国产毛细管流变仪制造商  实验原料

热塑性塑料如PE、PP、PS及其复合物粉料、粒料、条状薄片或模压块料等；实验前应根据材料类别和性质作相应处理，如干燥等。

    当塑料熔体通过毛细管口模时，由安装在毛细管口模处的压力传感器和热电偶测试出熔体的压力和温度，微机记录下熔体压力和温度数值。

 流变性能的仪器一般称为流变仪，有时又叫粘度计。在测定和研究塑料熔体流变性的各种仪器中，毛细管流变仪是一种常用的较为合适的试验仪器，它具有多种功能和宽广范围的剪切速率容量。毛细管流变仪即可以测定塑料熔体在毛细管中的剪切应力和剪切速率的关系，又可以根据挤出物的直径和外观或在恒定应力下通过改变毛细管的长径比来研究熔体的弹性和不稳定流动（包括熔体破裂）现象。从而测其加工行为，作为选择复合物配方、寻求 成型工艺条件和控制产品质量的依据；或者为辅助成型模具和塑料机械设计提供基本数据。

国产毛细管流变仪制造商  毛细管流变仪可以测定高聚物的软化点、熔点、流动点、粘度粘流活化能，热固性材料的固化温度等性能指标。这些数据对研究高聚物流变性能有重要的作用。

     如果要寻找一台精密的熔融指数仪，那么可以考虑使用毛细管流变仪。一般的熔融指数仪测量的只是剪切速率/黏度曲线上的一点，只能对材料的流动性或平均分子量进行的评估，而毛细管流变仪可以测定材料黏度随温度及压力的变化。试验时，温度恒定，活塞以几种不同的速率移动，这样就能知道黏度与剪切速率和剪切力之间的关系。

数据处理   

1、启动操作应用软件。

2、输入实验报告信息。

3、添加数据文件及输入实验参数,进行试验操作。

4、筛选数据。查看筛选的数据，检查数据的有效性和合理性。

5、显示曲线，显示数据。

6、试验结束，打印保存数据及曲线。

7、关闭系统。

Experimental raw materials

Thermoplastic materials such as PE, PP, PS and their composite powders, granules, strip films or molded blocks; Before the experiment, corresponding treatments such as drying should be carried out according to the material category and properties.

When the plastic melt passes through the capillary die, the pressure and temperature of the melt are measured by pressure sensors and thermocouples installed at the capillary die, and the microcomputer records the values of the melt pressure and temperature.

The instrument for rheological properties is generally called a rheometer, sometimes also called a viscometer. Among various instruments for measuring and studying the rheological properties of plastic melts, capillary rheometer is a commonly used and suitable testing instrument, which has multiple functions and a wide range of shear rate capacity. The capillary rheometer can measure the relationship between shear stress and shear rate of plastic melt in the capillary tube, and can also study the elasticity and unstable flow (including melt fracture) of the melt by changing the aspect ratio of the capillary tube under constant stress or based on the diameter and appearance of the extruded material. Thus measuring its processing behavior as a basis for selecting composite formulations, seeking optimal molding process conditions, and controlling product quality; Or provide basic data for auxiliary molding molds and plastic machinery design.

Capillary rheometer can measure performance indicators such as softening point, melting point, flow point, viscosity, viscous flow activation energy, and curing temperature of thermosetting materials of polymers. These data play an important role in studying the rheological properties of polymers.

If you are looking for a precise melt index analyzer, you may consider using a capillary rheometer. A typical melt index meter only measures a point on the shear rate/viscosity curve and can only evaluate the flowability or average molecular weight of materials, while a capillary rheometer can measure the changes in material viscosity with temperature and pressure. During the experiment, the temperature remains constant and the piston moves at several different rates to determine the relationship between viscosity, shear rate, and shear force.

