Abstract: The present invention relates to a process for compounding, and in particular to a process for compounding a polymer with a pellet masterbatch, which process comprises passing the polymer and the pellet masterbatch to a compounding extruder, the temperature of the polymer being T° C., characterised in that the pellet masterbatch is heated using a heating fluid to a temperature of T-10° C. or higher prior to being passed to the extruder.

Abstract: The present invention relates to an extruder for a polymer, and a process for extruding a polymer using said extruder. In particular, the present invention provides an extruder comprising: (i) two or more barrel sections (1a, 1b, 1c) arranged sequentially from: (a) an upstream feed barrel section (1a) to which polymer feedstock to be extruded is fed, the upstream feed barrel section containing two or more screws each having a diameter of X; to (b) a downstream barrel section (1c) from which melted polymer is passed to a die and extruded; and (ii) one or more feed ports for feeding polymer feedstock to be extruded into the extruder at its upstream end, characterised in that the total area of the one or more feed ports through which polymer feedstock is introduced is greater than 4*X, and a process for extrusion of polymer comprising feeding a polymer feedstock to the feed port of such an extruder.

Abstract: Process for extrusion of polymer by feeding a polymer feedstock to the feed port of an extruder having (i) two or more barrel sections arranged sequentially from (a) an upstream feed barrel section to which polymer feedstock to be extruded is fed, the upstream feed barrel section containing two screws each having a diameter of X, to (b) a downstream barrel section from which melted polymer is passed to a die and extruded, and (ii) a feed port for feeding polymer feedstock to be extruded into the extruder at its upstream end. The polymer feedstock is in the form of a powder, and the feed port area is a rectangular shape with width limited by the width of the upstream feed barrel section to 2*X and with a length greater than 2.5*X. The total area of the feed ports through which polymer feedstock is introduced is greater than 5*X2.

Abstract: The present invention relates to an extruder for a polymer, and a process for extruding a polymer using said extruder. In particular, the present invention provides an extruder comprising: (i) two or more barrel sections arranged sequentially from: (a) an upstream feed barrel section to which polymer feedstock to be extruded is fed, the upstream feed barrel section containing two or more screws each having a diameter of X; to (b) a downstream barrel section from which melted polymer is passed to a die and extruded; and (ii) one or more feed ports for feeding polymer feedstock to be extruded into the extruder at its upstream end, characterised in that the total area of the one or more feed ports through which polymer feedstock is introduced is greater than 4*X2, and a process for extrusion of polymer comprising feeding a polymer feedstock to the feed port of such an extruder.

Abstract: A process for the separation of volatile material from particulate polymer which has been substantially freed from unreacted monomer in an earlier separation step, comprising (a) feeding the particulate polymer to a purge vessel, optionally causing it to move through the vessel in substantially plug-flow mode, (b) heating the particulate polymer in the purge vessel to a temperature greater than 30° C. but insufficiently high to cause the particles to become agglomerated, and/or maintaining the polymer at a temperature in this range in the purge vessel, (c) feeding air to the purge vessel counter-current to the movement of the particulate polymer to remove volatile material therefrom, (d) removing the particulate polymer from the purge vessel. Preferably the particulate polymer fed to the purge vessel is caused to move through the vessel in substantially plug-flow mode. The process is particularly suitable for polyethylene.

Abstract: A process for the separation of volatile material from particulate polymer which has been substantially freed from unreacted monomer in an earlier separation step, comprising (a) feeding the particulate polymer to a purge vessel, optionally causing it to move through the vessel in substantially plug-flow mode, (b) heating the particulate polymer in the purge vessel to a temperature greater than 30° C. but insufficiently high to cause the particles to become agglomerated, and/or maintaining the polymer at a temperature in this range in the purge vessel, (c) feeding air to the purge vessel counter-current to the movement of the particulate polymer to remove volatile material therefrom, (d) removing the particulate polymer from the purge vessel. Preferably the particulate polymer fed to the purge vessel is caused to move through the vessel in substantially plug-flow mode. The process is particularly suitable for polyethylene.