Abstract: A method and apparatus for impregnating a fibrous base material with a varnish liquid, wherein the so-impregnated base material is substantially air free. A base material is passed under the surface of and through a supply of low-viscosity liquid such as to impregnate the base material with the low-viscosity liquid and displace air from the base material so as to provide a substantially air-free base material. The air-free base material is passed through an entrance for and into a syphon. An inert gas is supplied to the syphon so as to maintain an inert gas atmosphere therein sufficient to maintain the air-free condition of the base material. The air-free base material is then passed through an exit of the syphon and under the surface of and through a supply of varnish liquid sufficiently to displace the low-viscosity liquid from the air-free base material and impregnate the air-free base material with the varnish liquid.

Abstract: The present invention relates to a method and apparatus for drying a continuous material impregnated with a hardenable synthetic resin. The material is moved through at least one treating chamber within which radiant heat is applied onto the material and into which air is introduced in order to dilute the gaseous substances generated during the drying process and to at least partially exhaust them. The method is characterized in that heat is applied onto the continuous material in the form of radiant heat, and in that air is conducted in a controlled manner into the treating chamber as preheated fresh air and is guided to form a laminar air current that is substantially parallel to the continuous material as is possible. The installation has in the treating chamber (10, 11) at least one radiant heater (34, 36) and at least one fresh air inlet device (26) which is connected with a controlled fresh air supply device (40) and a heating device (38).