flows inwardly over respective recombination lands 62 a 62 d 72 a 72 d or through recombination channels 61 a 61 d 71 a 71 d 61 c 61 d 71 b 71 c and 71 d are not shown between adjacent ends of portions of the lands to inner recombination channels 64 74 the upper melt then flows out of inner recombination channel 64 between final land 66 and divider plate 42 d while the lower melt flows out of inner recombination channel 74 between final land 76 and divider plate 42 d recombination seals 47 and 49 prevent melt from leaking outward from outer recombination channels 60 and 70 respectively the upper and lower melt flows join at the inner tip of divider plate 42 d forming combined flow 68 that is conveyed inward to the outside wall of inner mandrel 12 where it forms cylindrical plastic melt flow 14 a in the illustrated embodiment the recombination channels recombination lands and final land are cut into the surfaces of recombination rings 45 46 and the facing upper and lower surfaces of divider plate 42 d of distribution ring 42 are generally flat in other embodiments some or all of these may be cut into the divider plate the arrangement of the recombination channels and lands at the lower surface on upper recombination ring 46 is shown most clearly in fig5 which is a schematic straightened out plan view of the recombination areas symmetrical about port 56 a viewed from above flow enters outer recombination channel 60 through upper port 56 a as viewed in fig4 a one half flows clockwise down outer.