改性豆基蛋白胶杨木刨花板的制造工艺

探讨利用改性豆基蛋白胶压制杨木刨花板的工艺,分析热压温度、热压时间、施胶量和防水剂加入量对杨木刨花板性能的影响,提出厚12 mm、密度0.70 g/cm3杨木刨花板的最佳工艺条件为:热压温度170℃,热压时间14min,施胶量10%,防水剂加入量1.4%。在此条件压制的板材的性能超过GB/T 4897.4-2003的要求。     

Valorisation of Jatropha curcas: Solubilisation of proteins and sugars from the NaOH extracted de-oiled press cake

In this study, we investigated the possibilities for increasing the valorisation of de-oiled Jatropha press cake (DO-JPC). The studied raw material is the by-product of the alkaline protein extraction of the DO-JPC: NaOH Extracted DO-JPC (NEDO-JPC). Protein solubilisation of NEDO-JPC was performed under neutral and acidic conditions (pH 2, 100 mM maleic acid), at elevated temperature (100, 120, and 140 °C), and at 5% (w/w) dry solids loading. After the treatment, the amount of solubilised protein was determined, as well as the solubilisation of polymeric sugars and formation of sugar degradation products furfural and 5-hydroxymethylfurfural (HMF). Although a clear influence is shown for temperature, no difference in protein solubilisation was found between treatments at pH 7 and pH 2. A maximum of 25% (w/w) of the available protein was solubilised, at 140 °C. The lignocellulose fraction of NEDO-JPC proved relatively recalcitrant to acid hydrolysis, suggesting a more intense treatment to be necessary to sufficiently increase accessibility for cellulolytic enzymes in a lignocellulosic bioethanol process. At €8.00 per tonne DO-JPC, it is concluded that the possibilities for valorisation of the protein fraction of NEDO-JPC at neutral and acid pH are limited, leaving the lignocellulose fraction as a source of valorisation to be investigated.     

基于RBF神经网络的中密度纤维板连续热压板厚动态面控制

针对中密度纤维板(MDF)连续热压工艺特点,考虑到定厚段外负载力干扰对板坯厚度产生的影响,提出一种基于径向基函数(RBF)神经网络的动态面板厚度跟踪控制策略。将连续热压机的电液位置伺服系统作为被控对象,首先利用RBF神经网络逼近其外负载力干扰,设计自适应律对网络权值进行调整;然后采用动态面控制(DSC)方法,通过引入一阶低通滤波器计算虚拟控制量导数,避免了反步法设计控制器时易出现的微分项膨胀问题;最后通过选择合适的Lyapunov函数,证明了闭环系统所有信号半全局一致最终有界,且跟踪误差最终渐进收敛为零。仿真结果表明,所提方法可以有效地确保MDF板厚度跟踪控制精度,并使系统具有较强的鲁棒性。     

水稻插秧机分段式压膜装置的设计

通过对高速插秧机进行改进和设计,研制水稻插秧机分段式压膜辊装置。介绍水稻插秧机分段式压膜装置的工作原理、工作参数以及各部位的结构设计思路。机具试验结果表明:该机覆膜667 m~2所需时间为4.88 min,覆膜效率高,故障率低,适于在有机水稻无公害化生产中推广应用。     

桤木旋切单板以及用于制造细木工板的工艺研究

通过设置不同的旋切厚度对不同树龄的桤木原木进行单板旋切试验,分析单板厚度和背面裂隙率,探讨桤木单板旋切的适应性和制造细木工板的工艺,并采用正交法优选最佳制造细木工板的热压工艺参数。结果表明:当杉木板芯厚度为12 mm、桤木单板厚度为2.8 mm时,热压温度为125℃、热压压力为1.3 MPa、热压时间为8 min、施胶量为220 g/m~2时,横向静曲强度最大。     

