| 摘要 |
Mechanical insulation foam can serve as an insulating and decorative building layer. The foam is formed from suitable materials on a building site and is applied directly to building faces intended to be thermally insulated or modified in their appearance. To form a mechanical foam, appropriate raw materials and equipment are needed. Basic raw materials may be usual building materials like cement, gypsum, lime, various dry premixed plasters, water dispersions of polymeric binders (polyacrylates, etc.), various fine-grained fillers (inorganic powder, polymeric powder, wood powder, etc.), foaming agents (tensides, soaps, polysiloxanes, etc.) and water. Machine equipment consists of a mechanical foam formation equipment and equipment for its application onto building faces. To form a mechanical foam, as great number of small air bubbles as possible should be mixed into water dispersion of binder and additives. A foaming agent must provide adequate surface tension on the boundary layer between air bubbles and water dispersion. Adjustment and keeping of proper conditions for formation and stability of a mechanical foam depends also on rheological properties of water dispersion. A binder shall enable the applied mechanical foam to harden quickly enough on a building surface. The speed of hardening of the mechanical foam shall be greater than the speed of decay of its stability. Fillers and various other additives shall be added according to the basic binding material and decorative requirements. A stable mechanical foam resembles whipped cream used on fancy cakes by its appearance. The mechanical foam formation procedure and its application to a building face also do not differ essentially in principle from the whipped cream and its application to a fancy cake. After final hardening the mechanical insulation foam does not differ essentially also from chemically foamed porous concrete insulating plates (such as Ytong, for example). Due to the simplicity of its manufacturing procedure and ease of application to building |
