Rigid Plastics

Chemical Enhancers

Posted: June 15, 2012 by
Patrick Henry

Chemical and natural additives extend plastic’s functionality, enhance its appearance, cut its processing costs and increase its sustainability—all in ways that can help packaging creatives improve their designs or broaden their design choices. Ray Buckwalter, vice president, sales and marketing, Pinnacle Polymers (Garyville, LA), estimates that because of increased customer demand for performance-enhanced plastics, 80% of the base resins that his company ships to package producers and other plastic-product manufacturers now contain additives.

When Aveda (Blaine, MN) launched its Invati line of hair-care products, an additive was the key ingredient for assuring the look and sustainability that the brand owner wanted in the packaging. Tricorbraun (St. Louis, MO) supplied bottles made of recycled, 100% post-consumer PCR HDPE resin plus a colorant from Clariant (Muttenz, Switzerland). The result was a high-end appearance that also delivered a compelling brand message about being of nature and protecting it.

“By having the colorant added to the PCR HDPE resin, virgin resin was not necessary, and any additional coatings and processes were not required to achieve the desired aesthetic look,” says Nicole Call, Aveda’s manager of package development. “This achieves Aveda’s environmental mission of creating a package with minimal materials and ingredients.”

But there was nothing minimal about the visual effect that the additive lent to the container. “The color palette we chose was designed to convey a deep richness. We wanted to use a color different than any other in our current palette,” says Jason Troutman, design director, packaging. With the additive’s help, he says, “the deep wine color pops off of the retail shelf, calling awareness to the new product line.”

Look and feel

Additives can be “a very quick way to set yourself apart in a very mature and saturated market,” says Doreen Becker, packaging market development manager for Americhem (Cuyahoga Falls, OH). Her company provides the marketing pop in the form of master batches (solid or liquid concentrates of additives formulated to meet specific end-use requirements), colorants and other products that endow plastics used for packaging with a variety of properties and effects.

Americhem has additives that help plastics combat oxidation, thwart microbes and prevent static charging, among other protective functions. In packaging, however, Americhem’s most commonly used additives are those that introduce or enhance color.

Becker says these compounds create unique color that imparts something special to the brand. She notes that the colorants can be matched to PMS numbers and other color-specification systems. The additives typically contain dispersing agents that are designed to optimize the performance of the pigments for consistent results.
Additives also create the kinds of visual and tactile effects that can turn plastic packages into category leaders, often more economically than traditional materials. For example, Becker says there’s an Americhem additive that gives clear plastic an opaque sheen that resembles the look of much more costly frosted glass. Another relies on flax and other natural fibers to produce interesting surface textures. These fillers, Becker says, are affordable alternatives to titanium dioxide extenders normally used for the purpose.

Bigger role for polyolefins

Milliken & Company (Spartanburg, SC) supplies producers of polyolefin plastics—polyethylene and PP—with additives that give these materials more versatility for packaging applications. The company’s nucleation agents are engineered to streamline the transformation of plastics into packaging shapes and make structures more durable than unblended polyethylene and PP.

Wim van de Velde, Milliken’s global product line manager for PP clarifiers and plastic colorants, says that when the nucleation agents are formulated as clarifiers, the two materials can be made to look as transparent and crystalline as higher-density plastics such as PET and polystyrene. With the help of Milliken’s Millad NX8000 clarifier, he says, polyolefins can be used in packaging applications that they once weren’t considered suitable for.

Shampoo bottles, for example, must be flawlessly clear in order to show off the brand-linked color of the liquid within—a characteristic that bottles made from unblended polyolefins don’t possess. Now, van de Velde says, brand owners can have all the see-through they want in lighter-weight, more environmentally friendly plastics for water bottles, clamshells, food containers and other kinds of packages where a haze-free appearance is the paramount design objective.

MEDPort LLC (Providence, RI), the maker of Fit & Fresh products for healthy eating on the go, chose PP with Millad NX8000 as the material for a private-label line of Fit & Fresh containers. “We recognized that ultra-clear PP would help us differentiate this new private label line and strongly appeal to our target audiences,” says Vanessa Honeyghan, quality manager for MEDPort. “Milliken’s advanced clarifier not only met our high expectations, but also helped us win a new retail customer.”

Natural-cosmetics company Bielenda (Krakow, Poland) packages its Afrodyzjak, Ekstaza and Euroforia bath oils in extrusion-blow-molded bottles made of PP containing Millad NX8000. Magdalena Koc´win, Bielenda’s marketing manager, says that the ultra-clear transparency provided by the additive “helps our products successfully stand out from others on the shop shelf.” The clarity, she says, is particularly attractive to consumers looking for something special.

Earlier generations of clarifiers for polyolefins, van de Velde explains, were processed at higher temperatures than the solutions that Milliken now has brought to market. He says clarified polyolefins use less energy and run more efficiently at the cooler temperatures made possible by the additives, cutting production costs and carbon footprint at the same time. Lighter in weight than other plastics, polyolefins enhanced with additives also reduce energy consumption in transport and handling.

From sea bed to store shelf

U.S. Aragonite (Salem, MA) supplies Oshenite, a renewable, exceptionally pure variety of calcium carbonate that occurs naturally in shallow waters of the Caribbean over the Grand Bahama Bank. Gary Miller, U.S. Aragonite’s executive vice president for marketing, says that Oshenite’s unique crystalline structure, purity and consistency make it completely different in performance and benefits from mined calcium carbonate, a substance widely used as a functional filler for plastics.

Calcium carbonate can be substituted for PP, polystyrene and polyethylene resins intended for packaging and other products. It’s possible, he says, to replace from 25% to 30% of fossil-fuel-based plastic resins with Oshenite in flexible, blow- and injection-molded and thermoformed products. Depending on the application, Miller says, Oshenite’s load can be as high as 50%—two to three times more than mined calcium carbonate.

He explains that plastics blended with Oshenite allow more efficient production, reduce energy consumption, decrease overall cost and leave a smaller carbon footprint. Oshenite doesn’t affect product recyclability, he adds.

For a modern carbon footprint

First Choice Packaging Solutions (Fremont, OH), a contract packaging and thermoforming company, uses plastics containing up to 50% Oshenite in its Virtuweld protective packages and in custom thermoformed products such as trays for gift sets, cosmetics and foods. Steve Thomas, national sales manager, says that replacing large volumes of resin with the additive gives the packages a modern carbon footprint without compromising any other aspect of their performance.

Plastics with Oshenite, Thomas says, run through First Choice’s thermoforming equipment at lower temperatures than standard materials, with the same—if not better—properties of flexibility, strength and appearance. In some cases, he says, substituting the additive for resin reduces the manufacturing cost by 5% to 10%, a savings that can be passed through to the customer.

First Choice is so pleased with Oshenite that it actively promotes its use of the additive to customers. Thomas says that end users like the fact that packages containing it can go into the same waste streams as packages consisting entirely of resin.


For more information, visit
Americhem, www.americhem.net
Clariant, www.clariant.com
First Choice Packaging Solutions, www.firstchoicepackaging.com
Milliken & Company, www.milliken.com
Pinnacle Polymers, www.pinnaclepolymers.com
TricorBraun, www.tricorbraun.com
U.S. Aragonite, www.usaragonite.com