PET preform injection moulding is a highly competitive business, so production efficiency is critical to success. Hot runners in the mould are a fundamental element in the total system, so any anomaly in their operation can compromise output.
In addition to mechanical or electrical issues that can affect the efficiency of a hot runner system, there is also another problem that processors should be well aware of dust.
Over time, PET powder builds up on the actuators. As it accumulates, it inhibits the movement of the actuators, eventually severely compromising the quality of the preforms. If not treated, this accumulation can cause the system to seize up completely. This is especially true when processing rPET.
This trend, a response to growing concerns about plastic waste, presents a significant challenge for the entire PET bottle production chain. SIPA decided to take a new look at dust, and to devise an easier and more cost-effective solution to the problem. The target of the development was to find a solution that was smart and simple at the same time.
The goal was to have a complete hot runner system that needs maintenance only to carry out standard renovation operations – that is, to replace worn components. SIPA’s engineers came up with a patented system called XActive-Cleaning. The hot runner systemis equipped with a supplementary circuit incorporating a series of valves which govern the entry and discharge of air from the hot runner, making sure that any PET dust particles created in the system are evacuated every cycle.
This solution should on its own keep the system clean, but just to be sure, there is also a “boost” function to perform a forced cleaning cycle at intervals set by the user. This process has no impact on productivity. XActive-Cleaning was born for the Sipa Xform preform systems but is applicable to any injection machine in a very simple way.