摘要 |
To avoid the use of propellants which are harmful to the environment, a spraying apparatus employs a supply chamber which contains a material to be sprayed and includes a pressure chamber of variable volume. This pressure chamber of variable volume is connected to actuating structure which is provided for increasing the volume of the pressure chamber and thus for sucking material from the supply chamber into the pressure chamber. Since the material within the pressure chamber is kept under pressure by pressurizing structure, a nonreturn valve is disposed in the suction conduit leading to the supply chamber. Material can be sprayed with the aid of the spraying apparatus without any harmful effects on the environment, the use of conventional spraying heads being here possible.
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