In recent years, Mondi has made major efforts in innovation.That has led to more reliable industrial bags with reduced environmental impact and attractive added-value features, matching the customer’s requirements. One of the key drivers behind this continuous innovation process is the fact that Mondi is a fully integrated supplier. All steps involved in producing an improved paper bag can be handled in close collaboration between paper mills and bag converting plants.
INITIAL STEPS TOWARDS INNOVATION
Generally, the first step towards an improved industrial paper bag is to develop new or improved grades of sack kraft paper. As part of R&D activities at Mondi’s R&D Innovation Centre in Frantschach, Austria, Mondi’s sack kraft paper and industrial bag team members analyse and assess existing and proposed materials, including kraft pulp, with a view to improving paper strength, de-aeration properties and mechanical qualities of paper and bags. These R&D activities are often oriented to achieving steady improvement, with the overall goal of taking sack kraft paper and industrial bag solutions to a whole new level. Claudio Fedalto, Deputy COO, Mondi Industrial Bags, points out the importance of co-operation among business segments within the Group:“Being in direct proximity to our sack kraft paper colleagues helps the bag development process, as we can work closely together on each project.” The launch of Mondi’s Advantage Protect sack kraft paper and the recently introduced Splash Bag, a bag developed especially for the needs of the cement and building industry that shows a higher water-resistance than normal paper bags, is just the latest example of this close internal collaboration.
The next stage of the development process involves rigorous testing. Application engineers at Mondi’s Bag Application Centre (BAC) analyse bag strength, de-aeration properties and behaviour during filling and under different storage conditions. To test bag construction, simulations of specific situations are performed using advanced technology, e.g. a high-speed camera (1,000 images per second) for observing behaviour during drop tests, and a climate chamber for measuring performance under hot, humid or other demanding conditions. In 2014, the Bag Application Centre performed drop tests for around 400 bags, the water vapour transmission rate was assessed for around 300 bags, and over 900 Mega Gurley tests were performed.
CUSTOMER FOCUSED — EVERY DAY
Collaborating with customers and listening to feedback is also important. In keeping with the Mondi initiative ‘IN TOUCH EVERY DAY’, Mondi encourages customers with specific requirements — e.g. a bag needs to be developed or adapted — to collaborate closely during the development process. Recent examples include collaborations with cement producers: one bore fruit in the shape of the world’s first biodegradable industrial bag, the Terra Bag®. Another resulted in the above- mentioned SplashBag, a bag that, thanks to the perfect combination of Mondi’s sack kraft paper and industrial bag construction and know-how, is resistant to rain for two hours and can withstand moisture ingress for up to 12 hours.
Further progress in the evolution of industrial paper bags was the launch of a bag that offers uncompromising weather protection and significantly extended shelf life of its contents. Combining the best of two worlds — paper and PE — the HYBRIDPRO bag represents a whole new concept in industrial bag design. It is particularly suitable for building materials, including gypsum and cement, as well as many other moisture- sensitive products.
Like a hybrid drive in a car, the HYBRIDPRO bag is an excellent combination of the available options: the inner ply is made of 120g/m2 Mondi Advantage ONE sack kraft paper; the outer ply is a 40μm-thick layer of high-density polyethylene (HDPE). The innovative step here is that the HDPE forms a protective layer on the outside of the paper. Other bags also use a combination of paper and plastic, but not in this way. This is a considerable technical achievement that brings a new dimension to industrial bag design. paper ply is available in a bleached or an
The HYBRIDPRO bag allows high-speed filling, with de-
aeration twice as fast as with a standard three-ply bag (35m3/h
versus 18m3/h tested on Mega Gurley equipment at Mondi’s R&D
centre BAC in Austria).
Workplaces, such as construction sites, are cleaner with
HYBRIDPRO, as less of the contents adhere to the outer layer
— a benefit sure to appeal to end users.
HYBRIDPRO is an eco-friendly solution: the total grammage
of material used is less than with standard three-ply designs used
for the same purpose.
Last but not least, the plastic and paper components are easy
to separate, for optimum recyclability. Since the bag can be filled
on conventional paper bag filling systems, investment in FFS
systems, which tend to be expensive, is not required.
THE BENEFITS OF FILLING EXPERTISE
Mondi also recognizes the importance of having a filling
equipment producer in house. It therefore owns Natro Tech, a
company near Milan with a 90-year history of designing and
building filling systems for granular and powder products. Natro
Tech focuses mainly on filling equipment for industrial bags –
valve bags as well as open mouth bags. This in-house filling
equipment expertise is unique in the industrial bags market and
is well received by customers, as Natro Tech’s technicians visit
fillers on site to provide input on how to optimize bag
SUSTAINABLE — EVERY DAY
Nowadays many companies have sustainability targets, either
regulatory or voluntary. Suppliers such as Mondi which are fully
integrated across the paper and packaging value chain — from
the growing of wood and the production of pulp and paper to
the conversion of the packaging paper into industrial bags — are
well positioned to help their customers meet such targets.
Accordingly, Mondi offers a comprehensive range of green
solutions, which are optimized to save natural resources and
reduce waste and have internationally recognized sustainability
In addition to the above-mentioned innovative products,
Mondi has developed a number of important industrial bag
innovations suitable for the food industry over the years. Its
current industrial bags portfolio includes the following solutions:
- the Easy Seal valve is an optional feature developed by Mondi that can be applied to any valve bag and adapted to specific
customer requirements. Easy Seal employs thermo-media
technology to ensure strong, fast and leak-proof valve closure.
A special coating on the inside of the valve reacts to the heat
and pressure generated by ultrasonic welding. Since the
coating is non-adhesive, the valve cannot get blocked before
the filling process. Therefore, bags with Easy Seal valves are
ideal for high-speed filling processes, as filling and sealing can
be carried out with minimum downtime.
- Mondi’s Effusion Bag combines precise dosing with optimal
protection of the filling good. Thanks to this innovation, end
users can better dose the filled good via a funnel-formed
effusion opening. With a few quick hand movements, the
opening can easily be formed. The sturdy bag and a handle on
the bottom of the bag additionally facilitate a convenient and
controlled discharging of the bags’ content. The paper bag
itself is designed for best product protection and encloses the
filling material tightly. By using a PE-free film as a second ply, further protection against humidity and an extended storage
life of the filled bags can be achieved. Not only do customers
benefit from this innovation, industry experts have also
recognized its value in numerous product competitions.
ABOUT MONDI INDUSTRIAL BAGS
Mondi Industrial Bags, a business segment of Mondi’s Europe &
International Division, is a major international producer of
industrial paper bags, selling around 5 billion bags per year.
Thanks to its broad range of bag specifications, Mondi Industrial
Bags serves major industries including cement and building
materials, chemicals, food, feed and seed. The business segment
operates a dense sales and service network, the specialized filling
equipment department Natro Tech, as well as its Bag Application
Centre, where researchers develop and test innovative packaging
ABOUT MONDI SACK KRAFT PAPER
Mondi Sack Kraft Paper is a business segment of the business
unit Packaging Paper and ranks among the leading European
suppliers of both high-quality sack kraft papers and bleached and
unbleached market pulp. It maintains five production sites that
are focused on producing sack kraft paper with excellent
runnability and printability ensuring optimized converting
Mondi Sack Kraft Paper fosters innovative research and
cutting-edge technology. Its commitment is reflected in the work
of its R&D and Bag Application Centres, the Print Competence
Centre, where packaging and printing solutions are developed
and tested in close cooperation with customers. In addition, the
team of specialists at our Food Safety Laboratory develop
optimized solutions that meet highest requirements for food
contact and other sensitive applications.