橡胶护舷挤出过程中机头内的流场分析

在橡胶护舷挤出过程中,机头结构影响胶料的流动,而胶料的流动对胶料所产生的剪切和拉伸作用是影响护舷规则成型的重要因素。利用ADINA对橡胶护舷挤出机头内的流场进行模拟分析,对判断机头结构的合理性,并优化机头结构,缩短机头的研发周期,具有重要的意义。模拟分析主要包括压力场、速度场、黏度场等。     

超宽幅橡胶片材挤出机头的研制

介绍了研制的超宽幅橡胶片材挤出机头以及相关挤出机的主要技术参数。重点介绍了保障该重大装备制造成功的基础理论研究工作。首套超宽幅胶片挤出生产线试车情况显示,其核心部分——机头在保证片材质量的同时,可生产出厚度为2～20mm,幅宽达2800mm的橡胶片材,同时也验证理论分析方法和模拟结果的正确性。     

五复合橡胶挤出机头

正授权公告号:CN 103171113B授权公告日:2015年12月23日专利权人:桂林橡胶设计院有限公司发明人:黄发国、江建平、邓文忠等本发明为五复合橡胶挤出机头,包括安装于模座上的上模、上中模一、上中模二、中模、下中模、下模,模座上开有连接挤出机机筒、按骑背式结构布置的5个挤料口。倾斜设置挤料口连通合模后各模体之间的分型面流道腔。上模挤料口、上中模挤料口、中模挤料口、下中模挤料口、下模挤料口的     

L型片材挤出机头流道速度分布三维有限元分析

利用大型有限元计算软件ANSYS进行以三维模型为基础的L型机头内部流动速度分析和模拟研究。通过顺次截取沿挤出方向上 4个不同区域的速度分布图和 7个截面中间层节点横向速度分布曲线 ,分析了物料在L型片材挤出机头中的流动分布情况 ,即物料在机头内部经过几次速度调整逐步达到横向速度分布基本均匀     

L形片材挤出机头流道压力分布三维有限元分析

采用ANSYS有限元分析软件对L形防水片材挤出机头内部幂率流体的压力场进行模拟和分析,通过运算得出了加工过程中聚合物熔体在流道各处的压力分布图。     

橡胶挤出扩胀工艺及挤出机头的初步研究

橡胶挤出扩胀法，是一种新的橡胶加工方法，适宜于宽幅橡胶薄片材料的生产。该法使用的挤出机，具有机头结构简单、价廉、占地面积小，挤出物质量好等优点。对三组不同结构的扩胀机头进行试验，结果得出：橡胶挤出扩胀方法的适宜扩胀比为２．０～２．５；在挤出扩胀过程中对胶片施加纵向牵引力比横向牵引力好。     

四复合橡胶挤出机组研制

介绍国产四复合橡胶挤出机组结构形式、螺杆及驱动功率选择、四复合机头的理论力学受力分析、三维建模及有限元分析、液压系统,四复合橡胶挤出机组的参数确定、温控系统和三维集成,并将投入使用的国产四复合橡胶挤出机组与国外同类产品进行对比。结果表明,国产四复合橡胶挤出机组性能达到国际先进水平。     

L型宽幅片材挤出机头优化设计及流场模拟

构建L型宽幅片材机头的三维物理模型,利用ANSYS WORKBEM、H和POLYFLOW软件对机头内部幂牢流体的压力场和速度场进行模拟。分析结果表明,当口模高度为4 mm、阻尼高度为3.5mm、主流道首末端直径比为1.2：l-l：1时,L型机头具有较好的挤出效果。     

螺杆挤出机的胶管挤出机头

本文根据生产实际，扼要介绍了几种螺杆挤出机的胶管挤出机头的结构及其特点。文章最后指出，胶料在机头内的流速和压缩比是影响胶管挤出机头的重要因素。     

橡胶护舷无模挤出法

正由烟台泰鸿橡胶有限公司申请的专利(公开号CN 102848545A,公开日期2013-01-02)"橡胶护舷无模挤出法",涉及的一种橡胶护舷配方为:丁苯橡胶80~90,氯化聚乙烯20~10,再生胶150~160,炭黑47,轻质碳酸钙35,绢云母粉35,氧化锌5~6.5,轻质氧化镁2,硬脂酸2.6,防老剂4010NA 1,防老剂RD1,增塑剂DOP 8~10,防焦剂CTP 0.4,芳烃油15,硫化剂TDDS 0.5~0.6,硫黄1.6,促进剂NS 1.3,促进剂BF 0.4~0.5。该发明通     

