1. i
“PAANI GENIE – AN IMPROVED WATER
COLLECTION DEVICE”
A PROJECT REPORT
Submitted by
Jay Puducheri 1021210349
Fajal Ashraf 1021210346
Tirthankar Bhattacharjee 1021210374
Under the guidance of
Mr. K.V. SREEJITH,
Assistant Professor
Department of Mechanical Engineering
in partial fulfillment for the award of the degree
of
BACHELOR OF TECHNOLOGY
in
MECHANICAL ENGINEERING
of
FACULTY OF ENGINEERING & TECHNOLOGY
S.R.M. Nagar, Kattankulathur, Kancheepuram District
APRIL 2016

2. ii
SRM UNIVERSITY
(Under Section 3 of UGC Act, 1956)
BONAFIDE CERTIFICATE
Certified that this project report titled “PAANI GENIE” is the bonafide work
of “Jay Puducheri ,Fajal Ashraf , Tirthankar Bhattacharjee ”, who
carried out the project work under my supervision. Certified further, that to the best of
my knowledge the work reported herein does not form any other project report or
dissertation on the basis of which a degree or award was conferred on an earlier
occasion on this or any other candidate.
SIGNATURE SIGNATURE
GUIDE HEAD OF THE DEPARTMENT
MR. K.V. SREEJITH MECHANICAL ENGINEERING
Signature of the Internal Examiner Signature of the External Examiner

3. iii

4. iv
TABLE OF CONTENTS
CHAPTER
No.
TITLE PAGE
NO
ABSTRACT v
ACKNOWLEDGEMENT vi
LIST OF TABLES vii
LIST OF FIGURES vii
1. INTRODUCTION 1
1.1 GENERAL 1
1.2 WATER CRISIS 1
1.3 EFFECTIVE AND EFFICIENT 3
2. LITERATURE SURVEY 4
3. 3.1 GENERAL
3.2 PRODUCTION PROCESS
6
10
3.1.1 ROTATIONAL MOLDING
PROCESS
11
3.1.2 RECENT IMPROVEMENTS 12
3.1.3 TYPICAL MOLDING
APPLICATION
12
3.2 MOLD RELEASE AGENTS 13
3.3 MATERIALS 13
3.4 PRODUCTS 14
3.5 DESIGN CONSIDERATION 14
3.5.1 PRODUCT DESIGN FOR
ROTATIONAL MOLDING
14
3.5.2 DESIGN 15
3.6 PROCESS: ADVANTAGES,
LIMITATIONS AND MATERIAL
REQUIREMENTS
15
3.6.1 ADVANTAGES 16
3.6.2 LIMITATIONS 17
3.6.3 MATERIAL REQUIREMENTS 18
3.6.4 CLAIMED BENEFITS 18
3.7 WALL THICKNESS 19
3.8 RESIN CHOICE 19
3.9 MELT INDEX 20
3.10 TYPES OF POLYETHYLENE 22

5. v
3.11 MOULDS FOR ROTATIONAL
MOLDING
23
3.12 TYPES OF MOULDS 23
3.12.1 FLANGE-MEETING,
SURFACES AND HINGES
23
3.12.2 MOULD MOUNTING 24
3.12.3 INSULATION LIDS AND
COVERINGS
24
3.12.4 VENTING 25
3.12.5 MOULD RELEASE 25
3.13 ROTOMOULDING
EQUIPMENT
25
3.13.1 HEATING STATIONS 26
3.13.2 MOULD COOLING STATIONS 26
3.13.3 INSTRUMENTATION 26
3.13.4 FINISHING ROTATIONALY
MOULDED PIECES
3.14 TESTINGPROCESSOF THE
PRODUCT
26
28
4. 4.1 CONCLUSION 31
4.1.1 FUTURE ENHANCEMENT 31
5. APPENDICES 33
6. REFERENCES 34

6. vi
ABSTRACT
The Paani Genie the most efficient and appropriate technology to achieve
this purpose. Instead of being carried on the head, the weight of the water
remains on the ground in a drum. A steel clip-on handle allows the
women and children to roll the drum by either pushing or pulling it,
depending on gradients. Compared to a bucket, the Panni Genie allows 5
times more water to be carried home. As an additional benefit, it saves
time and while women can use it for other household tasks, children can
attend school more often, resulting in better education. Basic hygiene and
health can be significantly improved and long-term injuries from carrying
heavy weights are prevented. The durable design ensures a lifespan of 5
to 7 years and often even longer, depending on prevailing conditions. The
maintenance-free design and no consumable parts, ensures sustainability
and long-term success in remote locations.
The manufactured product was a rotomoulded HDPE water roller
carrying 90 litres of water. The HDPE material was chosen due to its
impact, and wear resistant, flexible, can have very high elongation before
breaking, generally good chemical resistance, food contact grade. This
product was then tested and distributed to various remote locations.

7. vii
ACKNOWLEDGEMENT
We would like to acknowledge the help of a few in our journey. Akhil
Nichani, Maanasa Madhu Krishna, Achintya Bansal, Shantanu Vyas, Hiroshan G and
Trishanka Menon who are all part of the Paani Genie team. Mukesh Ambani and
INFRA, our manufacturers who have helped us bring this product to life. Vinod
Saraogi and the Rotary Club for providing us with their resources to find suitable
villages to pilot this project in. All of our generous donors. Lady Andal Venkatasubba
Rao School where 6 of the 7 Moving Forward members studied has shown us great
support and encouragement. Mr. Jayaprakash and Dr. Sharma for early advice and
guidance with respect to producing Paani Genie and for connecting us with Infra. The
Hindu, Chennai Live 104.8 and other media agencies who have given us much
appreciated exposure. Bhaskar, a junior level Panachayat official in Vinayaganallur
who has been our contact in the village and has helped us co-ordinate with the
villagers. Mr. Sreejith, Dr. Haridasan for guiding us through this entire process.

8. viii
LIST OF TABLES
TABLE No. Name Page No.
3.9 An increase in Melt Index and Density 20
6.2 Table 3.3 Test Results from CIPET 22
6.3 Tensile Strength for Isopthalic. 24
6.4 Flexural Test for Polyester. 27
LIST OF FIGURES
TABLE No. Name Page No.
2.1 Mould 11
3.1 Finished Product 27
3.2 Lid 27

