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Nowadays, all industrial products are designed with a view towards recovering and recycling as many reject components as possible. In certain sectors, for example in the Food&Beverage packaging sector, a decision is often made not to change raw material, in order to continue the existing recycling channels and methods. The need to develop recyclable materials influences and determines choices in the research and development sector. For this reason, granulators have assumed a fundamental role in the plastics sector, having been specifically designed to recover plastics processing waste and make it reusable.
Piovan has redeveloped its range of recycling products introducing very high quality machines able to satisfy all recycling needs throughout the plastics sector. In all cases where plastic is used in the packaging, medical, automotive, textiles and electronics sectors, recycling is common practice, confirming the need for increasingly efficient and reliable granulators. Piovan has therefore introduced a new range complete with small, medium and large granulators, characterised by innovative technical and design-based features.
Most importantly, all new machines are fitted with an absolutely unique tangential cutting system. The rotary blades are inclined with respect to the fixed blades and are positioned as close as possible to the geometric tangent of the cutting circle, therefore optimising and improving cutting precision. In this way, high production capacities are achieved using smaller motors, with the additional benefit of minimising dust production and heat generation. These features ensure a more regular cut and more dimensionally consistent regrind.
Without a cutting chamber of this quality, the regrind, in addition to being irregular, will also have a higher dust content and will therefore be more difficult to process.
The new Piovan granulators are a step ahead of current versions available in the market thanks to the way they are manufactured
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The cutting chamber is made from machined pieces, which are then assembled rather than being cast or welded. This design has enabled the construction of high-precision components that improve the efficiency of the cut and the quality of the ground product, while improving the life of the granulator, as worn pieces can be replaced.
Another distinctive feature of Piovan granulators is the possibility for customisation. Even the most basic versions can be modified to suit the specific needs of the process (e.g. blow moulding, extrusion, injection) and to comply with specific customer requests in terms of space, granulator loading and unloading requirements and protection of the operating environment - these machines also guarantee extremely low noise levels.
N35-60: the state-of-the-art granulator
At Fakuma 2015, Piovan presented the N35-60, a machine encompassing all of the characteristics described above, in addition to featuring a 90° adjustable hopper for 4 loading positions, ensuring that if fed by conveyor belt, the direction of the belt can always suit the granulator hopper inlet. Maintenance is therefore simplified and less operating space is required.
Fast access to the machine is another important factor, given that in certain operating conditions cleaning operations may be necessary on a daily basis. This feature is a response to a specific request by numerous users who need to insert the granulators at the end of production lines where space is often limited.
N35-60 is part of a family of three granulators designed specifically to process large pieces or such as injection moulded food containers, large bottles or cans (blow moulding), tanks, bins, gardening products, toys (rotational moulding process). These objects are normally quite large and light and can therefore bounce and be difficult to cut.
Single-shaft shredders: the complementarity of a product
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, if we consider a facility with 200 moulded items, equipped with 30 presses: in one year they may need to change moulds 600 times, each time the injection unit needs to be purged. The weight of an average purging (from 2 to 4 kilos) multiplied by the number of mould changes, produces numerous tonnes of engineering polymers that can be recovered with a shredder.
Shredders are machines whose role partially overlaps that of granulators and sometimes even integrates their function. At times, to granulate and recover medium to large-sized waste, it may be more convenient to use a shredder rather than a large-sized granulator. Granulated waste can then be ground by smaller and more economical granulators.
With the same-sized parts, a shredder uses much smaller motors compared to a granulator, which translates into significant energy savings in cases where high throughput is not necessary.
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.
Piovan recycling line: excellent results using less energy
We've already meantioned that one of the advantages of a tangential cut, with the same size parts, allows us to use much smaller motors.
Piovan granulators are also fitted with energy efficient electrical and control systems: the entire transmission system has in fact been revised to achieve effective energy savings when used 24/7. Even if the granulator doesn’t work continuously, it is possible to optimise peak loads to reduce energy consumption.
For example, in the case of blow moulding, the granulator is used heavily at start-up, while during operation it is used intermittently to grind 20-30% of production. Between one mould and another 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 optimise consumption.
The new range of Piovan high-efficiency granulators guarantees energy savings between 15% and 35% depending on the application.
