Method of and apparatus for foaming a viscous material

摘要

The invention resides in mixing low-pressure gas in a viscous material. The flow of the gas can be easily controlled so that the dispersion of the mixing ratio of the viscous material to the gas may be confined within a small tolerance and fine bubbles may be uniformly distributed in the interior of the viscous material. The gas is mixed in the viscous material by means of a first pump 42, from which a mixture of the gas and the viscous material is delivered. Pressure is applied to the mixture by means of a second pump 51. The gas is distributed in the interior of the viscous material by allowing the mixture under pressure to pass through a conduit assembly 61. The viscous material is foamed when the mixture is discharged from a nozzle 73 through a discharge pipe 71.