A Step-by-Step Guide to Easily Switching to Water-Based Printing Inks
Environmentally friendly, safe to use for employees, easy to store - and all this with a print quality that is in no way inferior to conventional printing inks. In this article, André Altevogt, Director Sales Packaging Solutions, explains how you can utilise the advantages of water-based printing inks in the future. Because the changeover is easier than you think.
Environmentally friendly, safe for employees, and easy to store—all while delivering print quality that rivals traditional printing inks. In this article, André Altevogt, Director of Sales Packaging Solutions, explains how you can embrace the benefits of water-based printing inks. And the best part? Transitioning to them is easier than you might think.
Getting ready for technological change: water instead of solvents
Conventionally used coloured printing inks are based on:
- monopigmented colour concentrates
- coating binders
- a proportion of functional blends
Solvents such as ethanol, ethyl acetate and ethoxypropanol ensure the desired printing viscosity and drying behaviour. Water-based coloured printing inks do not use solvents: the water ensures the viscosity. The ready-to-print inks consist of monopigmented colour concentrates and at least 60 percent functional waste. And the most important thing for users: with the appropriate adjustments, you can achieve the same or better colour quality and brilliance as with conventional printing inks.
Why do printing companies still use solvent-based printing inks?
The answer to this question is often: out of habit. This is because most printing companies work with solvent-based printing inks. They have systems with which they extract and burn off the solvents. Print shops are also aware of the potential risks of working with solvents. Printing with water-based inks requires a rethink. We support you in the changeover. And throughout the entire process.
Before you change anything, we'll talk to you in detail
Have you decided in favour of water-based printing inks? Then let us advise you first. Because we won't start the changeover without a consultation.
Our focus is on the machines you have on site. We clarify how you can also use the machines for water-based inks. And, of course, we present our water-based inks and auxiliaries in detail and answer all your questions - until you are sure that the changeover will be successful.
We usually talk to managing directors and technical managers of printing companies. But of course we also talk to the people who are crucial when it comes to printing: the printing company manager, the printers, the colour preparation staff - in the ink kitchen. In this way, we take all the employees in your print shop with us in the technological change. In some cases, environmental managers or quality managers are also present during the consultation.
Water-based printing inks are more cost-effective
At first glance, water-based printing inks appear more expensive per kilo than solvent-based inks. However, water-based printing inks reduce production costs in almost all other aspects:
- Lower raw material costs: you only buy water instead of solvents - and this is not only easier to provide, but also cheaper.
- Lower costs for safety measures: Water-based printing inks have no risk of fire or explosion. This saves you costs for safety measures in production, storage and transport. And also on health and safety and insurance costs.
- No costs for exhaust air purification: No gases are produced during printing - you don't have to invest in expensive exhaust air purification and subsequent combustion.
So if you look at the overall costs, water-based inks are cheaper than solvent-based inks. This is proven by our many years of experience with customers.
These 5 steps will help you switch to water-based printing inks
At Follmann, we have supported companies in switching to water-based printing inks. The process takes around two to three weeks. With the following 5 steps, you too can make the switch without any problems:
1. In-depth consultation:
Are you looking for new printing inks or are you looking for a new, reliable supplier? We will advise you in detail and discuss with you how you can use water-based printing inks in your printing company.
2. The choice of colours:
You choose the colour, order and we deliver. We manufacture all our products exclusively at our German production site in Minden. The advantage for you: fast, reliable delivery.
New printing ink does not automatically mean new printing machines. A machine on which you previously worked with solvent-based inks can also be converted: You can then also use machines from your inventory with water-based inks.
Whether a new or used printing machine - you should pay attention to the following:
Drying of the ink film
- Provide a sufficient volume of air (adapted to the selected printing speed).
- The air must be dry.
- The air must no longer be charged with solvent vapours.
- For intermediate drying with a central cylinder press, you must adjust the air outlet speed, temperature, volume and angle of impact of the air to the ink film.
Ink feed
- Important: Parts carrying ink must not be made of aluminium or copper. Use ink containers, tubes and hoses that are suitable for contact with water-based inks.
- Water-based inks can foam during the printing process: To prevent this, the pumps should be adjusted accordingly.
- Do you already have a viscosity control system? This can also be used for water-based inks after appropriate adjustment. Make sure you have a water connection.
