Apparatus for welding and discharging sacs containing sterilized loose products, wherein said apparatus comprises: - a support frame comprising a lower frame and an upper frame; - a lower unit comprising said lower frame; - an upper unit comprising said upper frame; - an engagement device configured to selectively move the upper unit with respect to the lower unit in a linear direction of movement to a working position suitable to receive the loose products and to bring the upper unit back into an inactive position, in the direction opposite the direction of movement, when the reception of the loose products is finished; - a sac store; wherein said lower frame is configured to support said engagement device and said sac store; - a discharge device to discharge the sterilized loose products; - at least one removal device configured to remove one sac at a time from the sac store; - a sac-stretching unit comprising two grippers configured to grip and stretch from both sides a sac removed by the removal device and respective gripper actuators configured at least to move the grippers towards and away from the sac in a direction transverse to the direction of movement; - at least one positioning device configured to take the sac-stretching unit into position and to dispose a respective sac in cooperation with the discharge device; - at least one sac-opening device configured to selectively open the sac located in cooperation with the discharge device; - at least one welding device configured to weld said sac; - at least one transport conveyor configured to automatically discharge the welded sac; wherein said upper frame is configured to support said removal device, said sac-stretching unit, said positioning device, said sac-opening device, said discharge device, said welding device and said transport conveyor. - a support frame comprising a lower frame and an upper frame; - a lower unit comprising said lower frame; - an upper unit comprising said upper frame; - an engagement device configured to selectively move the upper unit with respect to the lower unit in a linear direction of movement to a working position suitable to receive the loose products and to bring the upper unit back into an inactive position, in the direction opposite the direction of movement, when the reception of the loose products is finished; - a sac store; - a discharge device to discharge the sterilized loose products; - at least one removal device configured to remove one sac at a time from the sac store; - a sac-stretching unit comprising two grippers configured to grip and stretch from both sides a sac removed by the removal device and respective gripper actuators configured at least to move the grippers towards and away from the sac in a direction transverse to the direction of movement; - at least one positioning device configured to take the sac-stretching unit into position and to dispose a respective sac in cooperation with the discharge device; - at least one sac-opening device configured to selectively open the sac located in cooperation with the discharge device; - at least one welding device configured to weld said sac; - at least one transport conveyor configured to automatically discharge the welded sac;