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 a polymer, the method comprising:
selecting a polymeric feed;
heating said polymeric feed to produce a molten polymeric material;
placing said molten polymeric material through a depolymerization process in a reactor to produce said depolymerized wax; and
mixing said depolymerized wax with said polymer to create a modified polymer.
2 . The method of claim 1 wherein said polymeric feed is a post-consumer or a post-industrial feed.
3 . The method of claim 1 , wherein said method is continuous or semi-continuous.
4 . The method of claim 1 , further comprising:
filtering said polymeric feed.
5 . The method of claim 1 wherein said polymeric feed comprises an amount of polypropylene.
6 . The method of claim 1 wherein said polymeric feed comprises an amount of polyethylene.
7 . The method of claim 1 , wherein said depolymerization process employs a catalyst supported on zeolite.
8 . The method of claim 1 , wherein said depolymerization process is conducted at a temperature between 325° C. and 450° C.
9 . The method of claim 1 , wherein said depolymerized wax has a melting point between 40° C. and 135° C.
10 . The method of claim 1 , wherein said depolymerization process employs a catalyst supported on alumina.
11 . The method of claim 1 , wherein mixing said depolymerized wax with said polymer comprises adding between 1-8 weight percent of said depolymerized wax.
12 . The method of claim 1 , further comprising:
purifying said depolymerized wax using at least one of flash separation, absorbent beds, clay polishing, or film evaporators.
13 . The method of claim 12 , wherein said purifying uses an absorbent bed.
14 . The method of claim 1 , wherein said modified polymer has an increased melt flow index compared to said polymer prior to mixing with said depolymerized wax.
15 . The method of claim 1 , further comprising:
cooling said depolymerized wax prior to mixing with said polymer.
16 . The method of claim 1 , wherein said polymeric feed contains up to 20% polypropylene.
17 . The method of claim 1 , wherein said method employs a second reactor, wherein said reactor and said second reactor are connected in parallel.
18 . The method of claim 1 , further comprising:
employing an oil produced during said depolymerization process as a fuel to run said depolymerization process.
19 . The method of claim 1 , wherein said method further comprises filtering said molten polymeric material.
20 . The method of claim 1 , further comprising:
employing a gas produced during said depolymerization process as a fuel to run said depolymerization process.