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A fresh look at liquid colorsA fresh look at liquid colors

May 19, 1999

2 Min Read
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Whether you are aware of it or not, color affects your mood and psyche in a variety of ways. If you are molding colored products, especially consumer goods, it also greatly affects your business. Today’s market is demanding more varied and exotic colors along with lower costs and faster turn-around times. Looking for a solution? Liquid colorants may be your answer.

Before you flip the channel, consider this fact: Several multinational manufacturers are sold on liquid colorant. We asked John Haugh of ColorMatrix why custom molders still shy away from them. “When liquid colors first came out 30 years ago, the pumps and metering equipment developed to deliver them to the press were not perfected,” he explains, “giving liquids a bad name.

“Equipment technology has progressed, however, and today, pumps and metering systems can be customized for specific applications. Although equipment issues are no longer valid, the perception remains. In addition, solid colorants have been around longer and molders are more familiar with them.”

On the plus side, liquids take up roughly 75 percent less inventory space than solids and offer quicker color changes. “Rather than purging the hopper, molders can simply change the color tube at the feed throat and purge the barrel,” says Haugh.

Color matching doesn’t appear to be a problem for liquids either, providing manufacturers use appropriate color measurement devices. “We have invested in spectrophotometer and quality assurance software systems from X-Rite,” says Haugh, “after evaluating what was available. We’re able to bring portable units to customer facilities to take readings,” he explained, “then verify and troubleshoot onsite.” ColorMatrix also took advantage of classroom sessions offered by X-Rite to help build its internal color database and train field technicians to use the equipment.

Another benefit: Liquids have an inherently higher pigment loading compared to solids because the organic carrier accepts higher amounts of color. Even micropellet colorants are not as highly loaded as liquids. Because of the higher pigment loading, molders can use smaller let-down ratios, and resulting cost benefits range from 5 to 20 percent, according to Haugh.

What about processing differences? Liquids, unlike solids, act as internal lubricants and thus increase melt flow. If the color decision is made early enough, gates can be optimized for liquids to produce faster cycle times.

One drawback to liquid colorants, says Haugh, involves housekeeping practices. “Switching to liquid means making a change in how you handle and deliver colorants on the shop floor. Molders need to train their workforces to avoid spillage and contamination, and may need to make improvements to their delivery systems.” ColorMatrix audits its customers’ plants for housekeeping to prevent problems before they happen.

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