[admin]

Q1: Why does my UV coating still show scratches even when the resin has high hardness?

High hardness does not automatically guarantee excellent scratch resistance. A UV coating’s ability to resist surface marking depends on resin chemistry, cross-link density, flexibility, adhesion, film thickness, and curing completeness.

A highly cross-linked film may provide good hardness but become brittle under impact or bending. Meanwhile, a softer coating may offer better flexibility but show marks more easily during handling or use. The final performance also depends on monomers, photoinitiators, additives, pigments, fillers, substrate characteristics, and curing conditions.

For this reason, scratch resistance should be evaluated as part of the complete formulation rather than judged by a single resin specification.

Q2: Does higher resin functionality always improve scratch resistance?

Not necessarily. Higher-functionality UV resins can form denser cross-linked networks, which may improve hardness and surface durability after curing. However, excessive cross-linking can increase brittleness, shrinkage, or stress at the interface, particularly on flexible substrates.

The appropriate functionality depends on the application. Glass, metal, and rigid plastic coatings may require higher surface hardness, while leather, TPU, flexible films, and other deformable substrates need a better balance between hardness, elasticity, and adhesion.

Resin functionality should therefore be considered together with monomer selection, film thickness, curing conditions, and the mechanical requirements of the finished coating.

Q3: Which Lencolo UV resins can be evaluated for scratch-resistant applications?

Several Lencolo grades provide potential starting points for different application requirements.

L-6207 is a two-functional polyurethane acrylate positioned for balanced wear resistance and flexibility, fast curing, and RCA resistance exceeding 200 times. It can be evaluated in 3C coatings, glass, plastic, and PVD applications.

L-6240 is an LED-curable resin described as offering high hardness, high gloss, high cross-link density, and excellent scratch resistance. It is indicated for coatings, inks, adhesives, OPV, plastic, paper, and nail applications.

For flooring and plastic coatings, L-6316 combines leveling, fullness, fast response, and scratch resistance. L-6360 offers scratch resistance together with wetting, slipperiness, anti-yellowing properties, and toughness for PVC flooring, paper, plastic, and wood coatings. L-6365 is positioned around fast curing, scratch resistance, and substrate adhesion.

These products should be treated as candidate materials, not automatic final recommendations.

Q4: What options are available for matte coatings that need scratch resistance?

Matte coatings present an additional challenge because the formulation must maintain low gloss, surface uniformity, and resistance to visible marking.

L-6380A is positioned for a gloss range of approximately 5°–10°, high hardness, and good scratch resistance in a smooth soft-touch film. Related grades, including L-6380A-4 and L-6380A-10, provide additional low-odor or anti-yellowing characteristics.

L-6380M is described as an anti-scratch matte resin with a stable low-gloss finish of approximately 1°–3° without haze. Its compatibility, leveling, adhesion, and interaction with the matting system should be evaluated during formulation development.

Q5: Are there resin options for more demanding abrasion requirements?

For applications requiring stronger abrasion or surface protection, L-6900 is positioned with high weather resistance, yellowing resistance, and scratch resistance. L-6902 and L-6902X, both high-functionality grades, reference steel wool resistance exceeding 5,000 cycles, alongside weatherability and yellowing resistance.

The L-6905 series extends surface-protection applications to anti-graffiti and anti-fingerprint coatings for plastics and films. For dual-cure systems, L-8469 is described as offering steel wool resistance, fast surface drying, low shrinkage, and high hardness for inks, mobile phone glass, and automotive interiors.

Q6: Can specialty coatings also achieve scratch and wear resistance?

Yes, but the performance target may differ from that of a conventional hard coating. L-8320 combines soft-touch characteristics with scratch and wear resistance for applications such as soft-touch coatings, PVC flooring, paper, and plastic.

Excimer UV resin grades, including the L-6367 series, are designed for soft skin-feel surfaces and may require a different balance of elasticity, texture, and surface durability. L-8461 combines fine matte texture, elasticity, weather resistance, and scratch resistance for applications including inks, mobile phone glass, and automotive interiors.

For nail coatings, L-8443 is positioned as a topcoat resin offering high hardness, low shrinkage, and scratch resistance.

Q7: How should scratch resistance be verified before production?

Scratch resistance should be tested under conditions that reflect the actual application. Important variables include substrate, coating method, film thickness, formulation ratios, curing equipment, UV intensity, exposure time, and post-curing conditions.

Evaluate scratch or abrasion resistance together with adhesion, flexibility, gloss, chemical resistance, yellowing, surface appearance, and curing completeness. A resin that performs well in one formulation may produce different results on another substrate or with a different curing system.

Lencolo products can be used as candidate materials for comparative trials, but final selection should be confirmed through testing under the customer’s actual operating conditions.

Q8: What is the main principle for improving scratch resistance?

Scratch resistance is a system-level performance characteristic. Start with the application and substrate, then match resin functionality, hardness, flexibility, monomer compatibility, additives, and curing technology.

Lencolo offers candidate UV resin grades for hard coatings, matte finishes, flooring, electronics, PVD, automotive interiors, and specialty applications. The most suitable material should be determined through technical data review and application-specific formulation testing rather than a single performance claim.

https://www.lencolo37.com/
Guangdong Lencolo New Material Co., Ltd.

[Author]

Posts