Most of us try to be aware of the environmental impact of the choices we make in our daily lives — and that extends to our professional lives as well. Who doesn't want to make a positive impact?
It may be as simple as taking mass transit or as complex as tracking our carbon emissions and trying to live carbon-neutral. The point is that the environmental movement has become a mainstream, ongoing and important part of society and commerce.
Many companies worldwide also are making an effort to be aware of the ecological impact of their products, as well as their manufacturing methods and materials. This effort has become an increasingly important part of their business plans, as it can increase brand value and profit margin and, ultimately, could decrease production costs.
Screen printed T-shirts have doubled as billboards for pro-environmental sentiments as far back as the first Earth Day in 1970. Because T-shirts have been so closely associated with environmentally conscious lifestyle choices, it only makes sense that our customers look to us to lead this movement. Thus, our impact on the environment becomes especially important to our businesses.
Not only do we want to make responsible ecological decisions because of our sense that it is the right thing to do, but we are learning that it will help our businesses to be more successful and profitable.
The market will increasingly demand that we make the effort to be more sustainable and will reward the companies that do it well. In addition, we will likely see more regulations put in place to ensure that all companies use more environmentally responsible manufacturing processes. We also are seeing consumer backlash against unsafe products and manufacturing practices, and heavily polluting industries.
Like many other industries around the world, screen printers need to implement serious and ongoing "green" initiatives in our factories. Simply put, we should try to be leaders in the effort to use sustainable production methods and materials.
Sustainability is usually defined as the ability to provide for the needs of the world's population without damaging the ability of future generations to provide for themselves. Green, in this sense, could be defined as something produced with little environmental threat or harm by using sustainable practices. One simple but commonly accepted way to think about sustainability is to consider the following:
How much material is taken from the Earth to make the product? How soon is it replaced naturally? How persistent is it or how long will it take to return to its original natural components?
Smart Screen Prep.
If you plan to sustainably screen print T-shirts, the first consideration should be film output. There are numerous devices available, and each has a different impact on the environment. A traditional imagesetter uses photographic film processed with chemicals. Although these imagesetters can produce film at very high resolutions, they are the least environmentally friendly output option available.
There are now a number of high-quality, Postscript-capable inkjet printers on the market that will print directly onto a clear polyester material that replaces chemically processed film. Even though these units have lower resolution than a standard imagesetter, they work fine for creating screens to print garments.
As a general rule, we can only make use of a resolution that is twice the final line count of the halftones used in the art. Because these inkjet printers don't use chemicals to process film, they are an improvement ecologically.
The newest option available is an output device that prints the image directly onto the screen for exposure — direct-to-screen (DTS), also known as computer-to-screen (CTS). These perform similarly to top-quality inkjet devices and are arguably the most environmentally friendly option in that no film is needed.
Therefore, film is not wasted, no chemicals are used for processing and there's no need to store or dispose of the film later. The emulsions used in making the screens usually depend on the type of ink that will be printed through the screen rather than any particular environmental concern.
We Ink You Can.
The inks used in screen printing generate the most concern, but they also provide the most opportunity to use green processes and sustainable materials. Plastisol inks are generally considered the easiest and most versatile inks for printing apparel. They also are commonly considered the least "green" ink option available.
While there is some genuine debate about this, my opinion is that plastisol inks are probably the least sustainable ink system used. These inks are made with polyvinyl chloride (PVC) resins.
This material is often considered objectionable to the sustainability movement because it is a heavily manufactured, non-natural material. PVC is persistent in the environment as it does not easily break down into natural components.
On the positive side, this is why plastisols are very durable and why plastisol prints will last much longer than the shirts on which they are printed.
Although the PVC used in inks form an extremely small percentage of the total amount of PVC manufactured, some environmental groups would like to see its use curtailed completely.
The good news is that within the print shop itself, plastisol inks can be handled in a completely sustainable way. The ink has a very long shelf life and it can be re-used almost indefinitely — therefore generating very little waste.
The ink does not cure by evaporation like water-based ink or other solvent-based inks. A closed-loop filtration system can easily be used during screen cleanup to control any material entering the environment.
Additionally, standard plastisols are easy to use and have unique performance characteristics. Plastisols allow the creative garment decorator to produce spectacular prints and special effects that are difficult or impossible to duplicate with other materials.
