Closure assembly with a cap having corrugated wings

A closure assembly for a container, comprising:

• a spout having a spout body that is injection moulded from a plastic material, the spout body having, an attachment portion configured to be sealed or sealed to a container, a tubular neck, wherein a product passage extends through the attachment portion and the tubular neck of the spout, the tubular neck having a vertical main axis and forming a mouth at a top end of the product passage allowing dispensing of a product from the container, the tubular neck having an exterior side;
• a rotational cap that is injection moulded from a plastic material and that is secured on or is to be secured on the tubular neck of the spout in a closed position of the rotational cap on the tubular neck such that the rotational cap seals the product passage, and removal of the rotational cap from the tubular neck of the spout by a user, tewill open the product passage, wherein the rotational cap is adapted to be manually rotated in an opening direction from the closed position to an open position;
• wherein the rotational cap comprises a top wall and a downward depending skirt, the skirt having an interior side, an exterior side, and a lower edge remote from the top wall,
• wherein the rotational cap has two wings, which are integrally moulded from a plastic material and extend vertically and outward in a lateral direction over a wing length in substantially opposite directions from an inner end to a tip,
• wherein the two wings each have a base portion, a center portion, a top portion, a front side and a back sides, wherein the front side is opposite the back side, wherein the base portion is located below the center portion and the top portion is located above the center portion,
• wherein at least the center portion of each wing is connected to the skirt of the rotational cap,
• wherein the base portion and the top portion of each wing are substantially flat,
• and wherein the center portion of each wing comprises at least one corrugation that extends along a part of the length of the wing and forms a groove on both sides of the wing, which the grooves of the corrugation, as seen from a sideways view of the wing, together form an alternating waveform.