All new machines are fitted with an absolutely unique tangential cutting system.
The rotary blades have a high angle of approach to the fixed blades to be positioned as close as possible to the geometric tangent of the cutting circle for the most efficient cutting action. The effect of this tangential cut/high angle of approach is higher capacity with less horsepower as less power is consumed. The quality of the regrind is greatly improved with this cleaner, less stressful cut, and heat generation is minimized due to this efficient cutting action.
The new Piovan granulators are a step ahead of current versions available in the market thanks to the way they are manufactured. The cutting chamber is made from machined pieces, which are then assembled rather than being cast or welded.
Another distinctive feature of Piovan granulators is the possibility for customization. Even the most basic versions can be modified to suit the specific needs of the process (e.g. blow molding, extrusion, injection) and to comply with specific customer requests in terms of space, granulator loading and unloading requirements and protection of the operating environment. With the tangential cutting system, reduced rotor speed and solid flywheel drive pulley, open rotors, and full integral sound enclosures, Piovan granulators operate at the lowest possible sound level.
Piovan granulators are also fitted with energy efficient electrical and control systems: the entire transmission system has in fact been designed to achieve effective energy savings when used 24/7.
Even if the granulator doesn’t work continuously, it is possible to optimize peak loads to reduce energy consumption. For example, in the case of blow molding, the granulator is used heavily at start-up, while during operation it is used intermittently to grind 20-30% of production. Between one mold changes there are a series of idle periods in which the granulator is inoperative, even if the motor remains on.
The energy saving system intervenes in this case to manage the idle periods and reduce consumption. The new range of Piovan high-efficiency granulators guarantees energy savings between 15% and 35% depending on the application.
Piovan introduces the N35-60, a machine encompassing all of the characteristics described above, in addition to featuring a 90° adjustable hopper for 4 loading positions. This special feed hopper design allows for the granulator to be positioned for optimal feed AND optimal access for maintenance and cleanout, ideal for limited operating spaces.
N35-60 is part of a family of three granulators (also N25-45 and N55-90) designed specifically to process large bulky parts such as injection molded food containers, bins; large blow molded bottles or cans; tanks, gardening products, rotationally molded toys and furniture.
These type parts are normally quite large and light and subject to bouncing on top of the rotor and not getting ingested. These three models are designed with a tangential feed cutting chamber that allows for these large parts to be presented into the downstroke of the rotor, reducing the bouncing effect for more efficient processing.
Complementing the range of granulators is the single-shaft shredder line, perfect for recovering purgings from start-ups or material replacements during all transformation processes.
To make an example, consider a facility having 30 presses producing 200 different molded items. In one year, they may need to change molds 600 times and each time the injection unit needs to be purged of the previous material. If the weight of an average purging (from 2 to 4 kilos) is multiplied by the number of mold changes, thousands of kilograms of purgings are produced - which could be recovered with a shredder.
Shredders are machines whose role partially overlaps that of granulators and sometimes even integrates their function. With the same-sized parts, a shredder uses much smaller motors compared to a granulator large enough to be able to process these parts without pre-sizing.
Since the granulator in a two-stage system is now only processing shredded material, a much smaller granulator, with significantly smaller motor, can be used for final size reduction. This two-stage shredder-granulator system provides for significant energy savings in cases where high throughput is not necessary. The smaller granulator will also be less costly and easier to maintain, have reduced rotor speed for higher quality regrind and significantly lower sound levels. The Piovan range of single-shaft shredders includes 4 different models, each with a hopper that can vary in size from 600x600 mm to 1500x1500 mm.