COSMETIC PAN STRUCTURES AND MOLDING METHODS

Abstract: A method of forming a cosmetic product by back injection molding is disclosed. The method includes: providing a pan having at least one removable wall therein, the wall forming at least two compartments in the pan, each of the at least two compartments having apertures therein; injecting a first liquid cosmetic through a first of the apertures; injecting a second liquid cosmetic through a second of the apertures, wherein the first and second liquid cosmetics may be the same or different; setting the first and second liquid cosmetics without compaction; and removing the at least one removable wall. Pans having breakaway or removale spacer walls, and pans having frame-like structures with open bottom panels are also disclosed. Methods and devices for setting and forming the surfaces of the resulting cosmetics are also disclosed.

Description: COSMETIC PAN STRUCTURES AND MOLDING METHODS This application is a continuation-in-part of copending U.S. patent applications Serial Nos. 08/853,992 for Cosmetic Compositions Containing Smectite Gels, filed May 9, 1997, and 09/001 ,392 for a Back Injection Molding Process, filed December 31 , 1997. The present invention relates generally to molding methods and pan structures used to make cosmetics, preferably by back injection molding processes. More particularly, the present invention relates to methods of molding multi-phase cosmetics in pans, preferably using back injection molding, and the pan structures used therein. The molded cosmetics can include two or more colors of the same cosmetic in a single pan, or can include two different cosmetics in a single pan. Furthermore, they can include two or more surface levels of cosmetic. BACKGROUND OF THE INVENTION Back injection molding processes are known in the cosmetic art. Typically, a cosmetic slurry or other flowable base is injected through a hole in the back, or bottom (which may be oriented upwards), of a metal pan structure to form a finished cosmetic product. Alternatively, a cosmetic base can be metered into a pan through its open top. Pans can be made of other materials, such as plastics, and can have a variety of shapes, such as square, oval or free-form. Pans are known and marketed that have permanent partitions forming more than one compartment. Different colors or different products can be injection molded or otherwise deposited into the separate compartments to form a multi-phase product. However, it is desirable to have multi-phase products that do not require a permanent internal partition in the pan. Such internal partitions can increase the cost of the pans, and are less aesthetically appealing, particularly when the product is worn away from the partition as it is used up. Moreover, such structures often require double processing and/or blotting of each pan. Packed, compressed multi-phase powder cosmetics are known that include two or more colors or types of compacted cosmetics in direct contact within a single pan. However, slurried back-injected cosmetics have not been formed in this manner, nor have other cosmetics that are not compacted powders. Accordingly, a need exists for pan structures and molding methods that can be used to form multi-phase cosmetics with back-injection molding techniques and other non-compaction methods. Similarly, pressed powders are known that have multi-phase surfaces, such as those having decorative embossments or raised areas. However, a need exists for a method to produce such multi-phase surfaces in slurried cosmetic cakes and other non-compacted products. SUMMARY OF THE INVENTION It is an object of the present invention to provide a multi-phase cosmetic in a back injection molding process or other non-compaction type process. It is a further object of the present invention to provide such a multiphase cosmetic that includes at least two distinct cosmetics in a single pan structure. It is another object of the present invention to provide a multi-phase cosmetic that includes decorative embossments or raised areas. It is a further object of the present invention to provide a pan structure for use in back injection of slurried cosmetics that permits formation of multi- phase cosmetics. Accordingly, the present invention provides a method of forming a cosmetic product by back injection molding. The method includes: providing a pan having at least one removable wall therein, the wall forming at least two compartments in the pan, each of the at least two compartments having apertures therein; injecting a first liquid cosmetic through a first of the apertures; injecting a second liquid cosmetic through a second of the apertures, wherein the first and second liquid cosmetics may be the same or different; setting the first and second liquid cosmetics without compaction; and removing the at least one removable wall. Pans having breakaway or removable spacer walls, and pans having frame-like structures with open bottom panels are also disclosed. Methods and devices for setting and forming the surfaces of the resulting cosmetics are also disclosed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a preferred pan structure according to the present invention, the pan having a breakaway separating wall between compartments; FIG. 2 is a perspective view of another preferred pan structure according to the present invention, the pan being used in conjunction with a removable spacer wall; FIG. 3 is a perspective view of another preferred pan structure according to the present invention, this pan being essentially a frame; FIG. 4 is a perspective view of the pan of FIG. 3 being used in conjunction with a pan cover; and FIG. 5 is a perspective view of the pan of FIG. 3 being used in conjunction with a branding iron. