Packaging of Cement Issues and Options
In the world of industrial packaging it isn't commonplace to see any significant shift in packaging material, never mind a clear departure from the status quo. As new packs have reached the market and the status quo has been challenged, customers have wholeheartedly embraced the change and a new expectation has been firmly established. But all of this isn't just about water proofing, reducing retail mess and enhancing shelf life - bags that includes polypropylene, ADStar, HDPE and UFlex offers a superior marketing vehicle, creating an unexpected opportunity for premiumisation in cement and has transformed the shelf-appeal of an otherwise commoditised product. Admittedly, the momentum behind the shift towards use of these bags certainly wasn't a eurekaism. The cement industry has long admired and sought the benefits of packing in polypropylene earlier, but had reached a significant stumbling block until recently.
A natural side effect of packing cementitious material into these type of bags is trapped air - exacerbated by intentional aeration of product, in the production and bagging process needed to create flow. In order to make polypropylene packaging a viable option for cement this air needed to be managed back out of the process to achieve a uniform and stable pack which is a crucial ingredient for efficient palletisation.
Ultimately, for instance a polypropylene sack in this application needs to be vented. Achieving this whilst maintaining the intended waterproof credentials of polypropylene is no easy feat, and a technologically advanced approach to venting is essential. It is exactly this requirement which can also decrease line speeds - something which has not fazed the cement industry whatsoever.
Explaining the cost structure, Rahul Akkara, Vice President (Strategy & Brand), JSW Cement, confirmed that a reasonable amount of cost is incurred towards packaging. Akkara appraised ICR while comparing an average cost per tonne. "Average costing for HDPE will be around Rs 220 per tonne, for UFlex it will be Rs 380, and paper will be little costlier at Rs 400 per tonne," he said. (For more insightful on packaging by JSW Cement, turn to page no 38)
Meanwhile, packaging plays an important role in the cement sector, because, it has to sustain the handling process. Since India do not have much of mechanised handling process, the quality of cement packaging has to be as per standards set by Indian authorities. However, there is a catch! Most of the handling of cement bag is manual, and in many cases, labourers apply hooks to the cement bags, which is not a correct method. This is why, Ashwin Moghe, Vice President - Technical Services, UltraTech Cement says, "most of the manufacturers prefer PP bags over paper bags, HDPE or UFlex bags as it is more cost effective way considering transportation, pilferage and importantly, handling." (Turn page no 40 for UltraTech's view on packaging)
Robots On The Move
Many of the sci-fi genre Hollywood movies have extensively used robots to draw crowd in theatres. However, that was just reel experience! In real life, especially in packaging, robots are a far-fetched idea to even think about. However, with science and technology going handy together, a plant in Stormville, New York, which produces 30,000 to 35,000 bags daily of portland cement-type products uses a workforce of about 40 humans and two robots.
These pair of robots from Taylor Products, a division of Magnum Systems, was installed in 2007 fall in Package Pavement's bag-filling operations. The two model TRV1000 robotic valve bag placers are mounted directly in front of dual-head valve-bag filler. The base system is a six-axis Model 6i robot from Fanuc Robotics (www.fanucrobotics.com). Taylor is a Fanuc integrator for packaging-related installations. Taylor also provides the custom-made end effectors, which were switched out for an improved version about a year after the install. Importantly, at a rate of 8 to 10 bags per minute/robot, the duo consistently packs 16 bags per minute, sharing the maximum load of their human peers.
The robots represent a strategic plan for continual, non-stop shifting, with no breaks required for ergonomic reasons, and they remove people from repetitive-motion tasks. That said, if the robots can play their part in streamlining complicated process of packaging, a simple intervention by replacing a package line will do wonders.
Calucem is a manufacturer of calcium aluminate cements used in the refractory industry. After the company replaced its previous packaging line with new filling, palletising and packaging systems, it simplified material movement and improved energy efficiency. The new filling machine uses an air principle popular in food and beverage applications as opposed to turbine technologies common in cement industries.
The technology simplifies changeover and reduces the need for manual labour. An ultrasound system ensures precise measurement of the bags before they are palletised at up to 600 bags per hour, resulting in optimal stack stability. A suction gripper and fork gripper work together to allow exact positioning as well as the flexibility to handle complex processes.
