| 摘要 |
A solventless, flushless hand held impingement mixing and dispensing gun for dispensing controlled quantities of a controlled thermal insulation grade reactive chemical foam composition is provided. The dispenser gun preferably includes a unitary socket member mounted to the gun body having a receptacle portion for receiving an extended service life impingement mixing and dispensing module. A converter subassembly is provided to convert variable pressure and flow rate streams of the chemical components into regulated controlled pressure metered flow rate chemical component flows for introduction to the opposed sides of the impingement mixing dispenser gun. In accordance with the invention, the controlled pressure, metered flow rate streams of components are gradually repressurized prior to entering side orifices leading to the impingement mixing chamber of the dispenser module to provide balanced pressure approach needed to consistently and reproducibly provide high quality thermal insulation grade foams of known composition and physical properties. The extended service life dispenser module includes a valving assembly employing a valving rod of hardened tool steel and scraper members to effectively reduce or eliminate foam build up induced module failures. In the preferred embodiment, high powered, double acting multi-piston air cylinder activator for controlling movements of the valving rod and an air purge foam propulsion delivery system are also provided.
|
