Performance Comparison of EPS and XPS

The current insulation board exterior insulation and finish systems are mainly: EPS board external wall insulation system, XPS board external wall insulation system,
    First, two kinds of system performance comparison
    1, thermal insulation properties:
The same thickness of the EPS and XPS insulation is gradually rising. EPS is 0.041, XPS is 0.030. Therefore, to achieve the same insulating effect of the case, XPS boards are thinner than the thickness of EPS board, but the price of a pure sheet of your XPS panels on the EPS board. If the full account of technology and building height, the price per square meter XPS but more expensive than EPS.
    For the heat insulation is concerned, the key is how thermal inertia index D, D, and the heat storage coefficient is proportional to the value. However, the system as a whole, 200mm concrete of the accumulator has been large enough, coupled with external thermal insulation layer, fully meet the requirements of energy conservation. This is also the national norms require an integrated wall heat storage coefficient of thermal conductivity and at the same time meet the requirements of reason. The current EPS or XPS thin plaster systems fully meet the requirements.
    2, intensity:
Point out here that the intensity should be the tensile strength and bulk density and tensile strength of polystyrene board has absolute relationship between the average tensile strength of EPS bulk density 18Kg/m3 for 110 ~ 120KPa, 20Kg/m3 bulk density in the 140KPa around. XPS of the bulk density of the normal from the 25Kg ~ 45Kg, intensity from 150KPa ~ 700KPa or higher. (Prerequisite is to meet the thermal conductivity coefficient of 0.03 or so).
    XPS intensity of the current board 200KPa-250KPa, this strength can not do many domestic XPS board, EPS plate in 100KPa below, in an increasingly rich facade decorations, as well as typhoons in coastal areas often have happened, the strength appeared to be very important, especially for the wall tiling or high-level, the two kinds of plates are required to reinforce or fixed pieces of auxiliary fixed. Tile of the drawing is greater than 400KPa, even the XPS can not bear, the solution is through expansion anchor bolt steel mesh to the grassroots level to solve, so that three-dimensional space can be distributed to the tensile stress, so as long as the anchor properly, drawing certainly undermine the Department composite steel mesh anti-cracking mortar layer, not a big problem.
    EPS, compared with, XPS board strength must be high, but compared with the EPS board due to the nature of the XPS (brittle), and paste larger, the external finishes of the possibility of cracking the high level, especially the paint surface. Flexibility is the material issues, take wiping surface, the perceptual usually Plastering batch rubbed polystyrene board, and then see to what extent the polystyrene plate bending, cracks do not Plastering, flexibility and good, then turn a few laps were will not be cracking. Similar to the waterproof material in the ductility index. However, the material itself, the flexibility EPS is superior to XPS.
    3, weather resistance:
    Weathering refers to the insulation system to the outside world climate change adaptability refers to the different climatic conditions, the system��s overall stability, thermal insulation effect of whether there is a series of changes in quality-related problems. Weathering is the insulation system, a very important indicator.
As the EPS board and have a higher water absorption compared to XPS, so his durability is better than XPS system. But the EPS board better scalability than the XPS panels can overcome some shortcomings. But as the system is concerned, a thin outer layer of plaster system, wiping rubber surface of the water itself has a certain capacity. In addition to the construction process, the integrity of the two kinds of systems can be waterproof. Rainwater contacts the outer wall and the wall is a vertical surface, as long as the surface layer of mortar is not cracking, water is no problem.
In addition wind pressure resistance performance is also weathering an important one, because the system, the more resistance to wind pressure capacity of the cavity, the worse. Therefore, the emphasis will depend on the thermal insulation system with the grass roots the size of the bond area. This XPS systems, and EPS systems are non-existent problem.
    4, air permeability:
    Air permeability and water absorption are two different issues! Air molecules and water molecules vary greatly in size! Of course, there are breathable impervious argument. There experiment can illustrate this point. An analogy, in Shenzhen. Put block cookies on the outside, you do not go crackers on the watering, one day, cookies will melt, because it is absorbent, while the absorption of water is in the air instead of liquid water, water.
The current insulation system, which products do not dare claim to both the permeability of the product is good, and good thermal conductivity, water resistance and good is not absorbent, good for a full accounting. Because it was contrary to a number of indicators, but also pay attention to the construction process permeability of water in the wet after permeability, as well as after the completion of the ventilation system.
On the material itself, EPS is much better than the XPS. XPS is almost no air permeability, the larger temperature difference between indoor and outdoor areas is very easy to make water vapor condensation on both sides of the plate.
    5, bond strength:
    For thin plaster systems, this indicator will directly affect the use of plates, EPS board low strength and shear strength also low, plate destruction, there may not be out of the bonding surface, but the direct destruction of the middle plate , XPS and good strength properties even feel relieved. 0.1MPa tensile strength is equivalent to saying that every square meter of the tensile strength is 10 tons of force, which is very large.
But the XPS system, there is an Achilles heel: Interface finish high, if not a very high emulsion polymer interface to deal with it is very difficult to do is stick, but the number of manufacturers willing to do substantial increase in costs?
    6, surface roughness
    XPS so difficult to ensure flatness of the external walls, the outside is difficult to conceal slab cracking mortar, especially in the curved section. XPS to do wall insulation layer of paint finishes, then made the board is impossible to do! Material determines the surface (paint finishes) is not smooth. Plate shadow in the sun and the shadow of Anchor is obvious. So you can say for sure that, including domestic Now, Dow, Owens Corning, including home-made extruded plate included, are not suitable for external wall finishes is the coating insulation board! Extruded plate construction technique is the need to wrench all the nap, brushing interface agent later mortar paste, and dried and then hit the firmware rivet reinforced, so when you play Mao extruded skin panels, board of the affected edge effects have been deformed, and when you are brushing interface fluid (liquid) is more distorted. Therefore, it is impossible for the plane wall control and deal with. Unlike EPS, as can be polished. As for the strength, aging resistance, permeability, and so on defects.