Installation for the manufacture of containers comprising a secure enclosure provided with a system for the insufflation of filtered air

Installation (10) for the manufacture of bottles (12) by blow moulding or stretch blow moulding from a thermoplastic preform (14), the installation comprising:

• an installation inlet (E);
• an installation outlet (S);
• a perform-supplying device (24) arranged to supply preforms to the inlet (E) of the installation (10);
• a thermal conditioning unit (26) arranged downstream of the inlet (E), the thermal conditioning unit comprising an inlet zone (32), an outlet zone (34), and an oven (28), the oven comprising perform heaters (30) arranged between the inlet zone (32) into which the preforms (14) are fed by the perform-supplying device (24) and the outlet zone (34);
• a transfer zone (36), the outlet zone (34) of the oven discharging thermally conditioned performs into the transfer zone;
• a moulding unit (42) comprising a wheel (44) and having a supply zone (40) and a discharge zone (48), the wheel (44) provided with at least six moulds (46) distributed circumferentially around the wheel, the wheel being driven in rotation so that each mould passes through a transformation cycle from said supply zone (40) to said discharge zone (48), said moulding unit discharging containers at the discharge zone, the rotation of the wheel (44) acting as a fan creating a current of air (C) moving from said supply zone (40) to said discharge zone (48) and to said outlet zone (34);
• a first transfer device (38) arranged in the transfer zone (36), the first transfer device transferring the thermally conditioned preforms (14) from the outlet zone (34) of the oven (28) to the supply zone (40) of a moulding unit (42);
• a second transfer device (50) arranged in the transfer zone (36) adjacent the installation outlet (S), the second transfer device transferring the containers (12) from the discharge zone (48) of the moulding unit (42) to the outlet (S) of the installation (10);
• a secure enclosure (52) forming a casing,
• the enclosure surrounding the moulding unit (42), the transfer zone (36) and the outlet zone (34) of the oven (28),
• the enclosure (52) defining a peripheral U-shaped zone (54) around the wheel (44) which, the U-shaped zone extending from the supply zone (40) as far as the discharge zone (48), the U-shaped zone successively comprising a first right-hand lateral zone (Z1), a second rear zone (Z2), and a third lateral left-hand zone (Z3),
• the current of air (C) originating in the first right-hand lateral zone (Z1),
• said first right-hand lateral zone (Z1) being i) encompassed longitudinally between a lateral part of the wheel (44) carrying the moulds (46) and an opposing wall (56) of the enclosure (52), ii) extending transversely to a rear from the supply zone (40) of the moulding unit (42) and, iii) extending vertically from a floor (66) to a ceiling (68) of the enclosure (52);
• and
• an insufflation system (70) for insufflation of filtered air inside the enclosure, the insufflation system creating an excess pressure in the enclosure by projecting a flow (F) of filtered air selectively introduced into the first right-hand lateral zone (Z1), the introduced air corresponding to an internal volume of the enclosure (52) in which a current of air (C) originates by the rotation of the wheel (44),
• wherein the projected flow (F) of filtered air into the first right-hand lateral zone (Z1) provides that the current of air (C) produced by the rotation of the wheel (44) consists of the filtered air, the insufflation of filtered air inside the first right-hand lateral zone (Z1) of the enclosure avoiding risks of airborne contamination including contamination of the preforms (14) in the outlet zone (34) of the oven (28) by the current of air (C) to said outlet zone (34) being filtered air.