Load bearing traction members and method
A lifting member for an elevator system is disclosed, including a rope formed from a plurality of strands comprising liquid crystal polymer fibers, with the strands extending along a length of the lifting member. A first polymer coating is disposed on outer surfaces of the fibers or on outer surfaces of the strands. A second polymer coating disposed over the first polymer coating.
1. A lifting member for an elevator system, comprising
a rope formed from a plurality of strands, each of the strands comprising liquid crystal polymer fibers, said strands extending along a length of the lifting member;
a first polymer coating on outer surfaces of the fibers or on outer surfaces of the strands;
a second polymer coating disposed over the first polymer coating;
a third polymer coating disposed over the second polymer coating;
wherein the third polymer coating is formed from a material different than a material forming the second polymer coating.
2. The lifting member of claim 1 , wherein the first polymer coating includes active groups selected from glycidyl, carboxyl, amino, isocyanate, amide or hydroxyl.
3. The lifting member of claim 1 , wherein the first polymer coating comprises an acrylic polymer, an epoxy polymer, a urethane polymer, melamine resins, or acrylamide polymer.
4. The lifting member of claim 1 , wherein the liquid crystal polymer comprises an aromatic polyester.
5. The lifting member of claim 1 , wherein the strands comprise at least 50 wt. % liquid crystal polymer fibers, based on total weight of the strands.
6. The lifting member of claim 1 , wherein the strands further comprise fibers selected from carbon fibers, glass fibers, polybenzoxazole fibers, or polyamide fibers.
7. The lifting member of claim 1 , wherein the second polymer coating comprises an elastomeric polymer selected from polyamides, olefins, elastomers, EPDM, fluoropolymers, chloropolymers, or chlorosulfurno elastomers.
8. The lifting member of claim 1 , wherein the third polymer coating comprises an ethylene propylene diene polymer.
9. The lifting member of claim 8 , wherein the third polymer coating further includes a UV stabilizer or both a flame retardant and a UV stabilizer.
10. A method of making the lifting element of claim 1 , the method comprising:
providing the plurality of strands comprising liquid crystal polymer fiber filaments, said fiber filaments or said strands coated with the first polymer coating or a precursor to the first polymer coating;
forming the plurality of strands into the rope;
disposing the second polymer coating over the plurality of strands;
disposing the third polymer coating over the second polymer coating as an outer layer of the rope.
11. The method of claim 10 , further comprising forming said strands from said liquid crystal polymer fiber filaments, said filaments coated with the first polymer coating or precursor to the first polymer coating.
12. A method of making the lifting element of claim 1 , the method comprising:
forming the plurality of strands comprising liquid crystal polymer fiber filaments into the rope;
impregnating the strands with a fluid composition comprising the first polymer coating or a precursor to the first polymer coating;
disposing the second polymer coating over the impregnated strands;
disposing the third polymer coating over the second polymer coating as an outer layer of the rope.
13. An elevator system, comprising
a hoistway;
an elevator car disposed in the hoistway and movable therein; and
a lifting member according to claim 1 , said lifting member operably connected to the elevator car to suspend and/or drive the elevator car along the hoistway.
14. The elevator system of claim 13 , wherein the first polymer coating includes active groups selected from glycidyl, carboxyl, amino, isocyanate, amide or hydroxyl.
15. The elevator system of claim 13 , wherein the first polymer coating comprises an acrylic polymer, an epoxy polymer, a urethane polymer, melamine resins, or acrylamide polymer.
16. The elevator system of claim 13 , wherein the liquid crystal polymer comprises an aromatic polyester.
17. The elevator system of claim 13 , wherein the strands comprise at least 50 wt. % liquid crystal polymer fibers, based on total weight of the strands.
18. The elevator system of claim 13 , wherein the strands further comprise fibers selected from carbon fibers, glass fibers, polybenzoxazole fibers, or polyamide fibers.
19. The elevator system of claim 13 , wherein the second polymer coating comprises an elastomeric polymer selected from polyamides, olefins, elastomers, EPDM, fluoropolymers, chloropolymers, or chlorosulfurno elastomers.
20. The elevator system of claim 13 , wherein the third polymer coating comprises an ethylene propylene diene polymer.