A unit and a method for carrying out a first operation and a second operation on a web

A method for carrying out a first operation and a second operation respectively onto a first area and a second area of a packaging material;

• said first area and said second area being spaced for a first distance along said direction when a portion of said packaging material comprising said first area and said second area is flat;
• said method comprising the steps of:
• feeding a web of said packaging material along a direction and in a first sense;
• carrying out said first operation on said first area and at a first desired position, by using at least one first tool;
• and
• carrying out said second operation on said second area and at a second desired position, by using at least one second tool;
• said first and said second tool being spaced for a second distance along a direction;
• wherein said step of feeding comprises the steps of:
• arresting said web in a position, at which said second area is spaced by an intentional offset from said second desired position;
• and
• moving said second area towards said second desired position, so as to recover said offset;
• the absolute value of the difference between said first distance (e) and said second distance being equal to said offset.

A unit for carrying out a first molding operation at a first pre-laminated hole in a packaging material web and a second molding operation at a second pre-laminated hole in the packaging material web, the first and second pre-laminated holes being located in a portion of the packaging material web and being spaced a first distance along a direction when the portion of the packaging material web in which the first and second pre-laminated holes are located is flat, the unit comprising:

• a first mold that injects plastic material to carry out the first molding operation at the first pre-laminated hole arranged in a first desired position;
• a second mold that injects plastic material to carry out the second molding operation at the second pre-laminated hole arranged in a second desired position;
• the first and second molds being spaced a second distance along the direction;
• a motor operable to feed the packaging material web along the direction and in a first sense, and to arrest the packaging material web at a position in which the second pre-laminated hole is spaced an intentional offset from the second desired position;
• an actuator configured to move the second pre-laminated hole towards the second desired position to recover the offset;
• and
• the absolute value of the difference between the first distance and the second distance being equal to the offset.