Page 76 - OHS, June 2022

PPE: PROTECTIVE APPAREL
Solution-Dyeing Versus Piece-Dyeing: Does it Make a Difference in PPE?
Understanding the complete fabric creation process can aid in making better PPE choices.
MBY RICH LIPPERT
ost of the discourse surrounding personal protective equipment (PPE) is justifiably concentrated
on the ability of a garment to minimize exposure to hazards, ultimately making workplaces safer. However, there is one important factor of PPE fabrics that is often overlooked—the dyeing process.
As you weigh your options for PPE workwear, you might be surprised to learn the differences between the “solution- dyeing” process and more traditional dyeing processes known as “piece-dyeing” or “stock-dyeing.”
Visualizing the Difference
In order to envision the contrast in solution-dyeing and piece-dyeing, consider the difference between a carrot and a radish. When cutting into a carrot, you’ll notice the orange color is consistent throughout the vegetable—top to bottom, in and out. Conversely, slicing into a radish will reveal a white interior color which is very different than its reddish exterior.
This is an excellent analogy for solution- dyeing versus piece-dyeing methods, with the carrot representing solution-dyed fabrics, which has pigmentation added directly to the polymers, and the radish symbolizing piece-dyed fabrics, which is dyed after the fiber has been created.
Technically Speaking
In solution-dyed fabrics, color pigmentation is added to the polymer at the very beginning of the process, rather than after it becomes yarn and woven into fabric. Colorless polymer chips are melted together with color pigments. This melted mass is then extruded through a spinneret, which is a device resembling a showerhead, to create the fiber, and then spun into yarn.
In comparison, piece-dyed fibers are dyed following extrusion, meaning the color only penetrates the outer surface of the material. Both methods have their
It’s important to evaluate whether the garments you are buying are inherently AR/FR, solution-dyed fabrics or treated, piece-dyed fabrics.
redeeming qualities, but the question still remains—how do these disparate processes impact PPE and its effectiveness?
Durable Dyes
There are many benefits to utilizing solution-dyed fabrics in PPE garments, most notably the increased durability in the workplace and improved color fastness following industrial laundering. Because the color is built-in to the fiber, solution- dyed PPE retains its color much longer than piece-dyed fabrics. The prolonged lifetime of these products underscores the fact that solution-dyeing maximizes an organization’s PPE dollars.
Sustainable Solutions
Aside from maintaining color uniformity
for PPE, which is integral for compliance and long-term cost-effectiveness, the solution-dyeing process consumes far less water and waste than its piece-dyed counterpart. It’s estimated that the textile industry loses up to 200,000 tons of dyes to effluence, or liquid waste, annually.1 While that is a staggering figure, the vast majority of that waste derives from traditional piece-dyeing methods, which can use one to three gallons of water per yard of material produced. In fact, research indicates the solution-dyeing process consumes 90 percent less water and results in 96 percent CO2e savings.2
Piece-Dyed Positives
Although data suggests solution-dyed fabrics are more economically efficient in
70 Occupational Health & Safety | JUNE 2022
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