Working with screen printing inks whether it be water-based or plastisol is a major component in screen printing. You will have to store and dispose of them properly or else there will be major repercussions if these things are done irregularly. This article’s purpose is to demonstrate to you how to do these tasks the right way to avoid missteps.
What is the right way to store and dispose of screen printing ink? Inks must be always maintained at room temperature whether they are stored or used currently. This is to maintain their usefulness and prevent waste. For disposal, there are rules and regulations to be followed here. Options here are water disposal, recirculation systems, and water filtration.
There is also a lot of common sense involved especially with waste disposal. For one, printers should know just how much ink would they be needing for this particular print job. I will discuss these things further and the screen printing inks storage and disposal options.
Storing Inks
The most important benefit that you can get when you store your inks properly is that it will be saving you unnecessary expenses and time.
Let’s face it that you do not prefer to use broken down and spoiled inks for these will definitely affect your prints. You will just end up throwing them away and getting new batches to replace them. This is such a waste.
Image by stokedonprinting
Inks Must Be Kept At Room Temperatures
The right temperature to maintain for your inks should be between 65 – 90F. Anything higher than this will automatically cure your inks which would lead to gelling. The ink consistency will then be compromised when you start using it. This will also make your ink develop odd textures.
Temperatures lower than this suggested range would make your water-based inks freeze. This will also have an impact on the ink’s consistency.
Just to be proactive, always check that the temperature is maintained at this level in all areas of your shops.
There could be locations there that are affected by direct sunlight and away from windows which makes the temperature higher compared to the rest of the room. Avoid placing your inks near walls that are exposed directly to sunlight especially during summertime. When inks are taken out for production, it is very critical that they aren’t exposed directly to the sun’s rays.
Places that are within uninsulated areas would tend to have lower than normal temperature prescribed.
No Sticks And Scoops In Ink Buckets
I know that this is extra work for you, especially when doing a big print job. However, do remember the effort and money spent compared to the little time needed to remove these sticks and scoops in ink buckets that will be reused later.
Stir sticks or scoops, especially if it’s made of wood or cardboard, have an effect on the texture and functionality of the inks. Absorbent materials that are allowed to remain in the ink buckets will absorb the plasticizer from the ink. This will have an eventual effect on the ratio of plasticizer to the ink.
Ink Bucket During Production
I suggest that you immediately replace the lid back on the ink buckets. Make this a habit so that this will become automatic for you while printing.
Inks on the production floor can easily take in the lint and other contaminants floating around the shop.
Avoid situating your inks near the conveyor belt and flash cure unit for the heat generated by these machines will cure your inks. Do not ever leave your ink buckets on top of the cold floor especially during winter time.
Another good practice here is to always stir the inks before using to smoothen the texture and to see if there inconsistencies and irregularities.
If there are any unused inks left from production, use a separate bucket to store them and label properly for easy identification. Do not put them back where they are taken from to prevent chances of spoilage in case the one that you used are already in this state.
Other Ink Tips
If the ink is being transported, do not place at the rear of an exposed pickup truck where it will be affected by the elements. Always check that there is a roof on top of these vehicles to protect these inks properly.
Keep the lids tightly sealed on the ink buckets always.
If you will be using an ink that has been in storage for an extended time, consider adding a reducer first prior to use.
Reducers are additives that lower the viscosity of the ink thus rendering it easier to print especially on high mesh screens. There are now two types of ink reducers used – plasticizer and curable reducer.
This will improve the feel of the garment to your hands and you don’t have to be concerned about ink cure times.
Although there is no limit to the amount of reducer that you can add, there are guidelines that must be followed. An increased amount of reducers will add more time to curing periods. Added reducers will also lower ink viscosity, bleed resistance, and opacity.
Disposing Inks
There are very stiff penalties for improper ink disposal. As a responsible printer and person, it is your obligation to check with all the federal, state, and municipal rules, regulations, and ordinances on this matter. You simply cannot claim ignorance as an excuse.
It is also your responsibility to educate your employees on this matter.
Disposing of Plastisol Inks
You are probably aware that plastisol inks are the more popular ink used in screen printing because of its cheaper prices. Since they are made primarily of chemical compounds, they contain more toxic materials, therefore, making them stand out as non-environmental friendly products.
Plastisol inks are cured when used. Fully cured plastisol inks can be disposed of through the local waste program. Contact your local government office for this to be sure.
Uncured plastisol can be recycled assuming there is a program in your community. Again, make the call to check first.
If there is none, you will have to use a licensed chemical waste disposal company to do the job and this is quite expensive. However, some of them offer a class on how to disposal wastes properly so do yourself a favor and participate here.
Find out from these companies as to how are they disposing of these inks. Incineration method will completely dispose of these wastes which will remove cleanup liability later.
Keep records of all your waste disposal activities for there will be a strong possibility that governmental agencies will come knocking on your door to see your compliance records.
There is obviously a common sense approach with regards to these inks and that is through an ink mixing system.
Just mix the right amount of ink you will need for the printing job. This will avoid the complication of what to do with excess ones. However, you can use remaining inks later or with other colors and inks.
Disposing Of Water-Based Inks
Pigments and binders in the water-based inks would have to be safely disposed of. They are composed of formaldehyde, oil, alcohol, and other chemical solvents. Their relative composition may make them hazardous therefore effective candidates for waste disposal.
Your municipal waste program may accept these inks after a period of time to allow for water evaporation. Check with your contacts.
Other Wastes
Handling materials such as paddles, ink stirring sticks, scoops, buckets, rags, and other items would also have to be disposed of properly or recycled, if possible.
Ink containers must be completely empty when disposed of. You can dispose of the metal drums to reconditioning companies for further reuse.
Cardboard drums have manufacturers instructions in them for proper disposal. Follow these instructions properly. If these same drums have liners, they can subsequently be crushed and thrown as garbage.
Plastic containers can be reused once cleaned properly.
Finally, I want to discuss other pertinent topics on this subject.
Recirculating Systems
This system is intended to minimize waste through the siphoning off the clear chemicals at the top of the container for further use by mixing it with a fresh product. The solid wastes that are settling in the bottom of this same container will also be collected and disposed of.
If you will use this system with an automatic screen cleaning machine, then you will effectively reduce your wastes. You will also achieve savings here for you are reusing your chemicals.
Water Filtration Systems
These systems protect your own plumbing system from these toxic chemicals aside from minimizing the environmental impact of your wastes.
First, solids, such as raw inks, solid inks, and tape, are filtered out. The wastewater is captured separately and set on a filtration process before finally being sent to a septic tank or made to dry outside for solid disposal.
Waste Disposal Companies
I mentioned earlier that licensed chemical waste disposal companies can help you dispose of ink wastes. They will remove these wastes from your workplace and leave you with a manifest letter stating as to how they will dispose of these materials.
You can use their waste container or purchase your own. These same containers may contain the solid wastes especially when you are recirculating your chemicals.
