Molded Cosmetic Applicators And Mold Therefor

Abstract

A molded cosmetic applicator head having a core that supports an array of semi-conical bristles arranged in rows and columns, such that the surfaces of the bristles assume certain orientations, and wherein at least some of the bristles have at one or more prominent depressions and/or prominent protrusions located on a curved surface. A mold for an injection molded applicator head is also described.

1 . A molded cosmetic applicator head comprising:
 a core having a longitudinal axis, and   an array of bristles projecting from the core, arranged in rows and columns, wherein:
 each bristle comprises a flat surface that extends the height of the bristle, and a rounded surface; 
 within each column of bristles, all of the flat surfaces lie in the same plane and are parallel to the longitudinal axis of the core; 
 within each row of bristles, the flat surfaces of adjacent bristles are oriented to each other at an angle γ=360°/M degrees, where M is the number of columns; and 
 one or more prominent depressions and/or prominent protrusions are located on the rounded surfaces of at least some of the bristles, but not on the flat surfaces of any of the bristles. 
   
     
     
         2 . The applicator head according to  claim 1  wherein each bristle has a horizontal cross section that is shaped as a circular segment having an arc of about 160° to no more than 180°. 
     
     
         3 . The applicator head according to  claim 2  comprising from 2 to 12 depressions and/or protrusions located on the rounded surface of at least some of the bristles. 
     
     
         4 . The applicator head of  claim 2  comprising from 5 to 50 rows bristles. 
     
     
         5 . The applicator head of  claim 2  comprising from 2 to 12 columns of bristles. 
     
     
         6 . The applicator head of  claim 2  wherein the core is approximately cylindrical. 
     
     
         7 . The applicator head of  claim 2  wherein the core is wider in the middle and tapers toward either end. 
     
     
         8 . A cosmetic applicator comprising the molded applicator head according to  claim 1  and a handle attached to the core of the applicator head, the handle having a threaded engagement. 
     
     
         9 . A mold for an injection molded applicator head comprising a number, M, of separable mold sections that when assembled, define a mold cavity, wherein
 each mold section fills an angle of 360°/M;   each mold section comprises an interior face, a flat lateral face, and a sculpted lateral face;   the interior faces define a core space that has a longitudinal axis that extends along the length of the core space;   the sculpted lateral faces are flat except for number of bristle spaces cut into them, such that the bristle spaces are regularly arranged in M columns that extends down the core space, parallel to the longitudinal axis;   
     
     
         10 . The mold according to  claim 1  wherein each bristle space comprises base and a tip, and wherein a horizontal cross section of the bristle space is shaped as a circular segment having an arc of about 160° to no more than 180°, and whose radius decreases as you move from base to tip. 
     
     
         11 . The mold according to  claim 10  comprising from 2 to 12 prominent depressions and/or prominent protrusions located on the rounded surface of at least some of the bristles spaces. 
     
     
         12 . The mold of  claim 10  wherein each sculpted lateral face has from 5 to 50 bristle spaces. 
     
     
         13 . The mold of  claim 10  wherein M=2−12. 
     
     
         14 . The mold of  claim 10  wherein the core space is approximately cylindrical. 
     
     
         15 . The mold of  claim 10  wherein the core is narrower in the middle than at the ends. 
     
     
         16 . The mold of  claim 11  wherein the prominent depressions and prominent protrusions have a draft angle that ranges from about 1° to about 25°.