modified in such manner that a nozzle package of conventional construction as well as the new nozzle package according to fig5 34 quick fit 34 could be employed side by side by way of this experimental arrangement influences which go beyond the differences of construction could be excluded to a large extent for the experiment the spinning beam was heated to a diphyl temperature of 290 u00b0 c subsequently the two nozzle packages were employed cold about 20 u00b0 c and the temperature was measured at the nozzle border and nozzle center fig6 shows the result of this experiment in fig6 the dashed curve a represents the heat up behaviour temperature course over a time after the assembly into the spinning beam without polymer of a conventional nozzle package in the nozzle center while the dashed curve b shows the corresponding behaviour in the border part of a conventional package curve c shows the heat up behaviour in the nozzle center of a package according to this invention e g according to fig5 while curve d which coincides to a large extent with curve c shows the heat up behaviour of the border part of the new package the new nozzle package with the improved heat flow clearly reaches the final temperature earlier than the nozzle package of conventional construction furthermore the final temperature of the new nozzle package is about 10 u00b0 c higher.