Effect of UV Top Coating Microcapsules on the Coating Properties of Fiberboard Surfaces

Ultraviolet (UV) coatings are widely used because of their good performance. However, the self-healing performance of UV coatings can be further improved. Microcapsule technology can be used to solve this problem. To investigate the effects of the compound use of two UV coating microcapsules on coatings of a fiberboard surface, three kinds of UV primer microcapsules (1#, 2#, and 3# microcapsules) with different contents were added to a UV primer, and a UV top coating was prepared with UV top coating microcapsules at a consistent ratio. The UV coating was used to coat the fiberboard surface by way of a two-primer and two-top coating method. The results show that as the content of the UV primer microcapsules was increased, the self-healing rates of all three groups of coatings increased and later decreased. The color difference ΔE of coatings with the content of the UV primer microcapsules at 4.0% and top coating microcapsules at 6.0% was 3.59, the gloss was 1.33 GU, the reflectance was 21.17%, the adhesion grade was 2, the hardness was 2H, the impact resistance grade was 5, the roughness was 1.085 μm, and the self-healing rate was 30.21%. Compared with the self-healing rate of the blank control group, the increase in the self-healing rate was 10.07%, and the improvement rate was 50.00%. The comprehensive performance of the coating was better. The results provide a technical reference for the application of the UV coating microcapsules in the UV coating on fiberboard surfaces. Incorporating the self-healing UV coating microcapsules into the UV coatings and applying the UV coating microcapsules on the fiberboard surfaces supports the microcapsule technology of self-healing UV coatings, lays the foundation for extending the service life of furniture while improving the furniture’s quality, and promotes the sustainable development of the coating industry.

Effects of Compound Use of Two UV Coating Microcapsules on the Physicochemical, Optical, Mechanical, and Self-Healing Performance of Coatings on Fiberboard Surfaces

Zou,

Xia,

Yan

2024

Effects of Mixed Microcapsules in Different Proportions on Aging Resistance and Self-Healing Properties of Waterborne Coatings for Tilia europaea L

Xia,

Han,

Yin

et al. 2024

In order to prolong the effective time of the self-healing properties of waterborne coatings containing shellac microcapsules coated with melamine rice husk powder (MRHP), three kinds of MRHPs with better microscopic morphologies, which contain 2.8% (type A), 5.5% (type B), and 8.0% (type C) of a rice husk powder (RHP), in shell materials were mixed according to three different proportions, and added to the waterborne coatings based on Tilia europaea L., under the conditions of the most proper addition amount of 6.0% microcapsules. The results indicated that the waterborne coatings containing mixed microcapsules can still maintain the best state in terms of optical properties and mechanical properties, with a chromatism of 1.10, an adhesion of zero, a hardness of 4H, an impact resistance of 7 kg·cm, and an elongation at break of 35.28%, respectively. According to the aging resistance test, the waterborne coating containing microcapsules “type A + type B + type C” demonstrated a longer effective time. After aging for 200 h in the UV climate resistance test chamber, the light loss rate at an incident angle of 60° was 2.91%. Through scratch testing, it is verified that the mixed microcapsules can prolong the self-healing time, reduce the crack size, and achieve a coating self-healing rate of 41.11%. They can also inhibit the crack growth rate to a certain extent. Roughness tests indicated that the surface roughness of the coating with mixed microcapsules increased by 0.038 μm in comparation with the single microcapsule, but the surface can still remain smooth after being covered by the topcoat without the microcapsules. Studying the ratio of mixed microcapsules provides new ideas for the optimization of a wood-based coating self-healing effect.

Preparation of Tung Oil-Modified Raw Lacquer Films and Application for Mechanical Carving Technique

Wu,

2024

Raw lacquer, known for its superior performance as a natural liquid coating, boasts excellent physical and mechanical properties as well as durability, making it widely used in manufacturing. However, the high hardness of the lacquer film upon complete curing poses challenges for carving and mechanical engraving. Therefore, it is necessary to study the curing process of lacquer films to obtain films suitable for carving or mechanical engraving. This study involves the preparation of raw lacquer with varying amounts of tung oil added, followed by the measurement of film drying time, surface roughness, glossiness, hardness, and adhesion on substrates to determine the optimal drying conditions. Additionally, SEM analysis of the carved surfaces and FT-IR analysis were used to investigate the impact of tung oil addition on lacquer carving performance and its variation. The results indicate that tung oil, to a certain extent, contributes to a smoother lacquer film but adversely affects film hardness and adhesion to Prunus serotina. However, with an increase in the amount of refined tung oil to 15%, the film exhibits improved glossiness, smoother carving tool marks, and reduced debris, thereby validating the feasibility of mechanical carving of tung oil-modified raw lacquer to some extent.