Methods for processing HDPE recyclates including, but not limited to, polyethylene and polypropylene and compositions therefrom are provided. HDPE recyclate can be visbroken to improve processing characteristics and/or devolatilized to remove waste byproducts to produce processed HDPE recyclates. Processed HDPE recyclates are compounded with pre-consumer polyolefins to produce blend compositions having acceptable or even improved processing characteristics. Such pre-consumer polyolefins can also be visbroken to further tailor processing characteristics of such polymer blends. A combination of extruders and/or extruder zones can be used at the same or different locations for visbreaking and/or compounding of both HDPE recyclate and/or pre-consumer polyolefins.

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 Mw, 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 Mw value from 50,000 to 500,000 g/mol; and C) from 1% to 59% by weight of a polyethylene component having a Mw value equal to or lower than 5,000 g/mol.

A multilayer thermoformable film to protect the surface of a workpiece includes an underlayer having first and second faces. The underlayer is made from an adhesive material configured to adhere to the surface of the workpiece by the first face. At least one layer of polymer material is attached to the second face of the adhesive underlayer. The layer of polymer material is resistant to erosion by solid particles and to erosion by liquid particles. It is formed from a polymer material chosen from a polyurethane, a polyether ether ketone and a polyethylene having a very high molecular weight, with a Shore D hardness of between 50 and 65 D. A method of surface protection of the workpiece includes thermoforming the film in a shape adapted to match the shape of at least a portion of the workpiece and applying the film thermoformed onto the surface of the workpiece.

A polyethylene composition comprising suitable for use in injection molding, the polyethylene composition comprising: from 2 wt. % to 25 wt. % of a high molecular weight component consisting of an ethylene/alpha-olefin copolymer, wherein the high molecular weight component has a density of from 0.910 g/cc to 0.971 g/cc, a melt index (12.16) of greater than 0.5 g/10 min to less than 1.5 g/10 min, a molecular weight distribution (Mw/Mn) of 6.0 to 20.0; from 75 wt. % to 98 wt. % a low molecular weight component consisting of an ethylene homopolymer or an ethylene/alpha-olefin copolymer, wherein the ethylene homopolymer or an and a molecular weight distribution (Mw/Mn) of less than 6.0; wherein the polyethylene composition has a shrinkage anisotropy that is less than the shrinkage anisotropy of the low molecular weight component.

The instant invention provides a polyethylene blend-composition suitable for blown films, and films made therefrom. The polyethylene blend-composition suitable for blown films comprises the melt blending product of: (a) from 0.5 to 4 percent by weight of a low density polyethylene having a density in the range of from 0.915 to 0.935 g/cm.sup.3, and a melt index (I.sub.2) in the range of from greater than 0.8 to less than or equal to 5 g/10 minutes, and a molecular weight distribution (M.sub.w/M.sub.n) in the range of from 6 to 10; (b) 90 percent or greater by weight of an ethylene/-olefin interpolymer composition, wherein ethylene/-olefin interpolymer composition has a Comonomer Distribution Constant (CDC) in the range of from 75 to 200, a vinyl unsaturation of less than 0.1 vinyls per one thousand carbon atoms present in the backbone of the ethylene/-olefin interpolymer composition; a zero shear viscosity ratio (ZSVR) in the range from 2 to 20; a density in the range of from 0.903 to 0.950 g/cm.sup.3, a melt index (I.sub.2) in a range of from 0.1 to 5 g/10 minutes, a molecular weight distribution (M.sub.w/M.sub.n) in the range of from 1.8 to 3.5; (c) optionally a hydrotalcite based neutralizing agent; (d) optionally one or more nucleating agents; (e) and optionally one or more antioxidants.

The present invention provides an ethylene polymer having a viscosity average molecular weight of 10010.sup.4 or more and 1,00010.sup.4 or less, in which a ratio between an isothermal crystallization time at 125 C. and an isothermal crystallization time at 123 C. obtained under specific isothermal crystallization time measurement conditions is 3.5 or more and 10.0 or less, and a degree of crystallization obtained using a differential scanning calorimeter (DSC) is 40% or more and 75% or less.

The present invention provides an ethylene polymer having a viscosity average molecular weight of 10010.sup.4 or more and 1,00010.sup.4 or less, in which a ratio between an isothermal crystallization time at 125 C. and an isothermal crystallization time at 123 C. obtained under specific isothermal crystallization time measurement conditions is 3.5 or more and 10.0 or less, and a degree of crystallization obtained using a differential scanning calorimeter (DSC) is 40% or more and 75% or less.

A method of forming a thermoformed article may include melt extruding polyethylene to form an extruded sheet. The rheological breadth parameter of the polyethylene may change by no more than about 5% after extrusion relative to the rheological breadth parameter of the polyethylene prior to extrusion. The extruded sheet may be thermoformed within a mold to form the thermoformed article. During thermoforming, the extruded sheet may be subjected to solid-state stretching in one or more directions. The thermoformed article may be retrieved from the mold. The polyethylene may have a rheological breadth parameter of from 0.20 to 0.40, a multimodal molecular weight distribution, a polydispersity (Mw/Mn) of from 5 to 18, a density ranging from 0.940 to 0.970 g/cc, may exhibit tensile strain-hardening, or combinations thereof.

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.

Provided are: a polyglycolic acid (PGA) solidification- and extrusion-molded article that is formed from a resin material containing PGA, the PGA having a weight average molecular weight of 100,000 to 300,000 and a melt viscosity (temperature: 270 C.; shearing speed: 120 sec.sup.1) of 100 to 2,000 Pa.Math.s, and that has a tensile strength at a temperature of 150 C. of 20 to 200 MPa; a downhole tool or component thereof for drilling and completion of petroleum recovery formed by machining the solidification- and extrusion-molded article; an isolation plug provided with the component; an isolation plug mandrel; and a method for manufacturing the PGA solidification- and extrusion-molded article and a method for manufacturing the downhole tool or component thereof that comprise the steps of: supplying the resin material to an extruder (preferably from a fixed-quantity feeder); and after solidification- and extrusion-molding, pressurizing the solidification- and extrusion-molded article, and drawing the same while applying back pressure thereto in a direction of a forming die to suppress the expansion of the solidified and extruded matter.