9. 1
CHAPTER 1
INTRODUCTION
1.1 GENERAL
The Paani Genie, is a device for carrying water more easily and efficiently
than traditional methods, particularly in the developing world. It consists of a barrel-
shaped container which holds the water and can roll along the ground, and a handle
attached to the axis of the barrel. It’s simple and purpose-built nature makes it an
example of appropriate technology. This project aims to alleviate the daily struggle
endured by women and children in rural India by helping them improve their ability to
transport more water, in less time with considerable ease. Paani Genie is a water roller
that has a capacity of 90 litres, which is five times that of the normal pot being used. It
has many advantages, which include saving time, energy and reducing suffering. It is
also environment friendly, as the wide rolling surface helps compact soil to minimise
erosion unlike narrow wheelbarrows. Another interesting application of Paani Genie
is that once it is damaged beyond its usefulness for water collection, it can be used as
a storage bin and when cut vertically in half, or as a feeding/water trough for animals
and a bath for washing clothes and children. This project is one that will substantially
increase the quality of life of people in rural India. Partner with us and help
underdeveloped communities improve their access to water for immediate benefits
and tangible results.
1.2 WATER CRISIS
There is an urgent need for the Paani Genie because it offers an immediate
solution to the relentless struggle to collect enough water for daily activities,
consumption and sustenance farming and results in improvements to health and living
standards. According to the United Nations, this affects approximately 1 billion
people who are without adequate access to water. The statistics on access to water
does not reflect the reality on the ground, where many people struggle to live a
dignified life. While the Paani Genie is not a permanent water solution, it does offer
an immediate and appropriate response to the issues surrounding water access and

10. 2
food security. With respect to our pilot village, we had three criteria that we wanted
our village to satisfy:
1) It must have a significant water problem with people walking at least 1.5
kilometres for their water.
2) The village must not have more than 150 homes. As this is our first project,
we want to start small.
3) The village must be within a three hour radius of Chennai. As this project is
run by a group of college students, we would find it hard to visit a village on a
regular basis if it were very far away. We wanted to find a village that we
could visit on a relatively regular basis so that we could develop a relationship
with the people in the village.
After visiting between 15 and 20 villages, we found Vinayaganallur, a village two and
a half hours away from Chennai with 125 homes. People walk 2 kilometres and more
to get their water between April and September. Vinayaganallur satisfied all of our
criteria and so has been selected as our pilot village.
Vinayaganallur is located in Kancheepuram district, 10 minutes away from
Vedanthangal bird sanctuary. We contacted the Rotary Club and asked them to help
us find a village to pilot this project. With their assistance, we visited over 15 villages
in Tamil Nadu over a span of 4 months hoping to find the ideal village. In our head,
the ideal village is one where:
1. There are 100-150 homes. This is in our size bracket.
2. People walk a minimum of 1.5 kilometers to reach the water source.
3. The village should not be further than 2 hours from Chennai. Most of the
Paani Genie team comprises of college students studying in Chennai and so
accessibility to the village where the project is being piloted is crucial.
After looking at many villages in areas like Jolarpet and Vellore, we happened
to connect with a Rotary member who invited us to take a look at Vinayaganallur. We
visited Vinayaganallur in January 2015 and were instantly struck by how aptly it met

11. 3
all of our base conditions. It has 120 homes and is located an hour and forty five
minutes away from Chennai. Vinayaganallur is located in a rectangle comprising of
ten villages. All the villages are similar to Vinayagallur. When water is in short
supply, the people of these 10 villages walk from village to village in search of a
water source that has not been exhausted. If the people of Vinayaganallur are lucky,
the first village on their walk will have a working water source and this is at a
distance of 1.5 km from their homes. If the first village does not have a working water
source, they continue walking from village to village until they find one that works. In
the worst case scenario, they end up walking close to 5 kilometers. This ridiculous
dependence on luck for the people of these villages hit home hard with all the Paani
Genie team members and we decided to adopt Vinayagallur as the pilot village. We
visit Vinayaganallur once in two weeks and have established a good relationship with
the people who live there. Gaining their trust is important as we gear up to helping
them make the step up from using 15 liter crippling Kodams to 90 liter Paani Genies
that make your life easy.
1.3 EFFECTIVE & EFFICIENT
Our innovation makes more water and time available for education, household
tasks and food production as smallholder farmers can transport up to 5 x more water
to their homes and food gardens. Currently, they tend to rely on traditional methods of
water collection that consume excessive amounts of energy and time, which could be
better spent on food production and school attendance to break free from the poverty
cycle. The Hippo roller is very user friendly for women, children and physically weak
as it makes the transportation of water much less strenuous than traditional methods.
It is specifically designed for rural and economically poor communities with its low to
none maintenance costs and there is no need to access spare parts which is very
difficult in these areas.

12. 4
CHAPTER 2
LITERATURE SURVEY
1. Social Impact of the Hippo Water Roller, retrieved 02 November 2015 - The
Hippo water roller, or Hippo roller, is a device for carrying water more easily and
efficiently than traditional methods, particularly in the developing world. It
consists of a barrel-shaped container which holds the water and can roll along the
ground, and a handle attached to the axis of the barrel. Currently deployed in rural
Africa, its simple and purpose-built nature makes it an example of appropriate
technology.
2. Ward, Noel M. (Winter 1997). "A History of Rotational Moulding". Platiquarian
Reprints - Rotational Molding (BrE moulding) involves a heated hollow mold
which is filled with a charge or shot weight of material. It is then slowly rotated
(usually around two perpendicular axes) causing the softened material to disperse
and stick to the walls of the mold. In order to maintain even thickness throughout
the part, the mold continues to rotate at all times during the heating phase and to
avoid sagging or deformation also during the cooling phase. The process was
applied to plastics in the 1940s but in the early years was little used because it was
a slow process restricted to a small number of plastics. Over the past two decades,
improvements in process control and developments with plastic powders have
resulted in a significant increase in usage. Rotocasting (also known as
rotacasting), by comparison, uses self-curing resins in an unheated mould, but
shares slow rotational speeds in common with rotational molding.
3. Beall, Glenn (1998), Rotational Molding, Hanser Gardner Publications, The
rotational molding process is a high-temperature, low-pressure plastic-forming
process that uses heat and biaxial rotation (i.e., angular rotation on two axes) to
produce hollow, one-piece parts. Critics of the process point to its long cycle
times—only one or two cycles an hour can typically occur, as opposed to other
processes such as injection molding, where parts can be made in a few seconds.
The process does have distinct advantages. Manufacturing large, hollow parts

13. 5
such as oil tanks is much easier by rotational molding than any other method.
Rotational molds are significantly cheaper than other types of mold. Very little
material is wasted using this process, and excess material can often be re-used,
making it a very economically and environmentally viable manufacturing process.
4. Crawford, R, Throne, James L., Rotational Moulding of Plastics, William Andrew
Size – Rotational molded products can be as small as a ping pong ball and as large
as a 20,000 gallon tanks. Dutchland Plastics is capable of manufacturing products
from 0 to 1000 pounds in weight and up to 17 feet long.
Design –Rotational molding allows much more flexibility in product design
compared to blow molding. Complex shapes and moving sections are easier to
manufacture and rotomolding offers a distinct advantage with uniform wall
thickness.

