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.

Continuous compounding systems include a feeding section and a compounding section. Method for compounding or mixing solid matter and liquid matter include providing a continuous compounding system, adding matter to the continuous compounding system, and mixing or compounding the matter.

A method of continuously manufacturing a cured membrane includes continuously compounding and mixing a vulcanizable rubber composition in a mixing extruder while continuously removing gasses from the vulcanizable rubber composition during mixing with a vacuum. The vulcanizable rubber composition may be continuously extruded to form an extrudate, which may be continuously calendered to form a green membrane. The green membrane may be continuously cured, such as by a hot air conveyor curing system, to form a cured membrane.

A method of continuously manufacturing a cured membrane includes continuously compounding and mixing a vulcanizable rubber composition in a mixing extruder while continuously removing gasses from the vulcanizable rubber composition during mixing with a vacuum. The vulcanizable rubber composition may be continuously extruded to form an extrudate, which may be continuously calendered to form a green membrane. The green membrane may be continuously cured, such as by a hot air conveyor curing system, to form a cured membrane.

A method for producing a fused unplasticised polyvinyl chloride (UPVC) article (126) is provided. The method includes feeding an UPVC blend (103) into a co-rotating twin-screw extruder (100). The method further includes melting the UPVC blend (103) and conveying fused UPVC to an outlet (120) of the co-rotating twin-screw extruder (100). The method also includes collecting the fused UPVC from the outlet (120) at a rate of at least 100 kilograms/hour per litre of free volume (124) of the co-rotating twin-screw extruder (100).

The invention relates to a process for removal of volatile components from an olefin polymer, the process carried out in an extruder comprising at least one vacuum degassing zone, said process comprising the steps of: (a) introducing a stream of an olefin polymer into the extruder; (b) extruding the olefin polymer in the extruder at a temperature which is higher than the melting temperature of the olefin polymer but lower than the decomposition temperature of the olefin polymer, thereby producing an olefin polymer melt having reduced amount of volatile components, wherein the process in the extruder has a residence time distribution broadness (σ2) in the range of 800 to 4000 as define by equation (1) wherein: σ2 is the residence time distribution broadness, T is the mean residence time, t is the interval of residence time a fluid element of the olefin polymer spends in the extruder, E(t) is the residence time distribution function, and wherein the process optionally comprises a step (c) where the melt of the olefin polymer is passed through a die zone to a pelletizer for pelletizing the obtained olefin polymer.
σ.sup.2=∫.sub.0.sup.∞(t−τ).sup.2E(t)dt  equation (1)

The invention relates to a process for removal of volatile components from an olefin polymer, the process carried out in an extruder comprising at least one vacuum degassing zone, said process comprising the steps of: (a) introducing a stream of an olefin polymer into the extruder; (b) extruding the olefin polymer in the extruder at a temperature which is higher than the melting temperature of the olefin polymer but lower than the decomposition temperature of the olefin polymer, thereby producing an olefin polymer melt having reduced amount of volatile components, wherein the process in the extruder has a residence time distribution broadness (σ2) in the range of 800 to 4000 as define by equation (1) wherein: σ2 is the residence time distribution broadness, T is the mean residence time, t is the interval of residence time a fluid element of the olefin polymer spends in the extruder, E(t) is the residence time distribution function, and wherein the process optionally comprises a step (c) where the melt of the olefin polymer is passed through a die zone to a pelletizer for pelletizing the obtained olefin polymer.
σ.sup.2=∫.sub.0.sup.∞(t−τ).sup.2E(t)dt  equation (1)

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.

An extrusion apparatus intended for the manufacture of a coextruded profiled element P for tyres, produced from rubber compounds of various compositions, comprises a profiling device (30) arranged at the outlet of at least two flow channels (34, 35) for rubbery compounds of different composition. The said channels receive the compounds from positive-displacement contrarotating twin-screw extruders (10, 20), the screw flights interpenetrating and having conjugated profiles.

An extrusion apparatus intended for the manufacture of a coextruded profiled element P for tyres, produced from rubber compounds of various compositions, comprises a profiling device (30) arranged at the outlet of at least two flow channels (34, 35) for rubbery compounds of different composition. The said channels receive the compounds from positive-displacement contrarotating twin-screw extruders (10, 20), the screw flights interpenetrating and having conjugated profiles.