凹凸模曲面热压成型制备塑膜增强薄木工艺优化
Optimization of Surface Forming Process of Plastic Film and Decorative Veneer by Concave Hot Pressing

为解决高热膨胀系数差异的塑膜与装饰薄木高温热压复合卷曲问题，制备各项性能良好的塑膜增强柔性装饰薄木，提高珍贵木材利用率和增加产品附加值，采用凹凸模曲面成型工艺进行塑膜与薄木的热压复合，并对其工艺进行优化，为塑膜增强柔性装饰薄木工业化应用探索科学方法和理论依据。以红栎为装饰薄木，等离子体改性低密度聚乙烯（LDPE）薄膜为胶粘和增强材料，以塑膜增强薄木剥离强度和卷曲度为性能指标，采用正交试验法优化凹凸模具曲面成型制备塑膜增强薄木的热压压力、温度和保压时间等工艺参数。结果表明：1）塑膜与装饰薄木热压曲面成型制备塑膜增强柔性薄木，可显著缓解塑膜增强柔性薄木高温热压卷曲变形现象。2）凹凸模曲面成型制备塑膜增强柔性装饰薄木的较优工艺参数为热压压力0.8 MPa、温度125℃、保压时间210 s。3）在优化工艺条件下制备的柔性装饰薄木，剥离强度达0.50 kN/m，横向抗拉强度达4.09 MPa，柔韧性可达钢棒直径4 mm，浸渍剥离性能达到国标I 类试验要求，表面平整度好。塑膜与装饰薄木热压曲面成型，可有效解决塑膜增强柔性薄木热压卷曲变形问题，保证后续饰面生产，为新型塑膜增强柔性薄木的制备和工业化应用提供重要理论依据。
The objectives of this study were to solve the problems of high-temperature thermal pressure composite curl of plastic film and decorative sliced veneer with high thermal expansion coefficient,to manufacture a variety of plastic film reinforced pliable decorative sliced veneer (PFRPDSV) with good performance,to improve the utilization rate of precious wood,and to increase the added value of the products.The technology of convex surface molding was used to carry out the heat pressure composite of plastic film and decorative veneer,and the process was optimized to explore scientific methods and theoretical basis for industrial application of PFRPDSV.The orthogonal test method was used to optimize the process parameters of PRPDSV manufacturing,such as hot pressing pressure,temperature and holding time,and the peel strength and curl deformation were used as the performance indexes.The results showed that：1) plastic film and decorative veneer hot-pressed surface forming convex molding could significantly alleviate the phenomenon of curling deformation of high-temperature hot-pressed PRPDSV.2) The optimized process parameters to make PFRPDSV were:hot pressing pressure 0.8 MPa,temperature 125℃,and holding time 210 s.3) The flexible decorative veneer prepared under the optimized process conditions had a peeling strength of 0.50 kN/m,a transverse tensile strength of 4.09 MPa,a flexibility of up to 4 mm of the diameter of the steel bar.The impregnation and peeling performance met the requirements of the national standard Class I test.The flatness was good.The plastic film and the decorative veneer hot pressing surface forming could effectively solve the curling deformation problem of PFRPDSV,and ensure the subsequent finish production.This paper would provide an important theoretical basis for the preparation and industrial application of new PFRPDSV