Rudrashis Biswas wrote a report on high density polyethylene (HDPE) for their 5th semester chemical engineering course. The report defined HDPE as a thermoplastic polymer produced from ethylene monomer. It discussed the history of HDPE's invention in the 1950s using catalysts. The report also covered the physical and chemical properties, production, applications, and advantages of HDPE, which include its strength, durability, recyclability, and resistance to chemicals and corrosion. It concluded with current and projected growth in global HDPE production and markets.

1. HALDIA INSTITUTE OF TECHNOLOGY
TOPIC: HIGH DENSITY POLYETHYLENE (HDPE)
NAME: RUDRASHIS BISWAS
DEPARTMENT: CHEMICAL ENGINEERING
SEMESTER: 5th
CLASS ROLL NO.: 18/CHE/25
UNIVERSITY ROLL NO.: 10300618025
COURSE: PETROCHEMICAL TECHNOLOGY
COURSE CODE: CHE-OE505 b

2. DEFINITION
 High Density Polyethylene (HDPE) is a thermoplastic polymer produced from the
monomer ethylene. It is sometimes called “alkathene” or “polythene” when used
for HDPE pipes. With a high strength-to-density ratio, HDPE is used in the
production of plastic bottles, corrosion-resistant piping, geomembranes and
plastic lumber. HDPE is commonly recycled, and has the number “2” as its resin
identification code.

3. HISTORY OF HDPE POLYMER
In 19th century German chemist Eugen Bamberger and Friedrich Tschirner
identified a compound named polymethylene, a close compound to
polyethylene. Thirty years later the high-density polyethylene residue was
created by American chemist at E.I. du Pont de Nemours & Company, Inc.,
Carl Shipp Marvel, by subjecting ethylene under an immense amount of
pressure.
As a result, a solid form of polyethylene was invented. Later in 1953, Karl
Ziegler of the Kaiser Wilhelm Institute (renamed the Max Planck Institute) and
Erhard Holzkamp finally invented high-density polyethylene. This process
included the use of catalysts and low pressure, which has already been the
basis for the formation of many varieties of polyethylene compounds. For
this invention, Ziegler was even awarded the noble prize in 1955.
After two years on the invention of this material, high-density polyethylene
pipes were invented. Today high-density polyethylene has become the most
commonly used material for pipes due to its toughness, flexibility and
chemical resistance.

4. PHYSICAL PROPERTIES
Thermophysical properties of High Density Polyethylene (HDPE)
Density - 940 kg/𝑚3
Melting point – 130.8 ºC
Temperature of crystallization – 111.9 ºC
Latent heat of fusion – 178.6 kJ/kg
Thermal conductivity – 0.44 W/m.ºC
Specific heat capacity – 1330 to 2400 J/kg-K
Specific heat (solid) – 1.9 kJ/kg. ºC
Crystallinity – 60%

5. PHYSICAL PROPERTIES
HDPE is known for its high strength-to-density ratio. The density of HDPE can range
from 930 to 970 kg/𝑚3. Although the density of HDPE is only marginally higher than
that of low-density polyethylene, HDPE has little branching, giving it stronger
intermolecular forces and tensile strength than LDPE.
The difference in strength exceeds the difference in density, giving HDPE a higher
specific strength. Its is also harder and more opaque and can withstand somewhat
higher temperatures ( 120 ºC for short periods).
High-density polyethylene, unlike polypropylene, cannot withstand normally required
autoclaving conditions. The lack of branching is ensured by an appropriate choice of
catalyst ( e.g., Ziegler-Natta catalysts) and reaction conditions.

6. CHEMICAL FORMULA
HDPE is a type of polyethylene, the most common plastic which accounts for
over 34% of the global plastic market. It is a polymer made up of a huge
number of repeating units (known as monomers), and its chemical formula
can be generalised as (𝐶2𝐻4)𝑛.The branching in high density polyethylene is
of a relatively low degree (when compared to other categories of
polyethylene). The general structure of HDPE is illustrated below.

7. PREPARATION OF HDPE
High density polyethylene is a hydrocarbon polymer that can be prepared
from ethylene via a catalytic process. Some common catalysts used here
include Zeigler-Natta catalysts (Phillips catalyst), and metallocene catalysts.
Generally, in the polymerisation process, these catalysts form free radicals at
the end of the growing polyethylene molecules. They also add new ethylene
monomers at the end of the molecules thereby forming a long linear chain.
HDPE mostly features a low degree of branching where the linear molecules
or the polymer chains are packed together tightly. The presence of a strong
intermolecular force results in a dense, highly crystalline material. However,
the true mechanism of the synthesis of high density polyethylene is still a
debated topic.

