A process air-assisted hot melt adhesive liquid dispensing system for dispensing heated hot melt adhesive liquid streams onto a substrate moving relative to the streams, the dispensing system comprising: a heated hot melt adhesive liquid manifold capable of supplying the heated hot melt adhesive liquid; a first dispensing module connected with said heated hot melt adhesive liquid manifold and configured to receive the heated hot melt adhesive liquid from the heated hot melt adhesive liquid manifold and to dispense the heated hot melt adhesive liquid as a stream onto the substrate moving relative to the stream and to dispense heated process air to impart a motion to the dispensed heated hot melt adhesive liquid stream; a second dispensing module connected with said heated hot melt adhesive liquid manifold and positioned in a side-by-side relationship with said first dispensing module across the width of the dispensing system, said second dispensing module configured to receive the heated hot melt adhesive liquid from the heated hot melt adhesive liquid manifold and to dispense the heated hot melt adhesive liquid as a stream onto the substrate moving relative to the stream and to dispense heated process air to impart a motion to the dispensed heated hot melt adhesive liquid stream; a first hot air manifold for receiving process air from a process air supply and for providing heated process air to said first dispensing module, and a second hot air manifold for receiving process air from said process air supply and for providing heated process air to said second dispensing module; characterized by a first flow control device positioned on the air inlet of said first hot air manifold operative to individually control a pressure and/or flow rate of the process air supplied to said first dispensing module; and a second flow control device positioned on the air inlet of said second hot air manifold operative to individually control a pressure and/or flow rate of the process air supplied to said second dispensing module so that the pressure and/or flow rate of the process air supplied to said first dispensing module differs from the pressure and/or flow rate of the process air supplied to said said second dispensing module. a heated hot melt adhesive liquid manifold capable of supplying the heated hot melt adhesive liquid; a first dispensing module connected with said heated hot melt adhesive liquid manifold and configured to receive the heated hot melt adhesive liquid from the heated hot melt adhesive liquid manifold and to dispense the heated hot melt adhesive liquid as a stream onto the substrate moving relative to the stream and to dispense heated process air to impart a motion to the dispensed heated hot melt adhesive liquid stream; a second dispensing module connected with said heated hot melt adhesive liquid manifold and positioned in a side-by-side relationship with said first dispensing module across the width of the dispensing system, said second dispensing module configured to receive the heated hot melt adhesive liquid from the heated hot melt adhesive liquid manifold and to dispense the heated hot melt adhesive liquid as a stream onto the substrate moving relative to the stream and to dispense heated process air to impart a motion to the dispensed heated hot melt adhesive liquid stream; a first hot air manifold for receiving process air from a process air supply and for providing heated process air to said first dispensing module, and a second hot air manifold for receiving process air from said process air supply and for providing heated process air to said second dispensing module;