No matter what kind of printing method can not be separated from the ink
Quick answer: In most UV systems, photoinitiators are selected by balancing wavelength fit, through-cure, color control, and line speed. Buyers usually compare a blended package instead of one isolated product.
No matter what kind of printing method is inseparable from the ink, this has become an inherent concept, and inkless printing technology will undoubtedly break this concept, if it can be achieved, this will become a new type of printing technology.
In inkless printing, the control system collects digital file information, and the microprocessor converts this digital file information into a series of emission instructions for each print head. The individual emitters in each print head then receive the corresponding data instructions, so that the specific pixels in the digital file are reflected to a specific point or area on the substrate, while determining the duration and/or intensity of irradiation required by each emitter in each print head. The color of each dot or area on the substrate is thereby changed to match the color of each image.
The individual emitters in each print head array have a dedicated radiation guidance mechanism. The guiding mechanism causes the radiation emitted by each emitter to form specific continuous or discontinuous irradiation points on the surface of the substrate. The radiation guidance mechanism consists of one or more lenses and/or one or more optical fibers adapted to each emitter.
The microprocessor can further manipulate the movement of the substrate with respect to each print head. This movement can be performed in a single direction or in multiple directions. Typically, the substrate moves unidirectionally in the direction indicated by the arrows, i.e., from the position irradiated by print head 1 to the position irradiated by print head 2 and then to the position irradiated by print head 3. In addition to the substrate can move, the print head can also move. For example, the width of the print head is smaller than the width of the substrate, and the print head can move in the direction of the arrow perpendicular to.
Throughout the movement, the substrate is sequentially irradiated by the radiant light emitted by the emitters in each print head. First, the infrared (IR)/near-infrared (NIR) light emitted by the print head is absorbed by the material in the corresponding region of the substrate, followed by an increase in the substrate temperature in that region, which activates the coacetylene material in that region from a low-reactive state to a high-active state. Subsequently, the substrate is exposed to UV photoresist from the print head, which causes the initiation of polymerization and color change of the coacetylene material. The color change depends on the exposure of the irradiated area. Finally further irradiation by infrared (IR)/near infrared (NIR) light emitted by the print head 3 completes the conformational change of the co-acetylene material. The reasonably sequenced thermal and UV radiation ultimately produces a change in the substrate from colorless to arbitrary color.
Since the emitters of each UV machine print head can be controlled individually, the specific sequence of irradiation for each area of the substrate can be diversified and controlled, resulting in a color image. The resolution of the image formed in this case will be determined by the size of the radiation dots formed by each print head; the smaller the dots formed, the higher the resolution.
UV ink raw materials : UV Photoinitiator Same series products
How formulators usually evaluate this photoinitiator topic
When technical buyers or formulators screen photoinitiators, the most useful decision frame is usually cure quality plus application fit: which package cures reliably, keeps appearance acceptable, and still works under the lamp, film thickness, and substrate conditions of the actual process.
- Match the package to the lamp first: mercury lamps, UV LEDs, and visible-light systems can rank the same photoinitiators very differently.
- Check depth cure and surface cure separately: a film that feels dry on top can still be weak underneath.
- Balance yellowing with reactivity: the strongest deep-cure route is not always the best commercial choice if color or migration risk becomes unacceptable.
- Use the final formula as the benchmark: pigment load, monomer package, and film thickness can all change the apparent ranking of the same initiator.
Recommended product references
- CHLUMINIT 819: Useful when a formulation needs stronger absorption and deeper cure support.
- CHLUMINIT 1173: A practical comparison point for classic short-wave UV initiation.
- CHLUMINIT ITX: A useful long-wave support route in many printing-ink packages.
- CHLUMINIT CQ: A direct reference for visible-light and color-sensitive curing discussions.
FAQ for buyers and formulators
Why are blended photoinitiator packages so common?
Because one product may control yellowing or lamp fit well while another improves cure depth or line-speed performance, so the full package is often stronger than any single grade.
Should incomplete cure always be solved by adding more initiator?
Not automatically. The real limitation may be the lamp, film thickness, pigment shading, or the rest of the reactive system rather than simple under-dosage.