ABS粉末塑料的选择性激光烧结成型工艺参数优化设计

阐述了在快速成型设备上实现选择性激光烧结的成型机理,探讨了激光加热原理.对ABS粉末塑料的选区激光烧结过程的成型工艺参数进行了优化设计,对其中影响最大的参数(扫描速率、激光功率、预热温度)的匹配以及成型参数的选择进行了优化设计,得出一组最佳组合的工艺参数.     

连续玻璃纤维增强热塑性塑料成型技术及其应用

综述了国内外连续玻璃纤维增强热塑性塑料的纤维处理方法、成型技术及应用状况，展望了连续玻璃纤维增强热塑性塑料发展前景。     

热塑性复合材料冲压成型技术的近况及趋势

本文介绍了增强热塑性塑料(FRTP)的优缺点、FRTP片材及其冲压成型技术的近况与发展趋势。本文的目的在于引起国内有关部门、人士对这一领域应有的重视,进而采取具体、有力措施,急起直追。     

竹纤维增强热塑性塑料复合材料研究进展

对竹纤维增强热塑性塑料复合材料的基体和增强体、成型工艺、界面改性技术的国内外研究现状进行了综述,分析了原料、物料配比以及成型工艺对竹纤维增强热塑性复合材料性能的影响,同时介绍了用竹纤维与可降解塑料制备复合材料的研究现状。重点阐述了原材料表面预处理、接枝共混以及硅烷、钛酸酯为主的偶联剂对复合材料改性效果的影响。最后简要分析了竹纤维增强热塑性塑料的发展趋势,并对竹纤维增强热塑性塑料未来研究重点进行了简要阐述。     

树脂基复合成型材料的选择性激光烧结

介绍选择性激光烧结及烧结技术的基本原理,探讨了树脂基复合成型材料选择性激光烧结工艺及参数。     

热固性塑料的中空成型

传统的中空吹塑成型技术只能适用于热塑性塑料？现在．利用熔芯中空成型技术便可以将热固性塑料制成性能优良的中空制品。[编者按]     

聚合物选择激光烧结成型的研究进展

选择激光烧结是一种新型的快速成型技术。简要论述了选择激光烧结成型原理、研究现状、聚合物成型原料的选择、影响因素、发展前景等。     

塑料烧结成型法

本文论述了烧结成型的多孔性塑料基材的广泛应用以及塑料烧结成型原理和工艺因素；分析表明，多孔性塑料基材的性能与塑料的特性、烧结成型工艺条件密切相关。     

热塑性弹性体SBS的成型加工

一、概况热塑性弹性体(TPE),常温下具有橡胶的弹性,高温下又能像热塑性塑料那样熔融流动,兼具橡胶和热塑性塑料的特性。这种材料的主要特点是无需硫化即具有高强力和高弹性,可以采用热塑性塑料的加工工艺和设备成型。如注射成型、挤出成型、模压和压延等。     

热塑性塑料包覆成型LSR的注意事项

近年来，软／硬包覆成型已成为注塑加工商掌握的基本技术，并且越来越多的注塑加工商正在扩大这种热固性／热塑性塑料相组合的技术。在某些应用中，LSR在耐热性、极端低温柔性、耐化学性和固有的润滑性方面提供了超过TPE的优势。获得良好的长期粘接性可以算作硬质热塑性基材包覆成型TPE的一个难题，而对于热塑性塑料包覆成型LSR而占，这一难题更具挑战性。     

Selective Laser Sintering 3D Printing: A Way to Construct 3D Electrically Conductive Segregated Network in Polymer Matrix