Plastisols are versatile. They can be used to create everything from densely textured designs to very subtle, soft-hand prints. Plastisols also are easily used in variable opacities and can be mixed to match nearly any color that's specified for garment decoration.
However, standard plastisol inks do present other environmental concerns. In addition to PVC, most plastisols contain a small amount of chemicals called phthalates. Phthalates are a large family of colorless, oily, liquid chemicals generally used to make vinyl soft and flexible.
Although they do a good job of this, there are some concerns and regulations regarding these chemicals. While the actual dangers of the phthalates used in inks are being debated, the major plastisol ink companies now offer many of their products in non-phthalate versions.
These non-phthalate inks are not as easy to work with as standard plastisols, but it is possible to use them to accomplish most of the common printing techniques.
They lack some of the softness and flexibility of their standard plastisol counterparts, which makes them slightly more difficult on the press. Nevertheless, while these inks still contain PVC resins, they can be a good compromise that satisfies concerned customers.
In addition to non-phthalate plastisols, there are some new acrylic-based screen printing inks that are sometimes referred to as non-PVC and non-phthalate plastisols. Why? Well, an acrylic-type resin replaces the PVC resins used in regular plastisol.
Also, the plasticizer in acrylic inks is normally non–phthalate, making these inks an even more eco-friendly alternative. Most of these acrylic inks have a fairly reasonable shelf life and can be re-used like standard plastisols.
Acrylics do have some of the same performance characteristics as standard plastisols, though they can be a little more difficult to print with and don't cure the same way. It can be hard to get a soft-hand print with these inks.
However, as with standard plastisols, the halftone and detail are very good. With some experience, acrylic inks can be successfully made into high-density designs. The finished prints lack the soft finish of a standard high-density plastisol print, but this may be an acceptable compromise to some customers.
Clear gels and clear gloss acrylic inks also are available. There are some performance drawbacks with these gels regarding stickiness and the amount of gloss but, again, they may provide an acceptable compromise.
Acrylic inks are usually a little more costly than standard plastisols and are substantially more expensive than standard water-based inks. As far as opacity, printability and ability to hold fine detail, they work well. Depending upon the type of printing you need to do, they can be a good alternative with regard to any green printing initiative.
Just Add Water.
An entirely different approach is to use water-based inks. There are many types of water-based inks available and each has very different performance characteristics. Some are very eco-friendly and can be used as part of a highly sustainable printing process. There are, however, some performance limitations with all water-based systems — so you have advantages and disadvantages.
There have been substantial improvements in water-based printing technology, but it's still not possible to duplicate all the varying looks a good printer can achieve with traditional plastisol inks.
There are very few water-based specialty inks, with the exception of puff, reflective and some jewel-tone inks. Also, there are no water-based inks that can do high-density or gel prints, and that will likely remain impossible with water-based inks for the foreseeable future.
Unlike all the plastisol inks we have discussed, water-based inks cure as water evaporates out of the ink. This means that the water — along with whatever in the ink evaporates with the water — enters the environment.
That's why proper shop ventilation is critical when using water-based inks. It also means the curing time is longer and more difficult to control.
Finally, all water-based inks can start to dry out during use, and overall shelf life is limited. This can make printing more difficult and, depending upon the type of water base, can limit the mesh count you can use and, therefore, the detail you can achieve in a print. The limitations of water-based inks are most apparent with "traditional" water-based inks.
These inks are inexpensive and easy to manufacture. In fact, with some experience and the proper equipment, printers can make them in small batches from basic natural components. These standard water-based inks have a very soft hand but little opacity and are generally used only to print light-colored shirts.
They have a very limited shelf life and are difficult to re-use, so they generate more wasted ink than regular plastisols or more complex, manufactured water-based inks. While this type of water-based ink is considered a very green alternative, this extra waste is something to consider.
Watering the Dark Side.
Of course, these thin, water-based inks cannot print on dark shirts. An eco-friendly alternative for printing darks is water-based discharge ink. This type of ink is very similar to traditional water-based ink, except that a chemical is added to the ink to remove dye from the garment being printed.
The chemical will bond with the dye and evaporate with the water during curing. This will work properly only on garments made with fabric colored with a dischargeable dye.
