Granulated Material The Fine art Of Packaging: Bagging Chemical Granulates and Powders
It all started with a customer’s request to pack his cement into tight, water-resistant PE bags — a challenge that Haver & Boecker, specialist for packaging and processing technology, was more than happy to accept. The result is a form-fill-seal system named Haver Adams. This system can not only pack powder-type products, microgranulates and powders into PE bags, but is also able to gently fill products with challenging flow properties.
Who would have imagined some years ago that cement and other powder-type construction chemicals could be filled into compact and weatherproof polyethylene bags in an environment friendly process? Almost ten years ago, Haver & Boecker, headquartered in Germany, took the initiative in cooperation with a bag manufacturer. The result is called Haver Adams: a form-fill-seal (FFS) packaging system that fills powder products into PE tubular film bags. At first, the industry was skeptical about the development.
The machine not only implemented an unusual bag concept, it took the idea to the next level by changing the entire filling process to FFS technology. The system then set out to conquer other sectors. Today, the filling system also achieves peak performance for customers in the chemical industry.
Understanding FFS packaging
FFS packaging systems are used for filling and packaging bulk material into bags. The bag is formed inside the filling machine, which obtains the continuous PE tubular film from a reel. The product is then transported into the bag via specifically adapted dosing and weighing systems, while the bag is formed and sealed in the packaging unit. Packaging granulated and grainy products with FFS machines has been part of daily production routines for a long time. But ultrafine products face completely different challenges, “It has very high dust content. At the same time, compaction is the most important prerequisite for clean and efficiently bagged products,” explained Head - Building Materials and Minerals Division, Haver & Boecker, Burkhardt Reploh.
To ventilate granular products in PE bags, the foil is normally needled or microperforated. “This is not possible for powder products, because they can even leak through micro-perforated foil. Subsequently, the long storage time required for hygroscopic construction material cannot be ensured,” said Reploh. Powder products like cement, on the other hand, have a packing factor of up to 1.6; the volume must be reduced by 60 per cent before the bag is sealed. If this is not the case, the bag might be damaged during transportation. Apart from insufficient outdoor storage possibilities, the inacceptable damages that occur during filling and transportation were the main reasons for the industry to start looking for alternatives.
Based on these requirements, the company teamed up with cooperation partners and developed a new bagging and filling concept. The PE bags are now not only clean, tightly closed and weatherproof; their compact size also facilitates space-saving transportation and storage. Reduced material loss is equally easy on the environment and budget. The PE bags also offer several advantages for marketing activities: They allow for multi-color full-surface printing, for instance with photorealistic images, product information or barcodes.
FFS technology re-interpreted
The first system was an intermittent, rotating packer with eight filling spouts and a performance of 1,000 to 1,200 bags per hour, depending on product fineness. “A list with all challenges formed the basis of our development work. We solved one item at a time, scientifically validated each point, and ended up with a compact machine,” explained Reploh. Different versions derived from this machine have established an entire product family, whose output begins at 200 bags per hour for stationary units and goes all the way up to 1,200 bags per hour for rotating machines.
When manufacturers started demanding even higher output and speed, the company went on to the next level for further development of the system. The objective was to achieve filling performances of minimum 2,000 bags per hour for bag weights of five to 50 kilograms, making the machine attractive for mass-oriented markets and companies. Up to this point, the multispout machine had operated in intermittent mode. The new continuous operation was able to increase performance from 1,200 to more than 2,000 bags per hour. Based on components from the rotating packaging machine, Haver Roto-Packer, the engineers developed a new filling module with gross weighing for shorter filling times. The bag handling modules that place and remove the PE bags on the new filling spouts are also new. The rotating modules have two gripper units each, which ensure highly accurate transfer.
Air or turbine units can be used as filling modules. The combined control and weighing electronics MEC, an in-house development, provided for exact filling quantities; internal and external vibrating units ensured the required product compaction. Thanks to micro-vibration, the air bubbles inside the product automatically move to the top. The main advantage of this mechanical procedure is its very high availability. In contrast to vacuum systems, micro-vibration does not suck off any fine particles. The filled bags are safely sealed in low-maintenance pulse welding stations and then transported to the bag forming section.
If required, a head seam cleaning and cooling system can easily be integrated. The modular configuration of the Haver Adams makes it possible to use between one and twelve filling spouts. This significantly increases the circle of applications. All products that are filled in valve bags and have a minimum bulk density can now also be filled in PE bags.
Service has Top Priority
Apart from high performance, ease of operation and noise protection range amongst the key features of modern filling systems. The complete enclosure of the system keeps noise development at a low level, leading to high noise insulation as well as significantly reducing dust. Thanks to the Haver Service Pad (HSP), remote support is accessible at the push of a button. The system, consisting of a touchpad, integrated camera and software, enables operators, service technicians and specialist workers to directly communicate via a high-speed Internet connection. The result is short reaction times and higher machine availability.
At present, almost 60 such machines from the company are used all over the world. And recently, it has found its use in a titanium dioxide filling plant. The filling system offers optimum product protection and extended storage times, even in case of adverse weather conditions. The machine delivers resilient packaging and a clean logistics chain in all fields of application. With its compact dimensions, it is suited for all production environments. For the chemical industry this means an entirely new, yet well-tried process FFS filling of powder-type products and products with challenging flow properties into PE bags.