Triboelectric spray pistol for covering object with layer of powder has profiled annular channel for air-powder mixture with tapering central body at end

摘要

The spray pistol (10) has a housing (11) containing a core (32) held on a positioning ring (60) and a spacer ring (61). The inside diameter of the housing and the outside diameter of the core have matching sinusoidal profiles which define a narrow annular channel (46) which alternately increases and contracts in diameter. The powder is blown through the annular passage by a carrier gas, and becomes charged with static electricity by rubbing against the inner and outer walls of the channel which are made of PTFE (Polytetrafluoroethylene). The central body ends in a cone (36), leaving a circular nozzle (2).