Coated mining bolt
View Patent ↗A mine support includes an elongate metal member and a coating comprising post-consumer recycled thermoplastic disposed on the member. The thermoplastic may include post-consumer recycled poly(ethylene terephthalate), and the coating may be an injection molded coating. A first layer of the coating may be provided with a thickness at least about 0.1 mm and a crystallinity between about 16% and about 30%, and a second layer of the coating may be provided with a thickness at least about 0.1 mm and a crystallinity between about 6% and about 14%. Either the first layer or second layer may contact the elongate metal member.
1. A method of forming an anchorable mine roof support for anchoring in a borehole with resin or grout, comprising:
placing an elongate metal member in a mold, the member having a first temperature at an outer surface thereof;
injecting polymer into the mold, an inner surface of the mold having a second temperature different from the first temperature;
forming a first semi-crystalline layer of the polymer proximate the outer surface of the member;
forming a first substantially amorphous layer of the polymer proximate the inner surface of the mold;
wherein the polymer forms a coating comprising post-consumer recycled thermoplastic disposed on the member, the post-consumer recycled thermoplastic having a portion with a thickness of at least about 1 mm; and
wherein the coating forms a textured surface on the member.
2. The method of claim 1 , wherein the first semi-crystalline layer has a crystallinity of between about 16% and about 30%.
3. The method of claim 1 , wherein the first substantially amorphous layer has a crystallinity of between about 6% and about 14%.
4. The method of claim 1 , wherein the first semi-crystalline layer has a thickness of at least about 0.1 mm.
5. The method of claim 1 , wherein the first substantially amorphous layer has a thickness of at least about 0.1 mm.
6. The method of claim 1 , wherein the polymer comprises an inhomogeneous mixture of poly(ethylene terephthalate) and polyethylene.
7. The method of claim 1 , wherein the polymer comprises an inhomogeneous mixture of poly(ethylene terephthalate) and polypropylene.
8. The method of claim 1 , wherein the polymer comprises an inhomogeneous mixture of polycarbonate and polyethylene.
9. The method of claim 1 , wherein the polymer comprises an inhomogeneous mixture of polycarbonate and polypropylene.
10. The method of claim 1 , wherein the polymer comprises polyethylene naphthalate.
11. The method of claim 1 , further comprising:
forming a fibrous structure on the member.
12. The method of claim 1 , further comprising:
forming a ribbon structure on the member.
13. The method of claim 1 , further comprising:
forming an interwoven structure on the member.
14. The method of claim 1 , wherein the polymer comprises first and second polymer phases that are substantially insoluble with respect to each other.
15. The method of claim 1 , wherein the first temperature is less than the second temperature.
16. The method of claim 1 , wherein the first temperature is at least 50° C. greater than the second temperature.
17. The method of claim 1 , wherein the first temperature is at least 100° C. greater than the second temperature.
18. The method of claim 1 , wherein the first temperature is at least 200° C. greater than the second temperature.
19. The method of claim 1 , wherein the polymer comprises (1) a first polymer having a first melt flow rate and (2) a second polymer having a second melt flow rate at least about 10% less than the first melt flow rate at about 270° C.
20. The method of claim 1 , wherein the polymer comprises first and second polymer phases and at least one of the phases has a glass transition temperature less than about 20° C.
21. The method of claim 1 , wherein the polymer comprises first and second polymer phases and at least one of the phases has a glass transition temperature less than about 0° C.
22. The method of claim 1 , wherein the elongate metal member is heated before placing the elongate metal member in the mold.
23. The method of claim 1 , wherein the first temperature is at least about 50° C., and the second temperature is at least about 50° C. less than the first temperature.