1 4 diaminobutane during the polycondensation process results within a short time in polytetramethylene adipamide of a quality suitable for drawing fibres which thanks to a good ratio of carboxylic acid and amino terminal groups and the virtual lack of cyclic terminal groups can be very quickly further condensed in the solid phase to obtain a high molecular weight product which means an important overall gain in time for the entire process if optimum conditions are chosen it even appears to be possible to prepare in a single process step a polyamide with such a high degree of polymerisation that it is directly suitable for a number of applications a further advantage is that the process is relatively simple to carry out in comparison with for example the process of ep a 0393544 as a result of which the process according to the invention is less sensitive to disturbances wherever this application refers to polytetramethylene adipamide this is also understood to be co and terpolymers of which at least 50 of the units consist of tetramethylene adipamide units other copolymerisable monomers are for example other dicarboxylic acids for example aliphatic aromatic or cycloaliphatic carboxylic acids which may optionally be substituted other diamines u221d aminocarboxylic acids lactams monomers supplying imide groups monomers supplying polyester and polyether etc the polycondensation process can be carried out in the absence of a diluent or in the presence thereof preferably a dispersing agent is present at the beginning of the polycondensation at least in order to effect uniform heat transfer suitable dispersing agents are water inert solvents for example phenols and.