Most of the people in the world are not familiar with materials like Polyethylene and HDPE. That’s why in this article, we are going to give you Comprehensive overview of Polyethylene vs HDPE. At the end of this article, you will be able to describe the concept of Polyethylene and HDPE, the usage of them and their difference. Polyethylene is nothing but the most produced plastic in the world. On the other hand, HDPE is a denser version of polyethylene. However, you need to know that polyethylene is the base for many other plastics. Polyethylene was created by England Chemical Industries in 1933. In 1939, Polyethylene became commercial and many companies and industries started using it in the process of manufacturing their products. In this article we will explain to you all of the concepts that are related to Polyethylene vs HDPE. So, follow us until the end of this article.

overview

What is Polyethylene (PE)?

PE or Polyethylene is a thermoplastic polymer made from ethylene gas. Polyethylene has a molecular and side branching structure. Different types of PE exist with varying densities. Typical density range of PE is from 0.88 to 0.96 (unit: g/cm3). Also, you must be aware that in solid form, polyethylene is harmless. Finally, if we want to talk about the common uses for PE, we must mention the industries such as: pipes production, bottles production, containers production, packaging production, healthcare services, agriculture services, electrical and non-electrical insulation, etc.

What is High-Density Polyethylene (HDPE)?

In this part of the article, High-Density Polyethylene or HDPE will be explained. HDPE is a higher molecular weight variant of polyethylene (PE). High-density polyethylene or HDPE has a low level of side branching which allows for a crystalline structure. If we want to talk about the density ranges for HDPE, we should say that it is between 0.93 and 0.97 (unit: g/cm3) which is equal to 970 (unit: kg/cm3). Another point that you should notice is that HDPE is stronger, less elastic, and more resistant to load distortion than LDPE. Finally, if we want to highlight common uses for HDPE, we should mention the following: most kinds of bottles, most kinds of pipes, some kinds of containers, most kinds of toys, lumber that is made from plastic, plastic bags, boxes for cereal, jugs for milk, food packages, some part of shoes, products for cleaning, etc.

Key differences between PE and HDPE

In this part of the article “Polyethylene vs HDPE”, key differences between PE and HDPE will be mentioned. However, you should be aware that the differences between these two materials is more than what we are going to say but the most important differences will be discussed.

Key differences between PE and HDPE are:

Density and Structure of Polyethylene vs HDPE

In the density and structure part, the molecular structure of PE and HDPE will be Compared and contrasted. Polyethylene is a kind of polymer that is thermoplastic and the structure of it is from ethylene gas. If we talk chemically, HDPE is identical to Polyethylene. HDPE has a lot of CH2 chains that are too long. However, the side branches of HDPE are different from HDPE in size and the regularity. With more emphasis, we can understand that the side branches of HDPE in CH2 are different from Polyethylene. Another point is that, the degree of side branching in the monomer CH2 has an effect on the density of HDPE. The density of HDPE is more than the density of Polyethylene.

Strength and Flexibility of Polyethylene vs HDPE

As we told you in the previous part, the fundamental structure of PE and HDPE is different. This difference in structure is not just a simple thing and it must be investigated more. The structural differences affect strength, flexibility, and resistance to impact. HDPE is strong, less elastic, and more resistant to load distortion whereas the resistance of PE in harsh situations is less than HDPE.

Resistance to Corrosion and Chemicals of Polyethylene vs HDPE

In this part of the article, the resistance of Polyethylene and HDPE to corrosion, chemicals, and UV light will be explained. Imagine that you are going to produce pipes. Both PE and HDPE are usable in this situation but which one is better? To answer this question, you must take a look at the place that your pipe is going to install in it. Resistance of HDPE to corrosion, chemicals, and UV light is more than Polyethylene. So in harsh conditions, using HDPE is a wiser choice.

Temperature Stability of Polyethylene vs HDPE

In this part, we want to highlight the differences in thermal stability and melting points of PE and HDPE. The melting point of HDPE is from 120 to 130 degrees centigrade while the melting point of PE is between 105 and 115 degrees centigrade. So, as you can see, the thermal stability and melting points of HDPE are more than PE but the difference is not too much.

