乙烯-醋酸乙烯酯共聚物薄膜增强装饰薄木的制备

Preparation and properties of EVA film reinforced decorative veneer

塑膜增强装饰薄木具有挠曲度高、表面不易开裂等优点,以此作为木制品的表面装饰材料饰面工艺简单、无游离甲醛释放、生产能耗低。本研究选用乙烯-醋酸乙烯酯共聚物(EVA)薄膜与水曲柳装饰薄木进行复合,制备EVA薄膜增强水曲柳装饰薄木,并采用此复合薄木对中密度纤维板(MDF)基材进行饰面,分析了热压温度对其柔韧性、横向抗拉强度以及二次饰面性能的影响。结果表明:EVA薄膜受热熔融渗透进入装饰薄木的多孔性结构形成机械互锁,可显著提升装饰薄木的性能。当热压温度为110℃时,EVA薄膜增强装饰薄木的最小钢棒直径为5.3 mm,横向抗拉强度达0.99 MPa,与原始薄木相比提升了412.5%。热压温度对饰面板的表面胶合强度和浸渍剥离性能也有显著影响。当饰面温度从90℃增加至100℃时,表面胶合强度从0.56 MPa增至1.28 MPa,浸渍剥离长度从4.5 mm降至0。继续增加热压温度,饰面板的表面胶合强度虽略有降低,但均可达到GB/T 15104—2006标准中Ⅱ类板材的要求。由于EVA薄膜的熔融温度不高,其复合薄木的制备能耗低,不会出现明显的卷曲情况。

Plastic film has received great research interest in the area of decorative veneer modification because of its good flexibility and water resistance. The plastic film is not only the flexible reinforcing material for the veneer, but also served as the adhesive in the process of veneer modification. Because there is no need to add additional adhesive, its preparation and finishing process are simple and green. In this study, the ethylene-vinyl acetate copolymer(EVA) films and Manchurian ash(Fraxinus mandshurica) decorative veneers were used to prepare composite veneers. The EVA film reinforced decorative veneers were subsequently used to decorate the Medium Density Fiberboard(MDF) panels. The influences of hot-pressing temperature on the flexibility, transverse tensile strength, and secondary facing performance of MDF were analyzed. The results showed that the EVA film melted and penetrated the porous structure of the decorative veneer to form a mechanical interlock, which could significantly improve the performance of the decorative veneer. When the hot-pressingtemperature was 110 ℃, the minimum curling steel rod diameter of EVA film reinforced decorative veneer was 5.3 mm, and the transverse tensile strength reached 0.99 MPa, which was an increase of 412.5% compared with the untreated veneer. The hot-pressing temperature also had a significant effect on the surface bonding strength and immersion peel strength of decorative veneered panels. When the secondary hot-pressing temperature increased from 90 to 100 ℃, the surface bonding strength increased from 0.56 to 1.28 MPa, and the immersion peel length decreased from 4.5 to 0 mm. When the hot-pressing temperature increased continuously, the surface bonding strength was slightly reduced. All decorative veneered panels met the requirements of the Type II immersion peel test according to GB/T 15104-2006. Since the melting temperature of EVA film was low, the processing energy consumption was relatively low, and the composite veneer did not show obvious curling.