engleski

Characterization of Novel Press-Cured Water-Borne Coatings for Wood-Based Panels

Wood-based panels have a wide range of structural and architectural/decorative applications in the construction industry. In both cases, the surface finish of wood-based panels plays a vital role in both function and appearance. The most common methods of surface finishing of wood-based panels are coatings and overlay papers and foils. Coatings are often applied in several layers, including drying steps between each layer or the use of ultraviolet (UV) curing. On the other hand, when phenolic surfaced film and melamine overlays are used for finishing wood-based panels, the producer needs to purchase and store different grades and sizes of the film or overlay. In this study, a new wood-based panel processing technology was tested. This method combines the advantages of surface overlay and coating technology. The novel product is a two- component (2K) water-borne coating which cures in-press at high temperature. It is applied in one layer without surface preparation, and the curing time is a few minutes. In this study, properties such as adhesion, chemical resistance, elasticity, and water absorption have been tested. The adhesion test was performed according to the standard ASTM D454, the standard test method for pull-off strength of coatings using a portable adhesion test. Chemical resistance was tested according to standard EN 13442, wood flooring and wood paneling, cladding, and determination of chemical agents' resistance. The elasticity of the free coating films was measured on a tensile strength machine. This machine provides controlled stretching until the free film coating sample cracks. Water adsorption was measured by immersion testing of the samples in water. The sawn samples' sides and back were sealed with two coats of two-component (2K) epoxy coating to measure water absorption only on the test surface. The results were compared with commercial coatings. The results show that the novel coating has water uptake from 300 g/m2 to 1400 g/m2. The elongation of novel coating is up to 300%. These results are comparable with tested commercial coatings.

Adhesion ; Chemical resistance ; Elasticity test ; Water adsorption ; Water-borne coatings ; Wood-based panels finishing

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