Mixing device with a pressure holding device

A mixing device comprising:

• at least one feed opening for at least one liquid;
• at least one further feed opening for at least one liquid curing or cross-linking agent, wherein the at least one liquid and/or the at least one liquid curing or cross-linking agent is or are mixed with a gas;
• a discharge opening for discharge of a mixture which can be produced in the mixing device and comprises the at least one liquid and the at least one liquid curing or cross-linking agent;
• and
• a pressure holding device for holding a predeterminable pressure which is greater than a pressure at which foaming-out of the gas in the mixing device occurs, wherein the pressure holding device includes an adjusting member arranged displaceably in the mixing device relative to the discharge opening, the adjusting member being configured to adjust a gap remaining between the adjusting member and the discharge opening, wherein the mixing device has a rotating agitator for mixing the at least one liquid and the at least one liquid curing or cross-linking agent, wherein the adjusting member is biased in a direction of the discharge opening by a force storage member, and wherein the agitator is adapted to be displaceable and forms the adjusting member,
• wherein the mixing device further comprises a mixing chamber, the mixing chamber having the discharge opening, the agitator being arranged within the mixing chamber, and
• wherein the agitator is configured to be displaced by a force of the at least one liquid and the at least one liquid curing or cross-linking agent in the mixing chamber applied directly to the agitator in a direction away from the discharge opening such that the force directly displaces the agitator away from the discharge opening so as to allow the mixture to be discharged through the discharge opening, and such that the force directly determines a size of the gap.