Despite entry of latest technologies like BOPP, woven bags are expected to see rise in their demand due to its cost advantage.

Cement is one of the largest bulk materials being handled on our planet. Producing a material in such massive quantities and distributing is a major logistics challenge. That is where bagging and packaging function comes in handy for the cement industry players.

Though there is hardly any change in the material consumed for manufacturing cement packaging, the new technologies and processes are making them high on productivity, safety, fast, leak-proof, and amenable to automation and ease of load and re-load, when compared to yester years when it was dangerous, hazardous and labour-intensive.

Bags are a common way of distribution in the industry, accounting for about 60 per cent of the product shipped to consumers/users. Bulk packaging, though is yet to catch up on a large scale in India, it is being patronised by some major cement manufacturers and bulk consumers.

Up to 1970s, all cement bags used to be made of jute, which had zero moisture resistance and was prone to high spillage during handling and transportation. Since then switchover to plain woven polypropylene (PP) sacks took place. To upgrade PP bags, concept of lamination was introduced which came with an increase in packaging and handling cost. Some manufacturers are also using BOPP laminated bags to enhance brand value.

Though there are several manufacturers of cement packaging bags in the country, most of the highly advanced automated machinery and systems are being imported from countries like Germany, Italy, Switzerland, the US, Taiwan etc.

Latest technologies
Innovation has been the key for growth of global players like Windmoeller & Hoelscher during the recent years, particularly when it has introduced hot air to seal the moisture-proof sacks that used to be closed with adhesives earlier, thereby reducing production costs and technical process limitations. Another global player, FLSmidth offers complete automation solutions by integrating various product types with that of fully automated packing plants, and automating even loading and unloading activities.

Latest technologies help produce much lighter woven sacks for cement packaging without losing on strength or performance of the cement sack. "Hot air sealed Block Bottom bags’ (BB bags) growth worldwide has also seen development of newer concepts. Very interesting solutions are now available in the market, especially Biaxially-Oriented Polypropylene (BOPP) laminated BB bags have picked up very well in the market," says Anuj Sahni, General Manager – Sales & Marketing, Windmoeller & Hoelscher India. These bags allow very high quality printing on the bags, even bags with metalized and holographic films are being used. BB bags with nonwoven fabric lamination and also with inner paper ply are also providing solutions for packing cement.

Referring to the latest and emerging technologies on the horizon, Pranav Desai, Vice President, R&D and Head Construction Development and Innovation Centre (CDIC), Nuvoco Vistas Corp, says, "The concepts of 2 – 3 ply paper bags are emerging gradually. These bags are biodegradable and protect the inside materials well, but only disadvantage being the cost and handling care – which again pushes up the cost."

In the process of introducing some innovative cement and concrete products into the market, Novoco has played the role of a catalyst for development of different kinds of packaging materials and consequently new packaging equipment. Nuvoco was one of the first building materials company to introduce wet ready-to-use premixed range of concrete and mortar "Instamix" in 35 kg bags. "With these ready-to-use concrete and mortar in bags, Nuvoco has ensured cost-effective and easy construction in any location. It is easy to use on site, as placing and spreading is more efficient," Desai adds.

Nuvoco has also introduced tamper proof bags by double stitching them for its Duraguard brand in the north after its market research showed concerns of duplication of the brand. This was done in order to reinforce its quality and commitment to customers.

Other cost-effective development on paper bags and equipment side are introduction of digital pasting technology. Digital pasting is a solution where the glue consumption on paper bags can be reduced drastically without compromising on bag strength, through precise gluing technology.

Cost-effective
A reasonable amount of cost is incurred towards packaging. However, the customer appreciates the benefits of better packaging and is willing to pay the additional price. ?In terms of stacking up of various options, HDPE bags are the most cost-effective, followed by Laminated PP, BOPP and Paper bags, says Desai of Nuvoco.

