Continuous extruder process for manufacturing rheology-modified polyolefin for cable insulation layer, and related products

A one-unit operation, continuous extrusion process for making a rheology-modified, additive-containing ethylenic polymer in a continuously operated multi-zone extruder sequentially comprising a first zone configured with a main feeder for adding a polymer into the extruder, a second zone, a third zone configured with a side feeder for adding one or more additives into the third zone of the extruder, and an outlet for discharging material from the extruder, wherein the first zone is in material communication with the second zone via 0, 1 or more intermediary zones disposed therebetween, wherein the second zone is in material communication with the third zone via 0, 1 or more intermediary zones disposed therebetween, and wherein the third zone is in material communication with the outlet via 0, 1 or more intermediary zones disposed therebetween, and wherein at least one of the first and second zones is configured with the injector for adding a high-temperature decomposing peroxide, the process comprising the steps of:

• mixing in the second zone of the extruder components consisting of (i) an ethylenic polymer and (ii) a high-temperature decomposing peroxide, at a temperature such that the half-life of the peroxide is equal to or greater than (≥) one minute and for a sufficient period of time to melt the ethylenic polymer and completely decompose all of the peroxide, and to modify the rheology of the melted ethylenic polymer to produce a rheology-modified, melted ethylenic polymer that is transferred to the third zone of the extruder;
• adding, after production of the rheology-modified, melted ethylene polymer, via the side feeder of the third zone a component consisting of one or more additives to the rheology-modified, melted ethylenic polymer to produce the rheology-modified, additive-containing ethylenic polymer;
• and
• forming pellets from the rheology-modified, additive containing ethylenic polymer, the pellets having a white color and a gel content greater than or equal to 40%.

A one-unit operation, continuous extrusion process for making a rheology-modified, additive-containing ethylenic polymer in a continuously operated multi-zone extruder sequentially comprising a first zone configured with a main feeder for adding a polymer into the extruder, a third zone configured with a side feeder for adding one or more additives into the third zone of the extruder, and an outlet for discharging material from the extruder, wherein the first zone is in material communication with the second zone via 0, 1 or more intermediary zones disposed therebetween, wherein the second zone is in material communication with the third zone via 0, 1 or more intermediary zones disposed therebetween, and wherein the third zone is in material communication with the outlet via 0, 1 or more intermediary zones disposed therebetween, and wherein at least one of the first and second zones is configured with the injector for adding a high-temperature decomposing peroxide, the process comprising the steps of:

• mixing in the second zone of the extruder an ethylenic polymer and a high-temperature decomposing peroxide at a temperature greater than or equal to 220° C. to the temperature at which the half-life of the peroxide is equal to or greater than (≥) one minute and for a sufficient period of time to melt the ethylenic polymer and completely decompose all of the peroxide, and to modify the rheology of the melted ethylenic polymer to produce a rheology-modified, melted ethylenic polymer that is transferred to the third zone of the extruder;
• adding, after production of the rheology-modified, melted ethylene polymer, via the side feeder of the third zone one or more additives to the rheology-modified, melted ethylenic polymer to produce the rheology-modified, additive-containing ethylenic polymer;
• and
• forming pellets from the rheology-modified, additive containing ethylenic polymer, the pellets having a white color and a gel content greater than or equal to 40%.