塑料容器型坯吹胀变形计算机模拟系统设计

现代设计与制造业离不开ＣＡＤ／ＣＡＭ技术。本文基于型坯挤出吹胀变形数学模型，采用Ｃ语言编写了型坯设计计算与吹胀变型系统程序，实现了型坯设计、变形仿真与计算，并对程序流程、示例及运行结果等进行了较为详细的分析与讨论。     

低密度聚乙烯二步法模压发泡的研究

本文介绍采用二步法模压发泡工艺制造密度较小的ＬＤＰＥ泡沫塑料。其工艺过程为先用模压法压制成预发泡型坯，然后趁热将此型坯放入烘箱中进行二次发泡，即得泡材。通过对交联—发泡体系的研究发现，合理地控制预发泡型坯的交联度和发泡剂的分解速率是二步法模压发泡工艺的关键，必须使ＬＤＰＥ的交联速率与ＡＣ的分解速率相匹配。该泡沫塑料的基本配方（质量）为：ＬＤＰＥ１００、ＡＣ２０、ＺｎＯ０．５、ＺｎＳｔ１．０、ＤＣＰ１．０、ＴＡＩＣ１．０。最佳成型工艺条件为：模压温度１５０℃，时间１０ｍｉｎ，烘箱温度１９０℃，时间１．５ｍｉｎ。所制泡材的性能：密度０．０４ｇ／ｃｍ３，邵氏Ｃ硬度３９，拉伸强度０．３８ＭＰａ，断裂伸长率１５７％。     

陶瓷坯体烧成过程中热应力场的三维有限无分析

根据三维有限元理论，把连续升温的温度场迭加到热应力的计算中，为了计算坯体热应力，对各种不同的生坯在不同的温度下进行了力学参数的测定，分别测试了试样的热膨胀收缩率、弹性模量及强度随温度变化的关系。以面砖和电瓷生坯为例，计算了不同条件下的热应力场。根据第一强度理论及热形变的概念，定义了最大无因次热载荷和坯体最大当量热变形两个新概念。分别以坯体内最大热压应力、坯体内最大热张应力、最大无因次热载荷以及坯体最大当量热变形作为标识，对所计算的热应力场进行了整理。结果表明：坯体内最大热应力在任何时刻总是出现在坯体表面边缘转用处；最大无因次热载荷与坯体最大当量热变形之间曲线形态有着很多相关关系，可以用坯体最大当量热变形来近似推测最大无因次热载荷的变化情况。     

国产全陶瓷摩擦盘在牵伸变形机上的应用

探讨了ＤＣＳ１２００Ａ型牵伸变形机上等离子喷涂陶瓷盘改用国产全陶瓷盘的可行性，对影响锦纶ＤＴＹ加工的稳定性和内在质量的因素进行了对比实验。结果表明：ＤＣＳ１２００Ａ型牵伸变形机在纺中、粗旦丝时，使用全陶瓷摩擦盘更有利于ＤＴＹ加工的稳定性及提高产品的内在质量。     

吹塑成型连续分析系统SIMBLOW

本文介绍用于中空成型的型坯、锁模、吹胀、冷却等过程的ＣＡＥ ＳＩＭＢＬＯＷ系统。     

微机轮胎辅助设计计算系统

轮胎设计过程中浩繁的计算，促使了该“微机轮胎辅助设计计算系统”的开发，本系统采用ｄＢＡＳＥⅢ与ＦＢＡＳＥ数据库和Ｂａｓｉｃ、ＦＯＲＴＲＡＮ高级语言以及ＡｕｔｏＣＡＤ等系统软件技术，结合轮胎设计计算问题，建立了各相应的轮胎材料参数库，开发出了一个完整的从设计到施工的轮胎辅助设计计算系统（适用于航胎或汽车胎）。该系统可提高轮胎设计工作效率、缩短设计周期、采用本系统其潜在的间接经济效益不止于此，是不可估     

含铌钛微合金化钢连铸坯高温变形试样中碳氮化物的析出

铌、钛微合金化钢连铸坯高温变形试样中主要有三类碳、氮化合物析出：（１）高温下析出的粗大块状ＴｉＮ析出物；（２）９５０～９００℃区间沿晶界和在晶粒基体内部析出的微细Ｎｂ（Ｃ，Ｎ）动态析出物；（３）温度低于９００℃后Ｎｂ（Ｃ，Ｎ）依附在ＴｉＮ颗粒上生成的复合析出物．在９５０～９００℃区间析出的微细Ｎｂ（Ｃ，Ｎ）是造成此温度区间试样延塑性急剧降低的主要原因．由于氮优先与钛反应，减少了低温时Ｎｂ（Ｃ，Ｎ）和ＡｌＮ的析出量，使铌、钛微合金化钢在８５０℃Ｃ～Ａｒ３温度之间延塑性没有进一步降低．     