14. 6
CHAPTER 3
3.1 GENERAL
The production of Paani Genie water roller was done by rotational molding
process. This process was chosen because of various reasons explained below, but
here we will explain briefly. The water roller is a 50 X 50 X 65 cm hollow drum, it
has a detachable rod handle; 100 X 70 X 3 cm, the opening diameter was designed to
be at 135 mm or 53 inches. This was done so that the opening extractions on the
finished product doesn’t affect the smooth rolling of the water roller. The detachable
rod enables the push and pull activity easily for most humans by just varying the
angle to the roller. The size of the rod make is very easy to handle and easily attach
and detach it from the roller. The usability of the rod was used to base the design
interpretations of it into the water roller. The water roller needed to be of the specific
height, diameter and width to meet the design requirements for the volume
specification, which needed the water roller to carry 90 liters. So the Paani Genie
water roller has a 90 liter water carrying capacity. Rotational molding process was
chosen as they had many advantages compared to other plastic molding process
methods. Most manufacturers of hollow type plastics usually prefer this the most in
producing their products. Other terms used to refer to the process are roto-molding
and roto-casting. Slush molding is also used in liquid-vinyl which is also a similar
process. Rotational molding has several benefits attached to it and some of the major
ones include; low residual-stresses levels and cheaper molds. They are:
 Size options: The process fits any size from the tiniest to larger sizes; this
means that there is a room for flexibility as compared to other systems. The
rotational molding can be done on a small Ping-Pong sized plastic to even
21,000 gallon-tanks. Many manufacturers of the moldings are able to make a
gallon of between 0 to 1000 pounds and as high as 17ft. This is a big

15. 7
advantage since different sizes can be manufactured using the process, in this
aspect the molding can make many sizes to be used for many purposes.
 Different designs: It’s very easy to design many shapes using the rotational
molding process; this is due to the fact that when the hot plastic or compounds
are put into a mold, they will take the shape of the mold, which makes it ideal
for creativity since any shape can be made from the process. Other types of
molding processes are rigid in nature with few options, but the rotational
molding can provide a lot of variety in the manufacturing phase. Also to keep
in mind is that there is more room for designing in the process when compared
to the blow molding method. Rotational molding can be used to manufacture
many complex designs and shapes especially moving sections. Besides it has
uniform-thickness of its walls, which is a distinct advantage in designing
different shapes.
 Inserts: The rotational moulding process can easily accept metal inserts while
producing the product and it also allows the possibility for additional
threading inserts. All these can be processed at very low costs, as compared to
other methods which are cumbersome. Assembly’s techniques can be easily
altered in the rotomoulding process, which offers the aspect of lower costs and
durability in all dimensions.
 Color sectioning: Color sectioning is much easier with this rotomold process
and the color-blending can be done in-house to a variety of shades. The color
matching is easily done on the rotational molding without extreme volumes;
any pattern imaginable can be created with this process. There are a number of
colors which can be achieved and at a lower cost. Some of the colors which
are available include; sandstone, marble and other color varieties.
 Quality surface finishing: The process offers high quality surface finishing
capabilities by exactly taking the shape of the particular mold plus the texture.
This makes room for very high gloss quality finishes on the product surface. It
also can reflect smoothness and quality artistic product design and take on a
high oriental texture finish on its surface.
 Decorations in mold: The rotomolding process takes any authentically
designed decorations which are made in the mold and will feature it on the
plastic in a vibrant manner. The in-mold techniques used to decorate and

16. 8
design graphics are a by-product of the rotational molding process. The unique
design of graphics will stick permanently in the final rotational plastic product.
This method makes it possible for items like serial numbers, bar-codes and
colorful logos to be molded easily. They often appear and are better quality as
opposed to the traditional ones.
 Quick tooling: Among the advantages of rotational moulding is the process of
quick tooling. The reason is, the process is slow-pressure without any need of
ejection or in-mold cooling. The cast aluminum manufactured molds are very
easy to use especially when cooling. The tooling process offers less expenses
when aluminum is involved. A new tooling-process takes about 4 to 10 weeks
depending on the design and complexity involved. Multiple molds are also
manufactured easily by aluminum casts. The actual fact is that the other
molding processes like the blow-molding and others can be expensive and
complicated. For variety of designs and even graphics, rotational molding has
an upper hand. Bottom line is that with the advantages of rotational molding
you get a much easier process with versatility and more cost savings.
The Paani Genie water roller’s material was selected to be HDPE, (High Density
Polyethylene). This thermoplastic is available in a range of flexibilities depending on
the production process. High density materials are the most rigid. The polymer can be
formed by a wide variety of thermoplastic processing methods and is particularly
useful where moisture resistance and low cost are required. Polyethylene is limited by
a rather low temperature capability (200-250 F) but is manufactured in billions of
pounds per year. Vinyl acetate can be copolymerized with ethylene. The resulting
product has improved transparency over homopolymerized polyethylene because of a
reduction of crystallinity in the copolymer.
Basic Advantages of HDPE over other plastics:
• Low cost
• Impact resistant from -40 C to 90 C
• Moisture resistance
• Good chemical resistance

17. 9
• Food grades available
• Readily processed by all thermoplastic methods
Basic Disadvantages
• High thermal expansion
• Poor weathering resistance
• Difficult to bond
• Flammable
In general, high density grades of polyethylene have densities up to 0.97 g/cm^. Low
density grades are as low as 0.91 g/cm^. Typically, the high-density material is more
linear and consequently more crystalline. As might be expected, this higher
crystallinity permits use at temperatures up to 130 C with somewhat better creep
resistance below that temperature. Low density polyethylene has less stiffness than
the high density type. Blends of the two types are common. With a high strength-to-
density ratio, HDPE is used in the production of plastic bottles, corrosion-resistant
piping, geomembranes, and plastic lumber. HDPE plastic has several properties that
make it ideal as a packaging and manufacturing product. It’s stronger than standard
polyethylene, acts as an effective barrier against moisture and remains solid at room
temperature. It resists insects, rot and other chemicals. HDPE creates no harmful
emissions during its production or during its use by the consumer. Also, HDPE leaks
no toxic chemicals into the soil or water. It works well in extreme hot or cold with a
temperature range from -100 to 120 degrees Celsius. This material has a tensile
strength of 4550 pounds per square inch. HDPE gets harder and stiffer as the
temperature drops, but does not get brittle like other plastics. HDPE is resistant to
many dilute and concentrated solvents containing acids, bases, or alcohol. HDPE is
Rot resistant, Remains cool to the touch in high temperatures unlike metal core trays
and its structural integrity is unaffected by UV rays.

18. 10
3.2 PRODUTION PROCESS
The rotational molding process is a high-temperature, low-pressure plastic-
forming process that uses heat and biaxial rotation (i.e., angular rotation on two axes)
to produce hollow, one-piece parts. Critics of the process point to its long cycle
times—only one or two cycles an hour can typically occur, as opposed to other
processes such as injection molding, where parts can be made in a few seconds. The
process does have distinct advantages. Manufacturing large, hollow parts such as oil
tanks is much easier by rotational molding than any other method. Rotational molds
are significantly cheaper than other types of mold. Very little material is wasted using
this process, and excess material can often be re-used, making it a very economically
and environmentally viable manufacturing process. Until recently, the process was
largely empirical, relying on both trial and error and the experience of the operator to
judge when the part should be removed from the oven, and when it was cool enough
to be removed from the mold. Technology has improved in recent years, allowing the
air temperature in the mold to be monitored, removing much of the guesswork from
the process.
Much of the current research is into reducing the cycle time, as well as
improving part quality. The most promising area is in mold pressurization. It is well
known that applying a small amount of pressure internally to the mold at the correct
point in the heating phase accelerates coalescence of the polymer particles during the
melting, producing a part with fewer bubbles in less time than at atmospheric
pressure. This pressure delays the separation of the part from the mold wall due to
shrinkage during the cooling phase, aiding cooling of the part. The main drawback to
this is the danger to the operator of explosion of a pressurized part. This has prevented
adoption of mold pressurization on a large scale by rotomolding manufacturers.

