中性樹膠

以磷酸二氫銨(MAP)溶液為阻燃劑,通過浸泡尾葉桉單板,研究了單板的載藥量;以Ⅱ類膠合強度為指標,利用正交試驗對常規(guī)膠合板生產(chǎn)工藝進行了優(yōu)選。在此基礎上,選取浸泡時間和最優(yōu)生產(chǎn)工藝試制了阻燃桉樹膠合板,并對其Ⅱ類膠合強度和燃燒性能進行了檢測。結(jié)果表明:不同厚度尾葉桉單板的載藥量隨浸泡時間的延長呈現(xiàn)相似的增長規(guī)律;試驗所得常規(guī)尾葉桉膠合板最優(yōu)生產(chǎn)工藝為施膠量210 g.m-2、熱壓溫度130℃、熱壓時間8 min,該條件下膠合板的Ⅱ類膠合強度達到了2.01 MPa;單板浸泡8h后,單板平均載藥量為32.05 kg.m-3,所制得阻燃膠合板氧指數(shù)提高了13.9%,炭化長度減少了8.3 mm(26.2%),阻燃性能明顯提高,而膠合強度也達到了Ⅱ類膠合板的國家標準。研究初步證明利用常規(guī)桉樹膠合板生產(chǎn)工藝生產(chǎn)阻燃桉樹膠合板是可行的。

Based on the results of more than ten year's scientific research and practice, some key techniques for cultivating poplar veneer glued wood were summarized systematically. The results were as follows: (1)Selecting appropriate poplar clones for various cultivation zones according to their growth rate and wood quality. (2)Choosing good sites being suitable for poplar clone growing (at least SI≥18?m). (3)Adopting reasonable planting density which can produce more timbers to meet the need of plywood(the tree spacing should be more than 5?m×5?m). (4)Using correct planting methods for different soil conditions, however, large seedling with 2 year old root and 1 year old stem (seedling height>4?m)were advocated. (5)Taking effective measures to tend the stand, the most effective measure was interplanting with crops. (6)Pruning was neccessary to produce non node timber, but pruning method, pruning intensity and pruning season should be controlled properly. If the 6 measures mentioned above were carried out, the poplar forests with a high yield and high quality could be ensured. In order to provied some theoretical basis for cultivating poplar veneer glued wood, 4 optimum cultivation patterns were also established using the method of two dimensions system.