Apparatus for thermoforming plastic containers

An apparatus for thermoforming plastic containers comprising:

• a pickup station (24);
• a feeder (25) for feeding flat sheets (8) of thermoformable plastic material to the pickup station (24);
• at least one thermoforming device (3) in turn comprising a shaped mould (4) and a closing element (5), the shaped mould (4) and the closing element (5) being movable relative to each other at least between a home position in which they are away from one another, and a forming position in which they are near to each other for, in use, clamping a flat sheet (8) between them;
• the closing element (5) comprising a resting surface (16) that is facing the shaped mould (4) at least when they are in the forming position;
• and being equipped with suction means designed to retain on the resting surface (16) at least one of said flat sheets (8) at least when the shaped mould (4) and the closing element (5) are in the home position;
• one or more heating elements (6) for heating the closing element (5);
• a transferring device (26) for transferring the flat sheets (8) from the pickup station (24) to the closing element (5);
• an extracting device (9) for extracting the thermoformed container (2) from the shaped mould (4);
• and
• an electronic unit (10) for controlling and checking operation of the apparatus (1);
• wherein:
• when the shaped mould (4) and the closing element (5) are in the forming position, the thermoforming device (3) can perform, in use, thermoforming of the flat sheet (8) to make a container (2) equipped with an upper flange (71) projecting outward;
• the extracting device (9) comprises at least one gripper element (68), shiftable between a pickup position and a releasing position;
• when the shaped mould (4) and the closing element (5) are in the extracting position, and the gripper element (68) is in the pickup position, the gripper element (68) being near to the shaped mould (4) and, in use, being able to grip at least one edge (66) of the flange (71) for retaining the container (2);
• and
• when the gripper element (68) is in the releasing position, it is away from the shaped mould (4) and can release a thermoformed container (2), retained by it, onto a conveying device (69).