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塑料挤出吹塑中空成型壁厚均匀性的控制 总被引:1,自引:0,他引:1
吴裕农;王树辉;许中明 《中国塑料》2011,25(1):106-109
通过对挤出吹塑中空成型设备增设壁厚自动调节装置、对型坯挤出模头结构进行改进以及对全工作过程采用闭环自动控制,可以大大提高中空成型制件壁厚均匀性。改进后设备的生产效率提高,成型制品的单件质量、质量偏差及平均能耗降低,实现了塑料挤出吹塑中空成型技术的重点突破,达到国内领先并接近国际先进水平。 相似文献
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《塑料科技》2021,(3)
以太阳能内胆为研究对象,通过Ansys Workbench软件对其吹塑成型过程进行模拟仿真,对制件的壁厚分布进行研究。通过建立响应面模型,以吹胀压力、型坯初始温度以及型坯初始壁厚为设计变量,以制件最终的壁厚均匀性函数值为响应目标,获得较佳的成型工艺参数组合。结果表明:当吹胀压力0.461 MPa,型坯初始温度213.169℃,型坯初始壁厚0.003 m,该成型工艺条件下制件的成型质量最好,壁厚均匀性函数值最小值为0.384×10~(-5)mm~2,较未优化前降低了0.024×10~(-5)mm~2,相对偏差为3.13%。通过响应面法能够有效地改善太阳能水箱内胆的保温性能。 相似文献
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大中型吹塑机微机电液比例型坯壁厚控制系统研究 总被引:2,自引:0,他引:2
电液比例型坯壁厚控制系统是塑料挤吹中空成型机——中空成型机中最重要的机型之一——的一个关键性的控制系统。它利用电液位置控制系统,可随意控制型坯的壁厚变化规律,保证吹膜后中空制品的壁厚均匀。主要介绍了塑料挤出吹塑中空成型机中微机电液比例型坯壁厚控制系统方案分析、比较及控制策略探讨,介绍了用单片微机实现型坯壁厚控制系统的构成,基本工作原理及软、硬件设计,并对今后开发全自动微机适应系统的可行性进行分析和展望 相似文献
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《塑料科技》2021,(1):120-124
为减小吹塑制件壁厚不均导致的翘曲问题,采用Polyflow软件对汽车油箱吹塑成型过程进行了模拟仿真,但是由于软件仿真计算过程极为缓慢,因此通过Isight软件首先对制件采用最优拉丁超立方抽样法随机采样,随后建立Kriging代理模型,减少软件仿真模拟时间,提高计算效率,并且通过模拟退火算法对代理模型进行全局寻优,对制件吹胀压力、吹胀时间、初始型坯温度以及初始型坯壁厚进行了多目标优化,以最终壁厚均匀性函数值为响应目标,从而获得一组最佳的工艺参数组合。结果表明:代理模型R2为0.977 75,预测值与模拟值基本一致,模拟退火算法优化后最佳的成型工艺参数吹胀压力为0.304 MPa,吹胀时间为3.008 s,型坯初始温度为199.020oC,型坯初始壁厚为4.998 mm。为改善制件翘曲提供了一定的参考。 相似文献
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《塑料科技》2021,(2)
汽车涡轮增压储气管采用尼龙加玻璃纤维材料挤出吹塑成型制得,其最大的成型缺陷就是挤出吹塑过程壁厚不均匀导致制件发生翘曲,严重影响制件的成型质量。通过Polyflow软件模拟储气管成型过程发现其存在的缺陷,通过响应面法对其成型工艺参数进行了优化,通过Minitab软件制作质量控制图,对其CPK值进行分析,对制件成型质量做出评估,并通过优化改进提高CPK值,从而提高产品成型质量。实验结果表明:通过响应面法优化后较佳的成型工艺参数为吹胀压力为0.11 MPa,型坯初始温度为256.20℃,型坯初始壁厚为0.003 m,该工艺条件下制件CPK值为1.52,成型质量较好。 相似文献
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3D挤出吹塑型坯吹胀的数值模拟 总被引:1,自引:0,他引:1
采用超弹本构模型对挤出吹塑型坯吹胀进行了3D数值模拟,得到了型坯在吹胀过程中的型坯轮廓曲线分布以及吹胀完毕时的型坯壁厚分布,模拟的结果与文献的实验结果相吻合;探讨了材料的性能、初始条件和吹胀压力等工艺条件对吹胀完毕后的壁厚分布影响,这为在实际生产获得最佳的加工工艺参数提供了依据。 相似文献
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An optical sensor has been developed which can measure the thickness profile of the parison on line just prior to its enclosure in the mold. The device determines thickness by striking the parison at an angle with a laser beam and measuring the separation between the beams that are reflected from the outer and inner surfaces of the parison wall. A prototype was built and tested. The prototype uses three lasers at different angles and can make up to 250 point measurements during a one second scan. A personal computer uses specially developed software to reconstruct the profile of the parison wall from the raw data with an accuracy of ±5%. 相似文献
