Today's KNOWLEDGE Share : XPS Vs EPS

Today's KNOWLEDGE Share

Extruded Polystyrene XPS Vs EPS Expanded Polystyrene

Physical Properties:

1. Thermal Conductivity

Both materials offer excellent thermal insulation properties, but XPS generally outperforms EPS in this regard. XPS typically has a lower thermal conductivity (λ-value) of 0.029-0.036 W/mK, compared to EPS’s range of 0.032-0.040 W/mK. This means that, for the same thickness, XPS provides slightly better insulation.

2. R-Value Comparison

When it comes to thermal performance, both EPS and XPS offer impressive insulation values, but their R-values differ significantly.

The R-value measures a material’s resistance to heat flow; the higher the R-value, the better the insulation.

EPS typically has an R-value ranging from 3.6 to 4.2 per inch, depending on the density and specific formulation. This makes it an effective choice for various insulation applications, especially where cost is a concern.

XPS, however, boasts a higher R-value, generally around 5.0 per inch. This superior thermal resistance makes XPS ideal for applications where space is limited, and maximum insulation is required.

3. Moisture Resistance

Moisture resistance is a critical factor in choosing insulation materials, particularly in areas prone to high humidity or water exposure.

EPS Moisture Absorption

EPS has a higher moisture absorption rate compared to XPS. Although it is resistant to water, prolonged exposure can lead to a decrease in thermal performance. To mitigate this issue, proper installation and protective barriers are essential when using EPS in moisture-prone environments.

XPS Moisture Resistance

XPS excels in moisture resistance due to its closed-cell structure, which significantly reduces water absorption. This characteristic makes XPS an excellent choice for applications such as below-grade insulation and areas exposed to water, such as foundation walls and under concrete slabs.

4. Compressive Strength

The compressive strength of insulation materials is crucial for applications where structural support is necessary.

EPS Compressive Strength

EPS offers decent compressive strength, typically ranging from 10 to 30 psi, depending on the density of the foam. While suitable for many applications, it may not provide the necessary support in high-load situations.

XPS Compressive Strength

XPS outperforms EPS in terms of compressive strength, with values often exceeding 25 psi and reaching up to 60 psi for high-density formulations. This makes XPS ideal for use in demanding applications, such as under heavy loads in commercial buildings and infrastructure projects.

5. Density

XPS typically boasts a higher density than EPS, ranging from 28 to 45 kg/m³. This increased density translates to superior compressive strength, making XPS an excellent choice for load-bearing applications. EPS, with its lower density of 15 to 35 kg/m³, offers a lighter weight option but sacrifices some strength in the process.

source:Shobeir shimi