The performance and application of two new types of roofing waterproof materials

Hard polyurethane foam

The rigid foamed polyurethane is used in roofing projects, both for waterproofing and for heat preservation. Among all building insulation materials, foamed polyurethane is one of the materials with the lowest thermal conductivity. Its performance characteristics are: the internal structure of the sealing rate ≥ 92%, the foamed surface layer to form a smooth film, the closed cell rate is close to 100%, has a very high hydrophobicity; density of 40kg/m3 when the compression Strength >1.5mpa; with certain elasticity, elongation of 10%; good adhesion to metal, concrete, masonry, wood, glass. Its use features are: rigid foaming polyurethane uses on-site spray foaming and composite prefabricated board two methods. Spray foaming uses two components to join together at the time of injection and immediately reacts to produce foamed polyurethane. This method can be used in large quantities for on-site foaming. In the case of unsuitable for on-site foaming, prefabricated composite panels can be used, and gaps between the panels can be filled with foam guns and the effect is also very good.

Use range: rigid foamed polyurethane can be used in a variety of roofing projects. The bases used are mainly concrete cast-in-place slabs, precast concrete slabs and cement mortar screeds. There is a single-site foaming polyurethane, both as a waterproof layer, also as a thermal insulation layer; some as a waterproof layer, but also a thermal insulation layer, composite with waterproof membrane or waterproof coating; also use waterproof coating, waterproof membrane, Three types of foamed polyurethanes are jointly compounded to form a waterproof insulation layer. The sloping roofing practice is mainly to foam on the base concrete and then to tile the roof. The fundamental solution to the problem of thermal insulation in flat roofs is to use structural sloping, especially cast-in-place concrete roofing, in the design of roofing structures using rigid polyurethane foam.

Biaxially oriented polyvinyl chloride board

Biaxial stretching refers to the fact that at a given high temperature, the polyvinyl chloride sheet is stretched by 100% in both directions perpendicular to each other, so that the molecular chains of the polyvinyl chloride sheet are re-arranged in order to make the molecular cohesive force thereof large. Increases significantly improve the physical and mechanical properties of the board. Before stretching, the UV protection layer and the PVC layer are co-extruded, and then the biaxial stretching process is performed. This ensures that the UV protection layer is evenly and densely covered on the surface of the sheet, and is completely integrated with the PVC layer. . This process overcomes the weaknesses of ordinary PVC sheets in terms of strength and durability, and becomes a high-quality material. Its performance characteristics are: strong impact resistance, more than twice that of ordinary PVC sheets; resistance to hail strength test, stone diameter 30mm, not broken; 50kg heavy sandbag test, able to withstand height 120cm (thickness 1.2mm); Used at low temperature of -30°C; light transmission performance up to 90% (80% after 10 years); 10 years impact resistance >900kj/m2; flexural impact resistance >500kj/m2 Corrosion resistance is strong, not affected by the atmosphere, rain and snow and chemical reagents, will not be phagocytosis by biological species; flame retardant performance is good, is a building materials flame retardant a material.

Scope of application: The biaxially-oriented polyvinyl chloride board is divided into two kinds of colored and colorless, which can be used for waterproofing of large public buildings, industrial plants, stadiums, flower planting and breeding greenhouses, shelters, pavilions and other roofs; also available Indoor screens, soundproof curtain walls, safety shelters, walls, guardrails, partition walls, site safety barriers and tunnels.