| 摘要 |
<p>Polymer materials having viscosities ranging from 1,000 up to above 1,000,000 centipoises are mixed with a gaseous foaming agent to provide a polymer/gas solution under pressure such that when the polymer/gas solution is subsequently dispensed at atmospheric pressure the gas is released from the solution and becomes entrapped in the polymer material to form a homogeneous polymer foam. Mixing is accomplished by a disc mixer (14) which includes a tubular housing (22), a pair of substantially parallel, oppositely driven shafts (24,26) extending along the length of the housing (22), and a series of spaced, solid, flat discs (48) fixedly mounted on each shaft (24,26) perpendicular to the axis thereof. The discs (48) on one shaft (24) intermesh with the discs (48) on the other shaft (26) to form a series of compartments spaced along the length of the mixer (14). The foaming gas enters into solution in the polymer in the compartments between the rotating discs (48). The process is characterized in that relatively high viscosity polymer materials are foamed with relatively low horsepower requirements, high throughput and low temperature rise of the polymer from conversion of the work of mixing to heat.</p> |
