Coated fabric and process for forming a polymeric coating on a liner
Fabrics are disclosed having a liner with a polymeric coating, the coating comprising 0.25 to 8 ridges per cm and pits at an area density of 20 to 2500 cm 2 . The fabrics provide good friction in oily conditions. Also disclosed are methods for producing such fabrics comprising applying to a liner a liquid comprising water and a precursor of a polymeric material, contacting the liquid on the liner with a water-sorbing material and curing the polymeric coating. The fabrics may find use in gloves.
1. A process for forming, on a liner, a polymeric coating having a surface containing ridges and pits, which process comprises the steps:
a) providing a liner;
b) applying to at least a portion of the liner a liquid comprising water and a precursor of a polymeric material to form a coating on the liner;
c) applying to the surface of the coating on the liner particles of a water-absorbing material selected from the group consisting of a cellulose derivative and a smectite clay;
d) allowing the particles of the water-absorbing material to absorb water from the coating on the liner thus causing shrinkage of the surface to form a wave-like pattern comprising ridges in the coating and coagulation of the precursor of the polymeric material around the particles to gel the ridges in the surface of the coating;
e) curing the precursor of the polymeric material to form a cured polymeric coating having ridges on the surface of the liner; and
f) leaching the cured polymeric coating with water to remove the particles of the water-absorbing material from the surface of the coating to leave pits in the surface of the cured polymeric coating.
2. The process as claimed in claim 1 , wherein the polymeric coating comprises an elastomer.
3. The process as claimed in claim 1 , wherein contacting the liquid with the water-sorbing material is by sprinkling the particles on the liquid, spraying the particles, shower coating with the particles or fluidised bed application.
4. The process as claimed in claim 2 , wherein the elastomer is a rubber.
5. The process as claimed in claim 4 , wherein the rubber is nitrile rubber.
6. The process as claimed in claim 1 , wherein the cellulose derivative comprises hydroxy ethyl cellulose.
7. A fabric comprising a liner having a polymeric coating on at least a portion thereof, which is formed by the process as claimed in claim 1 , wherein the polymeric coating comprises 0.25 to 8 ridges per cm and pits on the surface thereof at an area density of 20 to 2500 cm −2 .
8. The fabric as claimed in claim 7 , wherein the polymeric coating comprises an elastomeric coating.
9. The fabric as claimed in claim 8 , wherein the elastomeric coating is a rubber coating.
10. The fabric as claimed in claim 7 , wherein the coating comprises 50 to 2000 pits cm −2 .
11. The fabric as claimed in claim 7 , wherein the coating comprises 100 to 2000 pits cm −2 .
12. The fabric as claimed in claim 7 , wherein the polymeric coating comprises 1 to 5 ridges per cm.
13. The fabric as claimed in claim 7 , wherein the orientation of the ridges is substantially random.
14. The fabric as claimed in claim 7 , wherein the ridges are of varying height.
15. The fabric as claimed in claim 7 , wherein at least a portion of the ridges are of 4 mm height or less.
16. The process as claimed in claim 1 , wherein the polymeric coating comprises 0.25 to 8 ridges per cm and pits on the surface thereof at an area density of 20 to 2500 cm −2 .
17. A glove comprising a fabric as claimed in claim 7 .