Abstract: Treatment apparatus has up-stream rollers 2 and down-stream rollers 3. Between the rollers are provided a pair of upper and lower treatment zone plates 4,5, spaced by a gap 6 through which sheet material to be treated can be passed. The plates have grooves 9 occupied by strips defining up- and down-stream even slots 14,15 for flow of treatment liquid into the gap 6. The ends of the upper plate 4 are smoothly rounded at 37. When sheet material is fed into the gap flow occurs on top of the sheet and up over the rounded edge of the plate. Then it flows sideways off the top of the plate without flowing over the top of the upper rollers.

Abstract: A machine for processing of a web through a process tank containing process liquid and a tank containing wash water has in each tank an upper submerged guide and a pair of lower submerged guides, whereby the web passes on a sinusoidal path through the tank. Four drying guides are provided one above the over above the down-stream end of the processing tank. The guides have outlet slits 18 facing alternately up-stream and down-stream. A blower is provided for blowing air into the guides and out through the slits onto the web passing sinuously around the ducts. It acts both as a bearing medium holding the web off the surfaces of the ducts and as a drying medium.

Abstract: Treatment apparatus has up-stream rollers 2 and down-stream rollers 3. Between the rollers are provided a pair of upper and lower treatment zone plates 4,5, spaced by a gap 6 through which sheet material to be treated can be passed. The plates have grooves 9 occupied by strips defining up- and down-stream even slots 14,15 for flow of treatment liquid into the gap 6. The ends of the upper plate 4 are smoothly rounded at 37. When sheet material is fed into the gap flow occurs on top of the sheet and up over the rounded edge of the plate. Thence it flows sideways off the top of the plate without flowing over the top of the upper rollers.

Abstract: Air knives 109,110 for a solder leveller each comprises an air knife tip 111. The tip has a nozzle slot 114, up-and down-stream lands 119, 115, which are parallel to a back surface 130. Beyond the lands, the tip has a wing 120 and a lip 117, with a wing face 121 and a lip face 118 Downstream from the lip face 118, an extension 131 is provided. This is set back 132 sufficiently far from the land 115 to have no fluid dynamic effect on a board being processed. The geometry of the wing and tip faces 121, 118 is such that the bulk of air from the slit passes over the wing and back towards solder applicators, carrying with it excess solder. The tips 111, that is an upper and a lower one for upper and lower air knives are mounted on plenum chambers 133 via their back datum surfaces 130. The plenum chambers are mounted in the solder leveller with the back surfaces 130 parallel to the board path.