Using this chemical limits how eco-friendly we can consider this type of printing. Some of the chemicals that can be used for this are not as problematic as others, but adding any chemical for the purpose of discharging the garment dye affects the eco-friendliness of these inks to some degree.
In addition, once the chemical has been added to the ink, the shelf life decreases substantially. These inks generally require disposal after just 24 hours. Color matching also can be very difficult with discharge inks.
To prevent some of these issues, you can use a discharge ink as an under print and then print colors on top using non-discharge water-based inks. This limits the waste and chemical usage to only one color. The hand of a discharge/overprint is still very soft and the opacity of the print is improved.
Exact color matching still can be difficult, but it is much improved over printing multiple discharge colors. However, the flash time for water-based inks — including discharge — is longer than for plastisol inks, slowing production times.
There have been some major improvements in manufactured water-based inks in recent years. These newer inks have a number of performance advantages over the basic water-based inks discussed above and are as potentially eco-friendly and sustainable as any alternative.
Much like traditional plastisol, these water-based inks are sold ready to use as colors or underbases and have a thicker viscosity that yields greater opacity on finished prints. They can be reduced with water and other modifiers for a softer hand.
These new water-based ink systems resist drying, and remain useable far longer than traditional water-based and discharge inks. They can be re-constituted with water — and additional binder, if needed — which can cut back on waste. Shelf life of these newer water-based inks is substantially longer as well because the manufacturers have developed technology to encapsulate the water in the ink in such a way that it does not readily evaporate until printed.
Taken together, the properties of this new generation of water-based inks can be used to print greater detail and finer halftones through higher mesh screens. Unlike traditional water-based inks, the opacity of these new inks allows them to successfully print on dark garments, typically on a white underbase just as you would do with standard plastisol inks.
In short, the performance characteristics of these new water-based inks allow them to reproduce many of the same types of prints as plastisol.
By carefully adjusting viscosity of the colors — and, therefore, opacity — bright prints with excellent color matches are possible even on dark shirts. This new group of water-based inks is probably the most eco-friendly printing option on the market.
They are an obvious choice for any printer making an effort to use sustainable materials and methods.
On the down side, cost of these inks is generally much higher than traditional water-based inks. Even with the better performance and in spite of the higher price, special effect prints — such as high-density and gel effects — are not possible with these inks.
There also are many other compromises you have to make when using these new inks. The soft hand and the opacity need to be balanced, especially when accurate color matches are needed on dark garments. It requires a great deal of practice and experience to modify and use these new water-based inks to achieve all the different looks needed by most customers.
Having said all that, I think it is definitely worth the effort to become adept with these different types of printing materials to become as eco-responsible a printer as possible. In addition to film, inks and printing methods, there are numerous other aspects to any successful green initiative.
The clean-up and screen reclaiming areas in most screen printing factories are an obvious and important place to look for ways to improve ecological impact. Better and more complete filtration systems, newer technologies, cleaner and less damaging chemicals, and water usage limitations are all ways to make a factory more eco-friendly.
Take a careful look around your shop and you'll see many obvious ways to become more sustainable. For example, a roll-on, water-based adhesive for the printing platens can replace aerosols. Use less water throughout the shop and you can employ more environmentally friendly clean-up solvents and materials. Finally, monitoring and regularly cleaning the dryers can save energy.
We should all regularly evaluate every aspect of our production to see how we can become more responsible printers. This is the best way for us to continually upgrade to the most sustainable methods and materials available.
The Medium of Screenprinting explained
Screen printing, also called silk screening and serigraphy, is a fascinating and highly versatile printing technique that can be applied in many forms of arts and fashions. SilkScreeningSupplies.com has an excellent 10-minute overview video on silk screen / screen printing and a series of instructional how-to videos on screen printing. SilkScreeningSupplies.com, the Web sales engine for Ryonet Corporation, does sell some environmentally friendly soy-based cleanup products along with many not-so-environmentally-friendly inks and screen printing chemicals.
Unfortunately, conventional screen printing can be damaging to the environment, health of printers and wearers of silk screened fashions because of the toxicity of many of the chemical inks, cleaners, preparation products and waste products from the silk screening process.
