Ensure Successful Screen Printing with Proper Tools and Safety
Learn the five must-have supplies to keep handy at your press and the top safety precautions for quality, accident-free printing.
August 08, 2012
Having the proper tools and supplies on hand is the first step in successful screen printing.
Equally important are simple safety precautions that will ensure your shop runs accident-free. In this article, I’ll provide insight on both, starting with what’s important to keep near your press workstation:
1. Pallet Adhesive: This is a pressure-sensitive adhesive designed for adhering textiles to printing pallets during the screen printing process. There are generally two types of pallet adhesives: solvent-based and water-based.
There are a couple of solvent-based adhesives available, and the first type I want to mention is the kind that comes in a spray can with two types of nozzles — a fine mist and a web type. Both are tacky and are designed to hold the garments to the pallet securely. But the web type generally is better for adhering heavier fabrics to the pallet, such as sweatshirt material. Another solvent-type adhesive is one that holds up better under the elevated heat generated by flash units. This type of adhesive withstands the higher heat without affecting the fabric.
The water-based adhesive often is sold in buckets and usually is applied using a squeeze bottle and then spread out to quickly dry on the pallet. This type is considered to be less harmful to the environment, equipment and to humans. It also may be more economical than the solvent-based spray type since a single application can be reactivated once coated with lint by dabbing it with a damp cloth.
2. Pallet Tape: Back in the day, it was necessary to clean the pallets with solvents to remove residues that had accumulated during the printing process. The build-up — mainly caused by excessive squeegee pressure, adhesive and lint from thousands of shirts — would start to degrade the print quality. Needless to say, the cleaning process would take hours and was very messy and unhealthy, due to the fumes printers were exposed to.
Today, we can use a repositionable paper called pallet tape that can be peeled away along with the build-up and tossed out. The pallet tape protects the print pallet from ink stains and spillage and replacing it is easy.
3. Proper tools: As a former race car driver, I know the importance of “the right tool for the job.” For example, I cringe when I see adjustable wrenches being used on expensive automatic printing machines. After years of continual adjustments without using the proper tools, the nuts and bolts used to adjust levels, heights, etc. on the automatic press most surely will be rounded and will need to be replaced.
Printers often just neglect to adjust anything on the automatics because they find it too difficult to do adjustments without having the right tools. The resulting print quality will not be optimal, and the machine’s lifespan may also be shortened. Invest in the right tools for the job!
4. Tape: There are a lot of inexpensive tapes being used to block out the edges of the screen and for on-the-press pinhole repairs. But beware: When it comes to tape, you definitely get what you pay for.
Often, cheap tapes will leave a glue residue that will have to be removed before a screen can be reclaimed. This residue can get everywhere: floors, sinks, hands, etc. By saving money on a cheap roll of tape you could be losing hours in production time. My advice is to check with your supplier on which tapes they recommend and do some comparisons.
5. Ink Handling Tools for the Press: Printers working in a medium- to high-production shop need to use something to handle the ink in the screen as it is being consumed on long production runs. Many shops use a square piece of cardboard that can work for the short term, but I have been in shops that print jobs with more than 200,000 shirts or more and, in such conditions, cardboard definitely is not the best tool to use. Why? Because cardboard soaks up the oils in the ink and the ink’s viscosity (stiffness) can be affected. Often, the cardboard gets left in the ink container, which then contaminates the entire bucket.
I recommend using plastic spreaders instead, the kind often used in automotive body shops. These handy plastic spreaders are readily available, are soft and pliable, and won’t rip a screen or soak up anything. (These spreaders are also used to apply graphics on vehicles.) Check with your local distributor for what they offer.
In addition to having the proper tools and supplies handy, shop safety is of utmost importance to successful screen printing. I started printing in my mid teens and in those early days of the screen print industry, safety was not always a top priority in the shops I worked in. As a result, I have had numerous injuries stemming from chemicals, electricity and machines. Here are some of the main categories I consider of high importance to take precautions in order to prevent injuries:
1. Cleanliness and Orderliness: I cannot stress enough how important something so obvious is to the screen print process. Besides it impacting your overall bottom line (for example, by keeping individual ink colors from being contaminated), it also may prevent injuries. Be sure to have designated places for all your inks, equipments and tools. This will help you spend less time locating missing tools or equipment, avoid tripping over misplaced buckets, and avoid cuts stemming from misplaced razor blades or knifes.
2. Chemical Safety Precautions: During the screen printing process, there are many chemicals that are used in and around the print process. Many are solvents used to clean screens, spills and equipment while others are mixed into the ink to thin or thicken the viscosity. Since chemicals can be inhaled or absorbed through the skin, be sure to use any solvents in well-vented areas only and use gloves where necessary.
I have burned my skin using Zylene/MEK solutions and even using UV inks, so it is a good idea to use preventative measures that protect your eyes, skin and nose (to prevent inhalation) whenever handling chemicals. Be sure to read the labels of any chemicals to determine what safety precautions need to be taken. A product’s MSDS (Material Safety Data Sheet) also lists first aid measures and more safety instructions.
Let me give you an extreme example: A can of spray adhesive accidentally ended up inside a dryer at a shop I was working in. The temperature in the dryer heated up the can and the highly pressurized contents, resulting in an explosion that set the dryer on fire. Luckily, no one got hurt but the dryer was damaged and production had to be stopped for a time.
3. Equipment Safety Training: If a shop has any electronic equipment — be it a flash, a dryer, or an automatic printing machine — every staff member needs to be trained on how to safely use it. Be sure that the machines also have the necessary safety guards or covers in place so that the engine parts are not exposed. I speak from experience here, as I have gotten my foot stuck in the chain drive of a dryer that didn’t have a cover over the engine part and have had my hand smashed by an automatic machine.
4. Electrical Safety Precautions: When dealing with electricity, take extra precautions such as installing a lock out box over the electrical controls. This way, if repairs are needed, the repairing mechanic can shut off the electricity, lock the box and not have anyone else turn it on accidentally while repairs are in progress. If this safety precaution is not possible, let everyone in the plant know when repairs are being made so that no one accidentally turns on the electricity. Whenever possible, schedule repairs after hours when the work crew has left.
Again, I am mentioning this because I have been shocked several times while fixing wiring on lights or wiring a plug and someone turned on the electricity, not knowing that I was working on the repairs.
5. Stay Alert: Many accidents happen in the workplace due to lack of alertness or common sense. To help combat tiredness or drowsiness, take breaks and keep hydrated. Moving or walking around also will help energize the mind and body. Also, keep distractions to a minimum when working in a high-paced environment, especially around automated equipment. Whether the distraction comes in the form of music, cell phones, computers or interaction with other coworkers, minimize distractions to focus on the tasks at hand.
Use common sense in avoiding accidents and injuries. While this is easily said, I know I’ve done some stupid things. Once, I asked a co-worker to throw a can of spray to me while I was standing on the other side of an automatic machine. I’m usually a good catcher, but this time I failed to catch the can and it struck my forehead instead. I still have the scar to show for it.
While this list is not exhaustive in preventing or avoiding accidents or injuries, I hope that some of these safety tips will help minimize some safety pit-falls at your shop.
Kieth Stevens is the Western regional sales manager for International Coatings. He has been teaching screen printing for more than 10 years and is a regular contributor to International Coatings’ blogs. For more information, visit iccink.com and read the company’s blog at internationalcoatingsblog.com.