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Home / News / Industry News / UV Varnish Surface Always Adheres to Tape — How to Improve Surface Performance?
Industry News
UV Varnish · UV Coatings · Surface Performance · DH-4270
UV varnish relies on light curing to form the film, offering fast cure speed and high production efficiency — making it widely used in varnish, coating, and surface treatment applications. However, UV cure completion does not automatically mean the film surface state is ideal. In practice, some formulations develop insufficient film leveling, surface drag, high surface friction, or tape adhesion during subsequent use or processing — problems that relate to the resin structure, cure completeness, and surface additive selection.
Film Already Cured — Surface Not Flat Enough
UV systems cure fast. If the coating does not get sufficient flow and spreading time before cure, local surface undulations may remain — and adjusting application parameters alone may not resolve this from the formulation side.
Surface Friction Feel Noticeable
UV films typically have high hardness, but hardness does not mean the surface is necessarily slip. If surface friction resistance is high, both tactile feel and subsequent processing may be unsatisfactory.
Tape Adhesion After Lamination
Some UV varnishes are used in applications requiring tape, protective film, or lamination processes. If the film and adhesive material have strong interaction, peeling may show adhesion. Surface release performance therefore needs dedicated attention in formulation development.
Ordinary Leveling Agent and Surface Performance Difficult to Balance
Some additives primarily address coating spreading and film flatness, but when slip and tape release are simultaneously required, the compatibility between the additive and the UV resin, and its migration and fixation state during cure, need further consideration.
Why Surface Additives in UV Systems Need Reactive Consideration
Ordinary surface additives added to coatings participate in coating spreading and surface adjustment, but as time passes, their state in the film may change. For UV photo-curable systems, if the additive carries functional groups that can participate in the reaction, it can form bonding with the resin network during light curing — making it more stably present in the film surface layer. Therefore, when selecting UV surface additives, in addition to initial leveling and slip performance, consideration should be given to whether the additive can participate in the cure process and the surface state after cure.
DH-4270: Reactive Surface Additive for UV Varnish Systems
DH-4270 is a UV varnish surface additive with reactive acrylic functional groups that can participate in polymer network formation during UV curing, making the additive more stably bonded in the cured film. In practical formulation, it can be evaluated from three directions: leveling state (observing whether the UV varnish surface is flat after application, with any obvious retraction or orange peel appearance changes), surface slip (comparing surface state changes before and after addition through touch, friction, and subsequent processing), and tape release (testing with the actual tape, protective film, or lamination materials used, observing the peel state after bonding).
DH-4270 is applicable to solventborne UV coatings, UV photo-curable systems, and other acrylic resin systems. Reference addition: 0.05%–1.0% of total formulation. Actual application should be adjusted in combination with resin type, cure conditions, and application method.
UV varnish surface drag, insufficient leveling, and tape adhesion are not necessarily only cure condition problems. Resin structure, additive compatibility, and the additive's state during the cure process may all affect the final film surface performance. For UV formulations needing to balance leveling, slip, and tape release, testing from reactive surface additives can allow the additive to participate in the cured network formation — improving leveling and slip effect while providing a more stable formulation choice for UV coatings and varnishes.
Frequently Asked Questions
How does a reactive UV surface additive stay at the film surface if it is chemically bonded into the network?
The surface concentration of a reactive additive at the point of UV cure is established by the same surface migration driving force that acts on non-reactive additives — the lower surface energy of the additive compared to the resin causes it to preferentially concentrate at the air-film interface during the liquid state. When UV cure begins, the additive is crosslinked into the network at the positions where it is concentrated at that moment — primarily near the film surface. This locks the surface-active chemistry in place at the surface, rather than allowing it to redistribute over time as a non-reactive additive would.
Can DH-4270 replace a conventional (non-reactive) slip additive in a UV formulation, or does it work differently?
DH-4270 can be used in place of a non-reactive slip additive and provides the same functional effect — improved slip and surface lubricity — but with better durability through its reactive fixation in the cured network. In formulations where the non-reactive additive was providing adequate initial slip but the performance was declining over time (due to additive migration or loss), DH-4270's reactive structure addresses this durability gap. For formulations where long-term surface stability is not a concern, either approach is functional — the choice between them depends on the durability requirement.
