Introducing ICO-PRINT
03/10/2016
UNIPLAS Corporation partnership for Japan
21/03/2019
Water repellency of synthetic ropes by a PTFE free coating
By HvdC, LH, and KvG
Summary
A comparison is made to study the effect of coatings on the water repellency of PA, PES and HMPE ropes. To improve the water repellency ICO-REPEL 20 is advised to be used as a single coating and/or in combination with our ICO-THANE’s.
ICO-REPEL 20 is completely PTFE free and replaces ICO-REPEL which contained a PTFE, based on C6 technology. It can be used as a single coating on PA, PES and HMPE.
For PA and PES ropes it can also be combined with ICO-THANE 10. On HMPE ropes the combination with ICO-THANE 10 performs best in these tests, when a small amount of LAGO 45 is added to the recipe.
The Capillary Effect
Background
Generally wettability will vary from fibre to fibre and initially can be influenced by the spin finish. However, a standard spin finish will wash out. To verify the effect of a coating on the capillary effect, a simple test was conducted where the coated rope was immersed in water with a blue colorant. By measuring the height a relative comparison can be made between the different systems, see also sketch.
Coatings Tested
Three different polyurethanes were tested in combination with a PTFE free coating, to determine the relative water repellency:
- ICO-THANE 10 is a medium-soft, flexible, light-fast polyester-based aqueous aliphatic polyurethane dispersion compound. Applied on a rope or twine it will give a smooth touch.
- ICO-THANE 32 is a medium, soft flexible, light-fast polyester-based aqueous aliphatic polyurethane dispersion compound.
- ICO-REPEL 20 is a medium soft, flexible, acrylic, methacrylic esters, wax based dispersion with excellent water-repellence characteristics. It was especially developed to improve the water repellence of a strand, braid, rope or belt.
- LAGO 45 is a synthetic polymer based anionic polyurethane, especially developed for the impregnation and the textile finishes of ropes, twines and fishing nets made from HMPE fibres.
Results
All the tests described here, were conducted on small diameter braided ropes, with a standard construction. Please note that the capillarity effect is also influenced by the spin finish on the fibre and the rope construction. The results given here are indicative and for critical use, the actual performance should be verified in a representative design.
In the tests, the best results were obtained, when the coated ropes were cured after drying at a temperature of 80° - 90°C. When the coated rope is dried at room temperature, then at least two weeks should be allowed before the coated rope reaches its maximum water repellency.
| PA | PES | |||||||
|---|---|---|---|---|---|---|---|---|
| Coating | dilution | coating pick-up | uptake cm | WR | dilution | coating pick-up | uptake cm | WR |
| Uncoated | 17 | 0% | 10 | 0% | ||||
| ICO-THANE 10 | (1:2) | 4-6% | 10 | 41% | (1:2) | 3-5% | 9 | 10% |
| ICO-THANE 32 | (1:2) | 4-6% | 16 | 6% | (1:2) | 3-5% | 9,5 | 5% |
| ICO-REPEL 20 | (1:2) | 7-8% | 0,2 | 99% | (1:2) | 4-6% | 0,2 | 98% |
| ICO-THANE 10 + ICO REPEL 20 mix |
(1:2) | 4-6% | 0,3 | 99% | (1:2) | 3-4% | 0,2 | 98% |
ICO-REPEL 20 was applied in a dilution of 1 to 2 with water, giving 7-8% of dry coating weight on the rope.
Also in combination with the ICO-THANE 10, the water repellency of ICO-REPEL 20 is excellent on polyamide and polyester braided ropes. In the tests done here only 10% is needed to improve the water repellency of the ICO-THANE 10. For this recipe also a dilution of 1:2 with water is used, adding 4-6% of coating weight on the rope after drying. It was used as reference.
| HMPE 1 | HMPE 2 | |||||||
|---|---|---|---|---|---|---|---|---|
| Coating | dilution | coating pick-up | uptake cm | WR | dilution | coating pick-up | uptake cm | WR |
| Uncoated | 25 | 0% | 12 | 0% | ||||
| ICO-THANE 10 | (1:2) | 8-10% | 20 | 20% | (1:2) | 8-10% | 11 | 8% |
| ICO-THANE 32 | (1:2) | 8-10% | 25 | 0% | (1:2) | 8-10% | 8,5 | 29% |
| ICO-REPEL 20 | (1:2) | 11-14% | 6 | 76% | (1:2) | 11-14% | 0,1 | 99% |
| ICO-THANE 10 + ICO-REPEL 20 mix |
(1:2) | 8-10% | 10,5 | 58% | (1:2) | 8-10% | 7,5 | 70% |
| ICO-THANE 10 + ICO-REPEL 20 + LAGO 45 mix |
(1:2) | 8-10% | 1,7 | 93% | (1:2) | 8-10% | 0,5 | 98% |
For HMPE’s a slightly higher concentration of ICO-REPEL 20 is needed to get a good water repellency. Here a dilution of 1:1 with water is used, adding 11-14% of dry coating weight on the rope.
In combination with ICO-THANE 10 the best result is achieved when 20% ICO-REPEL 20 and 10% LAGO 45 are added to the recipe before dilution with water (1:2). See also graphs below.
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- Water repellence PA and PES
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- Water repellence HMPE
Conclusions
ICO-REPEL 20 is a newly developed PTFE-free coating, which renders PA, PES or HMPE ropes an excellent water-repellency.
PA and PES ropes become highly water repellent, when ICO-REPEL 20 is added to ICO-THANE 10.
HMPE ropes become highly water repellent when ICO-REPEL 20 and LAGO 45 is added to ICO-THANE 10
For maximum performance it is recommended that the coated ropes are dried and cured at 80 - 90°C.
