Long Neck Preform Mold

The core pins in a Long neck preform mold can be over 150 mm in length with a high length-to-diameter ratio. To prevent deflection from the melt flow, we employ a guided core system. The tip of each core pin locates into a gate-side bushing during injection, creating a closed loop that keeps the pin perfectly centered.

Ejecting a long, slender preform requires a delicate touch. The Long neck preform mold uses a three-stage ejection: first, the core retracts; then, a stripper ring pushes the preform off the core; finally, an assist device slowly peels the neck away. This sequence prevents stretching or marking the preform's long inner bore.

A long preform tends to cool unevenly along its length. Our Long neck preform mold features a contour-conformal cooling design that wraps around the core pin in a helical groove. This provides consistent coolant velocity from base to tip, eliminating the thermal gradient that could cause bowing or ovality in the preform.

With a very long flow path, the gate position and diameter in a Long neck preform mold are critical. We use a direct open-tip or valve-gated nozzle that delivers melt straight into the preform base without any off-center turbulence. This symmetrical flow front ensures the deep preform fills completely, with no hesitation lines. A Long neck preform mold thus enables the production of premium, functional dispenser bottles.

Powered by advanced engineering and precision manufacturing, DEMARK PET preform molds and injection systems are designed to deliver stable performance, fast cycle times, and long-lasting reliability for modern packaging manufacturers.