4 types of flexographic inks: Whitch is the best?
What is the flexographic ink?
Flexographic ink is a type of ink that is particular to flexographic printing. It employs flexible plates to transfer ink onto different substrates such as paper, plastic, and even fabric. This type of ink is usually fast drying enabling it to withstand multiple prints without compromising quality or color vibrancy.
Importance of Choosing the Right flexo printing ink
In flexographic printing, picking the right ink has to be one of the most important decisions.
| Aspect | Importance | Consequences of Poor Selection |
| Ink Type | Ensures the right adhesion and coverage for high-quality prints. | Inadequate adhesion, excessive smearing, and insufficient coverage. |
| Surface Tension | Affects the ink’s ability to transfer and adhere to the substrate. | Poor ink transfer, low print quality, inconsistent results. |
| Dyne Levels | The ink moves to areas with lower dyne levels, ensuring proper adhesion and smooth printing. | Poor ink adhesion, print defects, and misalignment. |
| Productivity and Efficiency | Right ink selection leads to smoother production and fewer issues during printing. | Increased maintenance costs, delays in production, and excessive smearing. |
| Maintenance and Downtime | A well-chosen ink reduces the need for constant maintenance and prevents issues during printing. | Increased downtime, higher maintenance costs, and longer setup times. |
Composition of Flexographic Inks
| Component | Function | Effects of Different Proportions |
| Resins | Bind the ink and form a durable film | Higher content improves adhesion and durability, but reduces flexibility |
| Pigments | Provide color and opacity | More pigments improve color vibrancy but can affect ink flow |
| Solvents | Control viscosity and drying speed | More solvents improve flow and drying speed, but may reduce color intensity |
| Additives | Enhance specific properties | Additional additives improve flexibility, adhesion, or UV resistance |
What are the 4 types of flexographic inks？
Flexographic printing inks fall into four main ink types based on the printing technology used and the requirements of the subtype. It is the same within this group of inks that has subdivisions based on the methods of drying/curing. These divisions are more two categories of flexographic inks: volatile inks and energy-curable inks. Now let us examine flexographic inks comprehensively:
| Ink Type | Key Characteristics | Applications | Benefits |
| Water-Based Inks | High surface tension, eco-friendly, low VOCs, minimal odor. | Corrugated packaging, food industry, elastomer plate printing. | Eco-friendly, odor-free, safe, suitable for multiple materials. |
| Solvent-Based Inks | Composed of alcohols, acetates, pigments, rapid drying, good adhesion to plastics. | Plastic packaging, shopping bags, industrial films. | Fast drying, durable print, excellent rub resistance. |
| UV and EB Inks | Cured by UV light or electron beams, fast curing, glossy, durable finishes. | Food packaging, industrial packaging, narrow-web printing. | Abrasive, heat-resistant, no curing time, high-quality print. |
| Oil-Based Inks | Made from hydrocarbons, pigments, slower drying, higher VOCs. | Publication printing, newsprint, high-volume printing. | Durable print, excellent pigment dispersion. |
Water-Based Inks
In water–based inks, the major constituents are water, pigments, and definers and drying agents to improve performance. Remember that Water-based inks are the most popular due to their eco-friendliness. The reason is that they have low volatile organic compound (VOC) content and low odor emissions compared to other inks.
Key Characteristics
Surface Tension: In comparison to other types of inks, water-based inks have the highest surface tension. This guarantees the substrate adhesion, which includes paper, cardboard, and some plastics.
Applications
Water-based inks are frequently seen in the corrugated packaging industry particularly in elastomer plate calling concerns. They are perfect for industries where food products are secured due to the need to focus on sustainability.
Benefits
Their emissions are minimal and they are eco friendly, odor-free and safe. Their scope of use extends to a variety of materials such as certain plastics and even paper which enables them to be used for multiple packaging applications.
Solvent-Based Inks
Composed of alcohols, acetates, and pigments, solvent-based inks are typically formulated with an 80 to 90 percent alcohol to 10 to 20 percent acetate blend. These inks are regarded to have very low drying times, as well as very good adhesion to challenging substrates.
Key Characteristics
A very important property is surface tension: Solvent-based inks have greater surface tensions than water based ink which renders them more useful plastic inks.
Uses
More commonly used in several plastic packaging products entails plastic shopping bags, industrial films, and other products needing fast drying varnishes. They are also typical in applications that use high speed rotary printing.
Benefits
Have very rapid drying times, very good print durability, and excellent rub and scratch resistance. While their performance is better than water-soluble based inks, they have a major disadvantage of emitting VOCs which when inhaled pose health risks. Thus, it makes their use less environmentally friendly when used in combination with other inks.
Ultraviolet (UV) and Electron Beam (EB) Inks
Energy-curable inks, such as uv flexo inks and EB inks, dry through a process that involves exposure to UV light or electron beams, which causes the ink to harden instantly. These inks are gaining popularity due to their fast curing times and high-quality prints.
