News

Knowledge

Company News

Application Mind Map

Test Report

Technical Article

Industry News

Solutions for Defects in UV Wood Coatings (Part 8)

Release time:

2026-03-20 23:30

Solutions for Defects in UV Wood Coatings (Part 8)

UV wood coatings occupy a prominent position in the furniture and wood-products finishing industry due to their outstanding advantages, such as rapid curing and environmental friendliness combined with energy efficiency. However, during actual production and application, these coatings often encounter undesirable issues, such as stickiness caused by incomplete curing, which severely compromises the aesthetic appeal and service life of the finished products. This paper examines the problem of stickiness resulting from inadequate curing in UV wood coatings and explores effective solutions to enhance coating quality.

I. Precise Assurance of Energy Supply

Insufficient UV energy is the primary cause of tackiness. As the lamp operates over time, its spectral intensity gradually declines; when the energy falls below the activation threshold required by the photoinitiator, the polymerization reaction remains incomplete. It is recommended to establish a lamp usage log and replace UV lamps on a regular schedule to ensure that the light source intensity remains adequate, thereby enabling complete polymerization.

An excessively high conveyor belt speed can result in insufficient dwell time of the coating film under the UV lamps, leading to inadequate total energy absorption. The conveyor speed should be precisely set based on the coating formulation and film thickness to ensure adequate cumulative energy exposure. Similarly, mounting the UV lamps too high can cause a substantial reduction in the energy reaching the coating surface; the lamp height must be adjusted to within the recommended range. Regularly use an energy meter to verify the lamp output, ensuring that the curing energy meets process specifications.

II. Rational Control of Coating Thickness

For pigment-based UV coatings or high-fill primers, excessive coating thickness limits the penetration depth of ultraviolet light. Once the surface layer has absorbed most of the UV radiation, the photoinitiators in the underlying layers no longer receive sufficient energy, resulting in incomplete curing of the bottom coat. Therefore, the single-coat application thickness should be appropriately controlled based on the coating formulation and the type of pigment used. For applications requiring thick coatings, it is advisable to apply multiple thin coats instead of a single thick coat, allowing each coat to fully cure before applying the next.

The absorption and scattering of ultraviolet light by pigments are major factors contributing to insufficient deep-layer curing. Pigments such as carbon black and titanium dioxide strongly absorb or scatter UV radiation, creating a shielding effect. When formulating tinted coatings, the impact of pigment type and dosage on curing speed should be carefully considered; where necessary, the amount of photoinitiator can be increased, or a photoinitiator formulation sensitive to long-wave UV radiation can be selected to enhance penetration.

III. Effective Countermeasures Against Chemical Inhibition

Oxygen in the air rapidly reacts with the free radicals generated by the photoinitiator, consuming these active radicals and preventing them from initiating monomer polymerization. As a result, the degree of polymerization in the very thin surface layer remains extremely low, leading to persistent tackiness. To address oxygen inhibition, the following measures can be employed: incorporate reactive amine-based photoinitiator accelerators into the coating formulation to increase the surface cure rate; establish an inert-gas-protected zone prior to curing and purge the chamber with nitrogen or carbon dioxide to displace the ambient air; use high-intensity irradiation to enable the surface layer to quickly pass through the oxygen-inhibition stage; and for topcoats, select resin systems with excellent resistance to oxygen inhibition.

IV. Adaptation and Optimization of the Coating System

The photopolymerization characteristics of the coating itself directly affect the curing performance. It is essential to select a coating system that is compatible with the curing equipment, ensuring that the absorption spectrum of the photoinitiator matches the emission spectrum of the curing lamp. For dark-colored or highly filled coatings, photoinitiators sensitive to long-wave ultraviolet light can be used to enhance penetration depth. During storage, the coating should be protected from high temperatures and direct sunlight to prevent premature decomposition and deactivation of the photoinitiator. Prior to application, the coating must be thoroughly stirred to ensure uniform distribution of all components.

V. Conclusion

The issue of poor curing and stickiness in UV wood coatings arises from the complex interplay of multiple factors, including energy input, coating formulation, and chemical interactions. By comprehensively implementing measures such as ensuring adequate energy exposure, controlling coating thickness, minimizing pigment shading effects, isolating the influence of oxygen, and strengthening process monitoring and inspection, the problem of inadequate curing and stickiness can be effectively addressed. The implementation of these measures will help improve coating quality, enhance product aesthetics and market value, and provide reliable protection and attractive decoration for wood products.

Disclaimer: The above content is sourced from the internet and is provided for reference only. If any infringement occurs, please contact us, and we will remove it promptly.

