A packer machine for the production of pouches containing portions of a loose product, in particular of the tobacco industry; the packer machine comprises: a frame; a conveyor device configured to move two bands of wrapping materials along two parallel packing paths next to one another; a wrapping station arranged along each packing path and where the corresponding band of wrapping material is wrapped so as to form a tubular wrap having a longitudinal development; a longitudinal sealing unit to longitudinally seal each tubular wrap in the area of an overlapping section of the band of wrapping material; and a feeding device comprising two feeding ducts, around each of which a band of wrapping material is bent so as to form the corresponding tubular wrap and each of which is configured to feed, one after the other, the portions of loose product into the corresponding tubular wrap; wherein the longitudinal sealing unit comprises two first sealing elements, each configured to carry out a longitudinal sealing of the corresponding tubular wrap; the packer machine is characterized in that the longitudinal sealing unit comprises: two first movable assemblies, each of which is mounted on the frame so as to move along a pressing direction independently of the other first movable assembly and supports one single corresponding first sealing element; and two first actuator devices, each of which applies an elastic force directed along the pressing direction to a corresponding first movable assembly independently of the other first actuator device. a frame; a conveyor device configured to move two bands of wrapping materials along two parallel packing paths next to one another; a wrapping station arranged along each packing path and where the corresponding band of wrapping material is wrapped so as to form a tubular wrap having a longitudinal development; a longitudinal sealing unit to longitudinally seal each tubular wrap in the area of an overlapping section of the band of wrapping material; and a feeding device comprising two feeding ducts, around each of which a band of wrapping material is bent so as to form the corresponding tubular wrap and each of which is configured to feed, one after the other, the portions of loose product into the corresponding tubular wrap; wherein the longitudinal sealing unit comprises two first sealing elements, each configured to carry out a longitudinal sealing of the corresponding tubular wrap; the packer machine is characterized in that the longitudinal sealing unit comprises: two first movable assemblies, each of which is mounted on the frame so as to move along a pressing direction independently of the other first movable assembly and supports one single corresponding first sealing element; and two first actuator devices, each of which applies an elastic force directed along the pressing direction to a corresponding first movable assembly independently of the other first actuator device. two first movable assemblies, each of which is mounted on the frame so as to move along a pressing direction independently of the other first movable assembly and supports one single corresponding first sealing element; and two first actuator devices, each of which applies an elastic force directed along the pressing direction to a corresponding first movable assembly independently of the other first actuator device.