Key Characteristics
Uv flexo inks: As the name suggests, these types of inks are cured with UV light, which in turn cures and dries in an instant, allowing the application of glossy, durable finishes on top of the surface. Uv flexo inks can be somewhat thick, however, they are always ideal for use on non porous surfaces.
EB Inks: Cured with electron beams, these inks one step further to become more eco friendly as they do not need photoinitiators.
Applications
EB inks are primarily used in food packaging, and industrial packaging solutions where resistance to damage is extremely high. However, UV based inks are commonly tended to in narrow-web printing, such as tags and labels.
Advantages
UV and EB inks are abrasive, chemically, and heat resistant. Their qualities in combination with the fact that they require no time for curing makes them ideal for any high speed or volume production setting.
Oil-Based Inks
Oil-based inks are made from hydrocarbons, pigments, and sometimes soy oil, with harsher solvents like naphtha or hexane. These inks are often used in more traditional printing methods but are now less common due to their environmental impact.
Key Characteristics
Surface Tension – These types of inks are known to have good pigment dispersion with them, however, their surface tension does not fare well against that of water-based inks.
Applications
Oil-based ink is widely used for publication printing in the production of newsprint and other printed materials that demand high volume. It is slower to lose its print quality, but it is not ideal for food packaging materials.
Advantages
They give a durable print and, at the same time, provide excellent pigment dispersion, but most oil-based inks tend to have higher VOCs and smell stronger which require proper ventilation, raising environmental issues.
Factors to consider when you choose a flexo printing ink
There are important things to keep in mind when selecting flexographic printing inks in order to achieve maximum performance, print quality, and cost. The most important ones are:
| Factor | Description | Considerations |
| Substrate Compatibility | The type of surface affects ink selection. Porous vs. non-porous materials require different inks. | Water-based inks for porous, solvent-based for non-porous. |
| Print Quality Standards | Some applications require high-quality, bright, and clear prints. | UV and EB inks provide high gloss and excellent quality. |
| Production Speed | Inks should support fast production speeds without sacrificing quality. | Solvent or water-based inks are ideal for fast production. |
| Environmental & Safety | Compliance with environmental and safety regulations, especially in food packaging. | UV and EB inks are safer and more eco-friendly. |
| Cost-Effectiveness | Consider the overall cost, including ink cost, waste, and efficiency. | High-quality inks like UV or EB may be more expensive. |
| Chemical Compatibility | Ink must be compatible with the substrate and other materials in the process. | Incompatible inks can cause issues like poor adhesion. |
Substrate Compatibility
The substrate type greatly determines what type of ink you select. Surfaces also differ in tension and the material selected, such as cardboard and paper or plastic films and foils, determines whether it is porous or non-porous. For example, as mentioned earlier:
Water-based inks have competitive advantages for use on porous substrates like paper and cardboard.
On the other hand, solvent-based inks work best on non-porous materials such as plastic films and foils due to their rapid drying and strong adhesion.
For substrates such as flexible packaging materials that require a high gloss finish, UV and EB inks are frequently utilized.
Expectations of Print Quality Standards
Certain applications such as packaging and labeling demand a high quality of print. In order to achieve bright colored graphics that are clear with well defined prints, consider:
Energy curable and EB inks have a high gloss, excellent print quality, rapid curing and are perfectly suitable for packages and labels.
Production Speed and Efficiency
Flexographic printing is known for its effective easily achieved production speed. To maintain high prints and the right performance:
Solvent or water based low viscosity inks are beneficial in speed intensive environments because they dry fast and promote rapid printing all while maintaining a high standard of quality.
Environmental and Safety Regulations
It is increasingly important to comply with environmental standards especially in food packaging and other sensitive applications.
In food packaging and other monitored industries, UV and EB inks are adequate options as they do not contain hazardous oils solvents.
Cost-Effectiveness
The selection of ink for a flexo machine should not only depend on its efficiency, but budget as well, To ensure quality and affordability:
Ink costs, waste reductions, and production efficiencies should all be incorporated in the total ownership cost. It is important to remember that while better quality inks like UV or EB will perform better, you need to justify their cost in comparison with the application.
Chemical Compatibility
The ink also needs to be compatible with the substrate and any other materials used in the production process. Failure to do so can result in various complications like low adhesion and ink bleeding.
Considering all of these factors—substrate compatibility, print quality, production speed, regulatory compliance, environmental damage, and ultimately budgeting—is the best way to achieve a quality flexo printed product.
Conclusion
In order to achieve a quality, efficient, and sustainable product, it is critical to choose the right flexographic ink.
Lishg aim to help you by providing advanced flexographic printing machines that are guarateed to work with all types of inks, providing unmatched results for your specific needs. We have the solutions and expertise to improve your printing results so trust us to enable your success. Reach out to us to learn more about what we can do for your business.
References
4 Types of Flexographic Inks & When to Use Them
Everything to Know About Flexographic Inks
Ink Types in Flexographic Printing
Choosing Flexographic Inks for Printing
