A skin-core fiber having

a skin of a propylene ethylene copolymer having:
i) xylene soluble fraction from 14 wt % to 27 wt %;
ii) intrinsic viscosity of the fraction soluble in xylene at 25° C. from 1.0 to 2.4 dl/g;
iii) melt flow rate, MFR, from 12 g/10 min to 60 g/10 min;
iv) an ethylene derived units content from 5.0 wt % to 12.0 wt %;
v) the ethylene derived units content of the fraction insoluble in xylene from 2.5 wt % to 6.0 wt %;
vi) the ethylene derived units content of the fraction soluble in xylene ranging from 15.2. wt % to 30.2 wt %;
vii) C13 NMR sequences PEP on the fraction insoluble in xylene from 3.5 mol % to 5.5 mol %; and
viii) C13 NMR sequences PEP on the fraction soluble in xylene from 11.0 mol % to 14.2 mol %; and
a core of a polyethylene having a density between 0.940 g/cm3 to 0.975 g/cm3.