19. 11
Figure 2 : Mould
3.2.1 ROTATIONAL MOULDING PROCESS
The rotational moulding process consists of four distinct phases:
1. Loading a measured quantity of polymer (usually in powder form) into the
mold.
2. Heating the mold in an oven while it rotates, until all the polymer has melted and
adhered to the mold wall. The hollow part should be rotated through two or more
axes, rotating at different speeds, in order to avoid the accumulation of polymer
powder. The length of time the mold spends in the oven is critical: too long and
the polymer will degrade, reducing impact strength. If the mold spends too little
time in the oven, the polymer melt may be incomplete. The polymer grains will
not have time to fully melt and coalesce on the mold wall, resulting in large
bubbles in the polymer. This has an adverse effect on the mechanical properties
of the finished product.
3. Cooling the mold, usually by fan. This stage of the cycle can be quite lengthy.
The polymer must be cooled so that it solidifies and can be handled safely by the
operator. This typically takes tens of minutes. The part will shrink on cooling,
coming away from the mold, and facilitating easy removal of the part. The
cooling rate must be kept within a certain range. Very rapid cooling (for example,
water spray) would result in cooling and shrinking at an uncontrolled rate,
producing a warped part.

20. 12
4. Removal of the part.
3.1.2 RECENT IMPROVEMENTS
Until recently, the process was largely empirical, relying on both trial and
error and the experience of the operator to judge when the part should be removed
from the oven, and when it was cool enough to be removed from the mould.
Technology has improved in recent years, allowing the air temperature in the mould
to be monitored, removing much of the guesswork from the process.
Much of the current research is into reducing the cycle time, as well as
improving part quality. The most promising area is in mould pressurization. It is well
known that applying a small amount of pressure internally to the mould at the correct
point in the heating phase accelerates coalescence of the polymer particles during the
melting, producing a part with fewer bubbles in less time than at atmospheric
pressure. This pressure delays the separation of the part from the mould wall due to
shrinkage during the cooling phase, aiding cooling of the part. The main drawback to
this is the danger to the operator of explosion of a pressurized part. This has prevented
adoption of mould pressurization on a large scale by rotomolding manufacturers.
3.1.2 TYPICAL ROTOMOULDING APPLICATIONS
Rotational molding permits production of a countless number of fully or
partially closed items. Design versatility of rotationally molded pieces is almost
unlimited. The rigidity or flexibility of an item is controlled by the properties of the
resin used (see section on Resin Choice) and by the wall thickness of the molding.
Some typical applications for which rotational molding is particularly suited include
the following:
• Commercial, industrial and agricultural storage tanks ranging in size from 5
gallons to 22,000 gallons;
• Containers for packaging and material handling;
• A variety of industrial parts, especially covers and housings, water softening
tanks, tote bins;

21. 13
• Numerous under-the-hood and in-the-cab automotive parts
Rotomolded parts are also used in portable outhouses, battery cases, light
globes, vacuum cleaner and scrubber housings and garbage containers. Furniture,
game housings, surf boards, traffic barricades, display cases and ducting can also be
produced by rotomolding. The list above indicates just some of the possibilities.
3.2 MOULD RELEASE AGENTS
A good mold release agent (MRA) will allow the material to be removed
quickly and effectively. Mold releases can reduce cycle times, defects, and browning
of finished product. There are a number of mold release types available; they can be
categorized as follows:
 Sacrificial coatings: the coating of MRA has to be applied each time because most
of the MRA comes off on the molded part when it releases from the tool. Silicones
are typical MRA compounds in this category.
 Semi-permanent coatings: the coating, if applied correctly, will last for a number
of releases before requiring to be re-applied or touched up. This type of coating is
most prevalent in today's rotational molding industry. The active chemistry
involved in these coatings is typically a polysiloxane.
 Permanent coatings: most often some form of PTFE coating, which is applied to
the mold. Permanent coatings avoid the need for operator application, but may
become damaged by misuse.
3.3 MATERIALS
More than 80% of all the material used is from the polyethylene family: cross-
linked polyethylene (PEX), low-density polyethylene (LDPE), linear low-density
polyethylene (LLDPE), high-density polyethylene (HDPE), and regrind. Other
compounds are PVC plastisol’s, nylons, and polypropylene.

22. 14
3.4 PRODUCTS
Designers can select the best material for their application, including materials
that meet U.S. Food and Drug Administration (FDA) requirements. Additives for
weather resistance, flame retardation, or static elimination can be incorporated.
Inserts, graphics, threads, handles, minor undercuts, flat surfaces without draft angles,
or fine surface detail can be part of the design. Designs can also be multi-wall, either
hollow or foam filled.
Products that can be manufactured using rotational moulding include storage
tanks, furniture, road signs and bollards, planters, pet houses, toys, bins and refuse
containers, doll parts, road cones, footballs, helmets, canoes, rowing boats, kayak
hulls and playground slides. The process is also used to make highly specialised
products, including UN-approved containers for the transportation of nuclear fissile
materials, anti-piracy ship protectors, seals for inflatable oxygen masks and
lightweight components for the aerospace industry.
3.5 DESIGN CONSIDERATION
3.5.1 Product design for rotational molding
There are many considerations for a designer when designing a part. Which
factors are most important to a client? For instance, a part may need to be cheap and a
certain colour. However, if another colour is cheaper, would the client be willing to
change colours? Designers are responsible for considering all the limitations and
benefits of using certain plastics. This may result in a new process being decided
upon.
Another consideration is in the draft angles. These are required to remove the
piece from the mould. On the outside walls, a draft angle of 1° may work (assuming
no rough surface or holes). On inside walls, such as the inside of a boat hull, a draft
angle of 5° may be required, this is due to shrinkage and possible part warping.
Another consideration is of structural support ribs. While solid ribs may be
desirable and achievable in injection moulding and other processes, a hollow rib is the