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention discloses improved methods of forming pan- based cosmetics via back injection molding or other molding methods. These methods preferably employ the improved cosmetic formulations disclosed in copending applications Serial Nos. 08/853,992 for Cosmetic Compositions Containing Smectite Gels, filed May 9, 1997, or 09/001 ,392 for a Back Injection Molding Process, filed December 31 , 1997. The disclosures of those applications are incorporated herein by reference. Most preferably, the heat- set polar smectite gels of the former application are used in the methods and structures of the present invention. These gels are formed from polar solvents combined with organophilic smectite clays. This mixture can be formed at ambient temperatures, and without the use of high shear. Moreover, the resulting slurry can be gelled and given structure by the subsequent application of heat to the system. In a first embodiment, the present inventors have discovered that the liquid cosmetic slurry can be back injected into, or otherwise deposited in, a cosmetic pan as shown in Figure 1 , and referred to generally by reference numeral 10. This pan 10 has a break-away separating wall 12 or walls. The break-away separating wall 12 is formed integral with the pan 10, or is affixed to the pan in a subsequent step, to form two or more separate compartments 14 for receiving the cosmetic. Wall 12 is capable, however, of separating from the pan structure after the compartments 14 have been filled and the cosmetics therein have set up (e.g., by heat setting or solvent extraction or evaporation). Preferably, the break-away separating wall 12 is removable by means of light mechanical effort. It is preferred that the wall can be simply pulled up and out of the cosmetic. If the wall must be bent or otherwise angled away from the vertical along its line of attachment, the set-up cosmetics may be marred so as to be unacceptable to the consumer without additional corrective steps. Structurally, the break-away separating wall is preferably affixed to the pan via adhesives, waxes or integral perforations formed during molding. The separating wall or walls can be straight, curved or angled, and can define any shape and any number of compartments. Alternatively, as shown in Figure 2, a spacer wall 16 can be used that is structurally separate from the pan structure. This spacer wall 16 can be handheld via handle 18, or can be mounted on a separate, movable support structure (not shown). Once the cosmetic slurries are placed in the compartments 14 formed by the spacer wall 16 or walls, and the slurries are set (e.g., by heat setting or solvent extraction or evaporation), the spacer wall 16 can be removed from the pan. Alternatively, spacer wall can be a three- dimensional spacer section. It could be placed into the pan from above during the first filling to maintain a void. This spacer would then be lifted once the cosmetic was filled and set. Cosmetic material could then be pumped into any remaining open areas through the hole or holes in the bottom of the pan. For purposes of this invention, then, the term "spacer wall" shall include substantially two-dimensional walls, as well as three-dimensional spacing devices for preventing a first pumped product from entering a specific area. In both of the foregoing embodiments, a heat-swellable, cold flowing cosmetic, such as the polar smectite gel discussed above, is highly preferred for use with the spacers and breakaway walls. When such spacers and walls are removed from the pans, the set or partially set cosmetics are capable of filling the gap left by the wall or spacer. No additional injection or application of cosmetic slurry is needed to fill the gap. Mechanical agitation of the pan (e.g., tapping) or subsequent application of heat can be used to facilitate the gap-filling process. Otherwise, the gap left behind would be aesthetically undesirable, and could serve to destabilize the product during transport or use. Consequently, these spacers or walls are preferably used with cold- flowing, heat set gels, or other compositions that are easily rendered slightly malleable after setting. Nonetheless, it is possible, although less preferred, to fill the gap left by the removed wall with a subsequent application of cosmetic material. The methods of the present invention enable the creation of clean, sharp lines of demarcation between adjacent cosmetics. Moreover, unlike traditional compressed powders, these preferred cosmetics do not require an additional compression phase. Accordingly, the methods of the present invention reduce manufacturing time and expense, and eliminate a high force compression step, which can contribute to product breakage and an elevated reject rate. For purposes of this invention, prior art high force compaction of powder-based cosmetics is distinguished from blotting or other surface pressure applications that are conventionally employed during back injection molding or other molding processes. The latter steps are not the source of the mechanical integrity of the resulting cosmetic product. On the other hand, without compaction, traditional powder- based cosmetics do not form a solid cake, but remain an easily disrupted aggregation of particles. A further embodiment according to the present invention is a cosmetic pan 10 (Fig. 3) for use in molding processes, preferably back injection molding processes, wherein substantially the entire bottom 20 or back of the pan 10 is