Basically, there are two main categories of screen printing inks: plastisol and water-based. Each has their technical printing advantages and disadvantages. Water-based inks are less toxic with fewer health and environmental hazards, but they are more difficult to use and offer less creative freedom. Plastisol inks do not soak into the fibers of the cloth like a dye or water-based ink; they wrap around and coat the fibers with a mechanical bond rather and a chemical bond.
Plastisol inks, commonly used for textile printing and especially for tee shirts, are a thermoplastic PVC-based ink composed of a clear, thick plasticizer fluid and PVC resin. The full name for PVC is â€śpolyvinyl chlorideâ€ť. According to Union Inks, â€śPlastisol inks are innocuous when used with reasonable care. A true plastisol ink contains no air-polluting solvents or volatile organic compounds. The manufacture, transportation, storage, use, and disposal of plastisol inks do not cause injury, illness, or environmental contamination as long as the appropriate safety and environmental protection procedures are followed. Most plastisol inks have a Health Rating of 1 (hazard - slight), a Flammability Rating of 1 (hazard - slight), a Reactivity Rating of 0 (hazard - minimal) and a Personal Protection Rating of B (wear safety glasses and gloves).â€ť
The major health concern about plastisol inks is not that they are PVC-based but that they contain phthalates. Phthalates are added to PVC plastics to transform a hard plastic into a soft, rubbery plastic by allowing the long polyvinyl molecules to slide against each other instead of rigidly binding together. Phthalates are more ubiquitous than lobbyists in Washington, DC. About 800 million pounds of phthalates are produced each year globally and they are used everywhere in a wide array of products such as cosmetics, perfumes, paint pigments, hair sprays, wood finishes, plastics used in making medical devices, automotive interiors, toys, soft rubber handles of kitchen utensils and workshop tools, and many, many other products â€¦ including textile screen printing inks.
Medical research has linked high doses of phthalates to damage of the liver, kidneys, lungs and testes in rats. Another medical studyRecent research at the U.S. Environmental Protection Agency strongly suggest that low levels of in utero exposure in rats to some classes of phthalates cause abnormalities in reproductive system development of male rat newborns. And there are a host of other studies casting concern about the health consequences of different classes of phthalates. suggest that phthalates contributes to allergies in children.
Even California Governor Arnold Schwarzenegger has jumped on the issues of phthalate safety and health concerns when he signed legislation on 7 October 2007 banning phthalates in toys and other product intended for children 3 years old and younger. Arnold decreed that â€śThese chemicals threaten the health and safety of our children at critical stages of their development.â€ť
But, the phthalates industry has been pushing back hard and donâ€™t forget that phthalates are a huge global industry that touches countless products around the world. Phthalates.org presents a strong defense for the safety of phthalates. They cite that a number of studies have found some classes and dosage levels to be safe or failed to support health concerns. They state that â€śNo governmental review has found any phthalate unsafe as used in products for the general public.â€ť Depending upon how you parse that statement from Phthalates.org that might â€¦ or might not â€¦ be factual. Levels of exposure also affect results and phthalates are a large class of chemicals with varying affects on the human and animal physiologies.
Exposure to one product containing phthalates might not cause reproductive organ abnormalities, cancer or asthma in children but when a small exposure comes from hundreds of sources everyday then the effects are uncertain but probably accumulative. Multiple chemical sensitivities are the result of a thousand chemical straws gradually wearing down the bodyâ€™s natural immunities breaking the back of the bodyâ€™s resistance to environmental impurities. According to the Phthalates Ester Panel of the American Chemicals Council, the EPA under the Great Lakes Water Quality Initiative has classified phthalates as non-bioaccumulating meaning that the body will not retain phthalates in tissues or organs. We will leave it to you to review the literature to decide to what degree you wish to expose your body and health to phthalates.
If you wish not to invite phthalates into every nook and cranny of your life, you might want to exclude them from your clothing which comes into close, personal and extended contact with your absorptive skin. And one way to do this is by requiring that your printed and silk screened clothing be printed only with inks free of phthalates and PVC's such as those from Chopper Couture.
To meet the growing demand for healthier clothes, more and more textile ink manufactures and suppliers and commercial silk screen printing shops are offering garment inks free of phthalates.
