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SPONSORED CONTENT: Rotogran granulators offer quality characteristics


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March 17, 2020 by Rotogran International

Since 1982, ROTOGRAN INTERNATIONAL INC. has manufactured granulators and closed-loop granulating systems for the plastics and recycling industries. In use around the world, ROTOGRAN granulating systems are the workhorse of the breed…OUT-PERFORMING and OUT-LASTING all others in the marketplace today.

Our 20,000-square-foot facility manufactures innovative equipment that’s durable, dependable, and cost-efficient.

ROTOGRAN GRANULATORS – QUALITY CHARACTERISTICS

Chamber:

Rotogran cutting chambers are made from solid 44W certified steel flame cut profiles which are then Blanchard ground to specification for accuracy and also to produce a cold worked surface finish. The ground profiles and internal chamber components are then assembled in a precision jig and solidly welded to produce a chamber far superior to offshore cast chambers as listed below:

  • Higher overall strength and resistance to structural failure
  • No cracks or casting flaws present in the chamber fabrication
  • No issues with casting metal impurities
  • No uneven material thickness
  • Ground and machined chamber components have a finer surface finish for less friction against granulated parts thus producing higher quality regrind.
  • In all our years of granulator manufacturing, we have never experienced a chamber failure, but have replaced cast chambers for customers who still have some non-Rotogran granulators.

Rotor:

Rotogran rotors are a welded and machined fabrication. This method produces a higher quality rotor in terms of material specification and long term durability.

The rotor is welded fabrication made from a 5” diameter C1045 HRS and several flame-cut profiles cut from C1045 plate comprising the rotor fins. The rotor shaft and fins are pre-machined for assembly and fitted together in an accurate positioning jig. The tack-welded fabrication is then pre-heated in a rotating heat soaking furnace after which final semi automatic welding is done while the shaft is still in the furnace.  After cooling, the fabricated rotor is sent for stress relieving and then on to the machine shop.

The rotor is turned on a lathe to bring the journals and fins to size, and then machined on a CNC boring mill to finish the blade seats and tap the blade mounting holes.  Finally, the rotor journals are precision ground to accept the bearings and the flywheel bushings.

Following machining, the rotor is dynamically balanced and inspected before assembly into the granulator chamber.

Blades:

Rotogran blades are made for CERTIFIED D2 tool steel purchased from local and European mills with full traceability of the material specification and testing. The blades are machined on a CNC machining center and then sent for hardening.  The hardening process is completed in a computer controlled vacuum furnace.  As an extension of the heat treatment process, the blades are then subjected to a cryogenic treatment to further improve the toughness specification. This extra attention to material sourcing, controlled manufacturing process, and cryogenic treatment produce the highest quality D2 blades possible for a granulator.

Parts:

All the parts for Rotogran granulators are stocked and/or manufactured on-site at Rotogran International Inc. This guarantees you local parts and service support. Also, parts are subject to manufacturing process governed by local quality control standards not subject to interpretation by distant manufacturing plants.

System Integration:

Rotogran often supplies complete granulation systems where more than one piece of equipment is involved. Rotogran can provide integrated controls to simplify the installation and communication between pieces of equipment. Electronic integration is only one aspect of a successful system design, mechanical and functional integration is equally important. This is where Rotogran excels since we have the capacity, knowledge, and North American application experience to provide successful and efficient turnkey systems.

Support:

Rotogran granulators are designed with ease of maintenance in mind. In the rare occurrence that in-house maintenance cannot provide the required service, Rotogran can provide support from various locations within North America.

Technical Assistance:

When you need a question answered, no matter what the topic, our sales, engineering, and service professionals are available here at Rotogran headquarters just a phone call away.