短切纤维在增强热塑性树脂上的应用

介绍了短切纤维增强后的热塑性树脂在机械强度、热稳定性、电性能等性能上的较大提升,短切纤维质量要求与控制,流动性的检测方法,复合材料应用中浸润剂的选择,短切纤维的浸润剂和纤维长度这两个因素对于增强热塑性树脂性能的影响,短切纤维对塑料改型的作用和特点,GFRTP的发展方向。     

PPG短切纤维添新品

PPG工业公司玻璃纤维事业部宣布推出三款新型CHOPVANTAGE短切玻璃纤维产品。这三款产品均具有良好的耐水解、耐高温、易加工性能。CHOPVANTAGE HP3270能广泛应用于聚丙烯改性塑料,可大幅提升其物性,提高干态模塑材料的性能,主要用于汽车与家     

短切纤维填充聚四氟乙烯的减摩耐磨性能研究

以聚四氟乙烯(TPFE)为基体,通过添加10%、15%、20%、25%、30%的短切纤维制备纤维填充复合材料,研究了其摩擦磨损等相关性能。结果表明:短切纤维的填充增强了材料的压缩强度和硬度,但拉伸强度减弱;随着短切纤维含量的增多,磨痕宽度越来越小,材料的耐磨性能不断提高,摩擦系数也随之下降;电镜结果显示TPFE复合材料摩擦表面短切纤维分布均匀且无明显带状磨痕,但存在少量短切纤维剥离现象,分析发现剥离主要发生于摩擦的磨合阶段,不影响材料稳定磨损阶段的性能。     

丁腈橡胶/芳纶短切纤维复合材料的制备及性能研究

采用高锰酸钾硫酸溶液对芳纶短切纤维表面进行改性处理,然后再与丁腈橡胶复合制备了丁腈橡胶/芳纶短切纤维复合材料。探讨了芳纶短切纤维表面不同处理时间对复合材料机械性能的影响。结果显示,当芳纶短切纤维表面处理时间为20 min时,复合材料的拉伸强度达到最大值;复合材料的扯断伸长率随纤维表面处理时间的增加呈上升趋势,但处理时间超过20 min后,扯断伸长率的变化趋于平缓;复合材料的撕裂强度和硬度随处理时间的增加变化不明显。     

丁腈橡胶/芳纶短切纤维复合材料的制备及性能研究

采用高锰酸钾硫酸溶液对芳纶短切纤维表面进行改性处理,然后再与丁腈橡胶复合制备了丁腈橡胶/芳纶短切纤维复合材料.探讨了芳纶短切纤维表面不同处理时间对复合材料机械性能的影响.结果显示,当芳纶短切纤维表面处理时间为20 min时,复合材料的拉伸强度达到最大值;复合材料的扯断伸长率随纤维表面处理时间的增加呈上升趋势,但处理时间...     

增强PET玻璃纤维无捻粗纱及短切纤维的研制

１前言我们从１９９２年开始与中国科学院化学所合作开发增强热塑性塑料ＰＥＴ的玻璃纤维无捻粗纱和短切纤维制品。该项工作是根据国家科委“八五”科技攻关项目“ＰＥＴ工程塑料用玻璃纤维表面改性”专题而展开的。ＰＥＴ（聚对苯二甲酸乙二醇酯）即聚酯树脂是当今五大工...     

PPG短切纤维添新品

日前,PPG工业公司玻璃纤维事业部宣布推出三款新型CHOPVANTAGE短切玻璃纤维产品。这三款产品均具有良好的耐水解、耐高温、易加工性能。     

短切芳纶纤维增强三元乙丙橡胶注射技术的研究

采用注射成型工艺制备了短切芳纶纤维增强三元乙丙橡胶胶料,并针对成型过程中出现的质量问题进行了优化改进。结果表明,采用改进后的注射成型工艺制备的橡胶胶料综合性能优异,力学性能较好,烧蚀性能有所改善,能满足设计需要。     

