Canadian Plastics

Special Advantage

By Michael Legault   



Special effects once referred to making the impossible happen in movies. Today the term applies equally well to making the impossible happen in the appearances of a wide variety of plastic products. F...

Special effects once referred to making the impossible happen in movies. Today the term applies equally well to making the impossible happen in the appearances of a wide variety of plastic products. From pearl-like swirls to granite, molten metal to oatmeal, you name and it’s more than likely you can find a pigment supplier that can simulate it. Even better, the costs of special effects are coming down, and that means the applications are expanding.

The US Food and Drug Administration has recently approved Shepherd Color Company’s StarLight FL 105 for use as a colorant in all types of food-contact applications. The pigment is designed to create sparkling effects in items such as plastic tumblers, dinnerware and packaging for food and cosmetics. It can also be used in a variety of consumer products, such as bicycle helmets, skis, swimming pools and cell phones, according to Katherine Brannon, the company’s marketing manager. The sparkling effect can be achieved at pigment levels as low as 500 parts per million, a result which normally can only be obtained with organic pigments at a much higher loading.

The StarLight product line uses so-called MicroMirror technology to obtain high brilliance and sparkle. MicroMirror technology is produced through the use of a well-defined glass base, which is uniformly coated with metallic silver, which yields a surface optimized for maximum reflectivity. Particle sizes range from 28 micron to 238 micron.

“The pigment is quite versatile, so at lower concentrations you get a luster effect, while at higher concentrations and larger particle size you see a striking glittering, sparkling effect,” says Brannon.

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She also notes that the product is easier to process and more robust in the injection molding machine or extruder.

EMD Chemicals’ line of Iriodin WMD pearlescent special effects pigments is produced using a new process that makes the pigments easier to use, with improved throughput.

“Normally handling mica-based pigments produces a lot of dust,” says Ted Porter, marketing manager for L.V. Lomas, Canadian distributor for the Iriodin line. “This process modifies the physical properties of the mica and produces a dust-free product that’s easier to disperse. The added lubricity means you can pump the material out of the extruder head faster in blow molding applications.”

Porter says the line is catching on in the U.S. and has just come to Canada. The easier dispersion of the product in the polymer matrix also enables production of concentrates with higher pigment loading. EMD Chemicals has introduced four products in the WMB family, Iriodin 100, 109, 120 and 123, with more to follow.

Teknor Color Company has launched a line of micro-bead color concentrates designed to create striking sparkling effects in PET beverage bottles. The company also claims the concentrates will help processors reduce bottle scrap rates from the typical 10 to 25% range to less than 5%.

The new series is based on PETek technology similar to that introduced by Teknor five months ago for PET health and beauty aid packaging, but is formulated for use at much lower concentrations typically used in beverage bottle manufacturing. Letdown ratios in the range of 3:10,000 to 5:10,000 are typical.

Improved dispersion of PETek concentrates is the result of unique micro-beads, in which color is dispersed in a proprietary carrier polymer that is totally compatible with PET. The diameter of beads can be as small as 0.050 in., depending on application requirements. The improved dispersion properties greatly reduce swirl, haze and other defects that occur with liquid colorants and waxed-based solids commonly used for PET beverage bottles

“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,” says William Clarke, Teknor Color’s manager of national accounts and business development. “On the basis of swirl reduction alone, one major U.S. producer of bottles for carbonated beverages has specified these concentrates for a national brand and expects to reduce scrap from the double digits to as little as 2%.”

Beverage-bottle grades of PETek concentrates are supplied for use in stretch blow molding, injection blow molding, extrusion blow molding and thermoforming, in frosted, pearlescent and other special effects.

Packaging expands ‘effects’ applications

The boom in special effects pigments in packaging has been largely driven by new applications in the personal care and cosmetics market. Now, on the strength of new technology and success in obtaining regulatory approval, suppliers are looking to expand special effects and brighter, fresh colors into a greater variety of packaging, including commodity food and beverage packaging.

Clariant Masterbatches has expanded its Soft-Touch special effects line, previously limited to blow molded containers, to injection-molded products such as caps and closures.