23. 15
best solution in rotational moulding. A solid rib may be achieved through inserting a
finished piece in the mould but this adds cost.
Rotational moulding excels at producing hollow parts. However, care must be
taken when this is done. When the depth of the recess is greater than the width there
may be problems with even heating and cooling. Additionally, enough room must be
left between the parallel walls to allow for the melt-flow to properly move throughout
the mould. Otherwise webbing may occur. A desirable parallel wall scenario would
have a gap at least three times the nominal wall thickness, with five times the nominal
wall thickness being optimal. Sharp corners for parallel walls must also be considered.
With angles of less than 45° bridging, webbing, and voids may occur.
3.5.2 DESIGN
With rotomolding, a plastics product designer can create a huge array of
innovative products. Typical design concerns that are handled routinely by rotational
molding include the following:
• maintaining uniform wall thickness – rotational molding can provide a more
consistently uniform wall thickness for a part compared to other plastic
processing methods;
• producing double-wall construction – rotational molding can provide uniform
double-wall construction on parts;
• Molding thicker corners – due to the process, rotomolded parts will have
thicker outer corners which help strengthen the parts;
• molding inserts, reinforcing ribs, kiss-off ribbing and undercuts these are
easily included in a roto-molded part.
3.6 PROCESS: ADVANTAGES, LIMITATIONS, AND MATERIAL
REQUIREMENTS
Another consideration is the melt-flow of materials. Certain materials, such as
nylon, will require larger radii than other materials. Additionally, the stiffness of the

24. 16
set material may be a factor. More structural and strengthening measures may be
required when a flimsy material is used.
3.6.1 ADVANTAGES
Rotational moulding offers design advantages over other moulding processes.
With proper design, parts assembled from several pieces can be moulded as one part,
eliminating high fabrication costs. The process also has inherent design strengths,
such as consistent wall thickness and strong outside corners that are virtually stress
free. For additional strength, reinforcing ribs can be designed into the part. Along with
being designed into the part, they can be added to the mould.
The ability to add prefinished pieces to the mould alone is a large advantage.
Metal threads, internal pipes and structures, and even different coloured plastics can
all be added to the mould prior to the addition of plastic pellets. However, care must
be taken to ensure that minimal shrinkage while cooling will not damage the part.
This shrinking allows for mild undercuts and negates the need for ejection
mechanisms.
In some cases rotational moulding can be used as a feasible alternative to blow
moulding, this is due to the similarity in product outputs, with products such as plastic
bottles and cylindrical containers, this is only effective on a smaller scale as it much
more costly to blow mould regarding a small output, and with fewer resulting
products rotational molding is much cheaper, due to blow moulding relying on
economies of scale regarding efficiency.
Another advantage lies in the molds themselves. Since they require less
tooling, they can be manufactured and put into production much more quickly than
other molding processes. This is especially true for complex parts, which may require
large amounts of tooling for other molding processes. Rotational molding is also the
desired process for short runs and rush deliveries. The molds can be swapped quickly
or different colours can be used without purging the mold. With other processes,
purging may be required to swap colours.

25. 17
Due to the uniform thicknesses achieved, large stretched sections are non-
existent, which makes large thin panels possible (although warping may occur). Also,
there is little flow of plastic (stretching) but rather a placing of the material within the
part. These thin walls also limit cost and production time.
Another cost limiting factor is the amount of material wasted in production.
There are no sprues or runners (as in injection molding), no off-cuts (thermoforming),
or pinch off scrap (blow molding). What material is wasted, through scrap or failed
part testing, can usually be recycled.
3.6.2 LIMITATIONS
Rotationally molded parts have to follow some restrictions that are different
from other plastic processes. As it is a low pressure process, sometimes designers face
hard to reach areas in the mold. Good quality powder may help overcome some
situations, but usually the designers have to keep in mind that it is not possible to
make sharp threads that would be possible with injection molding. Some products
based on polyethylene can be put in the mold before filling it with the main material.
This can help to avoid holes that otherwise would appear in some areas. This could
also be achieved using molds with movable sections.
Another limitation lies in the molds themselves. Unlike other processes where
only the product needs to be cooled before being removed, with rotational molding
the entire mold must be cooled. While water cooling processes are possible, there is
still a significant down time of the mold. Additionally, this increases both financial
and environmental costs. Some plastics will degrade with the long heating cycles or in
the process of turning them into a powder to be melted.
The stages of heating and cooling involve transfer of heat first from the hot
medium to the polymer material and next from it to the cooling environment. In both
cases, the process of heat transfer occurs in an unsteady regime; therefore, its kinetics
attracts the greatest interest in considering these steps. In the heating stage, the heat
taken from the hot gas is absorbed both by the mold and the polymer material. The rig
for rotational molding usually has a relatively small wall thickness and is
manufactured from metals with a high thermal conductivity (aluminium, steel). As a

26. 18
rule, the mold transfers much more heat than plastic can absorb; therefore, the mold
temperature must vary linearly. The rotational velocity in rotational molding is rather
low (4 to 20 rpm). As a result, in the first stages of the heating cycle, the charged
material remains as a powder layer at the bottom of the mold. The most convenient
way of changing the cycle is by applying PU sheets in hot rolled forms.
3.6.3 MATERIAL REQUIREMENTS
Due to the nature of the process, materials selection must take into account the
following:
 Due to high temperatures within the mold the plastic must have a high resistance
to permanent change in properties caused by heat (high thermal stability).
 The molten plastic will come into contact with the oxygen inside the mold—this
can potentially lead to oxidation of the melted plastic and deterioration of the
material's properties. Therefore, the chosen plastic must have a sufficient amount
of antioxidant molecules to prevent such degradation in its liquid state.
 Because there is no pressure to push the plastic into the mold, the chosen plastic
must be able to flow easily through the cavities of the mold. The parts design must
also take into account the flow characteristics of the particular plastic chosen.
3.6.4 CLAIMED BENEFITS
It is claimed that approximately five times the amount of water can be
transported in less time with far less effort than the traditional method of carrying 20
litres (approximately 5 gallons) on the head.
 time savings (fetching water can be very time consuming in some poor rural
environments);
 reduced effort;
 reduced strain (carrying heavy weights on the head every day for years puts
strain on the body, particularly the vertebral column);

27. 19
 increased water availability, with benefits for health and perhaps even
enabling vegetables to be grown
 Hygienic storage due to the sealed lid on the roller.
3.7 WALL THICKNESS
One benefit of rotational molding is the ability to experiment, particularly with
wall thicknesses. Cost is entirely dependent on wall thickness, with thicker walls
being costlier and more time consuming to produce. While the wall thickness can be
nearly any thickness, designers must remember that the thicker the wall, the more
material and time will be required, increasing costs. In some cases, the plastics may
significantly degrade due to extended periods at high temperature. Also, different
materials have different thermal conductivity, meaning they require different times in
the heating chamber and cooling chamber. Ideally, the part will be tested to use the
minimum thickness required for the application. This minimum will then be
established as a nominal thickness.
For the designer, while variable thicknesses are possible, a process called stop
rotation is required. This process is limited in that only one side of the mold may be
thicker than the others. After the mould is rotated and all the surfaces are sufficiently
coated with the melt-flow, the rotation stops and the melt-flow is allowed to pool at
the bottom of the mold cavity.
Wall thickness is important for corner radii as well. Large outside radii are
preferable to small radii. Large inside radii are also preferable to small inside radii.
This allows for a more even flow of material and a more even wall thickness.
However, an outside corner is generally stronger than an inside corner.
3.8 RESIN CHOICE
To obtain the desired end product, the choice of a quality powdered resin is
essential in rotational molding. One reason is the high temperatures used risk
chemical degradation in a less-than-quality product. Today, approximately 84 percent
of all resin used in rotational molding is polyethylene.

