Study On The Surface Properties Of Surface Decorated Plywood With Paper Impregnated Thermosetting Resins

Plywood overlaid with thermosetting resin impregnated paper is a kind of decorative board formed by pressing impregnated paper on plywood substrate,which has excellent decorative performance.However,the surface defects such as blister and craze are easy to be produced in the dry environment,which makes the decorative performance of the board decline and affects its surface quality,causing economic losses to the enterprise.In this paper,the raw material properties of impregnated paper and plywood substrate were tested,and the production technology of plywood with impregnated film paper was studied.The preparation was carried out with the technologies of primary film mulching,improved primary film mulching,improved secondary film mulching and secondary cold-pressed film mulching,and the surface properties were tested.The following conclusions were drawn:(1)The amount of impregnation,the degree of preconsolidation and the content of volatiles of the impregnated paper should be controlled within the standard range.Too high or too low content will affect the surface performance of veneer plywood to a certain extent,resulting in board surface defects.(2)At 140°C,the stability of resin is better,but at 180 °C,the resin is the most unstable.When the hot pressing temperature is 120 °C,the optimal curing temperature of the resin in the paper can be reached,followed by 160 °C.(3)In the hot-pressing process of glued paper veneer plywood,the primary coating method and secondary coating method are improved by adding non-woven fabrics,and the use of adhesive film as an adhesive can enhance the surface resistance of the sheet to a certain extent cracking performance,improve the quality of veneer plywood.(4)The better hot-pressing parameters for the improved secondary coating method are the first hot-pressing: hot-pressing temperature 160 °C,hot-pressing pressure 1.0MPa,hot-pressing time 45s;second hot-pressing: hot-pressing temperature 120 °C,hot pressing pressure 1.0MPa,hot pressing time30 s.(5)Impregnated paper veneer plywood was prepared by cold pressing process with secondary film covering.Non-woven cloth and kraft paper were added as reinforcing materials.The adhesive was liquid adhesive.The bonding strength and cracking resistance of the samples surface are improved significantly.(6)The better preparation process parameters of the second cold pressing lamination method are the first hot pressing: hot pressing temperature 160 °C,hot pressing pressure 1.0MPa,hot pressing time45s;second cold pressing: cold pressing temperature 23 °C,cold pressing pressure 0.6MPa,cold pressing time 40 min,using kraft paper as reinforcing material,adhesive YJ122.