Soft-Touch uses a soft-textured resin compound in combination with a masterbatch colorant system to provide a soft matte finish. The line also includes a soft-satin effect that provides a lustrous shimmer with minimal flow lines. The material line can be used on existing products without costly tooling modifications.

“More and more, we see products that have a radical position in the market, for example a synthetic motor oil that sells or twice what conventional oil does,” reports Len Kulka, Clariant’s director of creative development/packaging. “And if you have a radical market strategy, then you better have an equally radical package.”

In the personal care market, Kulka observes that colors in shampoo packaging, for instance, used to only tell which brand was for oily hair or dry hair. Today, Kulka says, color and effects are being used to differentiate between lifestyle, upscale versus mass-market or young versus conservative.

“Gone are the days when it was enough to take a Pantone swatch to a molder and say ‘match this.'”, Kulka says. “Brand managers need to have confidence that color, which is so critical to the positioning of their product, can be produced and reproduced correctly.”

Engelhard Corporation’s Lumina Russet and Lumina Copper are the company’s latest metallic-look offerings in the company’s Lumina family of mica-based pigments. Based on a tight mica particle particle-size distribution and an exclusive multi-layer coating technology, these pigments produce rich, earthy copper and rouge-tone looks. The powdered pigments are easily blended with resins to be used in injection molding, blow molding and extrusion processing; as well they can be used in inks for gravure, flexo and screen printing.

All-Plastics, Inc. manufactures the Mica-Tek product line of special effects colorants. The Mica-Tek family consists of non-dispersing pigments designed to impart granite-like and textured appearances in opaque polymers, and granite-like, glittering and sparkling effects in transparent and translucent polymers. The company’s Ultra-Gran blends, for instance, come in 36 different colors and are designed to create a densified granite or solid surface appearance in thermoplastic extruded or injection molded parts. Ultra-Stone blends are designed to mimic engineered stone or polished granite in coatings and seamless flooring systems.

Ciba Specialty Chemicals’ Cromophtal Pink PT and Cromphtal Red 2028 pigments are FDA approved for all food contact applications. Cromophtal Pink PT exhibits exceptional dispersion and outstanding fastness properties. It is compatible with polyolefins, as well as flexible and rigid PVC, styrenics, rubber and polyurethane. Potential applications include food packaging, toys and household goods. Cromophtal Red 2028 is an approved mid-shade red pigment designed to reduce shrinkage, warping and distortion problems in crystalline polymers. The pigment’s high-heat and distortion resistance makes it an ideal choice for products molded with fast
cycle times and high heat.

EMD Chemicals has launched a new generation of glittering pigments based on extremely thin (less than 1 micron) borosilicate platelets. The first offering, Mirival KU 28, combines dramatic, silver-white glitter with a colorful rainbow highlight. The pure white mass tone and minimal light dispersion of Miraval lend high transparency to the pigment, opening up numerous styling possibilities.

Clariant’s Kulka sees a new emphasis on clear containers to better display the product and provide a clean appearance.

“Packagers have been trending toward tinted translucent containers,” Kulka says. “This may be an outgrowth of the success of tints in durable goods, most notably translucent computer housings that made a splash several years ago.”

Kulka says there has also been a trend in packaging toward solid colors that are softer, diffused, smoky or frosted. Sometimes the colors are layered to create a unique, high-impact appearance. He cites a package developed for an Olay Quench product line that incorporated layers of iridescent golds and violets to produce a sophisticated look.

“Cost and processing barriers are being lowered every day, allowing us to offer customers myriad color and special effects combinations never before experienced,” Kulka says.

An alternative way to create striking visual effects on specialty products is through the use of film-insert molding technology. Bayer MaterialScience’s Fantasia portfolio of color and special effects includes Faria film-insert molding decorative options using the company’s Makrofol polycarbonate films, Bayfol PC/PBT films and Dureflex TPU films. The technology used in Faria produces sharp, long-lasting visual effects because the graphic design elements are protected by the film layer and integrated into the design of the part.

Today, as you can see, there is definitely more than one tool in the designers tool kit when it comes to creating a unique, aesthetic appearance for a new product.

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