Fremgangsmåde til fremstilling af et produkt baseret på celluloseacetat med blandet farve og produkt, såsom briller, opnået ved en sådan fremgangsmåde

摘要

A manufacturing process and the semi-finished product of thermoplastic material obtained therefrom, for obtaining products with aesthetic patterns which can be perceived in semitransparency also in depth is disclosed. The process provides the steps of (i) producing at least two initial elements (L1-Ln; S1'-Sn') of thermoplastic material with even but different aesthetic patterns, which have a different concentration of the dominating colouring (Cn...C2C1‰¥0), at least the dominating colouring being of the bleeding type in the specific thermoplastic material, (ii) shaping said two initial elements (L1-Ln; S1'-Sn') into strips or loaves (S1-Sn; S1'-Sn') being of a submultiple width, not below 1/5 of a characteristic dimension of the finished product to be obtained, (iii) inserting at least two of said strips or loaves (S1-Sn; S1'-Sn'), having different concentration of the dominating colouring, into a workform, arranging them side by side according to a direction of side-by-side arrangement, and then (iv) undergoing pressure and heat to allow the melting and hardening of the thermoplastic material into a single body, at the same time causing the migration of the dominating colouring at least from the strips or loaves (S1-Sn; S1'-Sn') with the greater concentration of dominating colouring towards those with the lesser concentration of dominating colouring, thus causing a blurred colour hue in the boundary areas between the different strips or loaves (S1-Sn; S1'-Sn').