| 摘要 |
Directionally flexibilized, rigid closed-cell plastic foam sheets with improved properties particularly desirable for low temperature and cryogenic insulation are prepared by mechanical compression of freshly expanded closed-cell thermoplastic foams having a density of 20-100 kg/m<3>, having a bulk density of 20-100 kg. an anisotropic cell structure oriented in the Y-axial (thickness) direction with a y-axial cell size of 0.05 to 1.00 mm and a Y- axial compressive strength of at least 1.8 kg/cm<2> which is flexibilized within 0.1 to 240 hours of expansion to give a flexibilized foam with improved elongation, workability, crack resistance and water vapor barrier properties, and having anisotropically wrinkled cell walls and specified cell sizes as measured in 3 axial directions. |
