Warpage control method during surface forming process of plastic film-reinforced flexible decorative veneer

The plastic film of the new plastic film reinforced pliable decorative veneer (PRPDSV) is used as a flexible reinforcement material and an adhesive material. It has good water resistance, impermeability, simple preparation and finishing processes, and no formaldehyde release. However, warpage phenomenon during hot pressing has been a bottleneck problem restricting its industrial development. In order to solve this problem solve, the study proposed a concave, and convex molds method, established an elastic–plastic FEA model of hot pressing processes of the PRPDSV using concave and convex molds with static/general static solution module in the nonlinear ABAQUS, and researched the effect on the performances of the PRPDSV from the parameters of temperature, pressure, and mold curvature radius theoretically and verified experimentally. Analysis results showed that the surface forming temperature had a great effect on warpage control for PRPDSV. The higher the temperature is, the smaller the curvature radius of the corresponding mold will be and the better the warpage will be. The curvature radius of the molds had a significant effect on the warpage control. Under the conditions with the same hot pressing parameters, the smaller the curvature radius is, and the better control on the warpage for the PRPDSV will be.     

Preparation and Characterization of Hydrophobic Bagasse Hemicellulose-based Films

To improve the hydrophobicity of bagasse hemicellulose-based films, glutaraldehyde was applied when preparing films of original and cationic bagasse hemicellulose with the addition of polyvinyl alcohol and sorbitol. The results showed that the cationic modification could increase the hydrophobicity of the hemicellulose-based film, and the hydrophobicity of hemicellulose-based films crosslinked with glutaraldehyde also increased. However, cationic modification of hemicellulose decreased the stress of the hemicellulose-based film. While crosslinking with glutaraldehyde increased the stress of both the original and cationic hemicellulose-based films. Macrophotography indicated that the film formability of the original hemicellulose was better than that of cationic hemicellulose. Through SEM observation, the degree of bonding of different components of the films was found to be increased due to crosslinking with glutaraldehyde. The crosslinking reaction between glutaraldehyde and hemicellulose was further confirmed by FT-IR spectroscopy.     

Investigations on hydrogen storage performances and mechanisms of as-cast TiFe0.8-mNi0.2Com (m=0, 0.03, 0.05 and 0.1) alloys

In order to improve the hydrogen storage performances of TiFe-based alloys, a new type of TiFe_0.8-mNi_0.2Co_m (m = 0, 0.03, 0.05 and 0.1) alloys were prepared through vacuum medium-frequency induction melting. XPS results showed that the composition of surface oxide film contains TiO₂, FeO and NiO for the cobalt-free alloy, and it also includes CoO and Co₃O₄ besides the above oxides for the cobalt-containing alloys. The activation temperature is 523, 403, 383 and 373 K for the TiFe_0.8-mNi_0.2Co_m (m = 0, 0.03, 0.05 and 0.1) alloys, respectively. The changes of the composition and microstructure of the surface oxide film are the root causes of the reduction of the activation temperature. XRD and SEM analyses showed that all the alloys are composed of the majority phase of TiFe phase and non-hydrogenated phase of Ti₂Fe phase. Adding appropriate amount of cobalt is beneficial to inhibiting the generation of Ti₂Fe phase and increasing the cell volume of TiFe phase. The hydrogenation capacity is proportional to the content of TiFe phase, which is 1.11, 1.48, 1.54 and 1.29 wt% for the TiFe_0.8-mNi_0.2Co_m (m = 0, 0.03, 0.05 and 0.1) alloys at 313 K, respectively. The hydrogenation plateau performance also is improved correspondingly.     

Inkjet-printed Ag@SDC core-shell nanoparticles as a high-performance cathode for low-temperature solid oxide fuel cells

This work demonstrates the superior thermostability of silver-based nanoparticle cathodes under continuous solid oxide fuel cell operation by coating the samarium-doped ceria (SDC) thin shell over silver nanoparticles. The Ag-core/SDC-shell (Ag@SDC) nanoparticles prepared by solvothermal synthesis (Ag core diameter = 48 nm; average SDC shell thickness = 2–5 nm) is inkjet-printed on electrolyte substrates as a thin film cathode. The Ag@SDC film survives the 48-h thermal annealing and its most porosities remain visibly un-agglomerated. The results of fuel cell current stability test show that the cell using the Ag@SDC nanoparticle cathode have only 3% of current degradation after 25 h, which is remarkably lower than that of the cell using the bare Ag nanoparticle cathode (96.1%). In addition, the electrochemical performance of the bare silver cathode in oxygen reduction reaction has significantly improved because of the enhanced surface oxygen adsorption/dissociation process provided by the SDC thin shell.     

