Energy-Saving Accumulator-Head Blow Molder

At K 2022, ST BlowMoulding SA of Italy introduced the AX 880 accumulator-head blow molder. Unlike the company’s ISIT and TA Series accumulator-head machines, the new model has an all-electric clamp; it also has electro-hydraulic parison push-out, along with the company’s trademark adiabatic extruders. These extruders are said to generate gentle plasticating without melt overheating, so no cooling fans are needed. On the contrary, double-layer thermal insulation on the barrel reportedly cuts heat losses to 10% as much as from a conventional extruder. The new machine thus reportedly outperforms the maximum energy-efficiency class 10 under Euromap 46.1 (< 0.29 kWh/kg processed), even among large industrial extrusion blow molding machines.

The new machine is offered with two clamp capacities, 80 and 100 metric tons, and accumulator heads from 10 to 25 liters. The new series will also include two smaller models (AX 440 and AX 560) and one larger (AX 1313). All have the electric clamp, in which clamping force is electronically checked and tuned on every cycle to ensure repeatability and consistency. The clamp is adjustable to accommodate molds with a wide range of stack heights. Parison push-out utilizes a variable-speed pump without hydraulic accumulator to push out the parison directly.

An optional feature on the AX Series (ER version) is rollout of the upper deck for simultaneous changeover of the head tooling and the mold. It clears the area above the clamp for mold handling from the top and moves the extrusion head to a side position for easy and safe access. The AX Series also introduces the Automatic Head tooling Changeover (AHC), described as a “revolutionary” device for quick changes with no tools, no screws to be loosened and tightened, and no human effort. The operator stands at a safe distance and presses a few keys on a portable keypad to control each step of the sequence.

To accommodate recycled plastics, the machine at the show was outfitted with two extruders, each of which feeds a separate melt channel in the accumulator head. A new design of the flow channels is said to significantly improve the balance of the two layers. And if a further layer is needed, the firm’s Outer Coating Technology with a separate accumulator chamber is available. What’s more, both extruders on the AX 880 machine at the show were prefitted with gas infeed ports for foaming to save material and add acoustic or thermal insulating properties.