计算机辅助型坯形状设计

本文提出了一种简单可行的自动设计型坯形状的方法。通过这种方法,可以实现由希望的吹塑制品形状求取其对应的最佳型坯形状。文中给出了设计型坯形状所遵循的数学关系、设计步骤以及相应的计算框图,同时也给出了简单的设计例子。     

AUTO CAD在工程设计中的应用

介绍ＡＵＴＯＣＡＤ在化工设计中的应用，比较ＡＵＴＯＣＡＤ与人工绘图的效益，质量以及设计周期的影响，探讨了ＡＵＴＯＣＡＤ的未来前景与市场竞争力。     

聚丙烯酸酯橡胶合成与共混的进展

主要对聚丙烯酸酯橡胶（ＡＣＭ）国内外近年来在合成与共混改性上的发展进行了述评。在合成上通过引入多功能性第二或第三单体共聚．使改性后的ＡＣＭ的耐寒、耐热、耐油、压缩永久变形及力学等性能得到较好的平衡。采用不同型号ＡＣＭ共混、ＡＣＭ与了腈橡胶、硅橡胶、氯醇橡胶等特种橡胶共混，弥补了ＡＣＭ一些缺陷．使ＡＣＭ性能价格比得到较大提高。     

The dynamics of parison development in blow molding

An experimental program was carried out to study the dynamics of parison swell and development in extrusion-blow molding. Two commercial blow molding grade polyethylene resins were employed in conjunction with an Impco, Model A13-R12 reciprocating screw blow molding machine equipped with a cylindrical bottle mold. Parison weight swell was measured with the aid of a parison pinch-off mold. In order to obtain more reliable and useful information regarding diameter and thickness swell of the parison and the dynamics of parison formation and development, high speed cinematography was employed. Data obtained by this technique are more reliable than results obtained with the pinch-off mold alone. They also give further insight into the phenomena of swell, sag, and parison spring back or recovery.     

挤出吹塑中型坯尺寸的在线分析

对型坯的视频图像进行了在线分析,并提出了一种不同于传统数字图像处理的新方法,用来定位型坯表面每个墨痕(在机头出口附近用画线方法形成)的位置。还使用了“sobel”和“canny”这两种传统的方法,来定位型坯的边界。这样,可在线确定出相邻两个墨痕之间的距离和对应每个墨痕的型坯外径。采用锥形圆筒来对墨痕之间的型坯段进行几何近似,根据质量守恒计算出对应每个墨痕的型坯内径。     

模拟技术在塑料中空成型中的研究进展

介绍了模拟技术在吹塑型坯成型中的研究和发展状况，对国内外学者针对型坯成型过程运用的数值分析方法和理论依据进行了论述，并着重介绍了神经网络方法。指出型坯成型过程是吹塑过程的核心，受聚合物材料性能、熔融温度、成型加工条件等因素的综合影响，有待进一步研究。     

模拟技术在吹塑型坯成型中的研究进展

介绍了模拟技术在吹塑型坯成型中的研究和发展状况，针对型坯成型过程，对国内外学者进行数值分析的方法和理论依据进行了论述，着重论述了神经网络方法。并指出型坯成型是吹塑过程的核心，是一个受聚合物材料性能、熔融温度、成型加工条件等因素综合影响的过程。     

Numerical simulation of blow molding—prediction of parison diameter and thickness distributions in the parison formation process

In our previous study, we calculated the time course of parison length in the parison formation stage, but it could predict only the parison area swell. The next target in our study is to calculate the parison diameter and thickness swell. Annular extrudate swell simulation is necessary for the understanding of various kinds of swelling ratios in blow molding. We have examined three kinds of swells (outer diameter, thickness, and area swells) obtained from simulation results of annular extrudate swell, using the Giesekus model, and have developed a method of predicting parison outer diameter and thickness swell values. The predicted values of parison outer diameters are discussed in comparison with experimental data, and reasonable results are obtained by the proposed method. This prediction method could also be applied to the parison formation process using a parison controller. As a result, it is possible to predict approximately the whole process of parison formation by numerical simulation.     

