Application device and system having helical-grooved bristles, and method of applying a product

A bristle for an application device for applying a cosmetic product, comprising:

• an outer surface having a length;
• and
• at least one helical groove extending over at least a portion of the length of the outer surface,
• wherein the bristle is configured to apply cosmetic product, and
• wherein the bristle is not yet attached to the application device.

An application device for applying a cosmetic product, comprising:

• a stem;
• and
• an application element on the stem, the application element including a plurality of bristles configured to apply a cosmetic product,
• wherein the plurality of bristles include at least one first hollow bristle having a surface with at least one helical groove extending over at least a portion of a length of the at least one first hollow bristle.

An application device for applying a cosmetic product, comprising:

• a stem having a longitudinal axis;
• and
• an application element on the stem, the application element including a plurality of bristles configured to apply a cosmetic product, the bristles extending from the stem in a direction substantially parallel with the longitudinal axis,
• wherein the plurality of bristles include at least one first bristle having a surface with at least one helical groove extending over at least a portion of a length of the at least one first bristle.

An application device for applying a cosmetic product, comprising:

• a stem;
• and
• an application element on the stem, the application element including a plurality of bristles configured to apply a cosmetic product, the plurality of bristles including at least one first bristle having a surface with at least one helical groove extending over at least a portion of a length of the at least one first bristle,
• wherein said at least one first bristle is twisted while in a softened state to form said at least one helical groove.

A method of making an application device for applying a cosmetic product, the method comprising:

• providing a plurality of wire branches;
• forming at least one thermoplastic bristle;
• twisting the at least one thermoplastic bristle, while the bristle is in a softened state, to form a helical groove;
• inserting a plurality of bristles between the branches, the plurality of bristles including the at least one twisted thermoplastic bristle;
• and
• twisting the branches to trap the plurality of bristles.

A method of making an application device for applying a cosmetic product, the method comprising:

• providing a plurality of wire branches;
• providing a plurality of bristles, wherein at least one of the bristles has a surface with at least one helical groove extending over at least a portion of a length of the at least one bristle;
• inserting said plurality of bristles between the wire branches, the plurality of inserted bristles including the at least one bristle having a surface with at least one helical groove;
• and
• twisting the branches to trap the plurality of bristles.