Extrusion plant for blow extrusion of plastic films with a system for removing vapours generated by the extrusion process

An extrusion plant for the production of plastic films by blow extrusion process, the plant comprising:

• an extrusion head with a die, from which die, in use, plastic material is extruded to form a bubble,
• a cooling ring located downstream of the extrusion head, and
• a vapour removal system for the removal of vapours of monomeric and aliphatic nature resulting from extrusion of the plastic material through the extrusion head,
• wherein said vapour removal system comprises a plurality of filtering devices separate from each other, and a suction unit connected to the filtering devices,
• wherein each filtering device comprises a support casing, a filter carried by the support casing to retain the vapours of monomeric and aliphatic nature contained in the air sucked in by the suction unit through the filtering device, and an intake duct connected on one side to the support housing, downstream of the filter, and on the other side to the suction unit, and
• wherein the filtering devices are arranged beneath the cooling ring and around the extrusion head and are attached to the cooling ring so as to be removable from the cooling ring independently of each other.