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分析了挤出机设备,材料配方特别是润滑荆、抗冲击改性剂、CaCO3、热稳定剂的选用,挤出工艺条件,以及模具结构等对塑料异型材表面光亮度的影响。经多次试验研究,对塑料异型材的配方、工艺条件和模具设计进行了调整,制得了表面光亮度好的塑料异型材。 相似文献
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探讨了单体橡胶挤出模具型腔的有效厚度设计、挤出模具型腔的修型调试和复合体橡胶挤出模具设计中各种复合材料的同步复合挤出、复合骨架导入模和挤出口型模具间的复合位置锁定、调整复合间隙以及配合倾角问题。在微波硫化过程中 ,通过模具设计、硫化工艺过程控制和异形垫带辅助等手段对产品进行保形 相似文献
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内容简介:本书以问答的形式,全面介绍了常用塑料成型工艺及模具设计制造方面的知识和技能。全书共分塑料概论、塑件的设计、注射成型工艺与成型设备、注射模设计、压缩成型工艺与模具设计、传递成型工艺与模具设计、挤出成型工艺与模具设计、其他成型工艺与模具设计、 相似文献
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探讨了从塑料蜂窝格产品最小规格参数确定到符合该合理规格的挤出模具设计过程和思路,提供可行的工程估算公式和计算机辅助有限元分析验证的方式,在SP挤出技术支持下,推算了与模具设计相关的基础参数,框定了模具设计的虑及范围,最终提供综合设计实例,为下一步的拓展系列设计建立了简便的重复模式。 相似文献
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介绍塑料异型材常见的内筋及表面缺陷形式,通过分析内筋的形成过程,找出了形成内筋及表面缺陷的主要原因。结果表明,适当的材料配方、异型材挤出模具设计中合理的内筋分料比例、内筋与主壁的压缩比关系及交汇段的长度设计是获得高表面质量塑料异型材的关键。 相似文献
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Rathindra Nath Das C. D. Madhusoodana Kiyoshi Okada 《Journal of the European Ceramic Society》2002,22(16):36-2900
The rheological parameters for a cordierite honeycomb extrusion were investigated using the Benbow–Bridgwater model. The extrusion pastes were formulated using typical binders, plasticizers, lubricants and pore-forming agents normally used for such extrusions. Pastes were found to have good pseudo-plasticity, low bulk yield and very low die-land shear stress, compared with the velocity dependent components of the respective pressure drops. In some formulation, reduced velocity contribution to the extrusion pressure with increased binder content found useful for better honeycomb extrusion. These characteristics of the honeycomb extrusion batches were analyzed by using dynamic bulk and shear stress components derived from the Benbow–Bridgwater six-parameter model and compared with the results of honeycomb extrusion trials. Plasticizing agents like polyethylenglycol (PEG) and glycerin were found to decrease the die entry pressure but showed no external lubricating effect leading to higher die-land pressure. Pore-forming agent, graphite was found to reduce both die entry and die land pressures, whereas, carbon increases the die entry pressure. 相似文献
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通过对非交联耐热聚乙烯(PE-RT)管材挤出过程的分析,针对实际生产中出现的口模积料问题,分别从材料配方、成型工艺、口模尺寸等方面进行了探究。结果表明:除材料中小分子迁移以外,口模积料与熔体出模应力有关。通过添加含氟助剂(PPA)、降低挤出速度、提高挤出温度、改变口芯模尺寸、提高拉伸比及模具电镀特氟龙等方式,可以有效减少口模积料的产生,延长清理时间;同时,管材的外观品质得到很大改善。 相似文献
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挤出制品熔接痕的形成、结构分析 总被引:3,自引:2,他引:1
对挤出制品熔接痕形成的原理进行细致的分析,指出制品的熔接痕有“V形槽”及“弱连接”两种形式。熔接痕的强度及物理力学性能远远低于制品的其它部位。研究发现,熔接痕的结构与材料配方、挤出机机头模具及加工工艺参数均有关系。 相似文献
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木纹结皮发泡PVC异型材的挤出 总被引:2,自引:0,他引:2
用普通单螺杆挤出机和自制结皮发泡模具,应用不同树脂进行配方工艺试验,结果表明:利用不同材料的流动性差异,并结合模具进行设计,可以挤出木纹效果良好的PVC结皮发泡异型材。 相似文献
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The numerical simulation of extrudate swell is significant in extrusion processing.Precise prediction of extrudate swell is propitious to the control of melt flow and the quality of final products.A mathematical model of three-dimensional(3D)viscoelastic flow through elliptical ring die for polymer extrusion was investigated.The penalty function formulation of viscoelastic incompressible fluid was introduced to the finite element model to analyze 3D extrusion problem.The discrete elastic viscous split stress(DEVSS)and streamline-upwind PetrovGalerkin(SUPG)technology were used to obtain stable simulation results.Free surface was updated by updating the streamlines which needs less memory space.According to numerical simulation results,the effect of zero-shear viscosity and elongation parameter on extrudate swell was slight,but with the increase of volumetric flow rate and relax time the extrudate swell ratio increased markedly.Finally,the numerical simulation of extrudate swell flow for low-density polyethylene(LDPE)melts was investigated and the results agreed well with others’work.These conclusions provided quantitative basis for the forecasting extrudate swell ratio and the controlling of extrusion productivity shape. 相似文献
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Terje Glomsaker Einar L. Hinrichsen Pl Thorsteinsen 《Polymer Engineering and Science》2001,41(12):2231-2248
The supermolecular structures present in S‐PVC during processing are dependent on the thermomechanical history and affect the rheological behavior. Motivated by the need to have reliable rheological data relevant for numerical modeling of 3D flows in extrusion dies, we compared standard off‐line capillary measurements with‐inline measurements obtained from an instrumented die mounted on an extruder. Different PVC formulations showed different slip behavior in‐line, and also differences in comparison with the off‐line results. Cogswell analysis on entry pressure drops was used in order to obtain elongational information. For one formulation, with plug flow both in off‐line and in‐line measurements, an analysis based on the resistance to flow in contracting zones was the only way to get flow data that could be used in 3D profile simulations. The temperature sensitivity of measurements was used in order to discuss our results in terms of structural changes within the melt due to differences in thermomechanical history and formulation. Finally, an example of a 3D simulation of the flow of this formulation in an industrial extrusion die is given and compared with observations. 相似文献
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比较了Polyflow用于挤出口模数值模拟的两种方法,即逆向挤出与给定口模的数值模拟,并介绍了Polyflow逆向挤出功能的基本过程;然后以一个典型十字型异型材的挤出口模设计为例,详细介绍了如何用Polyflow软件的逆向挤出功能对口模形状和尺寸进行数值预测。 相似文献