Moulding with lights out in the smart factory

Injection moulding machines running 24/7, remote monitoring of all processes, human intervention reduced to a minimum and no night-time supervision. This sums up the mode of operation of the automatic factory started three years ago in Loveland, Colorado, by Nordson Medical for the production of medical items, a concrete example of Industry 4.0 and “Lights Out Manufacturing” made possible thanks to a conveying, feeding and drying system supplied by Piovan.

This industrial model, fully in line with Industry 4.0, has been successfully applied at the Nordson Medical facilities with the idea of automating production as much as possible. Here, a giant class 100,000 clean room, occupying a surface area of 3,500 square metres, houses 56 injection moulding machines with clamping forces of between 15 and 200 tons that, operating non-stop, have the capacity to churn out, every day, 1.2 million medical items manufactured under controlled conditions and tracked at every stage in order to ensure the highest quality and safety standards. The moulding cells feature a complex conveying, feeding, drying and blending system designed and built by Piovan, in collaboration with Una-Dyn, a US company belonging to the Italian group. The Veneto-based manufacturer secured this supply contract thanks to its ability to satisfy, in the best way, the demand for extreme automation that underpins the entire plant offering widely tested solutions.

To allow the machines to work round the clock without stopping (except for scheduled maintenance or unplanned downtimes), granulate treatment and handling are managed and regulated by Winfactory 4.0 software, a veritable control unit that allows the operator, at any time, to access the process parameters remotely and monitoring the correct running of the equipment, without having to enter the department: a solution known as Lights Out Manufacturing.

The plant equipment includes: a drying system composed of four Modula units, corresponding to a total of 25 hoppers, five Easylink automatic coupling stations, Quantum blenders and Pureflo filterless receivers configured for medical applications and integrated with Ryng devices, each of which is equipped with its own control unit, capable of communicating with Winfactory 4.0, which in turn interfaces with the factory management system.

Until two years ago, an operator would be on hand at night, ready to step in when alarms sounded. Today, when this happens, the department managers are alerted by the control system through a pager or through messages on tablets or smartphones. In this way, they can assess the problem before intervening and, in some cases, solve it remotely.

The functioning

When the plastic granulate arrives at Nordson Medical, an operator passes the scanner on the barcode before loading it into one of the factory’s four 5,000-kg silos. In accordance with the production schedule, the Piovan Winfactory 4.0-MED system - this is the software version optimised for use in medical applications - automatically feeds the material to the machines, using five Easylink automatic coupling stations, a vacuum suction system (Varyo), which reduces stress on the material, and eight kilometers of steel pipes; when necessary, the granulate is dehumidified by means of four Modula units that handle 25 hoppers. One particular aspect of the drying system is worth underlining, as it is unique: whenever the material request from the injection moulding machines declines, the dryers are automatically switched off to avoid wasting energy; if, on the other hand, an alarm is triggered during the night and a dryer goes off, the remaining ones can keep the 25 hoppers running, without slowing down or halting production. Each machine is equipped with a Pureflo filterless receiver connected to a Quantum gravimetric batch blender with continuous extrusion control. The latter, after adding pigments and additives, adjusts, with precision and constancy, the quantity of granulate to be processed.

Nordson Medical also wanted an automatic system for the recovery of waste. Accordingly, each Easylink automatic coupling station, as well as conveying the virgin granulate to the single machine, can also direct the waste from the moulding cell to the appropriate recycling station, which is different for each processed material. The automatic management of this phase has made it possible to eliminate the presence of a human operator, opening the way for round-the-clock “lights out” production.