Tallpack line for cohesive mineral powder
Tallpack International recently realised a complete packaging line- which is used for very light, cohesive and immobile mineral powder- for the Russian Mining Chemical Company. The line includes a bagging machine, a bag flattener and press, a robotic palletizer and a pallet wrapper.
The mining company processes the mineral Brucite into very fine mineral powders. This mineral powder is then, for example, used in the agricultural sector to deacidify soil. The mineral powder is packed into big bags in the company's first factory, which was constructed in 2011. However, the market then expanded into other sectors that use the mineral powder in smaller quantities and in much finer varieties (used as product for water purification, but also as flame retardant in plastics and as raw material for composites.) This resulted in a second factory being constructed, where mineral powder is no longer packaged in big bags, but in valve bags (20 and 25 kg). The increase in sales possibilities then justified constructing a third production facility in Vyazma, which is around 200 kilometres to the west of Moscow. RMCC wanted suitable technology for this factory, whereby mineral powder would no longer be packaged in valve bags, but in bags based on the FFS principle (Form Fill Seal).
Why not valve bags?
“It is difficult to fill valve bags with Brucite powder”, explains Hubert Verheul. He is director/owner of Tallpack International and has been directly involved in realising the Vyazma Brucite project. “Mineral powder does not flow freely and retains a lot of air, which means it is difficult to dose. And this makes it difficult to determine the exact filling weight. Valve bags are difficult to close when used for mineral powder, and his results in waste and bags that are not uniform in volume. This makes it difficult to stack the bags in a stable manner, thus endangering the stability of the whole pallet. Our FFS bagging machine makes it possible to control the whole packaging process and create pallets that have been stacked in a stable manner. This has helped to considerably improve the effectiveness of the packaging line as well as the logistical process as a whole.”
Thanks to RMCC's contacts in Western Europe, including Dutch subsidiary Europiren, Geldermalsen-based Tallpack International was considered for the Vyazma Brucite project.
“The fact that we also have a division in Bulgaria, which focuses on the Balkan countries and Russia, made it easier to collaborate with the customer”, states Verheul. “Both these countries have an excellent working relationship, and the language barrier is barely an issue.
FFS bagging machine
The new FFS bagging machine is powered by a system developed in-house by Tallpack International. A bunker with a tossing mechanism, and a transport screw underneath it, first brings the Brucite powder into a ‘loss in weight’ weighing hopper. “Empirical research has been used to design this hopper with scraper, which means mineral powder passes through it without any problems”, says Verheul. “The mineral powder is then accurately weighed in the FFS machine and dosed into bags using a vertical filling screw.”
This filling screw reaches to the bottom of the bag. To ensure efficient filling, the bag moves downwards during the filling process. This involves vibrating the bag at high frequency so the mineral powder is effectively compacted and de-aerated.
The bags (PE) also feature a special filter strip that allows air to be released, without loss of mineral powder or infiltration of moisture. “It is very important to release air from the bags so stable pallets can be created”, says Verheul. “The thermally sealed bags then pass through a ‘flattener’ which uniformly spreads mineral powder throughout the bags, and a bag press that allows the remaining air to escape through the filter. A robotic palletizer then neatly stacks the bags and places cardboard top-sheets in accordance with the various programmes. The pallets are then wrapped using a Tallwrapper 2202-AE to give them extra stability and protection during storage and transport.
“The customer is very pleased with the whole bagging and packaging line”, says Verheul. “That is why we are in advanced discussions about a second bagging machine, so the two types of mineral powders can be packaged simultaneously. This will not require a new robotic palletizer because the existing installation has enough capacity to deal with two lines. The lay-out of the existing line has already been modified to cater for the planned expansion.”
About Brucite powder
Brucite is a mineral form of magnesium-hydroxide, which was discovered in 1824 by American physician Archibald Bruce. The Russian Mining Chemical Company (RMCC) extracts the raw material via open mining, after which it is broken and purified. The Brucite is then ground into two powder qualities; 3.5 microns and 10 microns. The product is light (0.36 and 0.70 kg/litre respectively) and cohesive, and does not flow smoothly.