透明红外硫系薄膜非均匀性检测及影响因素

薄膜非均匀性的无损检测对于制备大面积高质量的红外透明薄膜尤为重要。针对红外薄膜光学均匀性难以获取的困难,提出了一种同时获得单层透明红外薄膜厚度和折射率均匀性的无损检测方法。实验上,通过磁控溅射法在二氧化硅衬底上制备了厚度约1.4μm红外透明Ge-Sb-Se硫系薄膜,然后在该薄膜上标定出36个80μm×80μm区域,利用显微傅里叶红外光谱仪测得该36个区域的透射谱,通过分段滤波的方法滤除背景噪声,运用改进的Swanepoel方法计算得到了薄膜每一个区域的厚度和折射率,进而精确获得该薄膜的厚度和折射率均匀性,结果表明精度优于0.5%。     

柱塞副微观表面对间隙油膜压力的影响

根据分形理论中的W-M函数建立柱塞与缸体孔表面三维形貌数学模型,并利用MATLAB软件编写程序,分析分形维数对表面微观形貌的影响。将柱塞副间隙油膜沿轴向展成平面,建立油膜厚度及压力分布计算模型,采用有限体积法求解二维雷诺方程,分析粗糙度对柱塞副间隙油膜压力分布的影响。结果表明:随着分形维数的增加,柱塞表面粗糙度呈增加趋势,且表面粗糙度越大,压力峰值越大。     

悬浮于润滑油中的颗粒运动分析及其对油膜压力的影响

对含有固体颗粒的局部润滑流域建立格子Boltzmann(LBM)离散模型,分析固体颗粒在润滑油中的动力学特性;考虑颗粒形状的影响,推导计入单个固体颗粒运动的润滑方程,并分析得到油膜压力;将油膜流动特性与颗粒动力学计算相结合,分析不同形状的颗粒运动对于油膜压力的影响。分析发现,当颗粒进入润滑油后,经过很短的瞬时颗粒就会达到一个瞬态稳定的状态,无论颗粒在油膜厚度方向的初始位置位于两壁面之间的中线上侧还是下侧,颗粒都会向中线位置移动;当颗粒速度为0时对于油膜压力的影响较大,随着颗粒速度逐渐增大,颗粒对于油膜压力的影响逐渐减小;当颗粒的宽度在油膜厚度方向相同时,长宽比越大的颗粒对于油膜压力的影响也越大;当颗粒长轴相等时,颗粒在油膜厚度方向的宽度越大,则其对于油膜压力的影响也越大,即颗粒形状对于油膜流动的阻碍能力越强,则其对于油膜压力的影响越大。     

High‐performance printable paper‐like composites derived from plastic flexible film wastes

Owing to lack of proper recycling methods, plastic flexible film wastes are usually directly discarded or incinerated, which brings about severe environmental pollution. Therefore, converting plastic wastes into value‐added products has received more and more attention in recent years. In this work, paper‐like composites derived from plastic flexible film wastes were prepared via the thermally induced phase separation method by adding polyethylene‐graft‐maleic anhydride (PE‐g‐MAH) as a compatibilizer and fumed silica as an additive. The resulting paper‐like composites were characterized by SEM and infrared spectroscopy. Other properties such as mechanical properties, thermal properties, whiteness, printability and adsorption performance were also tested in detail. It was found that remarkable enhancements in mechanical, thermal and printable properties of the paper‐like composites were obtained when nano‐SiO₂ loading was 2.5–3 wt%. Uniformly distributed holes that can endow good printability by providing space for ink or other functional molecules were observed by using SEM. Furthermore, the CIE whiteness value of the resulting composites can reach 91.6%–96.7% on adding nano‐SiO₂. Additionally, the paper‐like composites integrating nano‐SiO₂ and PE‐g‐MAH exhibited good solid ink affinity and high water or oil adsorption capacity. Thus, according to this research, high‐performance printable paper‐like composites used as major components of multifunctional papers can be prepared based on plastic flexible film wastes. © 2019 Society of Chemical Industry     

淀粉/聚乙烯醇活性包装薄膜及其在食品包装应用中的研究进展

综述了淀粉/聚乙烯醇（PVA）活性包装薄膜及其在食品包装中的研究进展，主要对从不同比例共混、疏水改性、增强改性等方面对淀粉/PVA薄膜的改性研究，从功能特性和活性物质对薄膜性能的影响2个方面对淀粉/PVA活性薄膜研究和薄膜在食品包装中的应用3个方面进行了归纳总结，旨在为以淀粉/PVA为基材的活性包装薄膜研究提供参考。