Say 'Color'

DN Staff

February 23, 2004

7 Min Read
Say 'Color'

Kodak's latest single-use cameras may be almost as pretty as the photos they take.

Intended as a premium product that will appeal to consumers around the world, these "Ultra" cameras employ the same two-element optics and film-handling systems already used in the company's best single-use products. "These cameras perform very much like a re-loadable point and shoot," says John Erickson, a program manager for consumer imaging. But the exterior of the Ultra cameras really sets them apart from Kodak's earlier offerings. Instead of a square box with a label for decoration, the Ultra cameras sport a plastic bezel embellished with molded-in, special-effect colors. They also have a pocket-friendly design that's about 25 percent smaller and more contoured than earlier models.

Kodak transformed these cameras from label-covered black boxes to a sleek, colorful design for good reason. The marketplace for single-use cameras has increasingly become both crowded and global. The aesthetics of the new cameras help on both scores. According to Erickson, splashy colors help the cameras stand out on the shelves and reinforce the idea that they are premium products. "We used color to elevate consumer perceptions of the camera," he says.

The colored bezels, which attach to the rest of the camera with snap fits, also help Kodak adapt cameras to local consumer tastes. Creating different versions now involves changing just colors not tooling, a big plus in the cost-competitive world of single-use photography. Over the past year, Kodak has come out with at least six different versions of this camera aimed at consumers in Europe and Asia. It also introduced a silver-bodied black and white camera for the U.S. Though all these cameras share the same platform, they look strikingly different. A pink camera, for example, targets young female consumers in Japan. European models, by contrast, take cues from cell phone colors, reports Ann Fang, a Kodak color and material specialist. "These cameras are turning into something more fashionable," she says.

Special-effect colors may benefit marketers, but engineers are the real fashion victims here. "If engineers ruled the world, all cameras would be square black boxes," jokes Brett Blaisdell, the plastics engineer responsible for the Ultra's materials selection. Special-effect pigments can cause cosmetic problems, such as flow lines. They drive up part cost. And they can reduce impact properties too. Kodak engineers had some additional technical challenges on their hands when it came time to put special-effect plastics into a camera. In addition to the cosmetic and mechanical requirements, the company has a long list of requirements dictated by the need to protect the film, recycle the cameras, and maintain color consistency across manufacturing sites in Hungary, China, and Mexico.

Demanding Requirements

The film itself imposes two demanding material requirements. One has to do with avoiding photoactive agents, or chemicals that can react to expose the film. "Think of it as taking pictures without light," says Blaisdell. "There is a huge list of things that can cause this to happen." Kodak's long list of photoactive agents shares quite a few entries with the list of additives and colorants commonly used in thermoplastic formulations, including the high-impact polystyrene (HIPS) used for the camera bodies and bezels. Blaisdell cites carbon black as a prime example. "Some grades of carbon black contain sulphur, which is a known photoactive agent," he says. And many metallic materials, including aluminum, can cause the film to fog as well. "We're very cautious around any metallic additives," he says. And that made the Ultra line all the more challenging, since some of the sparkling looks use metal flakes-for example, aluminum flakes in the black-and-white model's silver body.

Kodak engineers also worry about the photo-opacity of the plastics, or their ability to block the light. "It doesn't take very much light to sensitize the film. So a lot of materials that look opaque to the eye are not opaque for our purposes," says Blaisdell. With black materials, engineers long ago got a handle on which material formulations and designs will keep film in the dark. "We understand black very well," Blaisdell says. "We know exactly how much carbon black to add for a given wall thickness."

Colored parts are inherently trickier, though, because they don't absorb light the same way black parts do. Instead, Blaisdell says, each color formulation absorbs, reflects, and refracts light in a slightly different way. "Colored plastics can bounce around huge amounts of light. And some of that light could potentially bounce its way right to the film."

Photo-opacity causes a couple of important design conflicts in a camera that combines color with a smaller size and increased impact requirements. The natural tendency when trying to bump up opacity is to load the plastic with more pigment or increase the part's wall thickness. Neither option worked here. Extra pigment could have reduced the material's impact performance-which Blaisdell says was already a bit lower than black due to the special-effect pigments. Increasing wall thickness likewise wouldn't work here. With the camera roughly 40% smaller than earlier models, there was less wiggle room. "We didn't have the luxury of thick walls," Erickson says. "So we had to ask more from our materials."

Test, Test, Test

Kodak managed to work around these materials challenges with a combination of experience and rigorous testing. "We don't just break a tensile bar and say, 'this is fine,'" Blaisdell says. To the usual battery of mechanical tests, Kodak has a number of homegrown tests related to its photographic requirements. To test for photo-opacity, for example, engineers mold a disc of material and place it over film in a fixture. They then zap it with aircraft lights and look at the condition of the film. They also use a densitometer to determine the material's optical density. When divided by the part thickness, optical density "does a pretty good job predicting opacity," Blaisdell says.

But not a perfect job. So Kodak qualifies all prospective resin formulations in real parts. Injection-molded parts tend to behave differently than samples used in lab tests, Blaisdell explains.

And because the company regrinds and re-molds the plastic from millions of cameras each year, engineers will evaluate materials after passing them through the company's recycling line five or ten times. "If the material can stand up to that, it has to be robust," Blaisdell says, noting that Kodak measures mechanical and physical properties of the material after each pass through the recycling line "to see if anything changes."

In the case of the Ultra's metallic bezels, all the testing in molded parts paid off. "We had shied away from metallics for years," Blaisdell recalls. But it turns out that they can be selectively incorporated in the cameras, not just in bezel parts that have more physical separation from the film but also in the bodies. How? Blaisdell theorizes that the resin-rich surface of injection-molded parts helps minimize the photographic activity of the metal flake.

Kodak engineers also worked carefully with their supplier, Clariant Masterbatch (Holden, MA), to come up with a formulation containing the right amount and type of metallic flake. "We couldn't give them as much of a metallic look as they would have liked," says Jean Sirois, Clariant's North American marketing manager. "There were some limitations on particle size and loading." But Clariant chemists kept the aesthetic compromises to a minimum by offsetting these limitations with other kinds of colorants and additives. "They understand our photographic requirements very well," says Blaisdell, explaining that Clariant chemists worked with a list of photographically active agents while helping Kodak come up with its color formulations.

Color matching and testing various color formulations turned out to be the most time-consuming parts of the 18-month development process. By performing much of the color matching and formulation, Clariant helped the camera get to market faster. "With labels, there's just not that much to match," Erickson says.

Senior Editor Joseph Ogando can be reached at[email protected].

Web resource

For more info on specialty chemicals from Clariant Masterbatch, Designing with special effects plasticsGo to http://rbi.ims.ca/3845-558

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