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.