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Common Defects in UV Gel Nail Polish (Part 6)

Release time:

2026-04-30 16:10

Common Defects in UV Gel Nail Polish (Part 6)

During the application of UV gel polish, incomplete curing is one of the factors that can compromise coating performance. When cured incompletely, the surface of the gel polish remains tacky after irradiation and shows fingerprint marks, or the interior of the coating remains liquid, preventing the formation of a hard, fully cured film. Unlike surface defects such as wrinkling and shrinkage, incomplete curing means that the product’s fundamental performance characteristics are not fully realized. Understanding the causes of incomplete curing can help users consciously avoid this issue during application.

I. Manifestations and Impacts of Incomplete Curing

Incomplete curing manifests in two typical ways. Surface incomplete curing is characterized by a sticky surface even after the coating has cured; light finger contact leaves fingerprint marks, and wiping with a cotton pad results in color transfer. Deep-layer incomplete curing occurs when the surface has hardened while the interior remains liquid; gentle pressure with a fingernail reveals a springy, elastic feel, and prolonged storage may lead to degradation starting from within. In either case, a partially cured coating cannot provide adequate adhesion or protective performance, resulting in issues such as chipping and abrasion within a short period.

II. Main Causes of Incomplete Curing

1. Insufficient curing lamp power is the primary cause of incomplete curing. UV lamps gradually degrade during use, resulting in a continuous decline in output energy. Even when the irradiation time is set to the same duration, the actual energy delivered by an aged lamp may still be insufficient to achieve full cure of the coating. Although LED lamps have a longer service life, their LED chips can also suffer damage or luminous flux depreciation. When the curing lamp’s power does not match the energy required by the coating, no matter how long the irradiation time is extended, it will be difficult to attain the desired curing performance.

2. Insufficient irradiation time is also a common cause. Some users shorten the curing time to save time, or set the conveyor speed too high, resulting in inadequate dwell time of the coating under the UV lamp. Curing time requirements vary depending on the product; dark-colored adhesives and thick-coat adhesives require longer irradiation times. Adhering to a uniform standard for short irradiation periods may lead to incomplete curing of certain coatings.

3. Mismatch between the photoinitiator and the light source is a commonly overlooked issue. LED lamps emit a relatively narrow UV spectrum, typically at 365 nm or 395 nm. If the absorption peak of the photoinitiator used in the gel polish does not align with the emission peak of the LED lamp, the photoinitiator will fail to efficiently absorb the light energy, making polymerization difficult to initiate. In this regard, UV lamps are more tolerant of such mismatches, whereas LED lamps have much stricter requirements for product compatibility.

4. Excessively dark tinting agents can also impede curing. Dark-colored tinting agents, such as black, deep blue, and deep red, contain a high pigment content; the pigment particles absorb and scatter ultraviolet light, thereby hindering its penetration to the bottom of the coating. Once the surface layer cures first to form a hard film, the underlying layers receive even less light, leading to the problem of surface drying while the interior remains uncured.

III. Cascading Effects of Incomplete Curing

Incomplete curing is not only a defect in itself but can also give rise to other problems. A surface that remains tacky readily attracts dust and fibers, compromising the aesthetic appearance. Moreover, uncured gelatinous material exhibits poor chemical stability; over time, it may undergo further reactions, leading to discoloration, blistering, or loss of adhesion. When applying a subsequent topcoat, monomers from the topcoat can penetrate the uncured layer, thereby further degrading the coating structure.

IV. Conclusion

Complete curing is the prerequisite for UV gel polish to perform optimally; incomplete curing will compromise other performance characteristics as well. The primary causes can be attributed to four factors: the condition of the curing lamp, the irradiation time, product compatibility, and the color of the gel. Aging or insufficient power in the lamp results in inadequate energy output; insufficient irradiation time leads to insufficient energy input; a mismatch between the photoinitiator and the light source prevents effective energy utilization; and dark-colored gels inherently present greater curing challenges. These factors, acting individually or in combination, can all lead to incomplete curing. Understanding the root causes of incomplete curing, regularly inspecting and maintaining curing equipment, setting irradiation times according to product specifications, selecting compatible products, and employing appropriate measures for dark-colored gels are essential steps to ensure optimal curing results.

Disclaimer: The above content has been compiled from public sources for reference only; if any infringement occurs, please contact us and we will address it promptly.

Bossin Recommended Products – UV Gel Nail Polish
Base coat
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-02H	Phosphate ester acrylate monomer	Enhances adhesion to substrates such as metal, glass, and plastic.
B-2016	Polyester acrylate	High molecular weight, excellent flexibility, strong adhesion, and low heat release.
B-2018	Aliphatic polyurethane acrylate	Good adhesion, good flexibility, and water resistance.
Colored tape
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-151DM	Modified epoxy acrylate	Low halogen, yellowing resistance, excellent plating performance, and strong adhesion.
B-162	Epoxy acrylate	Fast curing, low odor, high gloss, and high fullness.
B-166A	Modified epoxy acrylate	Good flexibility and strong adhesion
B-166A-85	Modified epoxy acrylate	Good flexibility, excellent adhesion, contains 15% HEMA
B-166A-85P	Modified epoxy acrylate	Good flexibility, excellent adhesion, contains 15% HEMA
B-27	Active amine photosensitizing promoter	Low color number, benzene-free, low odor, antioxidant and anti-polymerization
B-296	Aliphatic polyurethane acrylate	Fast curing, chemical resistance, yellowing resistance, and impact resistance.
Extended glue
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-210D	Aliphatic polyurethane acrylate	Fast curing, low exotherm, and good toughness
T-2022D	Aliphatic polyurethane acrylate	Non-stick, low heat generation, strong adhesion, high hardness
Sealant glue
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-376	Aliphatic polyurethane acrylate	LED yellowing is minimal, and the nail polish formulation exhibits excellent stability.
B-412T-6	Aliphatic polyurethane acrylate	Good toughness, tin-free, and excellent stability of the nail polish formulation.
Matte Sealing Layer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-328M	Aliphatic polyurethane acrylate	Low gloss, low viscosity, excellent wettability, and a pleasant hand feel.
B-328R	Aliphatic polyurethane acrylate	Low gloss, excellent matting, good wetting, and a fine, smooth, and silky hand feel.
B-329D	Aliphatic polyurethane acrylate	Low irritation, low viscosity, excellent wettability, and a pleasant feel.
One-step adhesive
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-315	Aliphatic polyurethane acrylate	Wear and chemical resistance, high hardness, toughness, and yellowing resistance.
A-grade film
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-216	Aliphatic polyurethane acrylate	Fast curing, high fullness, and excellent toughness
B-268M	Aliphatic polyurethane acrylate	Good flexibility, good adhesion, good plating performance, and excellent hiding power.
B-619W	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, wear resistance, and chemical resistance.
Single Product Recommendation
Product Model/English Abbreviation	Product Name/Product Type	Product Features
BM1211 (HPMA)	Hydroxypropyl methacrylate	HEMA-free, high strength, low irritation, high adhesion

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Common Defects in UV Gel Nail Polish (7)

Common Defects in UV Gel Nail Polish (Part 5)