Selective laser sintering (SLS), which can directly turn 3D models into real objects, is employed to prepare the flexible thermoplastic polyurethane (TPU) conductor using self‐made carbon nanotubes (CNTs) wrapped TPU powders. The SLS printing, as a shear‐free and free‐flowing processing without compacting, provides a unique approach to construct conductive segregated networks of CNTs in the polymer matrix. The electrical conductivity for the SLS processed TPU/CNTs composite has a lower percolation threshold of 0.2 wt% and reaches ≈10⁻¹ S m⁻¹ at 1 wt% CNTs content, which is seven orders of magnitude higher than that of conventional injection‐molded TPU/CNTs composites at the same CNTs content. The 3D printed TPU/CNTs specimen can maintain good flexibility and durability, even after repeated bending for 1000 cycles, the electrical resistance can keep at a nearly constant value. The flexible conductive TPU/CNTs composite with complicated structures and shapes like porous piezoresistors can be easily obtained by this approach.     

Preparation and properties of styrene ethylene butylene styrene / polypropylene thermoplastic elastomer powder for selective laser sintering 3D printing

As one of the most important thermoplastic elastomer materials, the application of styrene ethylene butylene styrene (SEBS) in selective laser sintering (SLS) has not been reported. In this study, SEBS and polypropylene (PP) are blended and then pulverized at low temperatures. We find that SEBS with high molecular weight and styrene segment content is difficult to melt and flow under laser irradiation, which is not suitable for SLS 3D printing. SEBS with low molecular weight can be printed, and its tensile properties can reach 2.1Mpa and 134% elongation at break. We test the enhanced absorption effect of two different infrared absorbers and find that graphene (GE) can enhance absorption mainly rely on its special structure to increase the optical path of the laser. The absorption enhancement effect of each enhancer rises first and then decreases. 0.4‰ addition of GE can bring 22.5% enhancement. With the enhancement of GE, we get a product of 2.8 MPa tensile strength and 176% elongation at break.     

Research on selective laser sintering of Kaolin–epoxy resin ceramic powders combined with cold isostatic pressing and sintering

In order to fabricate traditional products with complex shapes consisting of Kaolin ceramic, selective laser sintering (SLS) combined with cold isostatic pressing (CIP) process was used to consolidate Kaolin powder with additive of epoxy resin E06. To begin preparing the material, epoxy resin (10 wt%) and Kaolin were combined through mechanical mixing, which provided a good fluidity for SLS. Investigations on the shrinkage and micro topography of Kaolin–epoxy resin SLS samples were conducted to optimize the laser sintering parameters. It was found that SLS samples represented acceptable shrinkage and high density when laser energy density was 0.3300–0.3763 J/mm². Then the SLS samples were processed by CIP to eliminate the pores in green ceramics. Finally, the optimized SLS/CIP Kaolin samples were debinded and sintered to produce crack-free Kaolin ceramics. The “Yellow Duck” Kaolin ceramic product was fabricated by combining SLS/CIP with colored glazing. The study shows a novel and promising approach to fabricate complex traditional ceramic products via SLS combined with CIP and sintering.     

应用于选择性激光烧结的结晶性高分子材料粉末的工艺评述

从3个方面对结晶性高分子材料粉末在选择性激光烧结(SLS)的工艺进行评述,分别为高分子材料粉末的制备工艺、高分子材料粉末的复合改性工艺和高分子材料粉末的SLS工艺。其中在高分子材料粉末的制备工艺中对高分子材料粉末的制备方法和基本要求,以及高分子材料粉末在SLS工艺中的性能表征及使用的仪器设备等进行了介绍;在高分子材料粉末复合工艺中对复合改性方法和改性目的进行了叙述;在高分子材料粉末的SLS工艺中对影响成型件精度的各种参数进行了阐述。     

木质素磺酸钠吸收烟道气中的SO2

本文就木质素磺酸钠溶液脱除烟道气中SO_2进行了实验研究。实验采用双搅拌气-液反应器,探讨了木质素磺酸钠的浓度、温度等因素对SO_2吸收的影响,并求取了化学吸收增强因子。结果表明,木质素磺酸钠能有效地脱除烟道气中的SO_2。     