螺杆分配机头内部压力场分布的CAE分析

用ANSYS有限元软件对生产宽幅橡胶板材的螺杆分配机头流道内部的压力场进行三维模拟与分析，选择Fluid 142三维六面体单元划分网格，建立螺杆分配机头内部流道的三维有限元模型，得到在一定工艺条件下机头流道内部的压力分布。分析了阻尼块几何形状对压力分布的影响，指出阻尼块可以增加流道内原来速度和压力较高部位的流动阻力，选择合适的阻尼块高度可以使胶料的压力值逐渐趋于横向均匀。     

几种有限元分析方法在机头流道分析中的应用研究

研究了 3种有限元分析方法———流函数法、侧壁因子修正法和全高三棱柱单元法在挤出机平板机头流道分析中的应用情况。结果表明 ,流函数法只适合分析流道高度不变化或变化极小的情况 ;侧壁因子修正法误差较小 ;全高三棱柱单元法比较精确 ,但分析方法复杂     

Finite element modeling of the flow of a rubber compound through an axisymmetric die using the CEF viscoelastic constitutive equation

This work is devoted to the simulation of the flow of a high viscosity NR/SBR rubber compound through the die of a single screw extruder with axisymmetric geometry. An in-house developed computer code based on the use of continuous penalty finite element method was employed. Three constitutive equations including two generalized Newtonian models namely; power-law and Carreau and an explicit viscoelastic model named CEF (Criminale-Ericksen-Fillbey) were used to reflect the rheological behavior of the material. Using the parameters of the rheological models determined by a slit die rheometry technique, the flow of the compound was simulated through the die and results were compared with experimentally measured mass flow rates. It is shown that for high viscosity rubber compounds the use of generalized Newtonian models which do not take the normal stress in simple shear flow into consideration gives rise to significant errors in prediction of mass flow rates. On the other hand, comparing the simulations results using the CEF equation with experimental data revealed that this model is the best compromise between generalized Newtonian and full viscoelastic models which need high computational costs and effort. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

橡胶挤出机挤出性能指标体系的研究

从橡胶挤出机的挤出性能指标体系的构成,指标的定义、测定方法、相关要求等方面进行了较为详细的论述,对一些对挤出性能有关键影响的指标提出自己的见解。     

Influence of die angles on pressure drop during extrusion of rubber compound

The factors affecting pressure losses during extrusion of polymer melts are discussed in the present article. The rheological properties of an unvulcanized rubber compound were examined by using a Monsanto processability tester (MPT) under experimental conditions of temperatures varied 90 to 120°C and shear rates from 10² to 10³ s^?1. Furthermore, a set of dies with different entry angle (2α) was selected to identify the effects of die angles on pressure losses in capillary extrusion of the sample fluid. It was found that the total pressure drop (ΔP) decreased when 2α < 75 degrees, and then increased with increasing 2α. The ΔP reached the minimum value when 2α is around 75°. It suggests that the natural converging angle of the sample fluid be about 75° under the experimental conditions, according to the research results presented in previous work. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1150–1154, 2001     

Flow visualization and extrudate swell of natural rubber in a capillary rheometer: Effect of die/barrel system

An investigation was carried out to examine the effect of die/barrel system on the flow patterns and extrudate swell of natural rubber in the barrel of a capillary rheometer, using a colored tracer as the visualization technique. The capillary rheometer used in this work had two dies located along the barrel, which is novel in rheometer design. The flow of the rubber in the upper barrel was dependent on the piston/barrel action and changed with piston displacement, whereas the complexity of the flow in the lower barrel was dependent not only on the piston displacement, but also on the geometry of the upper die design. The flow patterns that developed in the whole barrel were independent of the die located at the bottom of the barrel. In addition, the change in extrudate swell was associated with the flow occurring in the barrel, residence time, elastic characteristic, and the temperature rise during the flow. It was concluded that the general style of the flow patterns of natural rubber was greatly dependent on the die geometry that the material had previously moved past. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2525–2533, 2001     

LDPE熔体在双螺杆挤出机中流动的有限元分析

利用大型有限元分析软件包ANSYS分析了低密度聚乙烯(LDPE)在双螺杆挤出机三头常规螺纹元件中的流动情况,讨论了整个流道的速度分布、压力分布、粘度分布及螺杆挤出特性曲线。计算结果表明：LDPE熔体在双螺杆挤出机中得到了充分的混合。     

三元乙丙橡胶在简单口型中的正向挤出分析及逆向口型设计

采用Polyflow软件、Bird-Carreau纯黏性模型对三元乙丙橡胶(EPDM)在简单口型(正三角形、矩形)及其流道中进行了正向挤出过程模拟和逆向口型设计分析,并加工了相应的口模,通过挤出机进行了挤出试验,试验数据与模拟预测结果比较接近,逆向计算所得到的口型比较合理。结果表明,可以采用Polyflow软件、Bird-Carreau纯黏性模型近似地模拟计算EPDM的正向挤出过程和逆向口型设计。