短切芳纶纤维增强酚醛泡沫性能的研究

为了改善酚醛泡沫的性能,选用短切芳纶纤维作为增强材料,考察了不同短切芳纶纤维用量对酚醛泡沫压缩强度、压缩弹性模量、泡孔结构以及热稳定性能的影响。结果表明,短切芳纶纤维可以有效地增强酚醛泡沫的压缩性能。随着短切芳纶纤维用量的增加,酚醛泡沫的压缩强度和压缩弹性模量呈现先增加后减小的变化趋势。当短切芳纶纤维用量为4份时,酚醛泡沫的压缩强度比未添加短切芳纶纤维的酚醛泡沫提高约38%。短切芳纶纤维用量影响酚醛泡沫的泡体直径及其分布。当短切芳纶纤维用量为8份时,短切芳纶纤维在酚醛泡沫中的分布很不均匀,酚醛泡沫脆断截面上泡体破损现象较为严重,集束分布的短切芳纶纤维对酚醛泡沫的结构和力学性能带来不利影响。添加短切芳纶纤维可以明显提高酚醛泡沫在高温条件下(400℃)的热稳定性。     

甲醇水塔工艺失控原因分析与对策

我公司是国内唯一一家采用劣质褐煤鲁奇加压气化制合成氨原料气的企业，粗煤气中酸眭气体的脱除采用低温甲醇洗流程。由于鲁奇炉气化温度低，造成气化炉出口粗煤气中含有一定量的气态轻油及芳香烃类物质。为保证甲醇洗工艺的．洗涤效果，须在脱除H2S、CO2、COS等酸性气。之前，用1．61m^3／h的冷甲醇洗涤粗煤气，以脱除粗煤气中的气态轻油、HCN和水等。这股洗涤甲醇经萃取器Ⅰ段、Ⅲ段闪蒸脱气后，送往萃取器混合室，用软水作萃取剂进行萃取，使轻油与甲醇、水分离，轻油送煤化工工号处理回收，甲醇与水的混合物先送至共沸塔，     

基于S7—1200PLC的短切玻璃纤维生产线控制系统

以短切玻璃纤维生产线为例,介绍了以西门子可编程控制器S7—1200PLC为核心控制部件去实现设备集中监控的设计思路,使设备操作更加方便。     

旋振筛在玻璃纤维短切纱生产中的设计与应用

介绍了旋振筛在玻璃纤维短切纱生产中独特的结构设计、原理和优点,解决了产品在装袋前由于系统的密闭性而由飞扬的毛纱逐渐形成的毛纱团及倾斜振动筛未筛尽的长节纱掉入产品袋中的问题,描述了参振部件质量计算和振动弹簧的设计、振动电机选取及应用实例。     

增强耐水解尼龙66用玻璃纤维短切原丝的开发研究

介绍了应用于耐水解尼龙66的玻璃纤维短切原丝浸润剂的试验研究过程,重点介绍了增强耐水解尼龙66用玻璃纤维短切原丝必须具备的性能,通过试验最终得出了同时满足拉丝工艺、烘干工艺和增强耐水解尼龙66性能的玻璃纤维浸润剂。采用该浸润剂配方生产的玻璃纤维短切原丝产品,不论是玻璃纤维的外观、性能,还是改性后尼龙66的力学性能以及耐水解性能,都能达到预期效果。     

提高热带硬木干燥产率的高温干燥系统

目前,商业化干燥高温干燥（HTD^TM）橡木和,或其他本土硬木未见报道。至目前为止,95％以上马来西亚木材干燥工厂采用传统低温蒸汽加热干燥系统。由马来西亚林业科学研究所（FRIM）开发的HTDTM系统,特别对于橡胶木家具行业提供了一个独特解决方案。这种技术无需采用标准贝塞尔化学处理,只需一级干燥操作即将生橡木锯材转化为可供下游制造加工过程使用的干木材。木材处理周期时间比现有过程减少75％以上。此外,经HTDTM处理过的木材质量好,与传统方法生产的木材相比,具有更好的外形稳定性。与行业伙伴合作,FRIM高温干燥橡木产品已经成功地用于试生产胶合板台面和其他的实木家具及组件。     

热泵干燥系统温湿度控制实验研究

针对闭式热泵干燥系统非线性,强耦合等特点,将干燥循环分成升温过程和降温过程,并针对不同过程设计了相应的温度模糊控制策略。干燥过程温度、湿度是影响干燥物料品质的关键因素,为了提高干燥物料品质在温度控制的基础上设计了湿度模糊控制方案并给出了温湿度解耦策略。对温湿度的模糊控制效果进行了实验检测。系统运行结果表明：温湿度控制效果显著,温度的偏差控制在±0.8℃,湿度的偏差控制在±3％RH。     

