Moulding material composition for hollow products made by gas-assisted injection moulding

The process involves injecting into mold a composition comprising thermoplastic matrix in form of thermoplastic polymer A, reinforcing filler in form of fibrous substance B with factor L/D above 20, fine filler C with form factor L/D below 20, and nucleation agent D. Substance B is selected from glass, ceramic, carbon and thermoplastic polymer fibers, while C is selected from mineral fillers such as glass spheres, ground glass, glass scales or their mixtures. The process involves injecting into mold a composition comprising thermoplastic matrix in form of thermoplastic polymer A, reinforcing filler in form of fibrous substance B with factor L/D above 20, fine filler C with form factor L/D below 20, and nucleation agent D. Substance B is selected from glass, ceramic, carbon and thermoplastic polymer fibers, while C is selected from mineral fillers such as glass spheres, ground glass, glass scales or their mixtures. Thermoplastic composition preferably contains 10-60 wt.% of total B + C fillers and wt. ratio of C to B is 0.2-10. The content of D is preferably below 1 wt.% per total wt. of composition. The composition may also contain additives such as pigments, colorants, thermo- and/or photo-stabilizers, and durability modifiers.