An interesting invention in polymer development was reported at the Chemistry World blog that caught our attention this week that raises some interesting questions (at least for those of us in fashion research).
“A new environmentally friendly concept in functionalising polymer allows coloured dye to be integrated directly into polymers that can be used in clothes and packaging,” say UK scientists.
For every designer’s collection there is a color story. The color story is nothing more (or less) than a collection of color swatches that designers pull from to create a coherent collection that uses one or more of the colors. The non-practitioner can get a good idea of a color story by looking at the 2010 Project Runway winner Gretchen Jones’ fashion collection, where her color story was a neutral palette of browns, blacks, and greys. All textiles and trims chosen for a collection must be dyed-to-match (DTM) the colors in the color story. And they must match as exactly as possible.
Patrick McGowan, Christopher Rayner and Richard Blackburn at Leeds University, UK (and founders of Leeds-based firm DyeCat) have invented a new way of producing a special man-made fiber (polylactic acid – PLA) that requires fewer dying steps and less water and energy to color it in the melt.
Polylactic acid (PLA) is a polyester material made from renewable resources that uses less petroleum to make than comparable petroleum-based fibers. According to DyeCat’s web site, it also degrades more easily in landfill. PLA has not been widely used on commercial fabrics partly because of difficulties in the dyeing process.
DyeCat’s invention is a catalyst with a dye molecule attached, which initiates the ring-opening polymerisation of lactide into PLA and then becomes covalently incorporated into the polymer. The dye molecule is also incorporated as part of this process, which causes the polymer to be colored. Traditional dying methods occur after the fiber is created (man-made) or harvested (natural) and require extensive inputs of water, energy, and dye chemicals. DyeCat’s technique starts sooner in the fiber process, at the ‘melt’. Melt is the point where the fiber feedstock has been melted and put into a liquid state prior to being extruded through spinners as a fiber.
DyeCat’s process incorporates the dye molecule as part of the PLA polymer structure. This means that there are no dye baths to dispose of which minimizes all of the multiplier effects that come from using a dye bath technique to color the fiber. The catalyst and molecule are embedded in the polymer (instead of being attached to the surface of the fiber) which has raised the usual consumer concerns about health and safety, and industry concerns about dye fastness (the ability of the dye to retain its original coloring throughout the final product’s lifecycle.)
McGowan says they ‘can tune the catalyst to incorporate the desired color,’ and they have made black, red, yellow and purple PLA fibers so far.
This new fiber sounds incredibly cool, but as a technical fashion designer I have to ask, ‘what about the lab dips?’
Wayne Hayes, a polymer chemist at Reading University, UK says, ‘The advantage this method offers in terms of processing and delivery to the customer represents a significant technological advance.’ And it does sound really cool, but again, what about the lab dips?
The DyeCat team believes the technique could be applied more widely with fluorescent or UV-active (optical brighteners) molecules could be useful for PLA used in packaging. The new technique could also be used to embed antimicrobials or even fragrance molecules into fibers, which could offer a new direction in fashion design. All of this is incredibly cool, but back in the fashion design trenches, we are still going to ask ‘But what about the Lab Dips?’
Lab dips are small swatches of textiles and trims that have been dyed by the manufacturing factory and sent on to the design team. Designers may be responsible for approving their own lab dips, but usually some poor victim is singled out of the team and her function is to manage and approve the lab dips. This entails staring at lots and lots of these swatches under a special light box where the spectrometry of the light is adjusted according to the design house’s needs, and comparing the swatches to color match system swatches (usually Pantone Match System, but sometimes other color match systems.)
The lab dip designee has to have a superb color sense and will often have to choose between lab dips that are extremely close in color value. The lab dip he/she chooses will then be the standard against which the production run textiles will be evaluated. Often factories and design will iterate on the lab dip process several times if the factory isn’t quite capturing the desired color. (Needless to say, once the lab dip victim is chosen, she’ll be approving lab dips at that company for her foreseeable future. The way people perceive color is variable and can be impacted by genetics, diet, age, health, and a plethora of other considerations. The best way to have a standard for lab dips is to make sure the same set of eyes always approves the lap dips. And yes, it is a hated role, almost as hated as speccing tech packs. Lucky, lucky lab dipper!)
Needless to say, evaluating lab dips is a nerve-wracking process. What if you, as the lab dip designee, get it wrong and the color doesn’t match and you approve the wrong one? The mind boggles. Ack.
So while this innovative new PLA dying process sounds very cool, we’re curious to know how lab dips are going to be handled. How are they going to tune the dye molecules to exactly match the color stories? How are they going to do this quickly enough to meet the apparel industry development process? As it stands now, it seems like this is a process that will be limited to the vertically integrated apparel manufacturers of the world. And that is a pity, because this really does sound like a great innovation. But unless DyeCat can figure out the color match and lab dip issue, it’s not likely this innovation will see really widespread adoption in the apparel industry.
And a final thought about lab dips is how are people going to do the lab dips for fragrance molecules and optical brighteners? We can see designers falling out of windows to avoid being the anointed one to handle lab dips that need to have both color and scent matched. Fashion design curricula may need to add more chemistry at this rate.