Disclosed herein are ethylene-based polymers having low densities and narrow molecular weight distributions, but high melt strengths for blown film processing. Such polymers can be produced by peroxide-treating a metallocene-catalyzed resin.

The present application relates to a polymer composition as defined in claims comprising (A) a polymer base resin, which comprises a blend of (A-1) a multimodal ethylene polymer and (A-2) an ethylene polymer, and carbon black, a drip irrigation pipe comprising said polymer composition, a process for producing said drip irrigation pipe, pellets comprising said polymer composition and the use of said polymer composition for producing said drip irrigation pipe.

An extrusion additive manufacturing process including the step of extruding a polyethylene composition having a melt flow index MIE of at least 0.1 g/10 min., the composition made from or containing: A) from 1% to 40% by weight of a polyethylene component having a weight average molar mass M.sub.w, as measured by GPC (Gel Permeation Chromatography), equal to or higher than 1,000,000 g/mol; B) from 1% to 95% by weight of a polyethylene component having a M.sub.w value from 50,000 to 500,000 g/mol; and C) from 1% to 59% by weight of a polyethylene component having a M.sub.w value equal to or lower than 5,000 g/mol.

The present disclosure concerns recycling of municipal by a process for preparing composite aggregates and feedstocks for injection molding from the municipal waste. The process involves blending a first source material derived from solid municipal waste and comprising more than 50 wt % of polymeric material, together with a second source material that comprises one or more thermoplastic polymers, to obtain a mixture comprising a total polymeric content of at least about 60 wt %, and mixing the mixture in a vessel under conditions permitting self-heating of the mixture to a temperature below the melting temperature of said thermoplastic polymers to obtain composite aggregates in which said thermoplastic polymers bind the particles of the first source material.

A method includes applying a stress to a polymer thin film to stretch the polymer thin film along a first in-plane direction, and subsequently applying a stress to the polymer thin film to stretch the polymer thin film along a second in-plane direction orthogonal to the first in-plane direction to form an ultra-high modulus polymer thin film. Calendaring or hot pressing of the ultra-high modulus polymer thin film may improve its optical and/or thermal properties.

Disclosed herein are ethylene-based polymers having low densities and narrow molecular weight distributions, but high melt strengths for blown film processing. Such polymers can be produced by peroxide-treating a metallocene-catalyzed resin.