water Absorption

0.00

0.10

0.20

0.30

0.40

0.50

0.60

72 Hour Immersion TL 4020-0015 - Method B

A

B

C

D

E

F

G

H

I

J

K

L

M

What happens if the rope is washed?

Results of testing.Water Absorption

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

1 Hour Immersion 1 Hour Immersion (After wash)

A

B

C

D

E

F

G

H

I

J

K

L

M

Results of testing.Water Absorption

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

FED-STD-191A (6011)

1 HourImmersion

2 HourImmersion

4 HourImmersion

24 HourImmersion

48 HourImmersion

72 HourImmersion

TL 4020-0015- Method B

1 Hour Immersion (After wash)

A

B

C

D

E

F

G

H

I

J

K

L

M

Conclusions

• All dry coatings are not equal.

• Ropes with better performance perform better in all tests.

• Some ropes have a barrier which allows them to float, this barrier is very fragile.

• These tests only address weight of water absorbed, not performance when wet.

Conclusions

• Best Test Method– Standard length samples.– Hold sample submerged to prevent surface

tension effect.– 1 hour duration, Longer is not necessary.– Drain on rack for 3 min.

Further Study Required

• Decrease in performance of nylon ropes vs. % of moisture gained.

• Real world exposure. Which method is most realistic?