of the cellulose pulp was carried out in accordance with din 53145 part 2 the determination of the degree of whiteness of the fibres was effected in accordance with the method described in wo 97 23666 page 6 the average degree of polymerisation of the cellulose pulps according to the cuoxam method amounted to about 550 the degrees of whiteness measured at the fibre are compiled in table 1 it can be seen from table 1 that with ece and tce bleached cellulose pulps of different provenances the degree of whiteness lies in a narrow range between 87 5 and 93 7 the degree of whiteness the degrees of whiteness of the spun fibres is likewise in a close range between 55 0 and 58 6 a higher degree of whiteness of the fibres spun from tcf bleached cellulose pulp was not perceptible our researches have now revealed that the cellulose decomposition in the course of the lyocell process i e essentially from the formation through to the coagulation of the spinning solution depends on the carboxyl group content of the bleached cellulose pulp used to form the spinning solution in this situation it has been shown that the cellulose decomposition of the spun fibres is less the lower the carboxyl group content is of the cellulose pulp used to form the solution it is therefore possible according to the lyocell process to create cellulose fibres with reduced cellulose decomposition by making use of a tcf or ecf bleached cellulose pulp with low carboxyl group content for the formation of the spinning solution the objective referred to above is therefore resolved with the.