Enigma is the new trade name for special-effect color concentrates from Clariant Masterbatches Div., Holden, Mass. The line has been expanded with the addition of several new products.
Among them is the expanded line of Spectrachrome color-shift colorants, which change color when viewed from different angles. The accompanying photo shows color-shift metallic sparkle effects in two-layer coextruded bottles. Each bottle has the same Spectrachrome concentrate in the outer layer, but a differently colored inner layer using conventional pigments. This series shows how a variety of effects can be achieved with a single concentrate.
Also new are thermochromic concentrates that change color with temperature. They are one color at room temperature and another when warmed (e.g., by sunlight or the touch of a hand) or cooled (by snow, cold water, or refrigeration). The container returns to the original color when it regains room temperature. The effect works well in PP and PE, but it is not approved for food contact.
In addition, Clariant reports that recent trials have demonstrated that its Soft-Touch effects work just as well in injection molding as in blow molding, where they were first applied. Soft-Touch uses a soft-textured resin compound in combination with a color concentrate to provide a soft matte finish. This effect has been applied to PP closures that are easy to grip when wet. Soft-Touch also comes in a soft-satin effect that provides a lustrous shimmer (less reflective than a pearlescent) with minimal flow lines. Soft-Touch can run in existing polished molds.