Device for spreading a substance onto a moving web of material

In a machine for the treatment of a moving web of material, comprising a support roller supporting said web,

• a device for spreading a substance onto said moving web of material, comprising:
• an extrusion head arranged near said web opposite said support roller;
• in said extrusion head a delivery slit for supplying the substance to be spread, said delivery slit having an outlet facing said web;
• in said delivery slit a profiled recess arranged at a predetermined distance from said outlet and extending in parallel relationship with said outlet over the entire width of said extrusion head;
• limiting blade segments inserted into said delivery slit in predetermined regions thereof in register with regions of the device in which no spreading is wanted, said limiting blade segments having a thickness corresponding to the thickness of said delivery slit and a height corresponding to the distance between said profiled recess and said outlet of the delivery slit, and having at the inner end a retaining head whose profile corresponds at least in part to the profile of said recess;
• a support member applied to said extrusion head near the outlet of said delivery slit;
• and a rotating bar carried by said support member outside said delivery slit near the outlet thereof, said rotating bar contacting said moving web opposite said support roller for spreading thereon the substance delivered by said outlet;
• said rotating bar having its outer surface contacting in operative relationship said web only in register with those regions of the delivery slit which are free from limiting blade segments.