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针对部分聚对苯二甲酸乙二醇酯(PET)成型瓶靠近底端壁厚较小的缺陷,采用Polyflow仿真软件对PET瓶拉伸吹塑成型过程进行数值模拟。重点采用交互作用的正交试验方法,对瓶坯的加热温度、拉伸杆拉伸速度、预吹压力、延迟时间和高吹压力等工艺参数进行优化组合,使瓶子的最小厚度增大,瓶体更加均匀。结果表明,较优组合工艺参数分别为:延迟时间0.06 s、拉伸速度为1.6 m/s、预吹压力0.7 MPa、瓶坯温度110 ℃;优化后最小壁厚增大了28 %,瓶体壁厚均匀度提高了63 %。 相似文献
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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. 相似文献
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在中空塑料容器的挤出吹塑成形工艺中,型坯壁厚控制技术是关系产品质量的关键技术之一。为此本文介绍一种应用微机控制型坯壁厚的新方法。 相似文献
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This paper reports on the development of a dynamic finite element procedure for the simulation of blow molding and thermoforming of thermoplastic hollow parts. The Principle of Virtual Work written herein takes inertia effects into account. The heat‐softened parison is assumed to be a nonlinear hyperelastic Mooney‐Rivlin membrane and is meshed with classical linear triangular finite elements. We adopt the explicit central differences time integration scheme with the special lumping technique. The moid is divided into triangular elements and the contact between the parison and the mold is assumed to be sticky. Therefore, contacted degrees of freedom of the parison are fixed on the solid boundary until the end of the simultion. Performances are highly improved by the use of an adaptive mesh refinement procedure based on a geometric criterion for detection and on the simple addition of a node at the mid‐side of the longest edge for subdivision. The method is illustrated through some examples of thermoformed and blow‐molded parts. Our results are compared with both experimental and numerical results from literature to validate the present theory. 相似文献
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挤出吹塑中型坯自由吹胀的动力学分析 总被引:2,自引:0,他引:2
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。 相似文献
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采用方形截面管件,以短玻璃纤维增强聚丙烯为原料,通过溢流法水辅助注射成型实验探究了熔体注射温度、注水延迟时间和注水压力等工艺参数对制件宏观现象的影响机理,并分析了高压水在方形管道中的穿透行为。结果表明,当熔体温度升高时,方管的直角边和斜边残余壁厚都呈减小趋势,但温度过高时会出现管件收缩现象,管件截面中空面积增大且截面形状与高压水的穿透前沿形状一致,偏圆形,但截面的圆率逐渐减小;当注水压力增加时,管件残余壁厚减小,截面中空面积增大,其截面形状随着注水压力的增加逐渐与型腔结构一致,偏方形;当注水延迟时间增加时,管件残余壁厚增大,中空截面减小且管件截面形状也与高压水前穿透前沿一致,偏圆形,但相较另外两个参数,注水延迟时间对方管件的影响程度更小,因而对截面的圆率影响不大。 相似文献