28. 20
While the effects of particle size on end-product properties and process ability
are less critical, those of melt index and density are considerable.
3.9 MELT INDEX
For rotomolding, a resin must have a good flow when molten. With
polyethylene, he flow is measured by melt index. The higher the melt index, the better
the flow. Most rotomolding resins have melt indices ranging from 2g/10 minutes to
10g/10 minutes. The term “g/10 minutes” refers to the weight of molten resin moving
through an orifice of a predetermined size in 10 minutes. The melt index is also a
rough measure of the molecular weight or the chain length of a resin. A resin
With a high melt index has shorter chains and a lower molecular weight or
smaller molecules. A resin with a low melt index has longer chains and a higher
molecular weight or larger molecules. Molecular weight distribution is also important
in a rotomolding resin. A narrow distribution is more advantageous, since the
narrower the distribution, the more uniform the melt properties. Density is a measure
of the specific gravity of a resin. The density of polyethylene is classified by types
according to the American Society of Testing and Materials (ASTM):
AN INCREASE IN MELT INDEX and DENSITY AFFECTS THESE PROPERTIES
LDPE HDPE
Melting Point decreases Increases
Flow Increases remains the same
Impact Strength decreases Decreases
Stiffness remains the same increases
Vicat Softening Temp. decreases increases
Resistance to Low Temp
Brittleness
decreases decreases
Barrier Properties remain the same Increase
Table3.9: An increase in Melt Index and Density

29. 21
Type I: Low Density Resins (range of 0.925 g/cm3 and below). Generally, low
density resins are preferable whenever stiffness is not essential or is undesirable, as
for many toys, and only when light loads are to be expected.
Type II: Medium Density Resins (range from 0.926 g/cm3 to0.940 g/cm3).
Most linear low density polyethylene resins fall within this range. Medium density
resins are useful for self- supporting items that require the higher heat-distortion
resistance or stiffness that low density resins do not provide.
Type III: High Density Resins (range from 0.941 g/cm 3 to 0.959 g/cm3).
High density resins impart the highest rigidity to the end product, which frequently
permits reduction in wall thickness.
Type IV: Very High Density Resins (0.960 g/cm3 and above.) These resins are
not currently used in rotomolding. In addition to lowering toughness and increasing
stiffness, increasing density raises the melting point, permits higher temperature limits
and improves barrier properties in the end product.
The polyethylene pellets that are normally produced in the resin
manufacturing process cannot be used for rotational molding; they must be reduced to
a much smaller particle size. This reduction is necessary to obtain good heat transfer
from the mold to the powder. The reduction also improves the flow of the particles
during melting so that oxidation does not inhibit the mold ability and development of
the physical properties of the resin. The size reduction is usually done by the resin
supplier, but can be done by the rotational molder who has grinding equipment. In
addition to mechanically ground powder, some resins are available as reactor powder
or granules. Several linear low density polyethylene’s come in powder or granular
form. Some other resins such as nylon, due to its high melt flow and small pellet size,
can be molded without grinding. Polyethylene’s have the following characteristics
that have made them the most widely used powders for rotational molding:
• They are easily ground to 35 mesh at high rates;
• They can be made thermally stable with proper stabilization additives;

30. 22
• They can be molded in high-temperature, high-speed rotational molding
equipment without excessive oxidation;
• They have excellent low temperature physical properties, such as impact
strength, allowing their use in a broad temperature range;
• They are relatively low in cost, making them a material to consider in all cost-
effective applications;
• They are available in a wide range of densities and melt indices to fit the needs
of simple, no stressed items as well as extremely large, highly stressed
applications;
• They can have their UV stability or outdoor life significantly improved by the
addition of pigment or UV stabilizer;
• They may meet FDA food contact requirements;
3.10 TYPES OF POLYETHYLENE
They are:
• Low Density Polyethylene (LDPE) is flexible and tough, easy to process and
has excellent chemical resistance.
• Linear Low Density Polyethylene (LLDPE) or Linear Medium Density
Polyethylene (LMDPE) has better mechanical properties than LDPE as well as
higher stiffness, excellent low temperature impact strength and excellent
environmental stress crack resistance.
• High Density Polyethylene (HDPE) is the stiffest resin of the polyethylene
family. HDPE has excellent chemical resistance and good process ability.
3.11 Molds for Rotational Molding (Inexpensive and Lightweight)
Since very little pressure is exerted in the rotomolding process and no coring
for cooling is necessary, rotational molds can be relatively simple. Because of this
simplicity, the cost of a rotational mold is a fraction of that for a comparable injection
or blow mold. Two-piece molds are the industry standard, but three piece molds are
sometimes required to facilitate proper removal of the finished parts. Molds can be as
simple as a round object or complex with undercuts, ribs and tapers. Selection of

31. 23
rotational molds depends on the size, shape and surface finish of the piece to be
molded, as well as the number of molds made for a particular piece. Molds should be
as thin-walled and lightweight as possible.
3.12 TYPES OF MOULDS
The most important property of a rotational mold is that its interior surface has
to be completely non-porous. Cast aluminum molds are by far the most frequently
used molds in the rotomolding industry. Most parts that are small- to medium sized
are molded with a cast aluminum mold. Cast aluminum has good heat-transfer
characteristics and is cost effective when several molds of the same shape are
required. The only drawbacks to cast aluminum are it can be porous and easily
damaged. Sheet metal molds are normally used for larger parts. They are easy to
fabricate and, in many cases, the sections of the mold need only be welded together.
Sheet metal molds are cost effective when larger single-mold parts are required. Other
molds, such as electro-formed nickel molds, yield an end product with very fine
detail. Vapor-formed nickel molds, like electro-formed molds, also yield very good
detail but are more costly. CNC-machined molds and composite molds with jacketed
heating elements are also used.
3.12.1 FLANGE-MATING, SURFACES AND HINGES
Each mold must be in two or more sections requiring good parting lines to
have proper fit of the mold sections. Proper fit of the parting lines also yields little or
no flash of the resin being used and provides correct formation of the finished part.
The mating surfaces should be machined smooth for a good fit and the molds should
be stress-relieved before the parting lines are matched. The best parting line cannot
function properly without a good clamping system. The most common clamping
system for small-to-medium parts is the “C” vise clamp. Spring-loaded clamps,
welded onto the sections of the mold, are another popular option. As the molds get
larger, nuts and threaded bolts are normally used. The threaded bolts are usually
removed and installed with an air gun.

