胶合板胶层温度变化规律的研究

<正>本文主要研究胶合板板坯中胶层温度测量方法及温升规律与胶合板胶合强度之间的关系。试验结果表明:胶层的温度变化可分为快速升温、缓速升温和降温三个阶段;当胶层升温到100℃后,必须再保持一段时间,才能使胶层具有一定的强度和耐水性,但过长反而使胶层质量变差,为了使胶合板本身质量变异性减少,板坯越厚应采用偏低的热压板温度。

TEMPERATURE VARIATIONS IN GLUELINES OF PLYWOOD DURING HOT PRESSING

Time duration of hot pressing determines not only the quality of the plye wood, but also the productivity of hot press. The required length of time duration of hot pressing chiefly depends on the rising speed of the temperature in the glueline. This paper deals with the regular patterns of the rising of temperature in the glueline during hot pressing and its relationship with the shear strength of the plywood. Our tests show: 1. The changes of temperature in the glueline can be divided into three stages: fast rising, slow rising and dropping. 2. After the temperature is raised to 100-, the glueline should be continuously heated for some time. However, excessive heating can decrease the shear strength of the plywood. 3. When thicker plies are used, lower temperatures should be applied.