Abstract: In the production of elastomers the product obtained from the polymerization process is often in the form of a slurry. Described herein are an apparatus and a process for “finishing” the elastomer, i.e., dewatering and drying the elastomer. The process comprises the steps of obtaining a slurry comprising water and elastomer; passing the slurry through a first dewatering device to produce a wet elastomer crumb, wherein the first dewatering device comprises two dewatering extruders in parallel; passing the wet elastomer crumb through a second dewatering device; and then passing the wet elastomer crumb through a drying device to produce a dried elastomer crumb.

Abstract: In the production of elastomers the product obtained from the polymerization process is often in the form of a slurry. Described herein are an apparatus and a process for “finishing” the elastomer, i.e., dewatering and drying the elastomer. The process comprises the steps of obtaining a slurry comprising water and elastomer; passing the slurry through a first dewatering device to produce a wet elastomer crumb, wherein the first dewatering device comprises two dewatering extruders in parallel; passing the wet elastomer crumb through a second dewatering device; and then passing the wet elastomer crumb through a drying device to produce a dried elastomer crumb.

Abstract: An apparatus for dewatering a slurry of elastomeric polymer and water, using an extruder or extruders provided with a device for measuring an actual water content of the elastomer at a position within the extruder or extruders, and a control system for controlling the moisture content of elastomeric polymer exiting the extruder or extruders through an exit die based, at least in part, on the measured water content.

Abstract: Halogenated isobutylene-p-methylstyrene polymers are stabilized against discoloration with a weak base such as 100 to 500 ppm sodium bicarbonate. The additive is added to the rubbery polymers after dewatering in the finishing step of their manufacture. The curability of the stabilized rubbers is not adversely affected by the sodium bicarbonate additive.

Abstract: A process is provided for producing a low molecular weight isoolefin polymer by contacting at conversion conditions a higher molecular weight saturated isoolefin polymer, for example, polyisobutylene or a copolymer of a C.sub.4 to C.sub.7 isoolefin and a para-alkylstyrene, in the melt phase, with an initiator, such as an oxygen-containing gas, an organic peroxide or an azo compound.

Abstract: A process is provided for producing a low molecular weight isoolefin polymer by contacting at conversion conditions a higher molecular weight saturated isoolefin polymer, for example, polyisobutylene or a copolymer of a C.sub.4 to C.sub.7 isoolefin and a para-alkylstyrene, in the melt phase, with an initiator, such as an oxygen-containing gas, an organic peroxide or an azo compound.

Abstract: A process for the recovery of dry polymer, wherein a polymer material containing water and/or volatile hydrocarbons is extruded through a die sleeve, cut into particles by means of a cutter mounted at the die discharge, and carried away from the cutter by an air stream. The die sleeve is provided with a plurality of die holes possessing a non-circular derived shape, which allow the material to be dried at lower temperatures and pressures. The cutter is a cage-type cylinder presenting large open areas for the flow of conveying air, thereby significantly reducing the local air velocity through the cutter and tearing of the particles. A bypass is provided to insure sufficient air being present after the cutter region to prevent condensation and to provide crumb transportation through the transport conduit. The invention reduces the generation of fines and results in an increase in the average particle size.

Abstract: A finishing process for water-slurried elastomers wherein a partially dewatered elastomer is presented to an enclosed, low shear, self-cleaning, long residence time dryer for drying at low temperatures in order to remove the remaining water and residual volatiles. The dried product is then cooled in a pneumatic conveyor to temperatures required for baling.

Abstract: A method for agglomerating and dewatering elastomeric material having a relatively high water content wherein the elastomeric material is fed to a pair of counterrotating pressing rolls with a tight nip opening. The elastomeric material is drawn through the nip opening and compacted and dewatered therein. The method of the present invention produces at least a doubling of the particle size of the feed material and a reduction in the water content of the feed material in the range of 30 to 80%.