Process for making a package for foodstuff products

1. A process for making a package ( 20 ) for foodstuff products comprising:

providing a first sheet ( 10 ) of wrapping, made of plastic material, and forming therein at least one first, hollow, portion ( 11 ), which is delimited, at least partially, by a second, perimetral, portion of said first sheet ( 13 );

inserting a foodstuff product within said first, hollow, portion ( 11 );

applying a second sheet of wrapping in contact with said second, perimetral, portion ( 13 ) so as to close said hollow portion ( 11 ) with said product inside; and

welding said second sheet ( 30 ) on said first sheet ( 10 ) along said second, perimetral, portion ( 11 ),

wherein forming of said first sheet includes:

providing a mould ( 21 ) having a mould cavity ( 21 ′);

providing a forming device ( 26 ) designed to co-operate with said mould cavity ( 21 ′) for forming said first sheet;

setting said first sheet ( 10 ) on said mould ( 21 ) and making on said first sheet, via said forming device ( 26 ), said first, hollow, portion ( 11 ) delimited by said second, perimetral, portion ( 13 ); wherein said first sheet of wrapping ( 10 ) has a thickness of less than or equal to 140 μm, and in that forming of said first sheet includes: providing said mould with a mould surface ( 221 ′) that surrounds said mould cavity ( 21 ′);

providing a first forming body ( 32 ) of the forming device ( 26 ) configured for pressing said first sheet of wrapping against said mould surface ( 221 ′);

during said step of formation of said first, hollow, portion ( 11 ), forming on at least said second portion ( 13 ) a series of pleats ( 122 ) identified by respective folding lines ( 122 ′) of said first sheet of wrapping that are oriented towards said hollow portion, wherein each folding line joins together two pleat sides of the respective pleat; and

via said first forming body ( 32 ) and said mould surface ( 221 ′), sealing said pleats ( 122 ) so as to prevent re-opening thereof;

squeezing said pleats ( 122 ) against said mould surface ( 221 ′) so that said pleats ( 122 ) and their respective pleat sides remain contained in the same general plane of the second perimetral portion ( 13 ); and

fixing said pleats squeezed against said mould surface in said position, via welding such that said pleats form an irregular arrangement.

2. The process according to claim 1 , wherein said step of welding said second sheet ( 30 ) on said first sheet ( 10 ) along said second, perimetral, portion ( 13 ) is performed via said first forming body ( 32 ) according to a process of heat sealing, ultrasound welding, induction welding, etc.

3. The process according to claim 2 , wherein said first forming body ( 32 ) is heated to a pre-determined temperature.

4. The process according to claim 2 , wherein said mould surface ( 221 ′) is heated to a pre-determined temperature.

5. The process according to claim 1 , wherein said forming device comprises the first forming body ( 32 ) and a second forming body ( 28 ) designed to co-operate with said mould cavity ( 21 ′) and the first forming body ( 32 ) configured for pressing said first sheet against said mould surface ( 221 ′).

6. The process according to claim 5 , wherein said first forming body ( 32 ) is heated to a pre-determined temperature, whereas said second forming body ( 28 ) is either not heated or else is heated to a lower pre-determined temperature.

7. The process according to claim 6 , wherein the ratio between the lower and the higher temperature (measured in degree Celsius) is lower than or equal to 1:1.8.

8. The process according to claim 1 , wherein said pleats ( 122 ) are squeezed in the generic plane defined as a whole by said second portion ( 13 ).