Method for injection moulding of plastic-material lenticular bodies for lights of motor vehicles and similar, and lenticular body for lights of motor vehicles and similar

Method for injection moulding of plastic-material lenticular bodies (1) for lights of motor vehicles and similar, wherein said lenticular bodies (1) are formed by at least a first (2) and at least a second plastic-material sheet (3), which are arranged side by side without reciprocal overlapping and are rigidly and continuously fixed sideways to one another, so as to form a rigid monolayer shell (1);

• at least a first segment of the peripheral edge (3a) of the second plastic-material sheet (3) being locally profiled so as to match with, and adhere to, a corresponding first segment of the peripheral edge (2a) of the first plastic-material sheet (2), along the whole length of the border line between the two sheets;
• the method being characterized by comprising, in sequence:
• the step of coupling a punch half-mould (15) with a first matrix half-mould (13) so as to define, on surface of the punch half-mould (15), a first closed cavity that copies in reverse the shape of the first plastic-material sheet (2);
• the step of filling said first cavity with a first plastic polymer in a liquid state, injecting the first plastic polymer in the first cavity from an injection point located by said first segment of the peripheral edge (2a) of the first plastic-material sheet (2);
• the step of separating, after the first plastic polymer has solidified to form the first plastic-material sheet (2), the punch half-mould (15) from the first matrix half-mould (13) maintaining the first plastic-material sheet (2) still on the surface of said punch half-mould (15);
• the step of coupling the punch half-mould (15) with a second matrix half-mould (13) so as to define, on surface of the punch half-mould (15), a second closed cavity that copies in reverse the shape of the first (2) and second plastic—material sheet (3), positioning the first plastic-material sheet (2) in said second cavity;
• the step of filling the second cavity with a second plastic polymer in a liquid state, so that the second plastic polymer completely covers said first segment of the peripheral edge (2a) of the first plastic-material sheet (2), so as to hide the surface injection trace present in said first plastic-material sheet (2);
• and
• the step of separating the punch half-mould (15) from the second matrix half-mould (13), after the second plastic polymer has solidified to form the second plastic-material sheet (3) and is welded to the first plastic-material sheet (2).