尿素-双醛淀粉树脂胶合板热压工艺优化

为探索尿素—双醛淀粉树脂用于胶合板制备的施胶、热压等工艺因素及其影响,扩展淀粉基胶粘剂在人造板工业的应用,促进无醛环保型室内用胶合板的研究与发展,对尿素—双醛淀粉树脂胶合机理与热压工艺进行试验研究,试验采用响应面分析法对胶合板热压工艺予以优化,选取热压温度、热压时间和施胶量3个因素进行Box-Behnken设计,利用Design-Expert 软件对胶合强度的二次多项式回归模型进行分析。结果表明：热压温度对尿素—双醛淀粉胶合板胶合强度的影响最为显著；当选用热压温度136℃、热压时间1.99 min·mm-1、施胶量416 g·m-2时,尿素—双醛淀粉胶粘剂胶合板的胶合性能最优,且最优胶合强度预测值为2.12 MPa,与理论预测值误差小,试验所得出的拟合方程与稳定性试验匹配较好。

Optimization of hot-pressing process for urea-dialdehyde starch adhesive plywood

To explore the process factors of gluing with urea-dialdehyde starch resin for plywood and hot-pressing as well as their effects, which extend the application of starch adhesive in the industrial usage of wood-based panel and promote the research and development of non-formaldehyde and environmentally interior plywood. The bonding mechanism of urea-dialdehyde starch resin adhesive and hot pressing were dealt with. Response surface analysis was used to optimize the hot-pressing process of urea-dialdehyde starch adhesive plywood. Pressing temperature, pressing time as well as the amount of adhesive were chosen to design the Box-Behnken, then the Design-Expert software was applied to analyse the quadratic polynomial model of bonding strength. The results showed that pressing temperature had the most significant effect on the bonding strength of urea-dialdehyde starch plywood. The bonding strength of urea-dialdehyde starch adhesive plywood was best whose predictive value was 2. 12 MPa when the pressing temperature, pressing time and adhesive consumption were 136 ℃, 1. 99 min·mm-1 and 416 g·m-2 , respectively. The predictive value in the conditions of the three factors has a small error with the theoretical prediction, fits the equation as well as a better stability test match.