ALTERNATE BUILDING MATERIALS TETRA PAK CARTONS AS ROOFING MATERIAL
Submitted to Dr. Kalaiselvi Department of Architecture School of Planning and Architecture ,Vijayawada
Submitted by
Soumendra Roy I YEAR , REG.NO- 1150500028
In partial requirement for fulfillment of the course of Master of Architecture
SUBMITTED ON: 1 February 2016
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SCHOOL OF PLANNING AND ARCHITECTURE, VIJAYAWADA 1. Introduction In today’s world over-exploitation of resources has led to the term sustainability to be the most important developmental agenda for the world leaders. Under sustainability there are three ‘R’s (reduce, reuse and recycle) which help us use the resources judiciously to their maximum potential. In this discussion, we look forward to suggesting an alternative material to the building industry in order to reduce the pressure on our limited resources. Instead of using natural raw materials to produce building materials, it would be better if these alternate building materials could be produced from the waste materials, provided there is enough bulk supply of the waste material available. This would not only reduce the consumption of resources but also recycle and reuse the waste materials, thus benefitting the planet in a better way which would be economical, feasible as well as ecofriendly. Let us have a look at the two materials to be chosen where the former is replaced by the latter- The cement and tin roofing by poly aluminium roofing.
2. Why Poly-Aluminium sheets
environment. Polyethylene is non-biodegradable and so cannot be naturally and safely be decomposed. So there is a need to recycle this material into something more useful material. The cement industry produces about 5% of global man-made CO2 emissions, of which 50% is from the chemical process, and 40% from burning fuel. It is necessary to reduce the excessive production of cement to lead to a sustainable future. Metals like iron and aluminium too are being mined at an alarming rate in order to feed the growing demands of the existing and the new manufacturing plants. Thus, in building construction industry, we can use alternative options to the first time use of metals and rather use recycled materials. Taking up roofing as one of the ways in which theses recycled cartons can replace metals and asbestos sheets, we would explore ways to do it.
3. Ways to recycle Tetra Pak cartons The carton consists of six layers of materials hot pressed together. Aluminium and paper layers are sandwiched alternatively between four layers of polyethylene as shown in figure 1.
roofing
Most of the urban population of India and of the world consume a lot of perishable items like milk, fruit juice, packaged food, etc. every day and thus come across a very useful product which is the carton produced by Tetra Pak to preserve the freshness of these items and protect them from being attacked by microbes. However one important aspect which we miss while using these product is that after the food has been consumed, these tetra pak cartons are dumped off either in landfills or are incinerated in garbage disposal plants. The total number of these packaging cartons delivered in the year 2014 was 179,888 million. Such a massive amount of waste material being produced every year would pose serious threat to the
Figure 1 : Layers of Tetra Pak carton
The aluminium helps to protect the food from oxygen and light under ambient conditions while the paperboard is used to provide strength, stability and smoothness to the carton. The
polyethylene prevents moisture from entering the carton and binds the aluminium and the paperboard together. Thus the carton can be reused as it is in some other ways like making tents, bags etc. One way we can us the cartons directly as a building material is by flattening them and then nail or attach them to roof like shingles but this method has many problems as water may leak, and it would be very labour intensive activity to nail each and every carton separately. In addition to this the various shape, size and colour of the different cartons would make it difficult to use different types of cartons together. To use the cartons judiciously and uniformly then can be recycled by converting it into another form using heat or pressure. But in order to recycle it, the layers of the carton need to be separated and the paper has to be removed from the poly aluminium layers. The paper can be separated from the used carton using a hydrapulper by converting it into a pulp and can be used as raw material for the paper industry. The remaining residue can then be used to produce rigid boards, sheets and corrugated sheets made of aluminium and polyethylene. Polyethylene – (C2H4) n
Aluminium --
Al
4. Case study in India
Figure 2 : Trash Mahal in Auroville
The roofing sheets were ordered from an organisation known as ‘The Daman Ganga plan’ is located in Vapi, Gujarat and owned by Tushar Shah. The plant is currently trying to increase its output to respond to a growing demand for the material it produces. Shredded tetra pak cartons are put in a mould and heated to activate the inherent plastics, paraffin and glues to form an adhesive mass. Then the resultant is pressed under a hot roller in a form of the designed product. In case of roofing it is pressed to form a corrugated sheet in order to be rigid and strong sheets. Then they are properly cut in exact dimensions as depicted in figure 3.
