New Colors for PET Beverage Bottles Yield Sparkling Containers and Dramatically Reduce Handling Problems and Scrap

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PETek (TM) Micro-Bead Color Concentrates Reduce Beverage-Bottle Scrap Rates From Typical 10-25% Range to Less than 5% and Make Possible Lower Letdown Ratios

PAWTUCKET, RI, U.S.A., February 17, 2005: A fundamentally new family of color concentrates enables manufacturers of PET beverage bottles to eliminate handling problems posed by conventional PET colorants, substantially reduce scrap, and produce sparkling clear and opaque containers, it was announced today by Teknor Color Company.

The new series is based on PETek (TM) technology similar to that introduced by Teknor Color three months ago for PET health and beauty aid packaging but is formulated for use at the much lower loadings typical in beverage bottle manufacture. Because of the huge production volumes typical in the beverage industry, the improved dispersion of PETek colors in PET may result in sizeable reductions in bottle scrap, according to William K. Clarke, manager of national accounts and business development.

Unlike the liquid colorants and wax-based solids commonly used for PET beverage bottles, PETek concentrates are unique micro-beads in which color is dispersed in a proprietary carrier polymer that is totally compatible with PET. The beads can range in size down to diameters as small as 0.050 in. (1.27 mm), depending on application requirements. As a result of tiny bead size and complete incorporation of the carrier in polyester, color disperses so efficiently and uniformly that swirl, haze, and other defects are dramatically reduced,

“PETek concentrates provide crystal clarity in transparent containers and beautiful, vibrant hues in opaque ones,” said Clarke. “On the basis of swirl reduction alone, one major U.S. producer of bottles for carbonated beverages has specified these new concentrates for a national brand and expects to reduce scrap from the double-digits to as little as 2%.”

The bead form of PETek concentrates eliminates the bridging, clumping, and stick-to-the-hand messiness of wax-based colorants and the screw-slippage and housekeeping problems posed by liquid colors, according to Clarke.

Teknor Color supplies beverage-bottle grades of PETek concentrates as custom formulations for use in stretch blow molding. Frosted, pearlescent, and other special effects are available. The company also supplies PETek grades for injection blow molding, extrusion blow molding, thermoforming, and other PET processing.

PETek (TM) Concentrates May Make Possible Letdown Ratios as Low as 3:10,000

PETek micro-beads can be as much as 60% smaller in diameter than the conventional 0.125-in (3.2 mm) concentrate pellets widely used in many other plastics applications. The latter are used typically at two to four parts per hundred of resin (2 to 4% loadings) but do not provide good color dispersion in PET beverage bottle molding, where letdown ratios are in the range of 3:10,000 to 5:10,000 (0.03 to 0.05%).

“Micro-beads make available to PET molders the advantages of pellets,” said Stephanie Fromm, business development manager, “including free-flowing conveyance and metering into the processing machine, workplace cleanliness, and avoidance of liquid carriers like mineral oil, which can cause inconsistencies in melt delivery that result in screw slippage. The outstanding dispersion of PETek concentrates may also enable processors to reduce colorant levels to the lowest end of the standard range, around 0.03%, without sacrificing color development in the finished product.”

Superior dispersion yields especially large cost savings in beverage bottle molding because of huge production volumes, according to Fromm. “Preforms are injection molded at high speed in large numbers per cycle and may even be blow molded at a different site. Color variations and defects like swirl and haze typically do not manifest themselves until the finished bottles tumble out of the mold. Scrap rates can range anywhere from 10 to 25%. With PETek colorants, we expect the percentage to be reduced to the single digits. In addition, the easier and more efficient handling and incorporation of these new products will also yield cost savings.”