An RM1350/2-2000 twin-shaft shredder made by Igling, Germany-based Erdwich Zerkleinerungs-Systeme GmbH is helping to process the wide variety of materials—including old corrugated containers (OCC), nonferrous metals, scrap iron, glass and electronic scrap—at Maag Recycling AG in Winterthur, Switzerland.
The firm, which also operates balers and sorting lines, had been operating a rotary shear starting in 1999. Because of signs of wear and tear and the increasing demands created by multiple materials, management at Maag Recycling decided to replace the rotary shear.
The company sought a shredder with the lowest possible maintenance requirements that also was robust enough to handle even the shredding of massive components without damage. According to Erdwich, the company found what it was looking for in the form of the Erdwich RM1350/2-2000 model.
Erdwich says it helped provide a weatherproof shredding system that “can be optimally adapted to process various input fractions, such as aluminum profiles, collected copper, zinc or cardboard tubes.” Despite the limited space available on site, an additional ascending discharge conveyor with an overbelt magnet and a sorting line have been integrated.
More than 50 percent of Swiss municipal solid waste (MSW) was recycled in 2017, according to a study by the Organization of Economic Cooperation and Development (OECD). Maag Recycling, a regional waste management company, likes to consider itself a factor in that high rate.
In Winterthur, it accepts scrap from both commercial and private customers, where the materials are sorted and processed. “In our company, sustainability and environmental protection play a central role in our corporate mission statement,” comments Judith Maag, managing director of the firm. “For this reason, we strive to achieve the highest possible recycling rate for all materials.”
As its rotary shredder aged, Maag says, “Based on the problem we were confronted with, a mechanical engineering company with whom we work recommended that we contact Erdwich for the new acquisition.”
Comments Florian Böhm, technical manager at Erdwich, “The twin-shaft shredder was designed in terms of size, drive power and its shredding set in such a way that various input materials can be processed without complicated adaptations. Thanks to our experience, we were able to design a plant that was a perfect fit for Maag´s requirements in a short space of time.”
While the rotary shear had produced strips as output, the new twin-shaft shredder processes fed material into what Erdwich calls, “a homogeneous output material thanks to 24 ripper blades.” Output material commonly measures 100 millimeters (mm; 3.9 inches) by 100 mm (3.9 inches) by 100 mm (3.9 inches).
Control programs installed in the RM1350/2-2000 can be adjusted and stored to make it suitable for different input materials. The machines two 55 kilowatt (kW) motors have been configured to provide “a considerable degree of robustness—even massive parts that occasionally arise can be processed,” says Erdwich.
Regarding maintenance of the new unit, “If signs of wear and tear appear on the knives, they do not have to be replaced completely, but can simply be re-welded or re-sharpened by an in-house technician at Maag,”says Böhm. “This results in savings in costs and time, with only short downtimes and brings us more independence from suppliers,” he adds.
The tight space conditions at Maag Recycling proved a challenge. The new shredder was to be installed at the same location as the old rotary shear. As configured, the input material is fed into the shredder’s hopper by an excavator and an scrap handler outfitted with multi-tine grapple, meaning the RM1350/2-2000 can be remotely controlled from scrap handler’s cab.
After shredding, the material falls onto a vibrating conveyor chute directly below the plant. In addition to the ripper, a discharge belt with an ascending element and an overbelt magnet are installed to separate the ferrous fraction. This is followed by a sorting station with protective roofing.
The two companies say the commissioning of the Erdwich shredder had to be carried out “very quickly and efficiently, as the site could only be closed for a very limited period of time.”
Maag Recycling says it has found the technology provided to be very convincing, and ultimately, say it has meet the firm’s requirements. “Despite the complexity of the circumstances and throughout the entire project, there was a level of cooperation which was balanced, pleasant and from person to person. Should there be a need for a new plant at some future point, we will be open to a further cooperation,” states Judith Maag.