Synthetic fiber with addition of natural material and method of its production

The volume content of the natural material in the resulting volume of the synthetic fiber (1) ranges from 0,5% to 45%. The natural material is milled into the form of particles (2) which have irregular shape with length differing from the width, whereby length (L) of the particle (2) of the natural material has a value ranging from 10% to 120% of the diameter of the synthetic fiber (1) and the width (W) of the particle ranges from 25% to 75 % of the length (L) of the particle (2). At the same time the width (W) of the particle (2) does not surpass 50% of the cross-sectional diameter (D) of the synthetic fiber (1). Hemp, jute, linen, cotton, sisal, kenaf, wood, cellulose, lignocellulose, coconut, nut shells, starch, wheat, zeolite can be used as a natural material. The basic synthetic polymer component includes at least one thermoplastic polymer, for example polyolefin, such as polyethylene PE or polypropylene PP. Before the fiberization the natural material in form of milled particles (2) is added into the melt and subsequently the mixture of the synthetic polymer and particles (2) of the natural material are mixed at least for 5 minutes.