Wax as a melt flow modifier and processing aid for polymers
An improved method forms and employs a wax to modify throughputs and melt flow in polymers. The method includes: (a) selecting a solid polymeric material, (b) heating the solid polymeric material in an extruder to produce a molten polymeric material, (c) filtering the molten polymeric material, (d) placing the molten polymeric material through a chemical depolymerization process in a reactor to produce a depolymerized polymeric material, and (e) adding the depolymerized material to a pre-wax mixture to produce a modified polymer.
1. A method for forming a depolymerized wax and employing said depolymerized wax to modify polymeric processing and material properties, the method comprising:
selecting a solid polymeric post-consumer or post-industrial feed;
heating said solid polymeric post-consumer or post-industrial feed in an extruder to produce a molten polymeric material;
filtering said molten polymeric material;
placing said molten polymeric material through a chemical depolymerization process in a reactor to produce a depolymerized wax material, wherein the depolymerized wax material has a melting point between 106° C. and 135° C.;
adding said depolymerized wax material into a pre-wax mixture to produce a modified polymer with an increased melt flow index, wherein said pre-wax material comprises a polymer.
2. The method of claim 1 , wherein said method is continuous or semi-continuous.
3. The method of claim 1 , further comprising:
filtering said solid polymeric post-consumer or post-industrial feed.
4. The method of claim 1 , further comprising:
cooling said depolymerized wax material.
5. The method of claim 4 , further comprising:
purifying said depolymerized wax material.
6. The method of claim 5 , wherein said purifying step employs one of flash separation, absorbent beds, clay polishing and film evaporators.
7. The method of claim 1 , wherein said depolymerized wax material is added to said pre-wax mixture via an in-line pump.
8. The method of claim 3 , wherein said filtering step employs a filter bed.
9. The method of claim 1 , wherein said depolymerization process employs a catalyst.
10. The method of claim 9 , wherein said catalyst is supported on zeolite or alumina.
11. The method of claim 1 , wherein said depolymerization process employs a second reactor.
12. The method of claim 11 , wherein said reactors are connected in series.
13. The method of claim 11 , wherein said reactors are stacked vertically.
14. The method of claim 1 , wherein said reactor comprises a static mixer.
15. The method of claim 1 , wherein said solid polymeric post-consumer or post-industrial feed includes recycled polyethylene.
16. The method of claim 1 , wherein solid polymeric post-consumer or post-industrial feed includes recycled polypropylene.
17. The method of claim 1 , wherein said solid polymeric post-consumer or post-industrial feed includes inorganics.
18. The method of claim 1 , wherein the amount of said depolymerized wax material mixed into said pre-wax mixture is between 1 to 5 percent of the weight of said modified polymer.
19. A method for forming a depolymerized wax and employing said depolymerized wax to modify polymeric processing and material properties, the method comprising:
selecting a solid polymeric post-consumer or post-industrial feed;
heating said solid polymeric post-consumer or post-industrial feed in an extruder to produce a molten polymeric material;
filtering said molten polymeric material;
placing said molten polymeric material through a chemical
depolymerization process hi a reactor to produce a depolymerized wax material, wherein the depolymerized wax material has a melting point between 106° C. and 135° C.;
adding said depolymerized wax material into a pre-wax mixture to produce a modified polymer with an increased melt flow index, wherein said pre-wax mixture comprises said solid polymeric post-consumer or post-industrial feed which has not been depolymerized.
20. A method for forming a depolymerized wax and employing said depolymerized wax to modify polymeric processing and material properties, the method comprising:
selecting a solid polymeric post-consumer or post-industrial feed, wherein said solid polymeric post-consumer or post-industrial feed comprises recycled polyethylene and inorganics;
heating said solid polymeric post-consumer or post-industrial feed in an extruder to produce a molten polymeric material;
filtering said molten polymeric material;
placing said molten polymeric material through a chemical depolymerization process in a reactor to produce a depolymerized wax material, wherein said depolymerized wax material has a melting point between 106° C. and 135° C.;
adding said depolymerized wax material into a pre-wax mixture wherein said pre-wax mixture comprises said solid polymeric post-consumer or post-industrial feed which has not been depolymerized to produce a modified polymer with an increased melt flow index,
wherein the amount of said depolymerized wax material mixed into said pre-wax mixture is between 1 to 5 percent of the weight of said modified polymer.