PETIII

PET preform moulding is its own discipline. The resin must be plasticised fast and gently — fast because cavitation is high and cycles are short, gently because shear and residence time drive up acetaldehyde, which taints the water or beverage the bottle will eventually hold.

The PETIII answers both with a low-shear, high L/D screw that raises plasticising efficiency by more than 30% while effectively reducing acetaldehyde level. Electric plasticising cuts energy use by 20–40%, reduces hydraulic oil and cooling water consumption, and — because plasticising runs at the same time as mould opening and part take-out — takes time off the cycle rather than adding to it. The tip set is bi-metallic and wear-resistant.

Preforms are long and deep, so the machine carries an extra-large opening stroke, an enlarged ejector for the speed, force and stroke that a full preform plate demands, and a linear guide rail injection unit that reduces mechanical back pressure. On the hydraulic side, a large-torque motor supplies the continuous high torque PET needs, with some standard units rated to 210 bar, feeding through a large-diameter pipeline. An integrated large-diameter water divider handles the substantial cooling load; machines of 300T and below come built in with 15 sets of ball valves with 10 mm quick-release fittings.

The result on the part is what matters: high transparency, even colouring whether you use masterbatch, pigment or liquid colourant, and even plasticising of resin with a higher proportion of recycled content.

Proven applications

Preform	Mould	Cycle time	Machine	Screw
Mineral water bottle	64 cavities, 14 g each	15 s	420PETIII/s	94 mm
Cooking oil bottle	32 cavities, 105 g each	40 s (incl. robot take-out)	480PETIII/e	105 mm
Wide-mouth bottle	32 cavities, 76 mm dia, 37 g each	27 s	480PETIII	94 mm
PP beverage bottle	48 cavities, 35 g each	35.8 s	320PETIII/h	100 mm

A 500PP-SeIII is also available as a special reference machine for PP beverage preform work — 500T clamping, 110 mm screw, 4,892 g PET shot weight, 920×1120 mm tie bar spacing.

Where it fits: water and beverage preforms, cooking oil bottles, wide-mouth jars, and PP preform work. A complete preform line also needs a dehumidifying feeder, hopper, chiller, cooling tower, take-out robot, conveyor and crusher — talk to us and we will quote the system rather than just the machine.

Shot weights in the table are quoted on PET, as the Welltec sheet does; the catalogue also lists PP/PE figures. The range covers both the servo-pump and the electric-plasticising (PETIII/e) builds — tell us the preform and the cavitation and we will confirm which suits.