UV Flexo Inks for No-Cracking on Flexible Packaging

Date: Jul 07 2025 From: Star Color Views:

In the flexible packaging industry, maintaining the integrity of prints during folding, bending, and handling remains a significant challenge. For inks, crack resistance is one of the most critical performance indicators, especially in high-speed flexographic printing applications. Starcolor's UV flexographic inks are specially developed with exceptional flexibility, adhesion, and durability, suitable for various substrates. Even on extremely demanding flexible packaging materials, they ensure that printed patterns do not crack.

Causes of Ink Cracking in Flexible Packaging

Ink cracking is usually caused by one or more of the following reasons:

Poor ink flexibility: A rigid or brittle ink film cannot adapt to the repeated deformation of flexible substrates.
Insufficient adhesion to substrates: For film materials such as BOPP, PET, or PE, if the ink fails to bond well with them, peeling or cracking is likely to occur under stress.
Improper curing: Inadequate UV curing leads to incomplete cross-linking reactions, making the ink film fragile or overly rigid.
High-speed processing: Mechanical stress during lamination, folding, or sealing processes may cause the fragile ink layer to break.

To address these issues, printing companies need UV flexographic inks that combine excellent flexibility and high cross-linking strength — and Starcolor has optimized this balance through advanced formulation design.

Zhongzhixing's Solution: UV Flexographic Inks Designed for Flexibility

Zhongzhixing's UV flexographic ink series is formulated with a new generation of oligomers, monomers, and photoinitiators, featuring the following characteristics:

Exceptional flexibility without cracking
The resin system in our UV inks is carefully designed to bend and stretch along with the substrate without breaking. This ensures crack-free printing on shrink films, PE, PP, and other non-rigid substrates.
Strong adhesion to plastic films
Our proprietary adhesion promoters allow the ink to bond tightly with low-surface-energy films — without extensive pre-treatment — significantly reducing the risk of delamination and cracking.
Compatibility with high-speed curing
Starcolor UV flexographic inks cure instantly under UV light, meeting high-speed production requirements without compromising flexibility. This is particularly important in multi-layer flexible packaging production, where rapid turnover after printing and subsequent processing are critical.
Resistance to folding, creasing, and handling stress
Tested in various packaging application scenarios, our UV inks maintain print integrity even during repeated creasing, bending, or bag-making processes.

Compliance and Safety

Our UV flexographic inks meet major global regulatory requirements, including:

FDA and RoHS; (Test reports available)
Swiss Ordinance Annex 10 raw materials;
Low-migration variants for indirect food contact applications are also available.

Technical Support and Customization Services

Zhongzhixing can provide customized formulations based on customers' printing press types, substrates, and curing conditions. Our technical team offers the following services:

On-site printing press support;
Substrate compatibility testing;
Verification of adhesion and crack resistance performance.

In the field of high-performance UV flexographic printing for flexible packaging, ink cracking is absolutely unacceptable. Starcolor's UV flexographic inks perfectly combine durability, flexibility, and adhesion, ensuring that printed patterns remain intact through various folding, creasing, and curling operations in modern packaging.