Composition for thin walled molded parts
View Patent ↗A polymer composition comprising an organic polymer and a mica containing effect pigment, e.g., a pearlescent pigment comprising mica, well suited for producing molded articles, in particular, for molding articles comprising thin sections and or delicate features, such as a hollow interior defined by a thin wall or structural features susceptible to tear or other damage and the like, is provided as are a method for preparing molded articles comprising the polymer composition and articles comprising the polymer composition, including, for example, an article used to deliver a medical or personal care component such as a tampon applicator, and a method for preparing molded articles comprising the polymer composition. Optionally, articles of the present disclosure have a varying translucency or opacity about a dimension of the article.
1 . A polymer molding composition, comprising, based on the total weight of the polymer composition:
from about 50 to about 95 wt. % of a moldable starch;
from about 0.5 to 10 wt. % of a pearlescent pigment;
from about 0.02 to about 1.3 wt. % of a colorant other than a pearlescent pigment;
from about 0.5 to about 10.0 wt. % of a lubricant comprising a fatty acid amide; and
from about 0 to about 40 wt. % of other polymers or additives.
2 . The polymer molding composition according to claim 1 , wherein the pearlescent pigment comprises mica.
3 . The polymer molding composition according to claim 2 , wherein the pearlescent pigment comprising mica comprises a mica particle coated with one or more layers.
4 . The polymer molding composition according to claim 1 , wherein the lubricant comprises erucamide, oleamide, stearamide, stearyl erucamide or bis-erucamide.
5 . The polymer molding composition according to claim 1 , wherein the other additives include one or more selected from the group consisting of: organic polymers, plasticizers, compatibilizers, flow modifiers, antioxidants, antistatic agents, fillers, reinforcements, surfactants, light/UV stabilizers, thermal stabilizers, flame retardants, biocides, antiozonants, blowing agents, and anti-foaming agents.
6 . The polymer molding composition according to claim 1 , wherein the polymer is extruded.
7 . The polymer molding composition according to claim 6 , wherein the polymer is extruded and thereafter cut into the shape of a pellet.
8 . A tampon assembly, comprising:
a tampon applicator defining a straight lengthwise axis, the tampon applicator comprising a polymer having about 50 to about 95 wt. % of a moldable starch; and a carrier material comprising: from about 0.5 to 10 wt. % of a pearlescent pigment, from about 0.02 to about 1.3 wt. % of a colorant other than a pearlescent pigment, from about 0.5 to about 10.0 wt. % of a lubricant comprising a fatty acid amide, and from about 0 to about 40 wt. % of other additives, the carrier material having a letdown ratio of between about 2% and about 6%; and the tampon applicator comprising:
an insertion tip region, the insertion tip region defining a forward-most portion of an applicator barrel, the insertion tip region having a tip thickness;
a barrel region adjacent the insertion tip region, the barrel region having a barrel thickness;
a grip region adjacent the barrel region, the grip region defining an aft-most portion of the applicator barrel and having a recessed region that has an exterior grip diameter less than an exterior barrel diameter of the barrel region, the grip region having a grip thickness;
a plunger that is coaxial with said applicator barrel, the plunger telescopically engaging the applicator barrel such that the plunger is at least partially interior to the applicator barrel; and
a pledget disposed within the applicator barrel.
9 . The tampon assembly according to claim 8 , wherein the insertion tip region of the applicator has one or more portions that are translucent and the tip thickness is less than the barrel thickness and less than the grip thickness.
10 . The tampon assembly according to claim 8 , wherein the barrel region has one or more portions that are opaque.
11 . The tampon assembly according to claim 8 , wherein the grip region is opaque.
12 . The tampon assembly according to claim 8 , wherein the tampon applicator is injection molded or compression molded.
13 . The tampon assembly according to claim 8 , wherein the plunger is injection molded or compression molded.