April '20

For the Business of Apparel Decorating

Issue link:

Contents of this Issue


Page 51 of 68

2 0 2 0 A P R I L P R I N T W E A R 4 9 degradant. Why use the chemistry only once when it is strong enough to use again and again? The key is to remove all residual ink from the screen before placing it into the dip tank. By first removing the ink you avoid staining the mesh which negates the need for haze-remover. I simply will not use haze remover, so the ink is removed then cleaned from the mesh with reusable rags prior to reaching the emul- sion degradant tank. This extends the life of the tank chemistry by avoiding ink sludge build-up that can weaken the tank's effec- tiveness. Make sure that you are recharging the tank with properly pre-mixed product as the reclaim tank chemistry evaporates or loses efficacy. Don't simply add more water or concentrated chemical. This will often work against you. If the product requires a 5:1 mixture, have a bucket of that mixture pre-made to add to the tank as needed. Recirculating chemical tanks are an effec- tive option for cleaning squeegees and flood bars. Some of the companies that offer these systems also offer removal and proper dis- posal of the used chemistry. Another tip to avoiding haze remover is to avoid using aerosol screen openers or press wash. You are wasting money on the can and the pro- pellant inside that can. Buy concentrated chemistry instead that you add water to in a reusable spray bottle. The propellant in your aerosol accounts for a portion of the weight you are unnecessarily paying to ship to yourself, never mind the fact that the aerosol chemistry can lock red and black ink stains into your screen mesh. While we are on the subject of tanks, con- sider adding a clear water dip tank to your screen making process. This tank is exactly what it sounds like, just a tank of clear wa- ter. As soon as your screens come off the ex- posure unit/system, place them in the clear water dip tank for no more than one min- ute. This will stabilize pure photopolymer emulsions from further exposing in ambi- ent room light, but more importantly, it will soften the unexposed emulsion on your screen so that it requires less energy and less water when applying your final rinse to the exposed screen. This also helps retain small details without washing away your screen stencil gasket. WATER WORKS Now that I've got you thinking more about how you can produce better screens with less impact on your local water treatment (and hopefully less impact on your bud- get), let's talk about your ink. We talked about buying your ink from a responsible manufacturer earlier in this article. What we did not cover are the different types of ink chemistries. The two main ink categories are plastisol and water base. Plastisol offers you the abil- ity to store and re-use leftover ink. If you buy your ink from a reputable brand that produces ink to be internationally compli- ant, plastisol offers you many options to prevent any uncured ink from leaving your facility. But what if you are required to be a PVC-free facility? There are PVC-free plas- tisols available, but they require a different approach to printing that requires more flashing. With that being said, we may as well look at water base. Water based sounds earth friendly, right? Well, again, that depends on who you source your water-based inks from. Water- based inks require their own chemistry to stabilize the product and keep it fresh. De- pending on where that water-based chem- istry came from, the word "water" does not promise the product is any less impactful than plastisol. Again, you want to be selec- tive with what brands you choose to print with. While responsibly developed water-based products are designed to eliminate restrict- ed substances from their formulas, they can produce more waste. You can control this by keeping your ink buckets sealed with lids, using an accurate scale to mix your inks, and by making use of the appropriate ink mixing calculator provided by the ink manufacturer. I know many of us are proud of our "mixing-by-eye" skills but remem- ber that the only way to correct a color is by adding more pigment. This means you are creating more waste at the end of the day. Use your ink calculator and reach out to your ink company's color matching labs. You are paying for that service when you pay for the ink, so you should use it. The benefit of water based that shines the brightest, aside from a soft hand, is that the cleaning chemistry is simply water. This means you are not paying for additional cleaning products, you are putting less stress on your water treatment system, and at the same time reducing your exposure to ag- gressive chemicals. At the end of the day, there is no perfect way to produce anything without hav- ing some sort of impact. The goal here is to identify and make use of responsible printing options, but more importantly, we have to reexamine our current print practices and identify where we can be more efficient and produce less spoilage and waste. Sustainability is a big picture is- sue. Simply clinging on to hot phrases like "green" and "eco" in product names is not enough. Considering how much wasted energy that can be eliminated in the form of electricity, gas, water, and human move- ment is just as important. Ask yourself if you are getting the most out of what you put your money and time into. PW John Magee has been involved with screen-printing and band merchandise since 1992. Additionally, he has also owned businesses in the Skate and Snowboard industry. Magee is currently a senior Technical Services representative at PolyOne. continued from page 48

Articles in this issue

view archives of Printwear - April '20