Roller conveyors transport the palletised bags to the stretch hood packaging system. To simplify maintenance, the system enables servicing at floor level. The operator panel offers graphical navigation, access to training content and an ergonomic work flow. Overall, the new system is compact and uses less energy to automatically fill, palletise and depalletise bags.
ADStar vs PP Bags
Cement packaging is a significant factor for cement producers and sellers regarding product protection, shelf appearance, cost margins, and sustainability targets. Recently, Markus Grabenweger, Sigrid Eder, Starlinger & Co. Ges.m.b.H conducted an independent study compared the environmental impact of paper cement sacks, sewn cement sacks made of recycled polypropylene tape fabric, and hot-air welded ADStar cement sacks made of coated polypropylene tape fabric.
In the course of the study the entire life cycle of the cement sacks, i.e. from sack production and transport to the cement plant, the use phase of the sacks, to their end of-life phase, was reviewed. All analysed sacks had a filling capacity of 50 kg cement.
In China, sewn woven sacks made of polypropylene tape fabric are the most widely used packaging for cement. The sacks are manufactured including varying shares of recycled polypropylene as input material, sometimes up to 100 per cent. The polypropylene-coated tubular fabric is cut and sewn mostly by hand in sack factories.
The recycled material used to produce the sacks is in most cases severely degenerated - it has been re-used various times, and often contains high quantities of mineral fillers from previous applications.
This means the sack fabric is rather brittle and breaks easier. To increase the sack strength, the fabric weight must be increased. In addition, the sewing process further weakens the material by up to 50 per cent. Two and three-layered kraft paper sacks in block bottom shape are the predominant cement packaging on the market in Saudi Arabia. Although the sacks are mostly produced in the country, the raw materials for the sacks - i.e. paper and glue - have to be imported from Europe. To achieve the necessary strength, the sack weight is comparatively high.
Still, sack rupture occurs frequently after dropping, sliding on uneven surfaces, or due to humidity. ADStar sacks are block bottom valve sacks made of woven and coated polypropylene tape fabric. The sack bottom and top are closed in a special conversion process by means of hot air welding. The use of high-grade virgin polypropylene for fabric production and the tight sealing of the sack bottom and top ensure low breakage even during rough handling, dropping, or after contact with water. ADStar sacks are produced and used all over the world and are wide-spread cement packaging in many African and South East Asian countries.
The study concluded that changing over to ADStar sacks would not only reduce CO2 emissions caused during production and thus relieve the environment; but would also contribute to automating the entire cement filling and transporting chain.
Currently, the manufacture and handling of the sewn woven PP sacks involves a lot of manual activities - starting with the sewing of the sacks in the production phase and the resulting size differences that cause problems on automatic filling lines, from putting them onto the spout during the cement filling process, to stacking, storing and transporting. Considering the current investments in modernising the Indian cement sector, the use of ADStar sacks which are produced automatically on sack conversion lines and allow fully automated handling of the packaged cement would seem a prudent step.
Sustainable packaging is the underlying principle that Uflex Ltd follow and this is replicated through their Flex-Safe-Pack, moisture-proof cement bags. Today, more than three per cent of the cement produced is lost in the supply chain and this loss is largely attributed to the cement bags being stored in open environments across the supply chain, making them vulnerable to damages caused due to exposure of cement bags to rain, unpredictable outdoor conditions and extreme climate. The micro perforation and absence of anti-counterfeit further leads to oozing and duplication of the bags causes adulteration resulting in a consolidated loss.
The company's Flex-Safe-Pack which has won the prestigious Dupont Award for global packaging innovation at Delaware, USA, has impressive use of nano technology, and addresses multiple industry challenges such as preventing waste, enhancing brand equity, and increasing worker safety. Another added feature of holographic metallic top and bottom patch saves from duplication.
As an environmentally conscientious organi-sation, says Ashwani Kumar Sharma, President & CEO - New Business Initiatives, Uflex Ltd, "we are mindful of our responsibility towards sustainable packaging. Our packaging is safe for individuals and communities throughout its life cycle." (To know more about Flex Safe Pack, turn to page no 42)
According to R Sankaran Unni, Sr General Manager - Marketing & Business Development, India Cements Ltd, "Flex SafePack designed by Uflex has not just provided a barrier to moisture from entering into the bag but has helped in reducing the loss of cement that occurs in supply chain - which is one of the most crucial for this industry. With this, we have also a freedom of choice in terms of getting visibility/branding as Safe Pack allows printing of high-quality graphics over the pack."