Compact preform system for long and heavy preforms (HOD)
by Alexander Büchler
At its in-house exhibition, Otto Systems presented its newly developed injection moulding system designed for producing 5 to 20l Home and Office Delivery (HOD) preforms. The Swiss company, with its strategic focus on special applications outside the mass market showcased a 160t system that allows for the efficient production of large-volume preforms, which traditionally would require a larger system to achieve a comparable output. The Swiss achieve the compact design thanks to an outward-bending toggle mechanism, intelligently arranged cooling stations on the post-mould cooling unit and an in-house developed injection unit.
The external, electrically driven toggle levers, developed in collaboration with partner BMB, enable a significant stroke of nearly 1m, while maintaining a compact structure. On the 160t system presented, eight preforms for one-way PET water containers weighing 330g and measuring 304mm in length have been produced per cycle. With a cycle time of 36 seconds, the system achieves an output of 800 preforms per hour. The two-row compact mould design helps reduce width, making the system smaller and more cost-effective without compromising on cooling-efficiency. The limitation, given by the mould, to two cooling stations can be enhanced to four post-cooling stations through the chosen layout of the take-out plate. Thanks to the duplication of the EOAT to 2+2 cooling stations high cooling efficiency is ensured.
The proprietary injection unit balances plasticising and injection performance, incorporating Otto Systems’ innovative Time Safe Unit (TSU). This TSU manages the extended holding pressure required for large and thick-walled preforms, allowing the screw to perform large dosing strokes at moderate rotational speeds with an ideal residence time. This combination results in optimal homogeneous plastification, ensuring superior process conditions.
In addition to the 160t machine shown, Otto Systems is expanding the HOD-Series with a larger 240t system designed to produce preforms up to 400mm in length and shot weights of up to 10kg. This model will also be capable of producing preforms for MW 5-gallon containers weighing 680-700g, demonstrating Otto Systems commitment to innovation and market adaptability. The extended clamping unit ensures flexibility and efficiency, even for the most demanding applications such as beer keg preforms.
The compact, high-performance HOD-Series is engineered for specialised applications, with a strong focus on energy efficiency and cost-effectiveness. Reflecting Otto Systems’ strategic focus on special applications outside the mass market, the 160t and 240t systems demonstrate Otto Systems leadership in the production of large, heavy preforms for various sectors, while ensuring maximum productivity in minimal space.
