Isostatic Molding of Complex-Shaped Ceramic Articles

Methods for molding complex-shaped articles using hydrostatic molding are discussed. The development of adjustable stopping devices and hydrovibrators provides for good filling of the ribs and flanges of articles by molding powder. The possibility of producing such articles by quasi-isostatic (volumetric) compression is demonstrated.__________Translated from Steklo i Keramika, No. 2, pp. 10 – 12, February, 2005.     

Certain Specifics of Quasi-Isostatic Molding (A Review)

The author considers specifics of the method of quasi-isostatic molding, which is the most perfect, economical, and simple method for molding products from powder materials providing for a high quality of products due to the volume compression of the molding material. The method can be used for molding articles from ceramic, metal, and graphite powders, glass ceramics, ferrite, abrasive materials, and in production of refractory articles.     

Use of Alumozane Oligomers as Binders in the Production of Aluminonitride Ceramics

It is demonstrated that alumozane oligomers can be used as binders and plastifiers in the production of aluminum nitride articles by semidry molding. This allows for a simplification of the molding mixture technology and increases the mechanical strength of the articles.     

The State and Prospects of Molding Based on Aqueous Slip of Inorganic Materials

Methods for accelerating molding of large-sized thick-walled (d _w = 16 – 20 mm) articles based on aqueous slip of inorganic materials (namely, quartz glass and lithium-aluminosilicate glass) are analyzed. The most promising is the method of electrophoretic molding of ceramics that shows good results in molding articles from quartz glass slip. The possibility of applying this method to ceramics based on lithium-aluminosilicate glass is yet to be investigated. The choice of material and design for the electrodes is another subject for investigation, since the authors have encountered the problem of articles sticking to the electrode surfaces.     

Improving the design and technology of molds for ceramic articles

Ways of improving the design and the manufacturing technology of porous and poreless molds for shaping ceramic articles by the methods of slip casting and plastic molding are considered. New techniques for the production of porous molds are suggested, which make it possible to decrease the cost of the molds and optimize the processes of slip casting and plastic molding of ceramic articles.     

仿瓷餐具材质与性能分析

利用红外光谱法对市售的仿瓷餐具和自制的蜜胺树脂模塑制品、脲醛树脂模塑制品及蜜胺和脲醛树脂共混物的模塑制品的结构特征进行了分析,采用热重分析方法分析了各种制品的热稳定性,并对各种 "仿瓷餐具"的耐湿热性、耐污染性和甲醛迁移性能进行了测试和分析。结果表明,蜜胺树脂模塑制品的性能明显优于脲醛树脂模塑制品、蜜胺和脲醛树脂共混物的模塑制品和脲醛树脂表面覆盖密胺的模塑制品。     

A freeze method of obtaining ceramic based on fused quartz

Conclusions The technology of producing materials based on fused quartz by freezing the blank in a liquid nitrogen medium has been studied.The advantages of this method over slip casting in porous molds are: a reduction in the molding time; the production of articles with a large variety of wall thicknesses and complexity of surface; the possibility of firing the blanks immediately after molding; the production of strong articles with a porosity of 40-0%; the possibility of making articles with specified dimensions without mechanical treatment; and the simplicity of the process.Assistance was given in the manufacture of the molds and the molding of the specimen material.Translated from Ogneupory, No. 7, pp. 49–52, July, 1980.     

压装工艺对CL-20基炸药性能及聚能破甲威力的影响

利用常温成型和热压成型两种工艺制备了典型的CL-20基混合炸药装药,测试了其装药密度、密度均匀性、力学性能、爆速,计算了格尼系数。对Φ50mm标准聚能装药进行了破甲试验。验证了不同压装工艺条件下装填CL-20基炸药装药聚能射流对45号钢靶的侵彻深度和穿孔直径效果。结果表明,与常温成型CL-20基装药相比,热压成型工艺条件时装药的密度提高不小于1.46%,密度均匀性、爆速和格尼系数和破甲能力试验数据均有不同程度的提高,且Φ50mm标准聚能射流对45号钢靶的平均穿深从310mm提高至343mm,平均穿孔直径由18.0mm增至23.5mm。     

型煤技术基础理论总结与探讨

总结了型煤技术基础理论中煤的粘结机理、几种成型假说;分析了成型过程从加料、加压、成型、压溃到反弹各阶段型煤的受力情况;并对影响成型的五个主要因素(煤料的成型特性,成型压力,煤料的水分,粒度及组成,粘结剂用量)进行了总结与探讨。     

Mechanization of molding of large-sized pottery

New technological parameters are developed for molding pottery on a semiautomatic production line. The labor-intensive process of molding large-sized pottery articles is mechanized. The technical, economical, and quality parameters are improved, the number of rejected pieces is decreased, and the efficiency is increased.     