open. In contrast to typical cosmetic pans, in which the bottom is enclosed or has only a small aperture for injection molding, the present invention discloses a pan structure that is essentially an open frame, having sides only, and optionally, internal partitions. This open pan structure can also be used with the break-away separating walls or the removable spacer walls disclosed above. This pan structure is simpler and less expensive to make, and requires less accurate alignment, than typical pans. This structure is also preferably used with a somewhat viscous slurry or pre-gelled composition that is less likely to leak out of the frame. Alternatively, this pan is preferably compressed tightly against a support when being filled, to prevent such leakage. The present invention further discloses a pan cover 22 that can be used to form raised or depressed designs on the top surface of the cosmetic (Fig. 4). Before the cosmetic is back injected, or after it is otherwise filled into the pan 10, a three-dimensional cover 22 is placed atop the pan. As the cosmetic sets, the cosmetic will take on the shape 24 or shapes molded or otherwise formed in the cover. The cover 22 can be removed during manufacture (e.g., for reuse) or by the ultimate consumer, revealing a cosmetic cake having an embossed or debossed appearance. It is also envisioned that the cover could include movable sections that can be elevated or dropped relative to one another to produce special visual effects. Once the cover is removed, a separate injection or application of cosmetic product can be used to fill the areas left recessed by the cover to produce different visual effects. Alternatively, the surface of the cosmetic can be embellished by use of a heated branding iron 26 (see Figure 5) that can be used to form a design on the surface, while simultaneously speeding the heat-setting process (e.g. with the polar smectite gels discussed above). The branding iron 26 can be applied to the pre-gelled composition and held in place until gelling is complete. The branding iron 26 can also be applied when preliminary gelling is completed, to aid final gelling and to add dimension to the surface of the cosmetic. For purposes of the present invention, this branding iron 26 can be any heated element capable of contacting the cosmetic and providing heat to the cosmetic at an acceptable level without burning, scorching or otherwise damaging the cosmetic. It will be obvious to one of ordinary skill in the art th at the foregoing description and drawings are merely illustrative of certain preferred embodiments of the present invention, and that various obvious modifications can be made to these embodiments in accordance with the spirit and scope of the appended claims.

Claims: What is claimed is: 1. A method of forming a cosmetic product by back injection molding, comprising: providing a pan having at least one removable wall therein, said wall forming at least two compartments in said pan, each of said at least two compartments having apertures therein; injecting a first liquid cosmetic through a first of said apertures; injecting a second liquid cosmetic through a second of said apertures, wherein said first and second liquid cosmetics may be the same or different; setting said first and second liquid cosmetics without compaction; and removing said at least one removable wall. 2. The method of claim 1 , wherein said removable wall is not affixed to said pan prior to removal. 3. The method of claim 1 , wherein said removable wall is a breakaway wall that is temporarily affixed to said pan prior to removal. 4. The method of claim 1 , wherein said apertures are substantially the size of a bottom of said compartments, and said pan is substantially a bottomless frame. 5. The method of claim 1 , further comprising the step of applying a cover to said pan prior to injecting the first and second liquid cosmetics, thus causing said set cosmetics to take on the contour of said cover. 6. The method of claim 5, wherein said cover has a three- dimensional contour, thus producing a raised or depressed design on a top surface of at least one of said cosmetics. 7. The method of claim 1 , further comprising the step of contacting at least one of said first cosmetic or said second cosmetic with a branding iron. 8. The method of claim 7, wherein said step of contacting at least one of said first cosmetic or said second cosmetic with a branding iron occurs prior to said setting. 9. The method of claim 7, wherein said step of contacting at least one of said first cosmetic or said second cosmetic with a branding iron occurs prior to said setting and continues until said setting is substantially complete. 10. The method of claim 7, wherein said branding iron produces a pattern on a surface of at least one of said cosmetics. 11. A method of heat-setting and shaping a heat-settable cosmetic composition, comprising applying a branding iron to said composition before its is set. 12. A pan for holding a molded cosmetic composition, said pan being essentially in the form of a frame with substantially no bottom face. 13. A pan for holding a molded cosmetic composition, said pan comprising a breakaway separating wall forming at least two compartments in said pan. 14. The pan of claim 13, wherein said breakaway separating wall is affixed to said pan by an attachment selected from the group consisting of adhesives, waxes and integral perforations.

Inventors: FLEISSMAN LEONA GIAT, PAHLCK HAROLD E, FLEISSMAN, LEONA, GIAT, PAHLCK, HAROLD, E.
Applicants: AVON PROD INC, AVON PRODUCTS, INC.
Application year: 1999
Main classification: A61K7
IPC codes: A45D33