Abstract: A process for the manufacture of ethylene polymers by homopolymerization and copolymerization of ethylene at pressures of from 500 to 5,000 bars and at from 50.degree. to 450.degree. C, with subsequent isolation of the polymers in high pressure product isolation zones and low pressure product isolation zones. The various parallel product isolation zones are at different temperatures, and the mean product residence times in the zones may be identical or different. Very different products, in amounts which can be chosen according to requirements, and with mutually independent polymer properties, can be obtained using only one high pressure polymerization system.

Abstract: A process for the manufacture of copolymers of ethylene with n-butyl acrylate in a polymerization zone at pressures above 800 atmospheres and at from 150.degree. to 350.degree. C, wherein the reaction mixture obtained is transferred, via a cooling zone which is at a pressure below 500 atmospheres and at from 150.degree. to 250.degree. C, into the high pressure product isolation zone, the mean residence time of the reaction mixture in the two zones being from 2 to 10 minutes. A copolymer which gives good films is obtained.

Abstract: A process for the manufacture of copolymers of ethylene with vinyl acetate at pressures above 800 atmospheres and at from 150.degree. to 350.degree. C, using mean residence times of up to at most 100 seconds. The reaction mixture obtained from the polymerization is kept for from 2 to 10 minutes at from 150.degree. to 250.degree. C under a pressure below 500 atmospheres. Homogeneous ethylene/vinyl acetate copolymers are obtained without the formation of substantial amounts of free acetic acid by decomposition of the vinyl acetate.