高固含量推进剂模压工艺

探索了一条高固含量推进剂较安全的成型工艺路线,重点介绍了一种高固含量球形药工艺.采用内溶法制得纯硝化棉黏合剂体系及硝化棉与ETPE(含能热塑性弹性体)混合黏合剂体系的高固含量(RDX(黑索今)质量分数为55％～60％)球形药,其球形药密度接近理论计算值,颗粒饱满,粒度均匀致密.采用模压成型工艺将其压制成推进剂药柱,药柱经无损检测,均匀致密,内部无气孔.同时药柱进行了各项性能实验.研究结果表明:该工艺方法简单可行,安全可靠.     

Effect of the mineralogical composition of the initial clay on the properties of ceramic articles

The regular features in the variation of molding, drying, and the physicomechanical properties of ceramic articles as a function of the mineralogical composition of the clays and coal cleaning waste are determined. The proportions of the basic clay minerals required for preparing high-quality building articles are established.     

滚塑发泡成型技术及其发展方向

介绍了一种新型的发泡成型技术———滚塑发泡成型技术。该技术既继承了传统滚塑成型的众多优点,同时又具有其独有的特点,即:具有发泡的芯层的同时又有光滑的表面,能大大提高产品的力学性能,弥补传统滚塑成型技术的缺点。主要从滚塑发泡成型技术的发展历程、工艺流程、加工原理、影响因素以及技术特点等几个方面,详细地介绍了如何利用滚塑发泡成型技术加工具有非发泡外壳和发泡内芯的塑料制品,并且着重介绍了一步法滚塑发泡成型工艺原理及影响因素,展望了滚塑发泡成型未来的发展方向。     

液压脉振塑化过程振动参数对LDPE性能的影响

采用新型液压脉振式注塑机成型低密度聚乙烯(LDPE)标准试样,测试成型过程整机能耗及试样的拉伸强度、密度等,探讨塑化过程中振动频率和振幅对制品性能的影响.实验发现,保持其他工艺参数不变,施加振动后,试样拉伸强度最大提高6.1%,密度增大3.3%,熔点向高温移动1.7℃,整机的加工能耗约降低6.8%,且呈现一定的变化规律.     

Rheomolding: A New Process to Mold Polymeric Materials

Polymer processing is an engineering field which deals with the conversion of synthetic high polymers into shaped articles ready for use. Impressive developments in the field of polymer processing in the last 20 years or so were precicipitated by the need to process plastic materials with an ever-increasing rate of production within stringent quality requirements. One of the most interesting methods for shaping plastic products is molding which involved all the possible ways for stuffing molds with thermoplastic or thermosetting polymers. Injection molding, compression molding, and transfer molding have now become some of today's routine approaches to plastics shaping.     

Dynamics of thermal conditions of molds in molding glass articles

It is proposed to introduce the concept of thermal stability in molds in the course of molding glass articles and a formula for calculating the stability coefficient, which will make it possible to model production conditions taking into account variations in the ambient temperature and molding duration. Translated from Steklo i Keramika, No. 5, pp. 6–7, May, 2000.     

Fluoride technology for fabrication of mullite articles from quartz-topaz

The results of studies of fabrication of mullite from quartz-topaz and molding of finished mullite articles directly in the stage of mullitization of topaz concentrate are reported. Using the proposed technology allows manufacturing light-weight refractory articles with a fibrous microstructure and minimizing the number of intermediate operations.     

Kinematics of flow in sheet molding compounds

Experiments utilizing charges constructed of black and white sheet molding compound (SMC) reveal the basic kinematic mechanisms controlling the flow of the fiber-filled compound in compression molding. The experimental results show that SMC deforms in uniform extension within individual charge layers, with slip occurring at the mold surface and, for slower closing speeds, also between the layers of SMC. When the mold closes rapidly, the charge extends uniformly through its thickness, with all slip concentrated at the mold surface.     

Flow analysis of rubber transfer molding

An experimental study has been carried out on rubber I transfer molding. It reveals that the filling is frequently limited more by the resistance of flow across the transfer pot than by resistance of flow through the sprue holes into the cavities. A mathematical model has been derived, which predicts semi-quantitatively the molding behavior observed. The mode1 predicts that fill time is proportional to the ratio of compound viscosity divided by molding pressure raised to about the fourth power. For the common cases where most of the fill time is from the resistance to the transverse flow on the top of the sprue plate, the fill time is proportional to about the fifth power of the ratio of transverse distance divided by the charge thickness. Experimental results showed that preheating and mastication of the compound reduced transfer time substantially. The charge pattern did not seem to have a major influence on transfer time.