- You will also need to make adjustments to the chamber blade. Select the appropriate doctor blades and seals. Follow the recommendations of the machine manufacturer.
- Adjust the cleaning of the ink-carrying parts: We offer a cleaning agent adapted to our ink system for this purpose.
For printing standard print motifs, we distinguish between 4 categories with different requirements for the anilox rollers:
Screened halftones:
- Screen rulings up to 80 lines/cm
- Amplitude and frequency modulated anilox technology
- Anilox rollers with a theoretical transfer volume of 3.8 to 4.4 g/m² wet, from 240 lines/cm to 560 lines/cm
Fine line: anilox rollers with a theoretical transfer volume of 8.5 g/m² to 11 g/² wet, from 160 lines/cm to 250 lines/cm
Solid coating (surfaces): Anilox rollers with a theoretical transfer volume of 10 g/m² wet, from 120 lines/cm to 200 lines/cm
White and varnish: anilox rollers with a theoretical transfer volume of 12 g/m² wet, from 120 lines/cm to 140 lines/cm²
It's not just printing machines that you can rely on: Existing printing plates can also be used with water-based inks.
- Pay attention to the quality of the printing plate. Depending on the quality, the printing result with water-based inks may differ from the result with solvent-based inks.
- Coordinate the plate quality, base and anilox roller for optimum results.
- Configure the best system with a fingerprint: this allows you to determine the print characteristic curve in halftone and thus achieve ideal reproduction.
- Modifications to the plate surface during surface printing (microscreening) enable excellent colour transfer with closed areas.
We ensure that your water-based colours do not differ from your sample. You provide us with wet samples of the concentrates, topcoat binders and offcuts used as well as your existing formulations in an Excel spreadsheet, for example. We then use these steps to create RTU colour formulations:
- Recreate base concentrates with Follmann's water-based concentrates
- Calculate the required waste and water content for the appropriate viscosity
- Create comparative sand prints with the reconstructed recipes to determine the quality and make corrections if necessary
- Correct anilox roller, printing plate and base settings
- Save the existing recipe database as an offline data backup
We then feed the newly determined recipes into your system - from now on you can produce jobs with water-based printing inks.
4. Use the new colours - we support you and your employees
You can print with water-based inks on any machine. The following adjustments are essential before you start printing: Drying, ink feed, printing plate, anilox roller and viscosity settings. We agree a changeover plan with you and your employees. During the changeover, we support you, are available to answer questions and monitor whether everything is running smoothly.
Water-based printing inks are more environmentally friendly
The printing process with solvent-based inks produces harmful emissions. Companies have to neutralise these, for example by combusting them. However, combustion produces CO2. This increases the greenhouse effect. With water-based printing inks, you don't have to burn anything: You therefore produce significantly less CO2.
In addition, solvent-based printing inks contain VOCs (volatile organic compounds): During the printing process, these chemicals are released into the atmosphere. There they trigger photochemical reactions. VOCs can contribute to the formation of ground-level ozone. This has negative effects on human and plant health. In contrast, printing with water-based inks does not emit any harmful substances.
There are currently many recommendations to purchase environmental certificates for a competitive advantage. The trade in emission certificates is booming. It is better to produce fewer pollutants right from the start. That way you are prepared for current and future EU regulations on sustainability.
At the printing machines - we accompany your printers
Companies often forget the printers during the changeover. But it's not just a technical changeover. Printers have many years of experience working with printing machines: processes, handling and their entire working environment are changing for them. That's why printers are sometimes against the changeover. We attach great importance to involving the press operators in the process. Our team stands by the machines and trains them in the use of water-based inks. And we speak the printers' language - so the changeover goes smoothly.
One thing is particularly important to us: the print result after the changeover must be the same as before. Whether water-based or solvent-based inks - your customers should not even notice the change.
Water-based printing inks are efficient
With the right adjustments to the printing machines, you can achieve the same results with water-based inks
- the same results as with conventional printing inks,
- even higher-contrast halftone prints, because the dot prints more sharply and generates less dot gain,
- an average process speed of up to 500 m/min
In a test, a Bobst system even achieved a production speed of 800 m/min under optimum printing conditions. And this
- with consistent print quality,
- with very good drying of the colour film and
- without blocking in the roll.
We also achieved excellent bonding values in the subsequent lamination process.
