METHOD OF MAKING EXTRUDED MICROCELLULAR POLYMER FOAM PIPE, A MICROCELLULAR POLYMER FOAM PIPE AND DIE

摘要

Described is an article a pipe of polymer micro-foam material having an impact strength value measured at which is higher than 100 % and up to 400 % of the impact strength as required in the BN-norm of a pipe of the same dimensions and basic material in non-foamed condition. Also are described methods for producing such pipe. Also a die (1) for an extruder is described having, before the slit (2) thereof, a channel (3) which narrows to the slit with an angle alpha between 10 and 180°, preferably 10 and 90°. Further is described an extruder including a die according to the invention