Cost of Polyethylene vs HDPE (Polyethylene vs HDPE cost)

In this part, we want to compare the cost of Polyethylene vs HDPE material, including recycled material (Polyethylene vs HDPE price). Both Polyethylene and HDPE materials are inexpensive but if we compare these two with each other, we will see that the price of HDPE is more than PE. So, you have to pay attention to the place where Polyethylene or HDPE products are going to be used in it. If the situation in the place is usual, PE can have a good performance but if the situation is severe and harsh, maybe it’s better to use HDPE.

Piping Applications: PE vs HDPE

Now, in this part of the article, the piping application of Polyethylene vs HDPE will be discussed. As you know, both Polyethylene and HDPE have usage in piping applications but there are some differences. PE is usually used in cold water supply systems whereas HDPE is usually used in hot and cold water applications. So, we can say that both Polyethylene and HDPE have their own benefits.

Piping Applications: PE vs HDPE

The benefits of PE piping are:

  1. The Polyethylene pipes have a long life and high durability
  2. The joints of Polyethylene pipes are leak-tight
  3. The Polyethylene pipes are too flexible
  4. The Polyethylene pipes have a lightweight
  5. The Polyethylene pipes have resistance to chemical materials
  6. The price of Polyethylene pipes is low

The benefits of HDPE piping are:

  1. The process of installation of HDPE pipes has a low cost.
  2. The HDPE pipes are flexible
  3. The joining process of HDPE pipes is simple
  4. The HDPE pipes have resistance to chemical materials
  5. The HDPE pipes have resistance to the shock of water
  6. The HDPE pipes have resistance to the Sun rays

If we compare HDPE pipes with Polyethylene pipes, we will realize that the strength, flexibility, and corrosion resistance of HDPE pipes are greater than Polyethylene pipes.

Types of PE pipes

Types of PE pipes are:

  1. PE pipes with high-density
  2. PE pipes (PE100)
  3. PE pipes (Barrier)
  4. PE pipes (high demand)

Types of HDPE pipes

Types of HDPE pipes are:

  1. HDPE pipes (PN 2)
  2. HDPE pipes (PN 4)
  3. HDPE pipes (PN 6)
  4. HDPE pipes (PN 8)
  5. HDPE pipes (PN 10)
  6. HDPE pipes (PN 12)
  7. HDPE pipes (PN 16)
  8. HDPE pipes (PN 20)
  9. HDPE pipes (PN 25)
  10. HDPE pipes (PN 32)
  11. HDPE pipes (PN 40)

Other Applications of PE and HDPE

In this part of the article, other applications of PE and HDPE will be discussed. Polyethylene and HDPE have diverse uses beside their usual uses. The diverse uses of PE are packaging, pipes, and various goods. Also, the diverse uses of HDPE are packaging, consumer goods, fibers, plumbing, and automotive.

Physical Properties Compared

In this part of the article key physical properties of Polyethylene and HDPE will be presented in a table:

key physical properties Polyethylene HDPE
density Lower than HDPE Higher than the other kinds of PE
hardness Lower than HDPE Higher than Polyethylene
tensile strength Lower than HDPE Higher than Polyethylene
elongation Lower than HDPE Lower than the other kinds of PE
modulus of elasticity Lower than HDPE Higher than Polyethylene
melting point A bit lower than HDPE Lower than the other kinds of PE
max service temperature A bit lower than HDPE Higher than Polyethylene

Recyclability and Sustainability

In this part of the article, Recyclability and Sustainability of Polyethylene vs HDPE will be discussed. Recyclability of PE is not easy but it’s possible. The problem in the process of recyclability of PE is sorting but this problem doesn’t exist in the process of Recyclability of HDPE. The recyclability of HDPE is relatively easy to sort. Also, this point must also be stated that both materials have environmental burdens but can be recycled. However, real recycling rates are minimal.

Alternative Materials

Based on different applications, there are alternative materials for both PE and HDPE. For example, PEX, PP, LDPE, and PP are the alternative materials for the above items.

Conclusion

In this article, key differences between Polyethylene and HDPE sheets have been discussed. Both of these materials can be used for plastic products but HDPE has a stronger texture and can be consumed in harsh situations. Finally, you should choose the appropriate material based on specific needs.