海拉尔盆地贝中地区南屯组物源分析

物源分析技术主要包括碎屑成分对比技术、重矿物分析技术、沉积相分析技术、地球化学分析技术、石英阴极发光分析技术等。研究区范围相对不大,但是构造相对复杂,受多方向物源供给的影响较大,因此,在确定贝中地区南屯组沉积时的物源区母岩性质和物源方向时,采用多种分析方法加以综合判别,其中以碎屑物成分和轻、重矿物组合和砂岩百分含量变化为主要手段,得出研究区存在2个物源方向:一是正东和北偏东方向的主物源方向,物源来自于东部布勒洪布斯隆起带;二是西南方向和西北方向的次要物源方向,物源来自于西部苏德尔特隆起带。     

Noncontact measurement of parison thickness profiles affected by swell and sag in continuous extrusion blow molding

Optimization of final part thickness distributions is crucial in the extrusion blow molding process in order to minimize resin usage. Prediction of part thickness distributions from basic process and material parameters would be ideal. However, attempts to do so have been unsuccessful, largely because of the inability to predict parison thickness profiles. One must therefore resort to measurement of the parison thickness profile and estimation of the final part thickness distribution by computational methods. This paper describes a new technique for the noncontact estimation of parison thickness profiles in continuous extrusion blow molding. The method accounts for sag and requires no previous knowledge of rheological data. It can be employed on-line for the purposes of process monitoring and control. The approach is based on the measurement of the parison length evolution with time during extrusion, the parison diameter profile, the flow rate, and the melt temperature gradient along the length of the parison. These parameters are utilized in conjunction with a theoretical approach that describes the extrusion of a parison under the effects of swell, sag, and extrusion into ambient conditions. Results are presented for three resins of various molecular weight distributions. The degree of sag is minimal at the top and bottom of the parison, and reaches a maximum near the center of the parison. Results are also presented to demonstrate the versatility of the method under other process conditions, such as varying flow rate, die temperature, and die gap.     

挤出吹塑中型坯自由吹胀的动力学分析

聚合物挤出吹疗程 型坯的自由吹胀受到多方面因素的影响。采用动力学方法对此进行了研究。模拟了史胀过程听型坯轮廓变化， 吹胀压力，材料模量，型坯初始壁厚对此过程的影响。     

Numerical simulation of suction blow molding process for producing curved ducts

During suction blow molding process, the extruded parison undergoes twisting deformation within the mold cavity, as the air drawing flow around the deforming parison exerts non‐uniform shear stresses on its surface. Such twisting deformation can compromise the specific radial and circumferential variations in parison thickness that are intentionally generated during extrusion. This research is devoted in developing a fluid–structure interaction model for predicting parison deformation during suction blow molding process, with a specific emphasis on the suction stage. A fluid flow model, based on Hele‐Shaw approximations, is formulated to simulate the air drag force exerted on the parison surface. The rheology of the material of the parison is assumed to obey the viscoelastic K‐BKZ model. As the suction process also involves the sliding of the parison within the mold cavity, a modified Coulomb's law of dry friction is used to simulate the frictional contact between parison and mold. The numerical results of this study allowed identifying a clear correlation between the twisting deformation undergone by the parison during the suction stage, also observed experimentally and the design parameters, namely, the air drawing speed, the geometry of the duct mold cavity, and the parison/mold eccentricity. POLYM. ENG. SCI., 59:418–434, 2019. © 2018 Her Majesty the Queen in Right of Canada     

New Strategies for Predicting Parison Dimensions in Extrusion Blow Molding

In this work, two new strategies were proposed for predicting the parison thickness and diameter distributions in extrusion blow molding. The first one was a finite-element-based numerical simulation for the parison extruded from a varying die gap. The comparison of simulated and experimental parison thickness distributions indicates that the new method has certain accuracy in predicting the parison thickness from a varying die gap. The second one was an artificial neural network (ANN) approach, the characteristics of which are in sufficient patterns that can be obtained without doing too many experiments. The diameter and thickness swells of the parisons extruded under different flow rates were obtained by a well-designed experiment. The obtained data were then used to train and test the ANN model. The dimension of one location on the parison can provide one pattern to train the ANN model. Trained and tested ANN model can be used to predict the dimensions at any location on the parison within a given range. The proposed two strategies can help search the processing conditions to obtain optimal parison thickness distributions.