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A new name among vinyl resins
CURRENT
TOPICS.
A New Name Among Vinyl Resins.-M. SCOTT MOULTON. (Modern Vol. 21, No. IO.) Coincident with the development of a series of vinyl-vinylidene chloride copolymers, the name “Geon ” has been selected to designate an entire family of polyvinyl resins presently including the new copolymers as well as two grades of polyvinyl chloride. These copolymers were developed specifically to furnish resins combining the unusual stability and chemical resistance of polyvinyl chloride with the solubility and plasticity essential to certain processing operations, particularly in the coating field. These copolymers round out the uses of vinyls to the point where they encompass nearly all possible methods of resin application. Compounded Geon resins can be calendered, extruded, molded, cast or applied to supplementary materials for extended applications by means of such methods as spreading or dipping, or by the use of various processes of impregnation. R. H. 0.
Plastics,
News-Record, Vol. 132, No. Refrigeration Aids Slime Control. -(Engineering 24.) Dehumidifying by cooling and then warming the air to the temperature of the surrounding structure has been found effective in reducing slime accumulations in the inspection galleries of mass concrete structures. S. 0. Harper reports this new use for refrigeration developed in connection with the operation and maintenance of large dams and power plants of the Bureau of Reclamation, of which he is chief engineer. During the humid season of the year, the normal temperatures of the galleries and of mechanical and electrical equipment within the dams are appreciably below the dew point temperature of the outside air. This leads to the condensation of moisture from air entering the galleries and its deposits upon the walls of the galleries and the mechanical and electrical equipment. Moisture accelerates the growth of microscopic organisms and the formation of slime upon the walls of the galleries and causes the rapid deterioration of paint films with the consequent corrosion of metal surfaces. Also, moisture permeates and causes the breakdown of electrical insulation on wiring and equipment. Since it is essential that a reasonable movement of air be maintained through the galleries, the complete solution to the problem of moisture condensation lies in the dehumidification of the ventilating air before it is introduced into the galleries. One installation of equipment for this purpose is in progress at the Marshall Ford Dam in Texas, and a second is projected for the Grand Coulee Dam in Washington. The equipment is designed to perform the following functions: (a) Filter the outside air. (b) Pre-cool the air in extended surface coils with reservoir water. moisture is removed from the air by condensation in these coils. 152
Some
TOPICS.
A New Name Among Vinyl Resins.-M. SCOTT MOULTON. (Modern Vol. 21, No. IO.) Coincident with the development of a series of vinyl-vinylidene chloride copolymers, the name “Geon ” has been selected to designate an entire family of polyvinyl resins presently including the new copolymers as well as two grades of polyvinyl chloride. These copolymers were developed specifically to furnish resins combining the unusual stability and chemical resistance of polyvinyl chloride with the solubility and plasticity essential to certain processing operations, particularly in the coating field. These copolymers round out the uses of vinyls to the point where they encompass nearly all possible methods of resin application. Compounded Geon resins can be calendered, extruded, molded, cast or applied to supplementary materials for extended applications by means of such methods as spreading or dipping, or by the use of various processes of impregnation. R. H. 0.
Plastics,
News-Record, Vol. 132, No. Refrigeration Aids Slime Control. -(Engineering 24.) Dehumidifying by cooling and then warming the air to the temperature of the surrounding structure has been found effective in reducing slime accumulations in the inspection galleries of mass concrete structures. S. 0. Harper reports this new use for refrigeration developed in connection with the operation and maintenance of large dams and power plants of the Bureau of Reclamation, of which he is chief engineer. During the humid season of the year, the normal temperatures of the galleries and of mechanical and electrical equipment within the dams are appreciably below the dew point temperature of the outside air. This leads to the condensation of moisture from air entering the galleries and its deposits upon the walls of the galleries and the mechanical and electrical equipment. Moisture accelerates the growth of microscopic organisms and the formation of slime upon the walls of the galleries and causes the rapid deterioration of paint films with the consequent corrosion of metal surfaces. Also, moisture permeates and causes the breakdown of electrical insulation on wiring and equipment. Since it is essential that a reasonable movement of air be maintained through the galleries, the complete solution to the problem of moisture condensation lies in the dehumidification of the ventilating air before it is introduced into the galleries. One installation of equipment for this purpose is in progress at the Marshall Ford Dam in Texas, and a second is projected for the Grand Coulee Dam in Washington. The equipment is designed to perform the following functions: (a) Filter the outside air. (b) Pre-cool the air in extended surface coils with reservoir water. moisture is removed from the air by condensation in these coils. 152
Some