The differences between EPS and XPS have led to different applications of these two grades of polystyrene in global industries. Expanded polystyrene, or EPS, is made from polystyrene beads; But extruded polystyrene, or XPS, is made from polystyrene crystal beads. EPS polystyrene has low water resistance, but XPS polystyrene is water-resistant and is used to insulate buildings and vehicles. These polystyrene grades have a variety of applications in global industries. In this PETROPROVIDERS article, join us to show you the differences between EPS and XPS.

Full introduction of EPS and XPS and their structure

Expanded polystyrene, or EPS, is made of styrene and pentane monomers. This material is used in construction and is known as polystyrene foams. This foam is also known as ionolite in global markets.

Extruded polystyrene or XPS is very durable and resistant to moisture and sunlight. This grade of polystyrene is more expensive than EPS, But it has more optimal structural features. In general, these polystyrene grades are used in various industries of plastics, foam, and insulation.

How is XPS polystyrene produced?

This material is produced by the extrusion process; In this process, the polystyrene resin is melted and poured into the mold. This mold causes the extrusion process and the polystyrene is dehumidified. This makes polystyrene very resistant to impact and water.

In the production process of XPS polystyrene, all standards set by global standard organizations must be observed. These standards include standards for workers, standards for polystyrene raw materials, and standards for safe use of XPS.

Production of expanded polystyrene

We know that polystyrenes are made from petroleum derivatives. EPS polystyrene is also produced by combining pentane foam solvent with petroleum derivatives, such as styrene. This polystyrene grade is produced in 3 stages; These stages are pre-expansion, stability, and molding and shaping.

To produce EPS polystyrene, the material is heated to a temperature above 90 ° C. Then, the solvent of this compound evaporates and the polystyrene swells about 50 times! It should be noted that to use EPS polystyrene, it should be stored in the factory for about 6 to 12 hours.

In the production process of EPS polystyrene, all standards set by international standard organizations must be observed. These standards include standards for workers, standards for polystyrene raw materials, and standards for the safe use of EPS. So we conclude that the standards set for EPS and XPS are the same.

Familiarity with the differences between EPS and XPS

EPS and XPS

EPS and XPS

These materials are different grades of polystyrene; The raw materials for the production of these grades are almost the same. One of the most important differences between EPS and XPS is how these polystyrenes are made. Polystyrene crystals are used to produce XPS polystyrene; But for the production of EPS polystyrene, polystyrene beads are used. It is interesting to know that EPS polystyrene does less harm to human health and the environment.

In addition, we examine the differences between EPS and XPS in 4 steps:

1. General definition of these two polystyrenes

EPS polystyrene is made from polystyrene beads and expands during production. This polystyrene has little resistance to water but is used as a building block.

XPS polystyrene is made of polystyrene crystals and is extruded during production. This polymer is water-resistant and is used as building insulation.

2. The raw material for the production of these polystyrenes

Extruded polystyrene is made from polystyrene crystals, but expanded polystyrene is made from solid polystyrene granules. In addition, it is used to produce extruded polystyrene, resins, and other chemicals.

3. Production methods of these polystyrenes

To produce EPS, polystyrene beads are heated to remove moisture; This causes the polystyrene to expand. XPS polystyrene is produced by removing the molten polystyrene material from special molds.

4. Impact of these polystyrenes on the environment

XPS polystyrene does the most damage to the environment; Therefore, this is considered the most dangerous grade of polystyrene. But expanded polystyrene does the least damage to the environment; Therefore, this is the safest grade of polystyrene.

Applications of polystyrene EPS and XPS

Comparison between XPS and EPS polystyrenes

Comparison between XPS and EPS polystyrenes

These polystyrenes are used as insulation in construction; These polymers are insulated against light and moisture and are lightweight. The use of these polystyrenes saves energy. These polystyrenes are insulating, but depending on their properties, they have various applications. In the following, we see 3 main parameters in the production of EPS and XPS:

Thermal conductivity in polystyrenes

Extruded polystyrene has very low thermal conductivity; This material is extruded and does not have a regular structure. Therefore, it can not easily transfer heat.

Expanded polystyrene has a regular and integrated structure; This polymer is widely used in buildings and industries. It transfers heat and conducts heat well.

Water absorption in XPS and EPS grades

Expanded polystyrene has low water resistance. This material is used in suspended ceilings and underground floors; Because if water enters it, it loses its important properties. In addition, increasing or decreasing the temperature can affect the structure of expanded polystyrene; Which makes this polystyrene not water-resistant.

Extruded polystyrene has a closed and dense structure; This grade of polystyrene is very resistant to water. In addition, temperature changes do not affect this feature of XPS polystyrene.

Compressive strength in EPS and XPS

Extruded polystyrene is much stronger and denser than EPS polystyrene. It has a dense structure and is resistant to pressure and pressure. Expanded polystyrene does not have a dense structure but is very large. For example, consider building blocks; These blocks are very large but very light. They break easily and are not resistant to high pressures.

A summary of the differences between EPS and XPS

Polystyrenes are produced in different grades; The 4 main and most widely used grades of polystyrene are: General Purpose polystyrene or GPPS, high impact polystyrene or HIPS, extruded polystyrene or XPS, and expanded polystyrene or EPS. In this article, we look at EPS and XPS polystyrene.

These polystyrene grades have a variety of applications in global industries. We know that expanded polystyrene, or EPS, is made from polystyrene beads; But extruded polystyrene, or XPS, is made from polystyrene crystal beads. EPS polystyrene has low water resistance, but XPS polystyrene is water-resistant and is used to insulate buildings and vehicles.

XPS polystyrenes are produced by molding methods and have a dense structure; These polystyrenes are used to produce durable equipment in the industry. XPS polystyrene is used to produce durable car parts and home appliances and building insulation.

But EPS polystyrene is produced by dehumidification and volume increase and has a much larger volume. EPS polystyrene is used as roof blocks in construction. In addition, it is used to insulate underground floors.

It should be noted that polystyrenes are generally produced from styrene monomers. These monomers have the molecular structure of (C8H8)n. What do you think about the differences between EPS and XPS? You can ask your questions in the comments section of our experts.


Is EPS polystyrene used to make building blocks?

Yes! EPS, also known as Ionolite in global markets, is used to make building blocks. This reduces the weight of the building and reduces the dead load of the building.

Does extruded polystyrene have a dense structure?

Yes! This polystyrene is produced by the molding method and has a regular and durable structure. XPS is used to produce durable parts in the industry.

What are the uses of polystyrene grades?

Different grades of polystyrene are used in different industries; For example, in medicine, engineering, home appliances, toys, and construction.

Are polystyrenes dangerous to human health and the environment?

Yes! The safest grade of polystyrene is expanded polystyrene. Extruded polystyrene is the most dangerous polystyrene for human health and the environment.