Packaging machine to make an airtight wrapper comprising a wrapping sheet wrapped airtight around a structured assembly consisting of an organized group of smoking articles associated with a reinforcement insert , wherein said packaging machine comprises, in working sequence on one or more cyclical conveyor devices of the wheel or carousel type: - a structured assembly formation unit , comprising a formation pocket of the structured assembly with a chamber having a lower wall , an upper wall and lateral walls , configured to obtain a structured assembly consisting of the organized group of smoking articles partly wrapped by the reinforcement insert ; - a combination unit suitable to combine the structured assembly with said wrapping sheet , with or without a reusable closing label , obtaining an intermediate combination of the wrapping sheet and structured assembly ; - a welding station , in which a first folding of the wrapping sheet is made along the longitudinal axis around the structured assembly , with connected positioning welding of respective upper and lower edges of the wrapping sheet , defining a welded transverse edge , to obtain a manipulable whole ; - a wrapping sheet work unit comprising a gripping member , configured to work the manipulable whole , and comprising a folding station provided with a folding device with folder means, in which both transverse lateral flaps and also longitudinal lateral flaps of the wrapping sheet are folded, obtaining a pre-wrapper provided with longitudinal layers ; - a welding unit , having at least one welding station provided with welding devices , configured to work the pre-wrapper at least in relation to the longitudinal layers in order to complete their welding, obtaining a closed and sealed airtight wrapper ; the packaging machine being characterized in that said gripping member of the wrapper work unit has an upper plane subjected to elastic members acting toward a fixed base plane , the upper plane and the base plane being equipped to contain and position the intermediate combination . - a structured assembly formation unit , comprising a formation pocket of the structured assembly with a chamber having a lower wall , an upper wall and lateral walls , configured to obtain a structured assembly consisting of the organized group of smoking articles partly wrapped by the reinforcement insert ; - a combination unit suitable to combine the structured assembly with said wrapping sheet , with or without a reusable closing label , obtaining an intermediate combination of the wrapping sheet and structured assembly ; - a welding station , in which a first folding of the wrapping sheet is made along the longitudinal axis around the structured assembly , with connected positioning welding of respective upper and lower edges of the wrapping sheet , defining a welded transverse edge , to obtain a manipulable whole ; - a wrapping sheet work unit comprising a gripping member , configured to work the manipulable whole , and comprising a folding station provided with a folding device with folder means, in which both transverse lateral flaps and also longitudinal lateral flaps of the wrapping sheet are folded, obtaining a pre-wrapper provided with longitudinal layers ; - a welding unit , having at least one welding station provided with welding devices , configured to work the pre-wrapper at least in relation to the longitudinal layers in order to complete their welding, obtaining a closed and sealed airtight wrapper ; <EOS>