Vecoplan develops stable single-shaft shredder for technical plastics: A robust powerhouse
When it comes to the manufacture of packaging for example, more and more processors are relying on hard plastics such as polyethylene or on the somewhat harder and more heat-resistant polypropylene. Materials such as PA, POM and PET with their outstanding mechanical properties are increasingly used for structural materials, as well as cast polyamide 6 as a universal material for machine construction. These hard plastics not only have special properties, they are also very difficult to shred as well as being expensive. In order to protect the environment and to safeguard raw materials, processing companies are therefore more and more frequently feeding back their process waste (post-industrial) into the production cycle in the form of purgings or reject parts. Vecoplan, in close collaboration with customers, has launched the powerful and extremely robust Vecoplan Heavy Duty single-shaft shredder (VHD 1600 T) in order to process the material efficiently. Users can feed in the material directly and without metering, almost regardless of size and weight.
Stable and reliable operation
The basis of the new development is the powerful VAZ 1600 XL, which, among other things, is suitable for demanding plastic parts. In order to ensure unbreakable and durable operation, the Vecoplan designers have re-engineered almost all components and redesigned them to be more robust or reinforced. A thick-walled, ribbed machine housing, reinforced side walls and stronger machine base ensure powerful, fault-free operation with maximum service life. In the machine stand, the base plate and the side walls have been reinforced. The engineers have raised the machine base and angled the base plate in order to minimise the impact force of the input material.
In the rotor area and screen chamber, the distance between the rotor face and side wall has been increased. This prevents strips and wires wrapping themselves around the rotor shaft. The free passage of material downwards also reduces the wear between rotor and side wall. A reworked matching of drive shaft and rotor bearing as well as low-wearing, replaceable sealing elements on the rotor and side wall prevent materials penetrating and setting in the area of the bearing. This increases service life and improves maintenance-friendliness.
Dynamic, robust and reliable drive
Depending on the requirement, Vecoplan fits a 111, 134 or 155 kilowatt HiTorc drive for the rotors. This operates dynamically, accelerates rapidly and develops high torque. The drive comes completely without mechanical elements such as gearbox, belts, couplings or hydraulic power packs. In contrast to machines with gearbox drive, the extreme shaking and vibration which occur with difficult shredding operations does not present a major challenge for the HiTorc direct drive.
Also, there is less wear, and less maintenance is required compared with mechanical and hydraulic drives. As a result of the direct fixing of the drive to the rotor shaft, there are no power losses in the drive train, and the HiTorc therefore achieves a higher efficiency. It can be controlled at speeds between 60 and 230 revolutions per minute. In order to increase throughput with easy-to-shred material, the user can simply increase the nominal speed. The high torque, which is available over the whole speed range, enables trouble-free starting under load. Fast and dynamic reversing is possible in the event of an overload. The Vecoplan Heavy Duty is therefore suitable for difficult and tough materials. For safe operation, among other things, the braking resistor enables the rotor to stop quickly if there is a risk of accident (emergency stop) and if extraneous material is detected. The main motor is protected against fire using thermistor technology.
Optimised cutting unit, high throughput, virtually no heat generation
The VAZ-XL cutting unit has a large diameter rotor, which is fitted with hardened, concave tools. These can be used four times and can be changed quickly.
For a more stable and tougher tool design, the core has been raised and the tool fixture optimised and modified to suit the demanding task.
The cross-bar is solid with screwed, hardened counter knives, which can be used twice and ensure a high service life. The cutting unit is also characterised by reduced heat development for energy-saving shredding with high throughput.
If different output particle sizes are required, the operator can easily change the robust VAZ screen. Material is removed at the bottom of the screen chamber. This is also available completely enclosed in order to prevent dust escaping.
A programme which detects the material to be shredded and measures the motor load in real time is incorporated into the PLC controller. The Vecoplan Heavy Duty therefore adapts itself fully automatically to different materials. The reliable automatic reversal feature in the event of rotor blockages also ensures continuous shredding. On no load, the system switches off automatically if required. The intelligent controller reduces reversing operations and increases productivity.
Powerful hydraulics and reinforced ram
The complete design of the hydraulic ram has been adapted to suit the difficult conditions. A stronger ram base structure, large guide rollers, modified hydraulic cylinders and optimised seals characterise the revised material feed and guarantee low-maintenance continuous operation with high availability.
The compact hydraulic unit is equipped with all safety functions such as oil temperature and oil level monitoring. Multi-stage, load-dependent speed control is also incorporated into the intelligent controller. The revised ram mechanics and the whole hydraulic system also compensate for jerky and impact loads without any problems.