Application of thermal-cure materials

Abstract

A system for extruding or spraying high molecular weight thermal-cure thixotropic material, such as structural epoxy, includes apparatus for supplying the material at constant flow rate and heating the material to elevated temperature above ambient. An extrusion nozzle has an inlet manifold in which flow of heated material is divided into a least two parallel flow paths. An extrusion head includes a cavity having a dimension perpendicular to the paths and into which the flow paths open at one longitudinal edge of the cavity. Side and end walls of the cavity taper narrowingly in the opposite direction to a rectangular orifice extending along the inlet-remote edge of the cavity. A spray nozzle includes a inlet manifold having a ball-type valve at its outlet for imparting shear stresses to thixotropes in the material exiting the manifold outlet, and thereby reducing material viscosity during passage through a transition chamber which extends from the valve to a spray tip. The length of the transition chamber in the direction of material flow is sufficient to permit activated thixotropes in the material to decrease viscosity sufficiently for airless spraying at the spray tip.

Dependencies are inferred from the claim text.