2013 Exhibitions

Italian auxiliary systems supplier has succeeded in securing a contract for its Modula drying technology at one of car maker BMW’s new German production sites of the BMW i3 and BMW i8 vehicles. BMW specified to all potential suppliers that any of the processes necessary to convey, dry and blend the different polymers in use, had to be energy efficient and self sustainable. Also, the output claimed would be tested and compared, to assess and subsequently determine the ranking of performance.

Piovan says that the testing period lasted six months and it had to compete with five major suppliers of auxiliary equipment. “Modula of Piovan was regarded by BMW as the best solution, for its efficient operation, energy utilisation, auto adaptivity and constant process conditions,” it says.

Modula is installed in the first phase that involves the installation of six lines, but the two Modula units supplied to BMW were configured to also support an expansion to 12 production lines.

The materials utilised by BMW are mainly blends, with a PP or PC base, like PP/EPDM and PC/SAN. The plastic part is first injection moulded and immediately transferred to the painting lines, which is a sensitive phase of the production process where silicone particles are banned. Says Piovan, “One very important feature of Modula is the absence of silicone components/parts within the system, making it fully suitable for applications such as the one of BMW.”

The purpose of hygroscopic plastic drying is to reduce moisture content to the required levels. This operation is generally performed by circulating hot dry air inside a drying hopper. In the case of applications that involve a number of materials of different kinds, a central unit is commonly used to generate dry air, which is then distributed to a series of hoppers, one for each material type, through a duct system.

As such, each hopper requires specific conditions for optimum operation (dry air flow, temperature and pressure) depending on the different material characteristics, such as the type, the required initial and final level of moisture, the hourly material consumption and the granule size.

A safety condition is systematically adopted and the drying system is sized based on the most critical processing parameters, such as maximum material consumption, at maximum temperature, with the highest airflow. “This basic model goes against any principle of energy efficiency and certainly does nothing to reduce or optimise the system running costs,” adds Piovan.

The two sets of Modula supplied are each configured with a single dry air generator and seven drying hoppers with volumes ranging from 600 to 1,000 l. The units automatically adjust and control all operating parameters for each individual hopper and hence use only the overall amount of energy strictly required. This is made possible through a specific controls software that interfaces the settings for each hopper with the data collected by the sensors installed on the system.

This means that, by using a Piovan patented measuring unit located in the air supply line and under each hopper, the airflow can be adjusted and controlled instantaneously and independently hopper by hopper. In addition, the total airflow is modulated automatically and efficiently by the central drying unit, equipped with IE3 class blowers, resulting in optimum process operating conditions.

The auto adaptive and energy efficient drying system with multiple hopper assembly was launched by Piovan in the market in late 2010. Recently, Piovan obtained a specific patent in certification of the innovative nature of the Modula solution. Modula is today available for medium and large capacity applications (200 to 2000 kg/hours) and provides savings of as much as 50% with respect to ordinary centralised drying systems of equivalent capacity, according to Piovan. It is also Winfactory ready.

Along with Modula, Piovan supplied to BMW the Varyo auto-adjustable vacuum conveying systems, MDW gravimetric blenders and Winfactory supervisory system.