32. 24
3.12.2 MOULD MOUNTING
Molds must be mounted on the spindle or arm of the rotational molding
machine. Large sheet metal molds are easily mounted by bolts or simple clamping
systems. With cast aluminum molds, a structure commonly known as a spider can be
used to mount several small-to medium-sized molds on the same spindle or arm. The
spider consists of several arms or mounting legs to which each mold is attached,
usually by bolts. In turn, the spider has one, central, mounting location that attaches to
the machine spindle. This design allows two- or three-dozen cast molds to be mounted
on one central structure. The spider or a single large sheet metal mold may be
removed easily with a forklift or crane. This is important because the rotomolding
process typically is used for short production runs of a variety of parts.
3.12.3 INSULATION LIDS AND COVERINGS
When openings are desired in rotationally molded pieces, insulating lids or
inserts can be used. An insulating material is applied to an area of the mold to keep
the powder from fusing at that point. Teflon and silicon foams, among other materials,
are commonly used. If thin-walled sections are desired in a molded piece, they can
also be obtained by covering a section of the mold with an insulting material that
results in a small amount of powder sticking to the mold. The wall thickness can be
controlled to a degree by changing the type or thickness of the insulating material.
3.12.4 VENTING
Because of the inherent build-up of gas in the heating cycle of the rotational
molding process, most rotational molds require a venting system. A vent reduces flash
and piece or mold distortion. It also prevents blowouts caused by pressure and permits
the use of thinner-walled molds. Depending on the size of the mold, vents can range
from 1/8" to 2" inside diameter (I.D.). An industry rule of thumb is to use 1/2" I.D.
tube for each cubic yard of part volume. Since vents leave holes in the molded parts,

33. 25
correct placement is essential. The vents should be located in an area that may be cut
out of the finished part or in an area where a patch does not reduce the aesthetic value
of the end product. Improper venting can cause many molding problems, such as
water tracking on the inside of the end product.
3.12.5 MOULD RELEASE
Since most rotational molds are designed with little or no draft angle, it is
important to condition the molds with a release agent. Normally, molds are cleaned
with a solvent and a lightly abrasive cloth to remove all foreign particles left on the
surface during fabrication of the mold. After the mold is cleaned, a light coating of
release agent is applied and baked-on to insure a good coating. With moderate use, the
release agent does not adversely affect paint adhesion after flame treatment.
Environmental concerns have led to the development of water-based mold releases
which are taking the place of solvent-based releases. Many molders are eliminating
mold releases altogether by having molds coated with a fluoropolymer.
3.13 ROTOMOULDING EUIPMENT
The equipment used in rotational molding is relatively simple but has many
variations. The most common type of rotomolding machine is a multiple-spindle or
carousel machine. Carousel machines are usually wheel-shaped. The spindles, each
carrying a group of molds or a single large mold, are mounted on a central hub and
driven by variable motor drives. Most carousels have the freedom to rotate in a
complete circle. The carousel consists of a heating station or oven and a cooling
station. In many cases, the carousel also is equipped with an enclosed chamber and a
loading and unloading station. The shuttle-type machine. A frame for holding one
mold is mounted on a movable bed. Incorporated in the bed are the drive motors for
urning the mold biaxially. The bed is on a track that allows the mold and the bed to
move into and out of the oven. After the heating cycle is complete, the mold is moved
into a non-enclosed cooling station. A duplicate bed with a mold is then sent into the
oven from the opposite end. The clamshell utilizes an enclosed oven that also serves
as the cooling station. This machine uses only one arm and the heating,cooling and
loading/unloading stations are all in the same location.

34. 26
3.13.1 Heating Stations
Most rotomolding ovens are fired by natural gas, using blowers to distribute
heat throughout the chamber. Some ovens have the capability to be heated by oil or
propane gas, but natural gas is the preferred method. Normal oven temperatures are
400° to 850°F (270° to 454°C). Ovens must be well insulated to minimize heat loss.
Hot-air convection is the most commonly used heat source, although hot-liquid
conduction and infrared radiation are also used.
3.13.2Mold Cooling Stations
The cooling station may use a system to provide forced air for initial cooling
and a water system to provide the necessary cooling of the molds and parts. Normally,
a spray mist is used for even cooling. In many cases, however, only air-cooling is
used. During the cooling process, the mold should be rotated. The cooling station may
or may not be enclosed.
3.13.3 Instrumentation
Several advancements in instrumentation include computer simulation
programs and data monitoring systems that help the rotational molder develop
optimum cycle times and improve their molding efficiency.
3.13.4 Finishing Rotationally Molded Pieces
Pigment loadings in polyethylene powders for rotomolding should be kept to a
minimum because high levels may cause reductions in the tensile, yield and impact
strengths of the end product. Any appropriate flame or electronic pre-treatment
method can be used to promote ink and paint adhesion in printing and painting. Other
than the desired end-product decoration, rotational molding requires practically no
post-treatment. If there is flash along the mold parting line, it must be removed,
although the creation of flash in rotational molding is usually negligible. The addition
of color to rotationally molded pieces is easily accomplished. The rotational molder
may dry blend a color pigment into the natural powder. In this process proper
dispersion is essential (one-quarter of one percent should be the maximum level
used). Another way to add color in the rotomolding process is by using a resin with

35. 27
compounded-in color. New developments in color technology allow parts to change
color when under temperature. Granite and sandstone colors are also available.
Graphics can be molded-in or applied as a post-molding step. Multi-axis routers allow
for precision trimming of parts.
Figure 3 : Finished Product
Figure 4 : Lid

36. 28
3.14 Testing Process of the Product
The finished Paani genie product was tested out, to check if it met with the
minimum design specifications and requirements, for the project to be successful.
The test’s performed are:
•Visual appearance - The visual appearance of objects is given by the way in
which they reflect and transmit light. The color of objects is determined by the
parts of the spectrum of (incident white) light that are reflected or transmitted
without being absorbed. Additional appearance attributes are based on the
directional distribution of reflected (BRDF) or transmitted light (BTDF)
described by attributes like glossy, shiny versus dull, matte, clear, turbid, distinct
•Capacity – The capacity of object is given by the way as how much volume of
liquid the object can contain within. This gives the total value of the internal
space provided.
•Overall height – This test will provide us with the total height of the whole
object. The vertical length, if it’s up to specified designed requirements.
•Overall diameter – This test will provide us with the total diameter of the whole
roller. This has to meet the product design requirement for the roller to have a
certain carrying volume capacity.
•Internal diameter of the manhole – This test will provide us with the results of
the internal diameter of the opening of the paani genie.
•Material identification - testing is the analysis of materials to determine the
chemical composition of a metal or alloy at particular (usually multiple) steps of
alloy manufacturing or in-process alloy installation. Knowing the exact
composition and grade of an alloy enables suppliers, plant workers, and other
responsible parties in the chain of custody of components to match alloy
specifications that are chosen for their specific properties such as heat resistance,
corrosion resistance, durability, etc. Having the right alloy in the right place is
essential in places like petroleum refineries and chemical plants, because the right
alloy with the right properties is often all that stands between a safe, efficient
operation and lost time and revenue.