石墨烯/玻璃块体复合材料的制备及性能

本文报道了还原氧化石墨烯/钠钙硅(rGO/SLS)玻璃块体复合材料的热压制备和力学性能。首先以3-氨基丙基三乙氧基硅烷为表面活性剂修饰玻璃粉微粒;然后在水溶液中带负电的氧化石墨烯(GO)纳米片通过静电自组装与被氨基修饰过带正电的玻璃颗粒相结合生成复合颗粒。通过高温真空热压烧结,GO被还原成rGO,从而原位生成rGO/SLS玻璃块状复合材料。结果表明,rGO均匀分布在玻璃基质中,并明显增强了复合材料的机械性能。rGO/SLS玻璃块体复合材料中rGO的含量为0.5%(质量分数)时,复合材料的弯曲强度比纯的SLS玻璃提高了约一倍。     

Microstructural Evolution in Clay-Based Ceramics I: Single Components and Binary Mixtures of Clay, Flux, and Quartz Filler

Microstructural evolution on heating kaolinite clay, quartz, nepheline syenite, and soda–lime–silica (SLS) glass to various temperatures to 1300°C was investigated in quenched and slowly cooled samples by XRD, thermal analysis and SEM, and by in situ XRD. In the individual components, the expected behavior was observed and in SLS glass, devitrification led to crystallization of cristobalite, quartz, devitrite, and wollastonite, which dissolved at 900°–1000°C. Significant effects of each component on microstructural evolution in the others were often observed in binary mixtures. For example, in SLS glass and quartz mixtures, devitrification of SLS glass to form cristobalite was delayed and two forms of cristobalite with different morphologies were identified. Albite and plagioclase crystallized on heating kaolin clay and SLS glass mixtures, decreasing the alumina content available for mullite formation. Melting of nepheline syenite promoted reaction with the clay, including accelerated phase dissolution. SLS glass accelerated dissolution of nepheline syenite and prevented leucite formation.     

Evaluation of Prosopis juliflora as a potential feedstock for the production of sodium lignosulfonate from the spent liquor of a laboratory digester

Abstract

Chopped stems of Prosopis juliflora, an invasive xerophyte, were digested in a laboratory digester following alkaline sulfite pulping process to generate spent liquor whereby lignin underwent sulfonation to produce sodium lignosulfonate (SLS). SLS was concentrated from the spent liquor by ultrafiltration. Raw wood was featured by high lignin (23.5%), low extractives (1.0%), low wax (0.41), and low ash (2.25%) content thus making it an ideal feedstock to produce lignosulfonates with appreciable physico-chemical property and relatively high mechanical strength. Attempts were made to provide basic information on SLS structure and structural changes that might occur during pulping of P. juliflora under the present experimental conditions. Spectral and X-ray diffraction studies on as-produced SLS revealed substantial depolymerization and structural modification of lignin during sulfite pulping. The derived SLS had higher crystallinity index than the feedstock wood. Effect of average size of raw wood chip and dose of sodium sulfite in the overall yield of pulp and SLS along with the kappa number of the pulp were also analyzed. Findings from this study would serve to cultivate a better understanding of the potential of P. juliflora as a feedstock, so far unexplored, to produce SLS???a value-added product with numerous commercial applications. The use of this particular plant species in paper and pulp industry could also be considered as an effective means of integrated agro management in rural areas.     

甲基膦酸二甲酯/木质素磺酸钠聚氨酯泡沫的制备及其阻燃性能

利用木质素磺酸钠(SLS)替代部分聚醚多元醇,同时将甲基膦酸二甲酯(DMMP)作为添加型阻燃剂,采用"一步发泡法"制备出甲基膦酸二甲酯/木质素磺酸钠聚氨酯泡沫材料(DMMP/SLS/PUF),通过极限氧指数(LOI)测试对其阻燃性能进行分析,探究了 SLS替代率及DMMP添加量对材料阻燃性能的影响.并利用锥形量热(CO...