The leading Swedish manufacturer Skruf Snus relies on a single-shaft shredder from Vecoplan® AG for shredding out-of-date snuff and chewing tobacco as well as faulty products, including tobacco tins, for disposal. The challenge: the charging material is wet or sticky. As a result, the knife pockets in the machine can become so clogged that the required throughput is significantly reduced. In extensive tests, Vecoplan® has optimised a standard machine so that it handles these particular requirements.
Coarse or fine, dry or moist, substantial or lightweight, fruit-scented, natural and with real tobacco, with or without menthol, with natural additives, high, low or no nicotine – snuff and chewing tobacco is available in all varieties. The Swedish company Skruf Snus AB, with its headquarters in Stockholm, is one of the leading manufacturers of this natural stimulant. Along with traditional tobacco, the renowned manufacturer also offers snus. This is a smoke-free tobacco product which is cleaner than traditional snuff or chewing tobacco.
Returns efficiently shredded
Although not many tobacco goods reach their sell-by date before they are sold, this is the case with some retailers. The shops then return the products to Skruf Snus. The manufacturer takes steps to dispose of the returns as special waste. Added to these are faulty production items and confiscated goods from the customs. The important thing is to shred the material appropriately – including the tobacco tins in which they are packed. Skruf Snus turned to J Mared AB to install an efficient system in its new factory in the southern Swedish province of Småland. The engineering consultancy based in Huskvarna, Sweden, is a sales partner of Vecoplan® AG. The machine builder, with its headquarters in Bad Marienberg, Westerwald, develops, produces and markets solutions for shredding, conveying and processing primary and secondary raw materials in the production and recycling circuit. Added to this are services such as overall project management and comprehensive service as well as installation, commissioning and maintenance work. The customer has the benefit of everything from a single source.
Charging material with special consistency
Vecoplan® received the order in September 2016. “Special requirements were placed on the shredder,” recalls Vecoplan® project manager, Patrick Pfeiffer. The machine has to process the material with a consistently high throughput of one tonne per hour. But this is not so easy due to the special consistency of the material. The different types of tobacco vary considerably in their water content. The extremes range from very moist to sticky compounds. During the process, this very combination can clog the milled pockets in which the knives are located, and thus drastically reduce the throughput of the machine. The workers have to clean them which, as well as personnel, requires time above all else.
Together with its Swedish sales partner, Vecoplan® took over the consultation and designed the system. “Our single-shaft shredder in the VAZ 1300 S range impressed those responsible at Skruf Snus,” says Pfeiffer. “With its different rotor variants and knife geometries, this product can easily handle the difficult material, even as standard”. The questions that were still outstanding were which combination would achieve the best results, and how could the material be fed and discharged efficiently?
Extensive tests lead to success
In 2014, Vecoplan® had launched the world‘s largest and most up-to-date environmental technology development centre at its headquarters in Bad Marienberg. Here, the machine builder can cover the whole added value chain for complex processes in-house, accelerate the development time of customised systems and achieve efficient test times. “We received samples of different types of tobacco from Skruf Snus,” describes Pfeiffer. The engineers carried out tests with the different machine components using the VAZ 1300 S in order to achieve the best possible throughput. Based on this series of tests, Vecoplan® was able to come up with a suitable processing strategy.
The machine builder delivered the shredder to Sweden in the middle of November 2016. “Our specialists installed and commissioned the system together with the J Mared engineering consultancy,” says Pfeiffer. The VAZ 1300 S has been running – very efficiently – in Småland since the beginning of 2017. Workers load the machine with the packaged returns and faulty production items via a hopper using a stacker truck. The hopper can be adapted to suit individual requirements, thus ensuring a continuous and cost-effective material feed. “We have optimised the geometry of the driven ram which feeds the material to be shredded to the cutting area of the rotor to enable the process to run constantly,” explains Pfeiffer. This is controlled automatically and dependent on load. The rotor has a diameter of 370 mm. An asynchronous motor with a power of 55 kW drives the machine in an energy-efficient manner. The screen with perforations of 20 mm mounted below the rotor determines the size of the output material. J Mared developed the control system and supplied a drag chain conveyor. This transports the shredded material from the machine into a container to await disposal. The shredded returns from the customs are sent back to to the authorities.