Process for spinning thermoweldable fibers obtained from polyolefin composition

The present invention relates to polyolefins containing one or more organic phosphites or phosphonites, or mixtures thereof, or HALS (Hindered Amine Light Stabilizer), or mixtures of the phosphites or phosphonites and HALS and optionally small quantities of one or more phenolic antioxidants, and thermoweldable fibers of the above mentioned stabilized resins that can be obtained through extrusion. Crystalline olefin polymers in the form of granules or nonextruded particles having regular geometric form, containing one or more of the following stabilizers:a) from 0.01 to 0.5% by weight of one or more organic phosphites or phosphonites or mixtures thereof; orb) from 0.005 to 0.5% by weight of one or more HALS (Hindered Amine Light Stabilizer); orc) mixtures of (a) and (b);and optionally one or more phenolic antioxidants at a concentration not higher than 0.02% by weight.The fibers obtained from said polyolefins have high thermoweldability and good resistance to yellowing and aging.