The advantages of a single-shaft shredder are well known: it is possible to fill a feed hopper which is then gradually emptied by means of a hydraulically operated ram without the assistance of operators: due to its special design, the rotor only “nibbles” at the material that is fed via the hydraulic ram.
Until now it has not been possible to obtain small granule sizes with these shredders: often a 15 or 20 mm-screen has been the lower limit, making intermediate conveying and a secondary granulator necessary in order to achieve smaller granule sizes ranging from 4 to 8 mm and a satisfactory throughput.
Fig. 1: Sectional view
Fig. 2: Small granule size
Now it is possible in one single size reduction step with the HERBOLD granulator of the HB series. The design of the HERBOLD HB granulator is a combination of a feed hopper and a hydraulic ram with a granulator. Due to the special design of the grinding chamber and the high cutting frequency, it is now possible to transform bales, cut open film rolls, mingled packs of sprue spiders, but also extremely large and thick-walled purgings into the finished product in one single step.
Abb. 3: SML 60/100 HB
Also bulk hollow bodies, e.g. whole IBC containers and rainwater collecting basins can be processed with this machine in a particularly economic way. An intermittent feeding of large quantities of material (e.g. a great many of bottle crates) is therefore possible without the necessity of dosed feeding or the risk of jammed material in the grinding chamber. Once the material has been fed and the hopper filled, no operators will any longer be necessary, thus enabling a semi-automatic operation.
Typical input material for the granulator of the HB series
Fig.4: Cut open film rolls
Fig.5: Film bales
The main advantage of this new development is its space-saving design since only one sizereduction step is necessary. In addition, only one size-reduction step also makes cleaning and colour and material changes much easier: there is no problematic and difficult to clean intermediate conveying by means of a belt conveyor. Only one machine will need knife change and maintenance, thus reducing maintenance times and costs. Compared to a twostep solution and a granulator fed by gravity, it has also a considerably favourable effect on the energy balance.
The HERBOLD granulators of the SB series, too, show these advantages, well-known characteristics found in all granulators of HERBOLD-product range.
- the placement of the rotor bearings outside prevents fines from penetrating into the
bearings and grease into the product - double-cross cutting action
- fracture-proof welded construction
According to the application, different rotor types are available for the HB series. If requested, this granulator can also be delivered as a turn-key package solution with the necessary ancillary equipment, e.g. suction unit with big bag filling station or feeding by automatic lifting/tilting device.
