1. 1. Basic introduction
Rigid polyurethane foam
(pur) (1) has low thermal conductivity. Among the existing thermal insulation materials, the thermal conductivity of this product is the lowest; (2) The operating temperature is high; (3) High compressive strength; ⑷ Good chemical stability and acid and alkali resistance. QB/T3806- 1999
Rigid polyurethane foam for building thermal insulation
1.2. Main technical performance and implementation standard of rigid polyurethane foam project
Density (kg/m) 40~60 ~ 60
Thermal conductivity ((w/m k)) ≤ 0.027
Moisture permeability coefficient ng/(m s pa) ≤ 6.5.
Water absorption (volume/volume) (%) 4 ~ 3
Working temperature range (℃) ≤ 100
Main features and key points of design and selection of 1.3
(1) has a high service temperature, generally reaching 100℃. After adding temperature-resistant auxiliary materials, the service temperature can reach 120℃. (2) The foaming agent in polyurethane will be constantly replaced with the air in the environment due to diffusion, resulting in a gradual increase in thermal conductivity with time. In order to overcome this shortcoming, the airtight material such as profiled steel plate can be used as the surface layer for sealing, so as to limit or slow down this displacement. (3) On-site spraying polyurethane foam has the advantages of high service temperature, high compressibility and simple construction, and is more suitable for roof insulation than EPS board. (4) Reliable waterproof and moisture-proof measures should be taken when it is used for pipeline (especially underground pipeline) and roof insulation. At the same time, we should consider that the thermal conductivity will increase with time, and try to use sealing material as a protective layer. (5) Because of its high temperature, it is mostly used for heat preservation of heating pipes. (6) The flue gas temperature is low, which will produce a lot of smoke and toxic gases when it meets fire, so it is not suitable for internal thermal insulation materials. (7) Although the water absorption rate is low, it can never be used as a waterproof material as a thermal insulation material.