Process for the production of plates made of transparent plastic material with non-transparent areas

A process for the production of plates made of transparent plastic material with non-transparent peripheral edges comprising:

• providing a mould, a first moulding station with at least one set of first injectors and a second moulding station with at least one set of second injectors, said first and second injectors being located in a position directly corresponding to at least one peripheral area of the plate to be produced;
• injecting the transparent plastic material within said mould in the first moulding station via said first set of injectors with the mould half-open according to a sequential modality so as to distribute uniformly the pressure, preventing lines of joining of the transparent material, wherein witness marks corresponding to said first set of injectors are provided on the injected transparent material at said at least one peripheral area;
• closing the mould, performing compression of the transparent material and forming of the plate;
• injecting the non-transparent plastic material within said mould in the second moulding station via said set of second injectors so as to overmould said peripheral edge on said peripheral area of the transparent plate wherein said witness marks are covered by said non-transparent plastic material;
• said first injectors arranged in a linear manner;
• and
• wherein said sequential modality comprises first the injection by a central injector of the first set situated in a position corresponding to the median part of said peripheral area of the plate until the areas of said peripheral area corresponding to a first pair of intermediate injectors are covered;
• then the injection by said first intermediate injectors until the areas of said peripheral area corresponding to a second pair of intermediate injectors are covered;
• then the injection by said second intermediate injectors until the areas of said peripheral area corresponding to a pair of end injectors are covered;
• and finally injection by said end injectors.