热压工艺对竹重组板材性能的影响

探讨了以竹材为主要原料的竹重组板材热压工艺的优化,研究了热压工艺对竹重组板材力学性能的影响,讨论分析了热压压力、热压时间、热压温度对竹重组板材吸水厚度膨胀率、耐沸水性、静曲强度、弹性模量、耐磨性、耐化学腐蚀性、浸渍剥离率和甲醛释放量等性能的影响。通过正交试验,得出的优化热压工艺为:①热压压力2.0MPa、热压温度145℃、热压时间1.7min/mm,热压压力对竹重组板材耐酸性、静曲强度和弹性模量等影响显著,对耐沸水性、耐碱性、耐盐性、耐磨性和浸渍剥离率等影响不显著。②热压时间对竹重组板材静曲强度有显著影响,对其他试验指标影响不显著。③热压温度对竹重组板材各试验检测指标均有一定的影响,但不显著。     

五水硫酸铜溶液对4种压花叶材保绿效果的影响

[目的]研究五水硫酸铜溶液对4种压花叶材保绿效果的影响。[方法]以杜英、小叶蚊母、金森女贞、大叶黄杨4种植物的叶片为试验材料,采用2%、5%、10%和15%浓度的五水硫酸铜(Cu SO4·5H2O)溶液对所有叶材进行80~90℃的热处理,研究了不同浓度的铜盐溶液对压花叶材的保绿效果。[结果]杜英叶片随着铜盐浓度的升高,微波压制后易脆,保色效果不佳。小叶蚊母、金森女贞、大叶黄杨在15%Cu SO4·5H2O溶液浸煮后微波压制可达到理想的保绿效果;铜盐浓度越高,叶片复绿时间越短。4种材料铜盐处理微波压制后保绿效果由强到弱顺序依次为大叶黄杨、金森女贞、小叶蚊母、杜英。[结论]该研究为为压花制作提供技术支持。     

干旱地区深松灭茬镇压联合整地机的研究与试验

为解决干旱地区现有保护型整地机功能单一、进地次数、镇压效果差等问题,设计一种深松、灭茬、镇压联合作业机。对深松铲与土壤的接触力学分析,设计弹簧缓冲装置,并对圆盘灭茬刀进行力学分析与试验。运用ANSYS模拟镇压辊与土壤接触过程,设计防粘土装置,对整机稳定性进行分析计算。田间试验结果表明:该机深松深度为(489.3±8.6)mm,深松稳定性94.6%,能完全打破犁底层;当机车前进速度为1.4m/s时,圆盘转速为500r/min,根茬粉碎率90.3%,碎土率89.3%,土地平整度30.8mm,整地效果较好。该机各项指标能够较好的满足设计要求。     

Manufacture and properties of binderless particleboard from bagasse I: effects of raw material type, storage methods, and manufacturing process

Binderless particleboards were manufactured from sugarcane (Saccharum officinarum L.) bagasse by steam-injection pressing and by using hot pressing as a reference method. The inner layer (core/pith) and the outer hard fibrous layer (face/rind) of bagasse were used as raw materials. The effects of bagasse type, manufacturing process, and storage method on the mechanical properties of binderless particleboards were investigated. The results showed that the bagasse pith particles provided better board properties than bagasse rind particles. It seemed that bagasse pith particles were more easily deformed than bagasse rind particles, enlarging the bonding contact area. The severe conditions of steam-injection pressing caused delamination on the bagasse pith binderless boards with densities of 0.6 g/cm³ or higher, and gave poor bonding quality. However, steam-pressed boards showed relatively higher board properties than hot-pressed boards. The storage method of sugarcane bagasse affected the chemical composition and the board properties. It was shown that the extent of self-bonding formation depends on the chemical and morphological properties of lignocellulosic materials, as well as on the manufacturing conditions. Part of this paper was presented at the 5th International Wood Science Symposium, Kyoto, Japan, September 2004     

地板用高密度纤维板的研制

研究了以酚醛树脂为胶粘剂制造地板用高密度纤维板的工艺条件,探讨了热压时间、热压温度、施胶量对高密度纤维板物理力学性能和防潮性能的影响。采用优选工艺制得的产品各项指标均达到或优于欧洲地板用高密度纤维板标准。