Reduce Waste; Reduce VOC's; Improve Product Performance

Methods for producing aluminum-based vacuum metallized pigments, or "VMP's," have changed little over the past 20 years - they generate a lot of waste and consumes vast amounts of solvent. In most cases, a polymer film is used as a carrier susbtrate and eventually discarded; in almost all cases, polymer "release," layers are deposited using environmentaly unsafe solvent-based formulations with very low solids content.

The Technical Challenge - Eliminate the Film and Phase Out Solvents in the Coating Process

VMP's use a polyester film as a support to carry alternating layers of polymer release and metallized aluminum. The film is transported back-and-forth between the solvent coating line and the metallizer until 6-8 layers of metal, separated by release, are deposited on both sides of the film. The metal and release layers are stripped from the film and the film is discarded. Eliminating the film necessarily meant that the polymer release needed to be deposited in the metallizer - inline with the metal deposition process. This would also mean that the conventional release chemistry could not be used and that a new, solvent-free, chemistry would need to be developed.

The Solution

Sigma developed a new solvent-free polymer release that was compatible with its VaporPhase™ deposition technology and able to dissolve in Silberline's organic solvent of choice. Rather than delivering rolls of polyester film with 12-16 layers of metal - Sigma delivers a composite raw material composed of thousands of layers of aluminum. The conventional process results in roughly 8 kilograms of wasted film + release for every pound of VMP produced [^1]. Sigma was able to reduce this to less than 60 grams per pound.

Silberline StarBrite effect pigments are produced by Silberline using raw materials developed and produced by Sigma in Tucson. StarBrite pigments can be purchased directly from Silberline and authorized Silberline Dealers in worldwide. Visit www.silberline.com