HDPE (High-Density Polyethylene): Production, Market, Price and its Properties
What is HDPE?
High-density polyethylene or polyethylene high density (PEHD) is also termed as “alkathene’ or “polythene” whenever used for pipes is a kind of thermoplastic made from petroleum. It is the most commonly used plastic globally. The polymer is labeled as #2 plastic, primarily found in plastic bags, refill plastic bottles or milk jugs etc.
The polymer with high-density ration is majorly used for producing plastic bottles, pipes which are corrosion resistant, geomembranes and plastic lumber.
High-density plastics have several distinguishing properties which make it ideal for the packaging industry. It is stronger than standard polyethylene and is a strong barrier against moisture, also maintains its solid state at odd temperatures.
As it creates no harmful emissions in the production process and during its consumption cycle, it has become the most preferred kind of thermoplastic. It leaks no toxic waste in soil or water which makes it more environmentally friendly. Recently it is seen that there is a large shift in demand for this polymer than other polymers.
The polymer waste can be easily recycled to create new reusable eco-friendly products. High-density polyethylene products are commonly recycled and have labeled number “2” as their resin identification code. Recycle HDPE is primarily used to manufacture lawn and garden products, automobile parts, office products, and crates etc.
HDPE Pricing Trend
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 high-density polyethylene on was 47.5 million tons in 2016. It occupied a share of 46% in total polyethylene production globally.
The leading region for production of high-density polyethylene polymer 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.
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.
High-Density Polyethylene 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.
High-Density Polyethylene Market Drivers & Constraints
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.
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.
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.
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.
History of High-Density Polyethylene 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.
Increasing agricultural activities in recent years have stimulated the demand for high-density pipes as high-density drainage pipes are majorly used for agricultural drainage systems.
How is High-Density Polyethylene made?
The polymer was initially made by applying immense heat to petroleum under controlled conditions. This process is known as “cracking” which helps to create ethane gas. In this process, gas molecules attach together to form polymers, which are further used to produce polyethylene.
After this process molding of polyethylene is done to produce a stronger polymer material known as high-density polyethylene, applicable to a variety of uses and applications.
It is now produced by catalytic polymerization of ethylene in either slurry (suspension), solution or in gas phase reactors. Several Alpha-olefin co-monomers such as butene, hexene, and octene are incorporated at low levels to modify the properties of the polymer. Some processes may also switch to linear low-density polyethylene production (‘swing’ between High-density polyethylene and LLDPE).
In this process choice of catalyst or the use of bimodal process help to modify the quality of material being produced. The traditional Ziegler-Natta and chromium catalysts have been changed by metallocene catalysts which have proved to give improved properties to the resins.
Properties of High-Density Polyethylene
The material is one of the most durable and versatile thermoplastics used on a very large scale in today’s market for plastics. It is used to produce a variety of different kind of materials such as bottles, automotive parts, furniture etc. due to its suitable properties. Basic properties which the polymer possesses are as follows:
- The materials have the large strength to density ratio.
- They are translucent and waxy in appearance.
- The resins are easily flexible and highly weatherproof.
- They have good low-temperature toughness quality.
- They are strongly resistant to chemicals and do not corrode away easily
- High-density polyethylene plastics are lightweight, readily available and economical in nature.
- They have low moisture absorption.
- The materials are easy to weld using thermoplastic welding equipment
- It is non-toxic and non-staining along with this it also meets FDA and USDA certification for food processing.
Tensile Strength 0.20 – 0.40 N/mm² and Notched Impact Strength no break Kj/m²
Thermal Coefficient of expansion 100 – 220 x 10-6
Max Cont Use Temp 65°C
Density 0.944 – 0.965 g/cm3
Resistance toward 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.
Applications of High-Density Polyethylene
This plastic is one of the world’s most popular plastics. It is a versatile polymer which is suited to a wide range of applications varying from heavy- duty damp proof membrane in buildings to light, flexible bags and films. It is most notably used for bottles and caps, fresh produce bags or thin gauge carrier bags etc.
Properties such as durability, recyclability and excellent vapor and moisture barrier etc make them applicable for producing a variety of goods. Some prominent uses of the polymer in plastic end segment markets are:
It is used widely to manufacture the sheets which are further used to produce a variety of plastic products. The sheets are strong and resistant to chemicals and temperature with a low coefficient of friction. Being highly durable make them perfectly suitable for products such as water tanks, industrial uses or bottles and caps etc.
Types of High-Density Polyethylene Sheets
There are a variety of high-density polyethylene sheets produced with different applications and uses, they are:
High-Density Polyethylene Matte Sheet
These sheets are primarily used to manufacture items such as cutting boards, as the material ensures durability and won’t dull knives. Matte high-density plastic sheeting is acid resistant, compliant with FDA regulations, and has been also approved by the National Sanitation Foundation (NSF).
High-Density Polyethylene Smooth Sheet
Smooth sheets have a variety of qualities which make it applicable for a variety of uses. Smooth high-density sheets can be easily fabricated and have good chemical resistance, tensile strength, and is also highly moisture and impact resistant. High-density polyethylene smooth sheeting is commonly used for tank lining.
High-Density Polyethylene Pipe Grade
These sheets have some improved features from standard high-density sheeting in terms of weight and performance which make them suitable for producing pipes.