Bossin Recommended Products – UV Wood Coatings
Putty primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
Sanding primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
Apply primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-02	Phosphate ester acrylate	Enhances adhesion to substrates such as metal, glass, and plastic.
B-05	Phosphate ester acrylate	Enhances adhesion to substrates such as metal, glass, and plastic.
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
B-535	Polyester acrylate	Excellent adhesion, rapid curing, good flexibility, and yellowing resistance.
B-546	Polyester acrylate	Good adhesion, fast curing, and excellent flexibility.
White primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
B-529	Polyester acrylate	Good adhesion, low shrinkage, and excellent resin compatibility.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
Gloss topcoat
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-21C	Active amine photosensitizing promoter	Low color number, antioxidant and anti-polymerization, and enhanced curing rate
B-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent grindability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost performance.
B-609	Aliphatic polyurethane acrylate	Fast curing, high hardness, scratch resistance, and chemical resistance.
B-868	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-910A2	Aliphatic polyurethane acrylate	Low viscosity, yellowing resistance, chemical resistance, and steel-wool resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and wear resistance.
Matte topcoat
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-21C	Active amine photosensitizing promoter	Low color number, antioxidant and anti-polymerization, and enhanced curing rate
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-333	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, good wettability, and good flexibility.
B-572	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-650A	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, fast curing, and good wettability.
B-868	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-910A2	Aliphatic polyurethane acrylate	Low viscosity, yellowing resistance, chemical resistance, and steel-wool resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and wear resistance.
Bright White Finish
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent grindability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost performance.
B-868	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and wear resistance.
Adherent
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-05	Phosphate ester acrylate	Enhances adhesion to substrates such as metal, glass, and plastic.
B-509B	Polyester acrylate	Good adhesion, good flexibility, and excellent pigment wetting.
B-531	Polyester acrylate	Good adhesion, impact resistance, excellent flexibility, and yellowing resistance.
B-535	Polyester acrylate	Excellent adhesion, rapid curing, good flexibility, and yellowing resistance.
B-546	Polyester acrylate	Good adhesion, fast curing, and excellent flexibility.
B-590	Polyester acrylate	Excellent adhesion, rapid curing, and good pigment wetting.
Filler type
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
B-529	Polyester acrylate	Good adhesion, low shrinkage, and excellent resin compatibility.
Color correction
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
Harden
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent grindability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost performance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and wear resistance.
Matte
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.
B-333	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, good wettability, and good flexibility.
B-650A	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, fast curing, and good wettability.
Solid-color paint
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-519	Self-curing polyester acrylate	Self-initiated photopolymerization performance
B-530	Polyester acrylate	Low viscosity, excellent hydrophobicity, thixotropy, and improved ink misting
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
Yellowing resistance
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-431	Cycloaliphatic Specialty Acrylates	Yellowing resistance, excellent wettability, low viscosity, and fast curing
Dip coating
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
Roll coating
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-100	Bisphenol A epoxy acrylate	High hardness, high gloss, excellent chemical resistance, and high fullness.
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
Solvent-free spraying
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-251	Aromatic Polyurethane Acrylate	Fast curing, excellent flexibility, and good wetting of black ink pigments.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
LED-UV
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-21C	Active amine photosensitizing promoter	Low color number, antioxidant and anti-polymerization, and enhanced curing rate
B-27	Active amine photosensitizing promoter	Low color number, benzene-free, low odor, antioxidant and anti-polymerization
B-570	Polyester acrylate	Low viscosity, benzene-free, low odor, suitable for LED UV
B-574	Polyester acrylate	Benzene-free, low odor, and VOC levels meet cigarette pack standards.
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
Excimer lamp
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-241	Aliphatic polyurethane acrylate	Fast curing, excellent skin feel, and yellowing resistance.
Skin feel
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-241	Aliphatic polyurethane acrylate	Fast curing, excellent skin feel, and yellowing resistance.
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-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-868	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
Single-item recommendation
Product Model/English Abbreviation	Product Name/Product Type	Product Features
BM2223 (TPGDA)	Di(propylene glycol) diacrylate	Good flexibility and low volatility
BM2224 (EO-HDDA)	Ethoxylated 1,6-hexanediol diacrylate	Good adhesion to plastics, good dilutability, and low volatility.
BM3231 (TMPTA)	Trimethylolpropane triacrylate	High crosslink density, high hardness, high gloss, and excellent wear resistance.
BM3235 (PET3A)	Pentaerythritol triacrylate	Fast curing, high crosslink density, high hardness, and excellent chemical resistance.
BM3380 (3EO-TMPTA)	Tripropylene Glycol Triacrylate	More flexible and less irritating than TMPTA.
BM6261 (DPHA-80)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.
BM6263 (DPHA-90)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.

Share to:

Solutions for Defects in UV Wood Coatings (Part 9)

Solutions for Defects in UV Wood Coatings (Part 7)