UV Printing vs. Solvent-Based Printing
Choosing between UV-curable and solvent-based inks comes down to the part material, how the ink runs on the press, and the drying or curing equipment available. This guide compares the two systems for industrial pad printing and screen printing.
Cure under UV light
The ink needs a compatible UV source and enough energy to cure the ink film. A dry surface alone does not confirm full cure.
Dry by solvent evaporation
Solvent evaporates as the ink film dries. Two-component inks also react with a hardener to develop their specified resistance.
UV curing vs. solvent evaporation
UV-curable ink hardens through a chemical reaction triggered by ultraviolet light. The lamp type, wavelength, UV intensity, UV dose and ink film thickness affect the result. Set and check the curing conditions for the ink series and printed part.
Solvent-based ink dries as its solvent evaporates. The approved thinner adjusts printing viscosity and evaporation speed. In two-component (2C) inks, the hardener also reacts with the ink binder. Once mixed, the ink has a limited pot life: the time it remains usable for printing.
Both ink types are available for pad and screen printing. UV-curable does not automatically mean solvent-free. Printcolor Series 747, for example, permits specified thinners. Additives must be selected for the individual ink series.
Technical references: Printcolor 747 data sheet (PDF) · Printcolor 600 auxiliaries (PDF) · Nazdar UV cure guidance.
UV vs. solvent-based inks in production
Compare drying time, ink transfer, adhesion and the cost of running the complete job. Neither ink type is automatically more durable or less expensive.
| Consideration | UV-curable | Solvent-based |
|---|---|---|
| Drying and cure | The ink cures under the specified UV exposure. Follow any additional processing or conditioning requirements in its data sheet. | Solvent evaporates as the film dries. Two-component inks also need time and suitable conditions for the hardener reaction. |
| Ink on the press | Protect the ink from stray UV light. Follow the series-specific guidance for viscosity and additives. | Evaporation changes viscosity. Thinner or retarder selection affects ink drying in the screen and transfer from the pad. |
| Equipment | Match the UV source, output and exposure time to the ink. Make sure the curing setup reaches every printed area. | Use the air-drying, forced-air or heated-drying conditions specified for the ink. Allow for drying space and handling time. |
| Adhesion and resistance | Test the actual material or coating after the required cure. Pretreatment may be needed. | Test the actual material or coating after the required drying and cure. For 2C inks, confirm hardener type, ratio and pot life. |
| Emissions and handling | Do not assume zero solvent. Review the ink, additives and cleaners, as well as the UV equipment safeguards. | Account for solvent released during printing, drying and cleaning. Follow the safety data sheets for handling and ventilation. |
| Production cost | Include curing equipment, maintenance, energy, ink consumption, production speed and rejected parts. | Include ink, thinner, drying time, ventilation, labor, drying space and rejected parts. |
Review UV curing and IR drying equipment alongside the available Printcolor screen printing inks and pad printing inks. For digital equipment, see direct-to-object digital printing machines.
Troubleshooting drying, cure and adhesion
Before changing ink series, check the conditions that affect the failed print.
The print fails an adhesion test
Check surface cleanliness, pretreatment and ink suitability. Then verify UV output, exposure and ink film thickness; an undercured print can look dry.
Ink dries in the screen
Check the approved thinner or retarder, shop temperature, airflow and pauses between print strokes. Use the addition limits in the ink data sheet.
The print fails a chemical-resistance test
Confirm the ink series, hardener ratio, pot life and cure time. Test against the actual chemical and exposure conditions required for the part.
Printcolor UV and solvent-based ink examples
These are examples, not interchangeable inks. Substrate listings are starting points for testing, not approval for every material grade or coating.
UV screen printing ink for plastics
Series 567 lists rigid PVC and polystyrene among its substrates. Applications include labels, signs, displays and tubes.
Printcolor Series 567 specificationsTwo-component solvent-based screen printing ink
Series 640 is intended for metal and plastic parts, including signs and cover plates. Printcolor specifies chemical and weather resistance for this series.
Printcolor Series 640 specificationsUV-curable pad printing ink
Series 747 lists rigid PVC, ABS, polyamide and polycarbonate among its substrates. Its technical data sheet also specifies the permitted thinners and UV curing conditions.
Printcolor Series 747 data sheet (PDF)One- or two-component solvent-based pad ink
Series 752 lists ABS, rigid PVC and polycarbonate among its substrates. Confirm the required one- or two-component process for the application.
Printcolor Series 752 specificationsHow to choose ink for your part
Start with the part and its end use, then match the ink and processing conditions. Have these details ready when discussing an application with Deco Tech.
- Material and surface. Specify the plastic grade, metal or coating, plus any mold release, cleaning or pretreatment.
- Printing process. Pad or screen printing, image size, ink coverage and required production speed.
- Drying or curing equipment. Identify the UV source or dryer, current settings and space available on the line.
- Finished-part requirements. List the chemicals, abrasion, weathering or flexing the print must withstand.
- Test conditions. Provide the acceptance test, exposure conditions and time allowed for the ink to dry or cure before testing.
UV vs. solvent ink questions
Is UV ink always more durable than solvent-based ink?
No. Compare the specific ink series and test conditions. A correctly processed two-component solvent-based ink can provide strong chemical and weather resistance; a UV ink still needs the correct substrate preparation and cure.
Does UV printing eliminate solvent handling?
Not necessarily. Some UV-curable systems permit solvent additives, and cleaning products may contain solvents. Check the actual formulation, approved additives and safety data sheets rather than treating all UV inks as solvent-free.
Can I use the same thinner for pad printing and screen printing?
Only when it is approved for both ink series. The solvent blend, evaporation speed and addition level must suit the ink and printing conditions. Do not assume that the same thinner or mixing ratio works in both processes.
Need help choosing a printing ink?
Send the material grade or coating, a photo or sample of the part, and the required chemical or abrasion resistance. Include your current ink series and drying or curing equipment.
