International packaging and paper group Mondi is about to launch an industrial paper bag that offers uncompromising weather protection and significantly extends the shelf life of its contents. The HybridPro is a combination of paper and plastic, and is suitable for many industries and applications, particularly construction materials such as gypsum or cement, providing excellent protection against direct rain during shipping or on site.
The HybridPro was developed alongside Mondi’s showerproof paper Splashbag, launched at the beginning of 2015. The first trade show at which visitors will be able to explore the new bag is FachPack in Nuremberg, Germany (29 September to 1 October).
Conventional industrial bags made of paper tend to be vulnerable to rain and moisture. When exposed to direct rain on an unprotected pallet, a standard paper bag absorbs water and may weaken as a result. Handling may then become awkward, and the shelf life of the contents may be affected. In some cases, a switch to plastic bags is the answer. But this may not be the optimum approach, as the cost of investing in form-fill-seal (FFS) machinery tends to be high.
"The innovative step here is that the HDPE forms a protective layer on the outside of the paper."
Form-Fill-Seal (FFS) systems, such as the one shown below from German company Ossid, as the name suggests, form, fill and seal a package on the same machine. Many contemporary FFS systems are highly sophisticated, featuring computer interfaces and control networks, and hence the high cost. Greater speed and versatility are the major benefits of FFS systems, providing fast changeover between many different packaging formats.
FFS machines employ a wide range of material types and are used across numerous markets including food, drinks, cosmetics, electronics, stationary, tobacco, chemical, medical, and pharmaceuticals. The main types are vertical form fill seal (VFFS) and horizontal form fill seal (HFFS) machines – a term often used to cover horizontal versions of flow-wrappers, sachet machines, blister pack machines, four side seal machines and thermoform fill and seal machines. In both cases packaging material is fed off a roll, shaped, and sealed. The bags/packs are then filled, sealed and separated.
In contrast, the HybridPro bag offers the advantages of a plastic bag, yet fillable on conventional paper bag filling systems, such as the Sigma Instrumentation model shown. The HybridPro allows high-speed filling, with de-aeration twice as fast as with a standard three-ply bag (35 m3/h versus 18 m3/h, tested on Mega Gurley equipment at Mondi’s R&D centre BAC in Austria). Workplaces, such as construction sites, are cleaner with the HybridPro, as less content adheres to the outer layer.
Other bags also use a combination of paper and plastic, but the innovative step here is that the HDPE forms a protective layer on the outside of the paper. The HybridPro bag’s outer ply – which forms the barrier against rain, moisture and dust – is made of a 40 micron thick layer of high density HDPE plastic film, giving it an attractive, modern appearance. The HDPE film can be printed in up to eight colours, including on the bottom patches, for a glossy, premium look, and the paper ply is available in a bleached or an unbleached version. This barrier layer allows genuine outdoor storage for lengthy periods and extended storage stability. The inner ply is made of 120 g/m2 Mondi Advantage ONE sack kraft paper.
Though particularly suitable for building materials, including gypsum and cement, it can also be used with many other moisture-sensitive products. The bag is suitable for filling contents at temperatures of up to 90C.
The HybridPro also provides excellent protection against gradual moisture ingress during outdoor storage, thanks to the 40µm thickness of the unperforated HDPE film. This means shelf life is longer than with standard paper bags. According to building materials producer Knauf, who collaborated in developing the HybridPro, gypsum so packaged enjoys an eight-month shelf life when stored outdoors with no further protective layer – this is twice as long as if packaged in a standard paper bag.
Wood-based plastic bag attracts venture funding – Update – October, 2015
Paptic is a Finnish startup company founded in April 2015. Its new patented technology enables the manufacturing of a revolutionary new fibre product with plastic-like properties and targeted at carrier bags and packaging. The company has raised a seed investment round of EUR 1.1 million.
The manufacturing of wood fibre material is to be started on a small scale in the autumn of 2015 at the KCL pilot plant in Espoo, Finland. The aim is to start industrial production and sales in 2016. Paptic is currently looking for value chain partners for testing industrial production and commercial cooperation.
The technology platform has been developed at VTT Technical Research Centre of Finland, based on long-term research in fibre products and processes. Paptic and KCL are working together to adapt the paper machine which will be used for pilot test campaigns conducted jointly with end-user customers and the carrier bag supply chain.
"Paptic is a practical example of Finnish excellence in the wood-based bioeconomy. 100 billion plastic bags are used every year in Europe alone. Our first product is a direct response to the EU directive that seeks to reduce plastic bags usage," says Managing Director Tuomas Mustonen. “Already 70% of the material used in the Paptic Bags is renewable and biodegradable, and it can be recycled.”
Meanwhile, as England gets set to start paying for plastic bags, researchers at The Open University (OU) are making inroads into developing alternative biodegradable materials that could potentially replace polyethylene single-use carrier bags derived from fossil fuel.
A team at the OU’s Integrated Waste Systems (IWS) research group is working to develop a new type of biodegradable single-use plastic carrier bags that is recyclable, biodegradable and will have no harmful effects on plants or animals. The UK Government is also committed to investigating the possibility of exempting biodegradable carrier bags from the single-use charge in future.
The results of this research and development are expected within the next year.
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