Low Temperature Peanut Drying Using Liquid Desiccant System Climatic Conditions

Field-dried peanuts having 25% average moisture content have been dried by using a liquid dasiccant drying system. This system cansirts of climate simulation subsystem, closed loop air drying subsystem, and regeneration subsystem. The closed loop drying subsystem used in this investigation provides low temperature drying with a little increase in drying air temperature. Regeneration temperature, liquid desiccant concentration, and air flowrate in the drying subsystem have heen kept unchanged during the experiments, but air of different humidity have been used to regenerate the liquid desiccant. Experimental measurements of the system performance have been carried out utilizing a new cost effective desiccant mixrure (CELD) which is composed of equal portions by weight of lithium chloride and calcium chloride. The drying process has been performed using different climatic canditions in the regeneration process. Experimental rasults demonstrate that drying peanuts by the use of a liquid desiccant system is promising.     

立式干燥工艺系统与回转干燥工艺系统比较

电石、铁合金等行业需要用干燥的焦丁做原料。早期焦丁价格在500~700元/吨左右,成本比较低;近年来,焦丁价格现在已经达到了1500元/吨以上,焦丁和焦末的差价已达500元/吨以上。随着项目规模大型化的发展趋势,原来传统的回转干燥工艺系统焦炭丁在干燥过程中的破损率过大对生产成本的影响已经不容忽视,立式干燥工艺系统由于其低破损率在电石等行业日渐倍受青睐。     

Inversion Temperature and Pinch Analysis,Ways to Thermally Optimize Drying Processes

This work studies the compatibility and suitability of a combined inversion temperature and pinch analysis with the process selection for air and superheated steam spray drying of milk solids. The inversion temperature is a good starting point for an energy analysis because it is a simplified rate-based approach to comparing the steam and air drying systems. pinch analysis enables process integration, at least on a heat recovery and heat exchanger network level.

The resulting inversion temperature for the studied system was estimated as 182°C for the dryer inlet temperature. However, mass and energy balances showed that a minimum inlet temperature for spray drying of 184°C was required for the superheated steam dryer in order to ensure that the outlet solids temperature above the dew point temperature.

The inversion temperature is still very relevant in the early stages of a design process because it allows a quick assessment of which drying medium should result in a smaller dryer. It was evident that the steam system is better from an energy perspective because of the recoverable latent heat of the water vapor carried out of the dryer with the recycled steam. The steam system has between 82 and 92% of thermal energy recovery potential as condensable steam, compared with 13–30% energy recovery of the air system. However, other important design and operational factors are not discussed here in detail.

Combining the inversion temperature and pinch analysis suggests that superheated steam drying both gives better energy recovery and is likely to give smaller dryers for all operational conditions.     

太阳能-热泵联合干燥系统的开发和测试

建设太阳能-热泵联合干燥示范平台,以期更好推广其在干燥行业的应用。使用自动控制系统,实现对干燥过程中恒温操作,并采用智能启停的热回收器回收排放的废热。基于干燥系统平台对新鲜蔬菜进行干燥实验,测试结果表明:新开发的联合干燥系统的能耗比传统干燥方式降低3~4倍,干燥后的菜干品相上乘。实验证明,本次开发的智能控制干燥系统节能减排效果显著,适合在干燥行业推广应用。     

Process-Based Drying Temperature and Humidity Integration Control Enhances Drying Kinetics of Apricot Halves

The effects of drying temperature (50, 60, and 70°C) and absolute humidity (65, 90, 115, 140 g/kg at the initial stage) on drying kinetics and color attributes of apricot halves under process-based drying temperature and humidity integration control (PDTHIC) were investigated. Results indicated that appropriate PDTHIC could reduce the drying time by 18.75% compared to the control group. The absolute humidity parameter should be controlled well rather than continuously dehumidify for traditional practices. The moisture effective diffusivity (D_eff) at 70°C presented drastic fluctuations with increasing absolute humidity parameters, calculated using the Weibull distribution model. The activation energy (E_a) of samples treated by continuous dehumidification and PDTHIC were 31.40 and 74.18 kJ/mol, respectively. The variation trend of color parameters was different from the conventional hot air drying probably due to the dehydration mechanism. Observation of the microstructure of the dried samples indicated that the PDTHIC process can enhance the drying rate of apricot through generating a larger pore network compared to continuous dehumidification at the same temperature. The findings of the current work clearly indicated that process-based drying temperature and humidity integration control enhances the drying kinetics of apricot halves, leading to a promising technology for energy savings.