| 主权项 |
1. A process for preparing a multimodal polyethylene product, said multimodal polyethylene product comprising at least two different polyethylene resins, the process comprising:
(a) producing a first polyethylene resin in the presence of a Ziegler-Natta catalyst in a reactor, wherein the High Load Melt Index (HLMI) of said first polyethylene resin is between 0.01 and 5 g/10 min, with the HLMI being measured by the procedure of ASTM D-1238 using a temperature of 190° C. and a load of 21.6 kg; (b) separately producing a second polyethylene resin in the presence of a Ziegler-Natta catalyst in the reactor or a separate reactor, wherein the Melt Index (MI2) of said second polyethylene resin is between 1 and 150 g/10 min, with the MI2 being measured by the procedure of ASTM D-1238 using a temperature of 190° C. and a load of 2.16 kg; and (c) physically blending together said first polyethylene resin and said second polyethylene resin to produce a multimodal polyethylene product;
wherein the Ziegler-Natta catalyst used for the production of said first polyethylene resin has an average particle size (D50) of at most 15 μm, with the D50 being measured by laser diffraction analysis on a Malvern type analyzer, and wherein step (c) is performed in a device for continuously melting and blending said first polyethylene resin and second polyethylene resin. |
