Powder may be encapsulated in well-defined mass lots (or shots) within a roll of paper tape. The tape can be wound onto a roll and then passed through a pressure chamber that connects directly to the spray torch. The operational concept is that a spike pierces each packet of powder so that its contents are then punched into the thermal source by a stream of compressed gas. Various valves and interconnected chambers are then synchronized so that three shots of material are expelled into the TS steam per second. This method has in fact only been used for one TS system (i.e. a detonation gun) and is considered awkward in operation.
Image – Powder-feeding system: encapsulated shots.
This information is from ASM Handbooks Online, Vol. 5A: Thermal Spray Technology, Coating Structures, Properties, and Materials. To find this information (subscription required), click on the link below and scroll down to Figure 21.
