Simulated foil and marble/wood effects for plastics packaging

Simulated foil-laminated tubes and molded caps and packaging components that can look like wood or marble - these are two of the Enigma special effects recently introduced by Clariant Masterbatches (Muttenz, Switzerland).

The new foil look is an effect that brings together Clariant's color expertise and bi-layer extrusion technology to replicate the high-end visual appearance normally achieved only by laminating a layer of aluminum foil between two layers of polyethylene (PE), a costly process. The new Enigma process marries a highly reflective plastic base layer (the inside of the tube) and a color-saturated transparent outer layer. The end result, created entirely in the extrusion process, creates a stunning visual appearance, reduces costs, and can be totally recyclable.

"Historically, most reflective effects have been achieved with pearlescent particles, and although the results have been pretty good, pearls can look flat," explains Len Kulka, Director of Creative Development - Packaging for Clariant ColorWorks. "In the new Clariant foil-look, we've developed a proprietary blend of reflective elements, which are incorporated into the base layer. That's where the reflectivity is created. The color, the brilliance and the depth are created in the surface layer, and the result is anything but dull."

An added benefit is the fact that a color change can be made quickly and easily because only the surface layer needs to be changed. The reflective base layer remains the same.

As environmental consciousness grows among consumers, interest in the beauty of natural materials has also increased, so Clariant has also introduced the next generation of marble- and wood-look special effects for plastics. These color solutions allow packagers to carry the natural materials theme into caps, closures and small packaging components where the real thing would not be economically or technically feasible.

The secret to the success of these new Enigma effects lies in the development of polymer materials that are dissimilar enough so that the different colors don't readily disperse evenly. This, along with special processing technology, creates color swirls and eddies that mimic the grain of wood and marble.

"Normally, we work very hard to make colors that will disperse evenly throughout the polymer matrix," explains Kulka, "but in this case we want to achieve the exact opposite. We want the kind of subtle separation between colors that you find in nature."

In the past, Kulka says, several different techniques have been employed to this sort of effect, including using color masterbatch particles of different sizes. These new Clariant effects, on the other hand, use smaller, more uniform particles and rely on the chemistry of the materials and a more gentle mixing action in the molding machine to create the desired result.

"It requires a slightly different approach to plastics processing," notes Kulka, "but we're able to show our customers how they can control the mixing and melting in the machine to achieve some really unique and interesting results."-[email protected]