One of the more interesting commercial screen printing companies is T.S. Designs and their REHANCE screen printing process which avoids using plastisol inks. TS Designs trumpets their new REHANCE printing process, which they developed in conjunction with Burlington Chemicals, as using a new technology of water-based chemistry for printing and dyeing fabric where the print chemically bonds with the cellulose fiber of the fabric. This bonding makes the screen printed fabric more breathable and softer to the touch. It also means that clothing printed with REHANCE can be ironed without worry of the plastisol inks melting.
In addition to having significant personal health and environmental safety benefits by being free of PVCâ€™s and phthalates, REHANCE also offers design and quality improvements. Another interesting feature of the REHANCE technology is that the design is printed on the fabric first and then the garment is dyed in whatever color the designer wishes. Conventional screen printing requires that the clothing be dyed first as that effects the types of inks that can be used in the screen printing. Designs printed with REHANCE will not flake or chip away after repeated use and washings like designs done with conventional screen printing using plastisol inks.
The Lancer Group International, a leading manufacturer and supplier of plastisol inks and screen printing equipment, is also greening their silk screening inks with their new EvolutionÂ® PVC Free Inks that print like conventional plastisol but do not contain PVC or phthalates. Instead, EvolutionÂ® PVC Free Inks are made with non-PVC resins and non-phthalate plasticizers.
Most non-PVC and non-phthalate inks are acrylic-based. An acrylic resin replaces the PVC resin in typical plastisol inks and the plasticizers used do not contain phthalates. Acrylic inks have many of the same favorable printing characteristics of plastisol inks but can be a little trickier to use in printing.
QuantumOne from Wilflex is another non-PVC and non-phthalate plastisol screen printing ink that has similar look, feel and characteristics of conventional plastisol screen printing systems.
The hazards of conventional textile printing inks are not just to personal health but also to environmental health. Garments coated with plastisol inks do not decompose and they are difficult to recycle. The result is that you may soon grow tired of your Rolling Stones concert tee shirt and trash it, but it will live on in immortality in the local landfill.
Screen printing is a messy business surrounded by solvents, cleaners, inks and other chemical compounds, many of which are environmentally hazardous, that are used heavily in the preparation, printing and cleanup. Regardless of the type of ink used, the waste waters from cleaning screens, squeegees, tools and the work area will contain pigments, binders, thickeners and solvents â€“ most of which are probably hazardous, non-biodegradable, and must be properly and environmentally disposed. Screen printing waste products can not just be dumped down the drain.
Michael Beckman has written an excellent article, â€śGreen Printing Uses Sustainable Methods and Materialsâ€ť, giving specific steps on how screen printers can improve the sustainability of the screen printing process. Michael Beckman, a highly innovative and respected authority on screen printing, is also the R&D manager in Portland, Oregon, of the European T-Shirt Factory, based in stanbul, Turkey.
The European T-Shirt Factory is an interesting green printing story with a strong â€¦ and sincere â€¦ sustainability focus supported by ethical workplace policies for their employees. For their large commercial clients like Nike, Adidas, Polo and Wal-Mart (of course), the European T-Shirt Factor does everything from the knitting of tee shirts using certified organic cotton on tubular knitting machines, to eco-friendly screen printing on the finest commercial screen print equipment, to packaging (including bar coding, tagging and bagging), to distribution directly to their retail stores. Besides screen printing, the European T-shirt Factory also does apparel embroidery in its Egyptian facility.
The environmental impact of screen printing is not just confined to the silk screening process and cleanup but also to the manufacturing of many of the chemicals used during the screen printing process. According to the textile printing experts at TS Designs, nasty dioxins are created during the production of PVCâ€™s. If clothing designed with PVC plastisol ink is incinerated, the trapped dioxins plus hydrochloric acid (a primary component of acid rain) are released into the atmosphere.
So what is the environmentally conscious consumer to do? If you have a Harley parked in your garage or have aspirations to cultivate a motorcycle biker chick mystique, check out the eco-fashions at Chopper Couture. If you are looking at screen printed clothing, ask the retailer if it is PVC-free and phthalate-free. Also ask if the textile was printed at a green eco-printing shop. Let retailers and manufacturers know that you are concerned about the environment and that you are an eco-conscious shopper.