Continuous gluing process of an adhesive compostion with a gluing nozzle having an extrusion die with a relaxation volume

A continuous gluing process for continuous gluing of a film of substrate by making use of a gluing nozzle comprising an extrusion die for extrusion of an adhesive composition over a predetermined width, the extrusion die comprising a lower lip and an upper lip, the upper and lower lips extending parallel to one another so as to form a transverse channel for the longitudinal flow of the adhesive composition, the transverse channel extending longitudinally between:

• a supply opening for supplying the adhesive composition;
• and
• an extrusion outlet for extrusion of the adhesive composition;
• the channel comprising a concave volume for relaxation of the adhesive composition between the supply opening and the extrusion outlet;
• and
• the process comprising:
• the provision of a supply of an adhesive composition to the gluing nozzle or the gluing system with a flow rate, the adhesive composition having a viscous behaviour with a relaxation time period;
• the extrusion of the adhesive composition by making use of the gluing nozzle, the relaxation volume of the die of the gluing nozzle being greater than the product of the relaxation time period and the flow rate of the supply of the adhesive composition.