Methods are disclosed for the continuous treatment of biomass comprising a pretreatment step, wherein said biomass is contacted with a first supercritical, near-critical, or sub-critical fluid to form a solid matrix and a first liquid fraction; and a hydrolysis step, wherein said solid matrix formed in said pretreatment step is contacted with a second supercritical or near-supercritical fluid to produce a second liquid fraction and an insoluble lignin-containing fraction. Also disclosed are apparatuses for the continuous conversion of biomass comprising a pretreatment reactor and a hydrolysis reactor associated with said pretreatment reactor.

A screw extruder with rollers includes a screw which extrudes a material; a casing which houses the screw and which is provided with a charging port for the material; and a pair of an upper roller and a lower roller which are arranged in front of the casing and mold the material extruded by the screw into a sheet, in which one of the upper roller and the lower roller has both end portions in an axial direction, and a main body portion between the both end portions, and a cross-section of the main body portion perpendicular to the axial direction has an oval shape.

A continuous method of producing polyamide foams by an extrusion foaming process is disclosed. The polyamide foam includes a polyamide resin compounded with a composite chain extender including an epoxy chain extender and a maleic anhydride grafted polypropylene (MAPP) wax. The produced polyamide foams have improved properties, including a smooth surface, low density, and small cell size.

Methods of making thermoplastic vulcanizate are provided, including the steps of (a) extruding an elastomeric component and a thermoplastic polymer component to form a dynamically vulcanized melt; (b) passing the dynamically vulcanized melt into a vessel, comprising two intermeshing, counter-rotating twin screws, to produce a uniform dynamically vulcanized melt; and (c) filtering the uniform dynamically vulcanized melt and recovering a thermoplastic vulcanizate.

The present disclosure is directed to a process for producing thermoplastic polyolefin roofing membrane. The process includes directly adding components of a high-load flame retardant TPO formulation to a counter-rotating twin screw extruder. The process includes extruding the formulation with counter-rotation of the twin screws and forming a TPO roofing membrane having a tensile strength of greater than 10 MPa and a flame retardance of rating of classification D as measured in accordance with EN ISO 11925-2, surface exposure test.

The disclosure relates to oxygen scavenging compositions, methods of making the compositions, articles prepared from the compositions, and methods of making the articles. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

A screw extruder for extruding a kneaded material includes a screw and a casing housing the screw and having a material supply port on an upstream side in an extrusion direction of the kneaded material and a tip-side opening on a downstream side in the extrusion direction. A pressure sensor for measuring a pressure inside the casing is provided between a downstream end of the supply port and the tip-side opening of the casing. A rotational speed of the screw is controlled depending on the pressure measured by the pressure sensor.

A method for producing a densified material includes: obtaining a film including at least one first layer of plastic material and one second layer with a composition distinct from the first layer, the first layer having a first melting temperature, or obtaining pieces of such a film; compressing the obtained film or the obtained pieces of film through at least one die of at least one extruder, and obtaining a profile of densified material, the extruder including at least one rotary endless screw pushing the obtained film or pieces of film along a screw axis; and optionally cutting the profile in order to obtain granules of densified material, the compression step being carried out at a maximum compression temperature for the obtained film or pieces of film, the maximum compression temperature being less than the first melting temperature. Also disclosed are installation and use of the densified material.

A screw extruder for extruding a kneaded material, includes: a screw; and a casing housing the screw and having a material supply port on an upstream side. The screw has a shaft portion and a helical flight portion provided on an outer peripheral surface of the shaft portion. Regarding a clearance between a top portion of the flight portion and an inner wall surface of the casing, the clearance at a downstream side end of the flight portion is larger than the clearance at a downstream side end of the supply port. No area where the clearance decreases from the upstream side toward the downstream side is present between the downstream side end of the supply port and the downstream side end of the flight portion.

An apparatus having an extrusion machine and a feeding unit. for producing foamed polymeric material, in particular polyethylene and polypropylene, is disclosed. The extrusion machine includes a cylindrical barrel which is connected with a first end thereof to the feeding unit to receive a blend of plastic material to be extruded, a parallel pair of screws in the cylindrical barrel, a driving unit for driving the screws into rotation in opposite directions, a gas tank containing CO.sub.2 as a foaming gas, injection means for injecting the foaming gas into the cylindrical barrel; a head mounted at a second end of the cylindrical barrel opposite to the first end and heating means arranged around the cylindrical barrel for transferring heat thereto.