8. WHY IS HDPE SO POPULAR?
MOLDABILITY
HDPE retains its rigid structure until its melting point is reached.
Once in the melt state, this polymer can be easily molded into any desired
shape.
This property makes it an ideal choice in the production of food containers,
water bottles, and plastic lumber.
RESISTANCE TO CORROSION
This polymer is resistant to mould and rotting, making it an ideal choice for
making underground water pipes.
Since HDPE can be sterilised via boiling, it is safe to use for food containing
purposes.
Its resistance to many chemicals, such as mineral acids and cleaning fluids,
make it easy to maintain. It is also resistant to many common solvents and
acids.

9. WHY IS HDPE SO POPULAR?
STRENGTH TO DENSITY RATIO
The density of this polymer ranges from 930 kg/𝑚3
to 970 kg/𝑚3
.
The structure of HDPE is linear and it contains very little branching, resulting
in stronger intermolecular forces.
The tensile strength of high density polyethylene is very high. It can withstand
heavier loads than most of the other types of polyethylene.
RECYCLABLE
The resin identification code of HDPE is 2, it can be recycled easily.
Despite being non-biodegradable, it is still considered an environmentally
responsible plastic.
Recycled HDPE is used in plastic furniture, automobile parts and rubbish cans.

10. RESISTANCE OF HDPE TOWARDS
CHEMICALS
• The materials are strongly resistant towards all kind of Dilute Acids and Alkalis.
• They have moderate resistance toward oil and greases.
• The resins have poor resistance to Hydrocarbons such as Aliphatic Hydrocarbons,
Aromatic Hydrocarbons, and Halogenated Hydrocarbons.
• They are highly resistant to alcohols.

11. ENVIRONMENTAL BENEFITS OF
RECYCLING HDPE
It has a huge worldwide market among all thermoplastics. Demand for high-
density polyethylene resins has been continuously rising since last few years
due to increase infrastructural activities globally. This is creating pressure on
the environment as the plastics produced do not decompose easily for years.
Recycling of plastic reduces a burden on the environment (landfills and water
bodies). For example amount of fresh high-density plastics used in producing
poly bags has reduced up to 70% in last twenty years.

12. APPLICATION
• 3D printer filament
• HDPE fibers can be spun into rope
• Disposable suits
• Housewrap
• Plastic mailing envelopes
• Flexible HDPE pipes
• Monobloc chair
• Banners
• Bottle caps
• Corrosion protection for steel pipelines
• Milk jug
• Heat resistant firework mortars
• Fuel tanks for vehicles

13. APPLICATION
• HDPE water bottles
• Bottle crates
• Stools for outdoor use
• Chemical containers
• Food storage containers
• Geomembrane for hydraulic application
• Ionizing radiation shield
• Microwave telescope windows
• Plastic surgery
• Swimming pool installation
• Water pipes for domestic water supply
• Wood plastic composites
• Telecom ducts

14. TYPES OF HDPE SHEETS
There are a variety of types of high-density polyethylene plastics, all which
have different applications and uses.
HDPE MATTE SHEET
Matte HDPE sheeting was specially formulated to manufacture items such as
cutting boards, as the material ensures a long product life and won’t dull
knives. Matte HDPE plastic sheeting is acid resistant, complaint with FDA
regulations, and approved by the National Sanitation Foundation (NSF).
HDPE SMOOTH SHEET
Smooth HDPE sheeting has a variety of qualities that make it an ideal material
for many applications. Smooth HDPE is easily fabricated and features good
chemical resistance, tensile strength, and is moisture and impact resistant.
One of the most common applications of HDPE smooth sheeting is tank
lining.

15. TYPES OF HDPE SHEETS
HDPE PIPE GRADE
Pipe grade HDPE plastic features improved weight and performance than
standard HDPE sheeting. The improved features of pipe grade HDPE make
the most popular HDPE sheet for outdoor applications.
HDPE COLORCORE
HDPE ColorCore features a coloured HDPE sheet core, that allows
manufacturers to create signs and letters that expose the interior colour.
Coloured high-density polyethylene sheet features the same strength and
durability features as smooth and matte HDPE.
HDPE ANTISKID
Antiskid HDPE sheet was created specifically for marine applications where a
non-slip or skid surface is required.

