Seal for applicator for personal care compositions

A personal care applicator apparatus seal has a structural element formed of a first material and a sealing element formed of a second material softer or less rigid than the first material. The structural element may have a sidewall with upper and lower ends and inboard and outboard surfaces. The sealing element may be molded to the structural element and may include a first portion circumscribing the sidewall.

BACKGROUND OF THE INVENTION

The invention relates to personal care. More particularly, the invention relates to applicators for underarm antiperspirant and/or deodorant.

A well-developed art exists regarding dispenser/applicators for personal care products. One particular area involves applicators for solid or gel antiperspirant and/or deodorant compositions. Applicators for solid and gel compositions are typically thoroughly similar to each other, with a piston (platform) upwardly movable within a cylinder (barrel) to progressively drive the composition out the barrel upper end. Due to the relative lack of stiffness of many gels, dispensers for such gels commonly include foraminate screen-like applicator elements across the upper end of the barrel. Many solid products, instead have a removable molded seal inserted within the upper end. In manufacture, the seal may serve to mold the composition during a bottom fill operation. At the first use of the product, the end user extracts and discards the seal exposing the upper end of the composition. As molded by the seal, the upper end may have an ergonomically or ornamentally advantageous shape.

SUMMARY OF THE INVENTION

One aspect of the invention involves a personal care applicator apparatus seal having a structural element formed of a first material and a sealing element formed of a second material softer or less rigid than the first material. The structural element may have a sidewall with upper and lower ends and inboard and outboard surfaces. The sealing element may be molded to the structural element and may include a first portion circumscribing the sidewall.

DETAILED DESCRIPTION

FIG. 1shows an applicator20having a barrel22and a cover24in an installed position on a barrel neck26. The barrel has a sidewall27extending along a central longitudinal/vertical axis500from a bottom (base) end28to an upper end formed by a rim30. A seal32is secured across the barrel upper end. A platform or piston34supports the composition35and is, itself, supported by an actuating mechanism36(e.g., a screw-type elevator mechanism) having a user-engagable element such as a knob or wheel38. The wheel38may be rotated about the axis500for progressively raising the platform toward the barrel upper end so as to discharge the composition. The directions are relative and reference typical product orientations in shipping and display.

The seal32includes a dome40having a doubly concave lower surface or underside42molding a doubly convex upper surface44of the composition35. The dome40extends upward through a sidewall46having an outboard surface48in sealing contact with the inboard/interior surface50of the barrel near the upper end. The seal further includes a flange52at the upper end of the sidewall46having an underside engaging the rim30.

As heretofore described, the apparatus20may be of any of a wide variety of known or yet-developed configurations.FIG. 2, however, shows further details of the exemplary implementation of the seal32as a two-shot molded product. The seal includes a first element (e.g., a single piece)60principally serving a structural purpose and a second element (e.g., a single piece)62principally serving a sealing purpose. In exemplary manufacturing processes, the first piece60is initially molded in a first mold and then transferred to a second mold where the second piece62is overmolded to the first piece60. The first piece60may be formed of a relatively rigid material (e.g., polypropylene). The second piece62may be formed of a material that is relatively soft and/or flexible and/or has a relatively high stiction property (e.g., a thermoplastic elastomer (TPE)). The softness and/or stiction of the second piece62provide an advantageous engagement with the barrel inboard surface50. The compliance and stiction may help sealing and improve retention compared with a unitary seal formed from a more rigid and/or less sticky material. The first piece60includes a sidewall64having a lower end66and an upper end68. A dome70extends upward from the lower end66and may extend above the upper end68. A flange72extends outward from the sidewall at the upper end68. An outboard portion of the flange72forms the seal flange52.

The second piece62includes a first portion74circumscribing the sidewall64up to the underside of the flange72. A second portion76depends from the first portion74and below the sidewall lower end66. In the installed condition ofFIG. 1, the outboard surface of the first portion74is in sealing contact with the barrel inboard surface50and forms an outer portion of the seal sidewall. The outboard surface of the second portion76may be tapered to guide insertion during installation of the seal into the barrel.

In the exemplary seal, the first piece60is molded with a channel80in the inboard/interior surface or underside82of the dome70.FIG. 3shows the exemplary channel80as having a central enlarged portion84(e.g., of a circular planform). A pair of narrower straight portions86of the channel80extend from the enlarged portion84all the way to the sidewall lower end66. In the overmolding of the second piece62, the overmolding fills the channel80with a third portion88of the second piece62spanning between opposite ends of the second portion76.FIG. 3shows the seal having an exemplary ellipse-like planform namely, it has symmetry across medial and transverse vertical planes510and512(or lines when viewed in section or plan), is longer along one of those two directions, and has a continuously curving concave interior. If a true ellipse, the semi-minor axis and semi-major axis would fall along the planes510and512, respectively. In the exemplary implementation, the channel80may serve to guide a flow of the material forming the second piece62. For example, the material may be centrally introduced within the channel portion84and flow outward.

In the exemplary seal, the interior surface of the second piece third portion88and the interior surface of the second piece second portion76combine with the first piece interior surface82to form a smooth continuously curving doubly concave surface42for molding a complementary doubly convex upper surface44of the composition.

In the exemplary seal, the first piece60has a structural fin100extending along a major portion of the length of the dome70and protruding from its outboard surface. The fin100may serve one of several functions. First, during the molding of the first piece60, the fin may be an artifact of passageways in the mold for introducing the first material. This, for example, may leave the fin with gate artifacts102. Additionally, the fin100may provide the end user with an easy grasping portion to pull and pry off the seal.

One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the principles may be applied in a redesigning/engineering of any of a variety of existing applicators or in the design/engineering of yet new applicators. Accordingly, other embodiments are within the scope of the following claims.