Color Tolerancing: When the Human Eye Isn’t Enough

As sensitive to color as the human eye can be, it simply cannot define color differences quantitatively for precise and repeatable analysis. In some cases, visual perception of color variance could mean shipping a batch of product that does not meet specification, and in other cases, it could mean discarding a batch of good materials. These costly mistakes can be avoided when tolerances are established and differences are quantified.

How can you tell if the color is right?

There are a number of ways to determine whether a batch falls within an acceptable tolerance; however, not all methods will provide precise results. At Americhem, we suggest that the best and most accurate way to test acceptable color tolerance is to use an elliptical pass/fail system, which is based upon an equation developed by the Colour Measurement Committee. This system places a customizable emphasis on hue and chromaticity value, allowing you to determine how much weight is placed on the hue and chromaticity differences of the two colors.

Having good tolerances in place for each product allows you to make quick and easy pass/fail or ship/don’t ship decisions that can directly impact the profitability of your business. At Americhem, we understand how challenging it can be to accurately define color tolerances. You can read an article in Plastics Engineering about Measuring Color from Americhem Color Expert, Ron Beck.

For more information on color tolerancing or to learn about Americhem’s services, visit americhem.com or contact Scott Blanchard at sblanchard@americhem.com.

How You Can Create Synthetic Fibers that Stand Out

The increasingly competitive landscape in the synthetic fibers market has made it essential for companies to seek opportunities to add value and create points of differentiation. This blog post is to review how color and additive solutions impact the functionality and stabilization of synthetic fibers during production and when going to market.

Define Your Goals

Differentiating your fiber products from the competition can be accomplished in a number of ways, it boils down to determining what you are trying to accomplish, and then working with suppliers to find the right solutions. For example, outdoor fabrics for awnings would require different attributes than the lining of a fleece jacket.

Color-Enhancing Solutions

Finding the right mix of polymer color and additives can be the key to unlocking new business opportunities, helping synthetic fiber producers enhance material properties and create improved efficiencies in the spinning process, which adds greater value to end customers when compared to lower-cost alternatives. To further achieve the look you are after, the following color and additives might also be considered.

Goal	Solution
Enhancing appearance	Custom colors, blacks and whites, delusterants, and optical brighteners
Extending useful life	UVA and light stabilizers
Inhibiting the spread of germs	Antimicrobials
Improving processability during spinning	Lubricants, antioxidants and heat stabilizers
Preventing ignition or spread of flame	Flame retardants
Removing static charge from fabrics	Antistatics
Enhancing performance	Moisture managers, odor absorbers, fillers, reinforcement, tracers and biodegradation

In the highly competitive synthetic fibers market, differentiation can be achieved by fine-tuning your processes and finding the right mix of color and additive solutions. By working with a trusted partner, you can effectively balance form and function that will add value to your operation—and your customers.

Americhem’s Product Development Services

Americhem is more than a supplier to the synthetic fiber industry—we’re a partner that can help enhance your existing products and bring new products to market faster. We become fully integrated in your processes to help improve efficiency and overall product quality by employing our unique value-engineering approach. For more information on best practices in the manufacture of synthetic fibers, or to learn more about Americhem’s products and services, visit Americhem.com.

Larry Campbell
Technical Development Director- Fibers
Americhem, Inc.

What Color is that Dress?

The internet is bustling over a photo that is causing lots of controversy.

What color is this dress?

Photo from Tumblr user swiked

This photo was posted to Tumblr with a simple question: What color is this dress? Who would have thought it would become an internet sensation. 

There are two main responses: White with Gold or Blue with Black.

The true colors of the dress are blue and black. You can see the same dress below.

By using Photoshop, you can see what happens to the photo when you limit the light coming in from the background. The dress is starting to look like the professional photo. Light is an important aspect to how we see color. Our brains are good at correcting for the effects of lights. 

Photo from wired.com

The reason "the dress" looks white and gold in some pictures and it looks blue and black in other pictures is because colorants in the dress can behave differently under different lighting conditions. If a colorant appears to be the same color under different lighting conditions, then it has color consistency. We interpret the color of objects based on how we interpret the light around objects.

This is why when you match a tie to a shirt in the store and then you wear it outside it may mismatch. This phenomenon is called metamerism and the only way to prevent this from happening is to spectrally match the color. The color may not be color constant, but it will match in various illuminations.

Tell us what you see? White and Gold or Blue and Black?

Ron Beck

R&D Manager – Core Technologies, Americhem Inc.

The Vinyl Siding Institute and Americhem

Americhem as been a member of The Vinyl Siding Institute (VSI) since the institute’s inception. VSI started off in the 1960’s and at that time, they were a part of the Society of the Plastics Industry. Americhem was involved with the organization from the very beginning of the vinyl siding industry, which also started in the 1960s.

Americhem has played a key role in the coloring and color retention of vinyl siding. Former Director of Research Rick Mathew knew that color retention was going to be crucial in the industry’s foundation.

Based on his knowledge of color science, he knew that the numeric ΔE value, which measures the color difference between the initial color and the color of weathered siding, does not always agree with visual assessments of color difference.  Rick lead the industry in establishing hand drawn ellipses for multiple regions of color space that corresponded to a visual assessment of the limits of acceptable color change in siding after weathering.

Back in those days, in order to determine if a vinyl siding color was within the acceptable color change limits, Americhem employees made hand drawn ellipses for each of the vinyl siding color spaces, plotting the ΔE’s by hand. This was in the time before personal computers which now make such tasks much easier. The work done by Americhem helped establish a new standard in the industry, ASTM 3679. This specification establishes requirements and test methods for the materials, dimensions, warp, shrinkage, impact strength, expansion, appearance, and wind load resistance of extruded PVC siding. The weathering component of the standard was an appendix which remained in place until the late 90’s, when Americhem scientist Phil Ledgerwood urged the industry to move to mathematical equivalents of the hand drawn ellipses. This resulted in a new, easier method of determining if weathered panels met the color retention requirements.

Americhem has continued its contributions to VSI until the present day, including the introduction of CIEL*a*b* ΔE2000 as the method of choice for vinyl siding color retention over the previous Hunter Lab method. This move redefined what was acceptable and unacceptable in the industry.

Americhem employees have served on committees within the VSI, including several polypropylene task groups, the heat distortion committee and the life cycle analysis group. Beyond the organization, Americhem has helped dozens of vinyl siding manufacturers over the years to optimize their product offerings.

In 2005, Ledgerwood won the VSI’s Ken Mieure Award for distinguished service, which was one of the first awards given to an employee of an industry supplier (most past awards went to employees of vinyl siding makers.) The award was created in the late 1990s and recognizes extraordinary efforts of members in helping to build and advance the industry. 

We continue our active participation in VSI and recently, market segment manager Mike Fair was named to VSI’s board. Americhem’s contributions continue with our work in dark color spaces, where the goal is to prevent heat distortion, and in variegated products that simulate the look of natural wood grain. The VSI has served a valuable role in the industry by establishing standards and monitoring for the industry’s products. Many industries could benefit from following VSI’s model.