Shredders and Granulators are a reclaimers production machine, and these systems have to be designed with high production, quality of regrind, ease of maintenance, and long life in mind.
As recycling has become increasing more important with plastics impact on the environment, necessary regulations for higher content of reclaimed materials over the last several years, Piovan has focused on innovating high production machines to meet this demand, designing and manufacturing innovative granulators able to offer a complete range of solutions featured by Adjustable Rotating Knives. The granulators are characterized also by the Tangential Cut – a high angle of approach of the rotating knife to the fixed knife. This higher angle of approach results in a significantly more efficient cutting action with higher cutting forces and lower frictional forces. While other granulator manufacturers maintained status quo with bed knives having no relief angle, the Piovan granulators recognized the need to have a relief angle for efficient cutting and not only developed a stationary knife with a relief angle, but one with two cutting angles to reduce the need to sharpen every time. The more efficient cutting action from all of these innovations allows for the ability to utilize smaller power motors to cut the same product as competitive products, resulting in lower energy costs. Their continuing quest for innovation, and their focus on making their high production machines more productive for reclaimers has led to their newest cutting innovation – Disposable Knives.
U&G Disposable Knives
U&G Disposable Knives are a clamped knife design allowing for a significantly smaller knife to be used. After a conventional knife is sharpened to its minimal level, 95% of the knife is rendered useless and scrapped. Since the U&G Disposable Knives are so much smaller, a more exotic, more expensive tool steel can be used for longer life and still cost less than conventional knives utilizing all that expensive D2 tool steel. Knives that stay sharper longer produce higher quality regrind, use less energy, generate less heat, cut quieter, and lead to less machine vibration. Disposable knives, so called because they are not sharpened but used once and scrapped, do not require gapping between the rotating and stationary knives. This results in significantly easier and faster knife changes – critical for production machines. A granulator in a plastics part processing plant such as an injection molding, blow molding, or extrusion plant, is typically scheduled for service when the plastic part processing machine is getting a new mold or regular maintenance. For a recycler, this downtime to change the knives is lost production. The faster the granulator knives can be changed, the higher the weekly production. U&G knives take about half as much time to change than conventional knives. The difference is even greater with older technology granulators with fixed knives and no knife gap pre-adjustment fixture. Those unsung heroes keeping the plants running maintaining the machines will love changing a 300 gram knife instead of a 15 kg knife. Between longer life using a more exotic tool steel and shorter knife changes, cost savings per ton of material processed is significant and proven with a study performed at a recycler in Europe. The New EV Series – designed with the Recycling Industry in mind First came the 916 – 30,000 pounds of cutting machine – designed for wet or dry grinding at rates up to 12,000 lbs/hr. The 36” diameter rotor and 63” wide cutting chamber will process parts whole that use to have to be pre-sized in a shredder. Processing up to 6 tons of material an hour will generate some heat which can be detrimental to the process. The 916 is ready with water cooling available for the attack side chamber, the bearing housings, and even the rotor. Long life is assured with bolt and dowel construction, wear plates for the cutting chamber made of Durastat steel (the same material used for earth moving equipment), hardface welding for rotor knife supports, wear resistance for bed knives support. There is even an anti-vibration plate between the machine base and the cutting chamber and nine (9) vibration isolation pads to keep it all sitting smooth. Knowing that not everyone is going to need a 36” cutting circle or the need to process 12,000 lbs/hr, all the new range of EV616 has been enhanced with all the same features and benefits, but with a 24” diameter rotor instead of 36”.
Production, Production, Production
That’s the name of the game for Recycling Industry. In addition to all of the innovative designs for efficient cutting described above, the EV series features fast and easy access for quick cleanouts and maintenance. A zero speed switch monitors rotor shaft speed and de-activates safety switched only after the rotor has a come to a complete stop – no more carpal tunnel causing time delay safety switches. A hydraulic screwjack opens the feed hopper back and the screen cradle down for complete access. A hydraulic rotor restraint keeps the rotor from moving during service.