37. 29
•Density – this will measure the mass of the atoms or molecules that makes up
the material and the volume or amount of space the material takes up. If the
molecules or atoms are “packed” in more closely, it will be denser.
•Melt flow index - is a measure of the ease of flow of the melt of a thermoplastic
polymer. It is defined as the mass of polymer, in grams, flowing in ten minutes
through a capillary of a specific diameter and length by a pressure applied via
prescribed alternative gravimetric weights for alternative prescribed temperatures.
Polymer processors usually correlate the value of MFI with the polymer grade
that they have to choose for different processes, and most often this value is not
accompanied by the units, because it is taken for granted to be g/10min.
Similarly, the test load conditions of MFI measurement is normally expressed in
kilograms rather than any other units.
•Wall thickness - Wall thickness measurement is the most often applied ultrasonic
testing technique. Precision wall thickness measurement is mainly used for the
quality control of individual and serial parts. It may either be carried out
manually or by means of ultrasonic systems integrated into the production
process. Suitable side conditions allow for wall thickness measurement with a
tolerance of ± 0,01 mm. This method is more often used for the detection of
erosion and corrosion damages than for precision wall thickness measurement. In
comparison with the mechanical measuring the ultrasonic wall thickness
measurement is of advantage because it may be carried out even if only one side
of the part to be tested is accessible for the NDT-technician. Thus for instance the
wall thickness of tubes in operation may be determined by ultrasound without any
problems. Layer thickness testing may be considered to be a special case of wall
thickness measurement. However, for this purpose are not only applied ultrasonic
but also electric-magnetic procedures.
•Resistance to deformation - Deformation testing evaluates the effect that load
has on the shape of a sample. It is the measurement of a sample material to
withstand a permanent deformation and/or the ability of the sample to return to its
original shape after deforming. Deformation is measured as the percent change in
height of a sample, under a specified load, for a specified period of time. A spring
test is a type of deformation test where a spring is compressed to an L1 and L2

38. 30
height and the load measurement is taken at each point and compared to a
specified load.
•Resistance to Impact - is an ASTM standard method of determining the impact
resistance of materials. An arm held at a specific height (constant potential
energy) is released. The arm hits the sample.The specimen either breaks or the
weight rests on the specimen. From the energy absorbed by the sample, its impact
energy is determined. A notched sample is generally used to determine impact
energy and notch sensitivity.
•Tensile strength - is a fundamental materials science test in which a sample is
subjected to a controlled tension until failure. The results from the test are
commonly used to select a material for an application, for quality control, and to
predict how a material will react under other types of forces. Properties that are
directly measured via a tensile test are ultimate tensile strength, maximum
elongation and reduction in area. From these measurements the following
properties can also be determined: Young's modulus, Poisson's ratio, yield
strength, and strain-hardening characteristics. Uniaxial tensile testing is the most
commonly used for obtaining the mechanical characteristics of isotropic
materials. For anisotropic materials, such as composite materials and textiles,
biaxial tensile testing is required
•Flexural Modulus - also known as modulus of rupture, bend strength, or fracture
strength, is a material property, defined as the stress in a material just before it
yields in a flexure test. The transverse bending test is most frequently employed,
in which a specimen having either a circular or rectangular cross-section is bent
until fracture or yielding using a three point flexural test technique. The flexural
strength represents the highest stress experienced within the material at its
moment of rupture.
The following tests were carried out at CIPET or Central Institute of Plastics
Engineering and Technology is an autonomous institute under the department of
chemicals and petrochemicals, Ministry of Chemicals and Fertilizers, Government of
India.

39. 31
Table 3.10 Test Results from CIPET
S.No Property Standard Units Resultsobtained
1
Visualappearance
Bothinternalandexternalsurfacesaresmooth,cleanandfreefromotherdefects
2Capacity litre 90
3Overallheight kg 8,8
4Overalldiameter mm 465,18
5Internaldiameterofthemanhole mm 134,46
6Materialidentification HDPE
7Density ASTMD792g/cc 0,92
8Meltflowindex ASTMD1238g/10min 5,34
9Wallthickness mm 8,457
10Resistancetodeformation % 0,12
11ResistancetoImpact NocrackNoPuncture
12Tensilestrength Mpa 19,3
13FlexuralModulus MPa 845,7
14OverallMigration IS9845
at70degC
a)distilledwater mg/dm^2 2,86
b)AgeousSolution mg/dm^2 3,46

40. 32
CHAPTER 4
4.1 CONCLUSION
The innovative design allows water to be placed inside the “wheel” rather than
carried above the wheel. The 90kg (200 pound) weight of water is borne on the
ground resulting in an effective weight of just 10kg (22 pounds) on level ground.
Children and the elderly can easily manage a full roller over most types of terrain.
Extensive field tests over many years and various awards have proven the
effectiveness of the Paani Genie. Approximately five times the normal amount of
water can now be collected in less time with far less effort.
The drum is manufactured from UV stabilized Polyethylene and has been
designed to withstand typical rural conditions such as uneven footpaths, rocks and
even broken bottles. The large opening (135 mm / 5.3 inch diameter) allows for easy
filling and cleaning of the interior. The sealed lid ensures hygienic storage of water
and the steel handle provides firm control over difficult terrain while pushing or
pulling the roller.
4.2 Future Enhancement
The project initially requires the input of donor funds in order to operate, as
the high cost of the Paani Genie places it out of the price range of the families who
need it most. The tremendous emotional appeal of the Hippo roller lends itself to
securing donor funding. Another major source of funding is the appeal for marketing
spin-offs from the CSI (corporate social investment) budgets which helps to
encourage corporate involvement. We also partner with other NGO’s that have their
own infrastructure and source of donor funding. We have also contracted a local
company that sells corporate gifts to corporate businesses. Their clients were asking
for social responsibility gifts and the project was a perfect fit. Current distribution
levels are around 1,500 rollers annually and we expect this to ramp up dramatically
this year. More students are welcome to join our cause, and to give them a platform to
serve the public. This platform enables students from our college to venture forward
and innovate new ideas to increase basic life in rural and needy India.

41. 33
5. APPENDICES
Article for the newspaper; The Hindu:
“When a Genie comes to rescue…”
Many may have seen people in the villages and in the outskirts of the city,
carrying pots or huge containers of water on their heads or hips. Have we ever
given a thought of how difficult it is carry it to and fro? Here is where ‘Moving
Forward’ comes to play.
Moving Forward is a non-profit organisation which aims at generating solutions
to tackle perennial problems of the underprivileged in India. Created by
likeminded college-goers, this organization has started their first project called
the ‘Paani genie.’ This is inspired by the Hippo Water Roller which is a South
African project that was started in the 1990s.
The Paani genie is a 90-litre cylindrical water roller. It has two holes in the
horizontal side onto which a rod is attached. It allows the user to pull or push the
roller at an angle of 180 degrees. So, it could reduce 6 trips of carrying 15 litre
water pots to one!
Figure 3: Paani Genie
After an immense survey, Moving Forward had selected Vinayanganallur as their
pilot village. Situated at a place which is two and a half hours from Chennai, this
village has 205 homes and survives on agriculture.

42. 34
Moving Forward has been successful in this village and has used crowd funding
to do this project. “This project has been successful in the first village. Now we
are planning to spread this project to other villages as well,” says Maanasa
Madhukrishna, who heads Moving Forward.
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