The Auroville ‘Trash Mahal’ (figure2) is one such excellent example where the roofing is made from hot pressed tetra pack after the paper has been removed from it.
Figure 3 : Cutting poly-aluminium sheets to size
The sheet so formed can be installed easily similar to installing metal or asbestos sheets using, nuts, bolts, angles, purlins and steel Page 3 of 6
sections. Figure 4 shows volunteers in Auroville fixing the roofing sheets to form the roofing of Trash Mahal. In fact the same material is now being used in many of the on-going projects in Auroville like the Sacred Groves Housing.
Table 1: properties of fibrocement roof and poly-Al roof
Flexion Resistance (N/m) Water Absorption (%)
Surface flame propagation index (1p) Heat evolution factor (Q)
Figure 4: Fixing of Poly Aluminum Roofing 5. Advantages of Polyethylene-
Flame propagation index (Pc)
Fibrocement Roofing Sheets
Daman Ganga Tuff Roof Sheets
4x103
7.63x106
37
6.5
Average
Min.
Max.
160
138
195
44.8
38.3
55.9
3.6
3.5
3.6
Aluminium Roofing sheets
The poly-aluminium sheets are strong and flexible thus making them difficult to break. Since plastic is non-conductor of heat and due to reflective properties these sheets have low heat absorption. Tests suggest that they keep the interior almost 25% cooler than cement or metal roofing sheets. Due to being made of plastic and aluminium these sheets are anti-fungus and are free of maintenance or colouring requirements. These sheets are very light with a density of just 148 kg/m3 and are convenient to be installed as well as reduce the dead load of the building. Due to its high flexion resistance, these sheets are also crack proof These roofing sheets do not absorb much water even during the monsoons in India. As claimed by the company which produces them, these sheets are also fire retardant under normal circumstances.
The comparison of the properties of the poly aluminium sheets made by Daman Ganga in Gujarat with those of common fibrocement roofing sheets is given in Table.1 below :-
6. Case study of Thailand In June 2010, Tetra Pack Thailand collaborated with the Princess Pa Foundation, the Thai Red Cross Society and Big C Supercentre to kick off the "Green Roof Project for Princess Pa Foundation". Under this project, used cartons dropped off at Big C outlets and other collection points are transformed into roofing sheets. The Green Roof Project was first launched in 2010, initially for a three-year period, but has proved so successful that it has now been extended to run to 2016. The project was inspired by earlier recycling campaigns, which delivered classroom sets and notebooks made from cartons to schools across Thailand. The project takes used cartons and recycles them into corrugated roofing sheets for the Princess Pa Foundation (part of the Thai Red Cross Society) to use when constructing homes and shelters for victims of floods and natural disasters – as shown in the figure 5.
Figure 5: Shelters for flood victims in Thailand
7. Conclusion
Thus the roofing sheets made from used Tetra Pak cartons are a good alternative to the fibrocement and metallic roofing sheets. In fact these sheets perform better than the conventional sheets used now. Though factories have been producing these roofing sheets but are not being used extensively all over the country or the world. This way of creating a building material not only reduces our resource consumption but also reduces the amount of waste generated. This in turn helps the environment and allows for a sustainable habitat for all of us.
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References 1. Fatoki, JG, Omoniyi, TE & Onilude, MA 2015, ‘Design and fabrication of a hydrapulper for Disintegrating disused tetra pak® beverage cartons’, European International Journal of Science and Technology, vol. 4, no. 6, pp. 113-123. 2. Hidalgo, M 2011, ‘Manufacturing rigid board by packaging waste containing aluminium and polyethylene, Journal of Scientific & Industrial Research, vol. 70, pp. 232-234. 3. Sullivan, D, Bannish, C, Fidanza, A, Peterson, N, Rungthanaphatsophon, P, Intaranukulkit, T & Jundee, P 2012, Environmentally Friendly Roofing Materials in Chiang Mai, Worcester Polytechnic Institute, Chulalongkorn University 4. Neves, F L & Zuben, F J 2003, Recycling of aluminium and polyethylene from Tetra Pak carton packages as plastic composite, Proceedings of the Global Plastics Environment Concil-2003, Detroit, USA, pp. 371-378. 5. Tetra Pak International n.d, The green roof project, viewed 26 January 2016, . 6. Deboonme, A 2013, Cartons can now become roofs, Business, The Nation Multimedia, viewed 27 January 2016, . 7. Daman Ganga Board Mills n.d, Polyethylene-Aluminium composite roofing systems,
viewed 26 January 2016, .