High-Density Polyethylene Color Core
These sheets are colored form of high-density sheets which are used by manufacturers to create signs and letters that expose the interior color. Colored high-density polyethylene sheet offers the same strength and durability features as smooth and matte high-density sheets.
High-Density Polyethylene Antiskid
These sheets are specifically manufactured for marine applications where a slip or skid surface of sheets is essential.
Properties of the Sheets
- They are lightweight and can be easily molded into any shape or design.
- These sheets have high chemical and impact resistance.
- They are highly durable and sustainable
- They can easily withstand in odd temperature conditions.
Applications of High-Density Polyethylene Sheets
They are used primarily to rotationally mold large complex products such as fuel tanks, trash containers, pallets, agricultural tanks, highway barriers etc. The sheets are also used widely for producing a variety of bags and bottles and in the packaging industry.
HDPE Pipe & Fittings
High-density polyethylene polymer is majorly used for manufacturing the pipes. The resins are used in large quantities to manufacture pipes as they are more durable, lightweight, weather resistant and offer an easy flow of materials. These pipes are used in a variety of sectors such as municipal, industrial, energy, geothermal and landfills etc.
High-density pipes have zero leakage because of the fusion process creates monolithic high-density polyethylene system, as a result, proves it as most suited material for pipes and fittings. These pipes are more environment-friendly as they are non- toxic and highly durable.
Basic Features of High-Density Polyethylene Pipes and Fittings
- They are Leak free and offer excellent flow characteristics.
- They are highly resistant towards chemicals, corrosion, and Abrasion.
- The pipes and fittings offer strong ductility and toughness.
- They are available in diameters from ½ inch to 63 inches which offer a wide variety to manufacturers.
- They can withstand freezing water better than traditional metal piping systems.
- It is highly durable and delivers long-term economy, value and dependency.
High-Density Polyethylene Bags
High-density polymers are also used to manufacture poly bags on a very large scale. The basic properties of the material make them highly suitable for producing a variety of poly bags. These poly bags are produced according to their application and uses. The resins are used to produce fresh poly bags, brad bags, food bags, thin gauge carrier bags and many others.
Advantages of High-Density Poly Bags
- These poly bags are resistant to high and low temperatures.
- It is an additive-free material so the bags become ideal for packaging of products.
- The poly bags offer non-scratch properties which again is suitable for the packaging industry.
- These bags are stiffer, stronger and have better moisture retention capacities.
Disadvantages of High-Density Poly Bags
- As the material is cloudy and frosty so it does not offer clarity to the bags produced.
- If the poly bags are notched it becomes very easy to tear these bags in the direction the film was extruded.
High-density polyethylene is widely used as geomembrane globally due to its availability in large amounts and low material cost. It is resistant towards chemicals, UV, and ozone which make it suitable to be used to produce liners. The liners are primarily used in landfill, waste water treatment lagoons, animal waste lagoons and in mining applications. These liners are available in form of large rolls with an approximate width of 22.5 inches.
Features of the Liners
- They are durable and UV stable materials.
- The liners are produced in form of wide rolls, approximately of 6.86 mt and 22.5 ft.
- They have good chemical and temperature resistance
- White surface or conductive layer of these liners can also be produced according to the user demand.
Applications of High-Density Polyethylene Liners
They can be used as Landfill liners, Heap leach, and mine ponds and even for treatment of all water contaminated bodies.
Other Uses of High-Density Polyethylene
The plastics, due to their durability, flexibility and light weight qualities are applicable for variety of end segment products such as plastic bottles and cap (water bottles, beverages etc), toys (outdoor and indoor playground systems), chemical containers (shampoo, conditioner, cleaning products, motor oil etc), marine construction and furniture (cabinets, lawn furniture, lockers, bathroom stalls) and many other household products used in daily lives.
Advantages and Disadvantages 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.
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.
Recycling of HDPE
High-density polyethylene plastics are the most commonly recycled plastics on a very large scale globally. The plastic is accepted at most of the recycling centers of the world as it is the easiest polymer to recycle. The plastics carry the universal symbol of number “2” in the recycling triangle.
The high-density polyethylene recycling process starts from a collection of used plastics. First, the plastic collected is sorted and is separated. As the plastics are often contaminated so the clean and dirty high-density polyethylene are segregated and recycled differently. The contaminated form of the plastics is cleaned before recycling to maintain the quality of recycled products.
General recycling machinery is used for recycling of HDPE bottles, but different recycling process is used for the films. HDPE film recycling machinery chews the plastic sheets into small pieces and then they are converted into pellets.
These pellets can be further turned into a variety of products with certain percentage of virgin high-density polyethylene combined with recycled high-density polyethylene. Finally produced recycled high-density polyethylene is usually dark in color like brown or black which is subjected to be used accordingly to produce new plastic products.
Uses of Recycled HDPE Plastic
Recycled high-density plastics can again be used to make new bottles or containers. They can also be utilized in the packaging industry. Recycled plastics are primarily used to produce household products such as containers (bins, boxes, and other storage items), construction pipe, ropes, Food packaging (Milk bottles) and household goods (fences, pots, furniture and other plastic household interiors).
Environmental Benefits of Recycling High-Density Polyethylene
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.
Developing countries like China and India have a high demand for the polymer due to an increased standard of living and rise in demand for pipes, cables etc from growing industries. As this plastic like all other plastic is non- biodegradable and takes centuries to decompose it is essential to recycle used high-density plastics to produce new products (bags, pipes, and containers etc) again to maintain stability in the environment.