Three most used variants in cement packaging in India and also most of the globe, are uncoated sewn cement bags, multiwall paper sacks and hot air sealed block bottom bags (BB bags). "Sewn cement bags are lowest priced than BB bags (extrusion coated), and generally paper sacks are costlier. This is the general trend but eventual costs can depend on more variables," says Sahni.

Woven cement sacks are used multiple times after their primary function for mobilizing sand, aggregates, rubble, bricks and other materials. Also the family of plastics used for producing woven sacks are single family polyolefins, so recyclability is very easy. Besides, plastic has other benefits and is an outstanding material. "We believe that woven bag consumption for cement packaging will keep growing due to above reasons, especially in India," Sahni adds.

But the eventual cost to end users or cement companies depends on various other factors besides only the direct bag costs, i.e., bursting of bags, leakers, pilferage, counterfeiting etc., besides business opportunities in terms of margins, sales turnover, brand value etc. "We have seen cement companies prefer BB bags or multiwall solutions once the end user does a detailed analysis of eventual costs and benefits," Sahni says. The final solution being used also depends on availability of raw materials, logistics available, storage conditions, climatic conditions, and the biggest of them all, i.e., solutions preferred by the end user.

Sustainable packaging is the underlying principle that Nuvoco follows which is replicated through our Laminated PP, moisture and tamper proof cement bags.

"Today, across industry, approximately 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 and use of hooks for unloading across the supply chain, making them vulnerable to damages," says Desai.

Automation
Use of automation in cement packaging is an imperative. "All our packaging machines are calibrated to discharge exact quantity of cement, ensuring higher consistency, speed and accuracy," says Desai.

A packaging solution which has strict dimensional tolerance control and has lesser number of ply would be more suited for automated filling systems. Automated systems are designed to handle a given specification of bags, if bags deviate from these specifications then the automated bag handling systems may show errors or stoppages, says Sahni.

Also cement packing is air assisted, the more the number of layers a packaging solution will have the more difficult it generally gets for the air to escape from the bag, thus reducing filling speeds. Well-designed perforation systems on multiply bags or high-porous paper can help overcome this problem, Sahni adds. Automation is being equally applied to loading and reloading of trucks to avoid congestion in factories.

The housing segment accounts for approximately 65 per cent of the cement consumption, with Affordable housing and Independent House Builders (IHBs) being major consumers. "The IHB’s tend to buy in small lots with constraints in storage space and security of the material. Hence the retail packaging dominates over bulk packaging at an overall level," Desai says.

The demand dynamics could change when we talk about large projects, where the concept of smart silos (capacity up to 8 MT) is picking up and contractors are shifting towards buying bulk cement. Also, with the increase in ready-mix usage, the share of bulk cement is gradually increasing, adds Desai.

Looking ahead
A well-designed packaging can help a cement producer work on all the issues positively and effectively- environmental impact, speed, product protection, shelf life, customer education and brand recall. Thus, the importance of bagging and packaging cannot be over estimated.

Coming to demand side dynamics, the past two years have witnessed a robust demand for cement and the momentum is expected to sustain on account of increased budgetary allocation towards infrastructure (including roads and railways), rural development and affordable housing demand in rural and urban areas especially under PMAY scheme, predicts Desai.

Cement demand has a strong co-relation with the GDP growth with an empirically established ratio of 1.2x to 1.3x, thus providing an outlook of approximately 8 per cent CAGR over next three years.

– B.S. SRINIVASALU REDDY

Factors to be considered for best packaging
The factors one should consider while searching for the best packaging production are:

• Sack geometry
• Sack converting
• Sack design
• Appearance
• Stack design

Each aspect can be more or less important depending on the region and market the customer is looking for. Furthermore, different applications, availability of the respective materials, or even regional differences, sometimes with historical root causes may influence the decision. The supplier must be able to provide machines for the production of each sack type and after installation service. -Windmoeller & Hoelscher