16. BENEFITS OF HDPE
• WEIGTH: HDPE is known for being extremely lightweight yet durable.
• MALLEABILITY: HDPE is easily molded and transformed into just about
any shape or design.
• RESISTANCE: Not only does HDPE sheet feature a high chemical and
impact resistance, but it also is resistant to rotting, insects, mildew and
mold.
• WEATHERABILITY: HDPE sheet is often used for outdoor applications as it
can stand some of the most extreme weather.
• LIFE-SPAN: Because HDPE has such high impact, chemical, and weather
resistance, HDPE can outlast traditional materials.
• DURABILITY: The durability of HDPE while being lightweight is one of the
things that contribute to its popularity.
• SUSTAINABILITY: HDPE sheeting is recycled, which is why many recycled
plastic products such as plastic lumber and trash cans contain HDPE.

17. WORLD PRODUCTION CAPACITY OF
HDPE
Polyethylene is one of the most used polymer globally. The production of
polyethylene polymer globally was 103 million tons in 2016. The production
for HDPE on was 47.5 million tons in 2016. It occupied a share of 46% in total
polyethylene production globally.
The leading region for the production of HDPE is Asia and Middle-East. In
past few years, there is a shift in major production region from North America
to Asian and Middle East. This is due to most of the incremental production
capacity has been added to this region.

18. PRODUCTION CAPACITY OF HDPE
BY REGION
Asia is the leading region in the production of high-density polyethylene. It
occupies a share of 36% in the global production capacity of the polymer.
China is the leading country in the production of the polymer in Asia. The
second largest region in the production of the polymer is North America with
a share of 20% followed by Middle-East at 17%. Middle-East and China are
the fastest growing regions in addition to new production capacity.

19. HDPE MARKET FORECAST
High-Density Polyethylene market is forecasted to grow more than US$84 bn
by 2023. The market was around US$63 bn in 2016 and will cross US$84 bn
by 2023 as per industry. The growth rate in the forecasted period will be
4.5%. It is a versatile product applicable to a variety of applications and uses
ranging from consumables packaging, beverage bottles, cosmetics, care
products, household goods to technical parts and even products used in
construction industry.

20. HDPE MARKET DRIVERS AND
CONSTRAINTS
DRIVERS
The major driving factor of the high-density polyethylene market is from
growing demand of in the packaging industry. It’s a preferred material in the
packaging industry because of it is comparatively a low-cost material. Rise in
demand for plastic pipes being widely used as a substitute for domestic
plumbing is the major driving force for this material in the global market.
Even growing Solar Panel industry in Asian-Pacific regions has resulted in
increased demand for High-density polyethylene over the forecast period.
Artificial knee-caps being made from DPE plastics could become the future
trend for high-density polyethylene market.

21. HDPE MARKET DRIVERS AND
CONSTRAINTS
REGIONAL OUTLOOK
The global high-density polyethylene material market has witnessed high
growth in recent years primarily due to increasing end-industry usage,
technological advancements and continuously growing demand from Asian-
Pacific regions. Easy availability of the polymer as a raw material in North
America and China has resulted in increased usage of this plastic for
packaging and construction sector.
CONSTRAINTS
As high-density granules are made with petroleum, therefore, price
fluctuation in petroleum can affect the prices accordingly. Competitive
materials such as polypropylene also restrict the growth of high-density
polyethylene market. These plastics like all other ordinary plastics emit
chemicals and are harmful to both environment and human health.

22. HDPE MARKET DRIVERS AND
CONSTRAINTS
KEY PLAYERS
Some of the prominent leading players in high-density polyethylene market
are Abu Dhabi Polymers Ltd. Borealis AG, Reliance Industries Ltd. National
Petrochemical Co, PetroChina Company Limited, LyondellBasell Industries N,
The Dow Chemical Co. Honam Petrochemical Corporation, Total S.A. and
Ineos Group Ltd etc.

23. ADVANTAGES OF HIGH-DENSITY
POLYETHYLENE (HDPE)
As it is a versatile polymer it is used for producing a number of plastic good
in different end segment markets. The polymer is often preferred over other
thermoplastics as it offers certain benefits such as:
• It is readily available and low-cost material.
• High-density polyethylene good impact resistance and tensile strength.
• The resins can be easily processed by all thermoplastic methods.
• The plastics are highly resistant towards chemicals, corrosion and climate
changes
• Plastics produced from the materials are durable, flexible, and strong and
light weighted.

24. DISADVANTAGES OF HIGH-DENSITY
POLYETHYLENE (HDPE)
Though, this is commonly used thermoplastics but also offers certain
limitations which are:
• It has high thermal expansion.
• It has poor weathering resistance
• The plastics are often subjected to stress cracking.
• The polymers are flammable and in certain conditions depict poor
temperature capability.

25. THANK YOU