Plastic closure device for a tubular bag

A plastic closure device (1) for a tubular bag from plastic or from a multilayered plastic film, wherein

• the plastic closure device (1) comprises at least one lower part (5) with a spout (7), a spout opening (8) and a flange (4) having a flange lower side and a peripheral region, and wherein
• an energy-introducing arrangement (10), which is connectable by means of ultrasonic welding to the plastic material or to the plastic film of the tubular bag, is arranged on the flange (4) on a face of the flange lower side (9), and wherein
• the energy-introducing arrangement (10) has at least one energy-conducting rib (12) which is arranged concentrically with the spout opening (8) in the peripheral region (11) of the flange (4),
• characterized in that
• a concentration rib (13), which runs centrically offset to the energy-introducing arrangement (10) and, with respect to the energy-conducting rib (12), protrudes higher from the face of the flange lower side (9) and is arranged immediately adjacent to the spout opening (8), is provided on the face of the flange lower side (9).