Data processing

1. Start operating the application software.

2. Enter experimental report information.

3. Add data files and input experimental parameters to perform experimental operations.

4. Filter data. View the filtered data and check its validity and rationality.

5. Display curves and data.

6. After the experiment is completed, print and save the data and curves.

7. Shut down the system.

试验原理

       毛细管流变仪测试的基本原理是：设定一个无限长的圆形毛细管中，塑料熔体在管中的流动为一种不可压缩的粘性流体的稳定层流流动；由于流体具有粘性，它必然受到来自管壁与流体方向相反的作用力。通过粘滞阻力应与推动力相平衡等流体力学过程原理的推导，可得到管壁处的剪切应力和剪切速率与压力、熔体流速的关系如下：

材料流经毛细管时的剪切应力为： 

               τ=R·⊿P/2L                                    

 （1）

其中  R—毛细管的内半径，这里   R=0.635 mm          

          ⊿P—材料流经毛细管的压力差kg/cm²          

          L—毛细管的长度，例如选择长径比为30：1的毛细管，L=38.1mm

剪切速率为： =4Q/πR³                      

(2)

其中 Q—挤出流量cm³/s

由此，在温度和毛细管长径比（L/2R）一定的条件下，测定不同的压力下塑料熔体通过毛细管的流动速率Q，由流动速率和毛细管两端的压力差⊿P，可计算出相应的剪切应力和剪切速率，将一组对应的τ和在对数座标纸上绘制流动曲线，即可求得非牛顿指数（n）和熔体的表观粘度（ηa）；改变温度或改变毛细管长径比，则可得到代表粘度对温度依赖性的粘流活化能；以及离模膨胀比等表征流变特性的物理参数。

毛细管流变仪是一种用于在高应力下测量剪切应力率的装置。可以测定热固性材料的流动性和固化速度，可绘制热塑性材料的应力应变曲线、塑化曲线，测定软化点、熔融点、流动点的温度。测定高聚物熔体的粘度及粘流活化性，还能研究熔融纺丝的工艺条件。

用于测量高分子熔体在毛细管中的剪切应力和剪切速率的关系，直接观察挤出物的外型，通过改变长径比来研究熔体的弹性和不稳定性，测定聚合物的状态变化等。对聚合物流变性能的研究，不仅可为加工提供 的工艺条件，为塑料机械设计参数提供数据，而且可在材料选择、原料改性方面获得有关结构和分子参数等有用的数据。模拟加工模式更多，剪切速率范围更宽。

物料在电加热的料桶里被加热熔融，料桶的下部安装有一定规格的毛细管口模（有不同直径 0.25～2mm和不同长度的0.25～40mm），温度稳定后，料桶上部的料杆在驱动马达的带动下以一定的速度或以一定规律变化的速度把物料从毛细管口模种挤出来。在挤出的过程中，可以测量出毛细管口模入口出的压力，在结合已知的速度参数、口模和料桶参数、以及流变学模型，从而计算出在不同剪切速率下熔体的剪切粘度。

毛细管流变仪的系统组成

毛细管流变仪是一种基于塑化分析研究的材料流变性能测试设备，其突出的特点是可以在接近真实加工条件下，对材料的流变行为进行研究。毛细管流变仪主要由驱动系统、控温系统、软件系统和各种附件组成。

驱动系统

毛细管流变仪的驱动系统主要为各功能单元提供动力和控制功能，其腔体是一个圆柱形的塑化器，是流变仪的重要组成部分。在高分子材料的加工过程中，通常根据试验材料对剪切强度的要求，选择不同的口模。通过记录物料在测试过程中的温度、表观切应力、粘度随剪切速率的变化。可研究材料在加工过程中的分散性能、流动行为及热稳定性等。并得到流变曲线。客观呈现材料的加工塑化过程。

控温系统

毛细管流变仪的控温系统主要通过传感器测量腔体的温度值，并将其转换为信号，再输入温度显示调节仪表，与设定的信号相比较，经过运算后改变执行器输出操作变量，从而改变国热腔体的热量，达到控制温度的目的。当腔体内的温度大于限定区间时，控温系统自行下调温度，当腔体的温度小于此区间时，控温系统自行上调温度，以保障系统硬件设备和传感器连接正常。

Experimental principle

The basic principle of capillary rheometer testing is to set an infinitely long circular capillary tube, and the flow of plastic melt in the tube is a stable laminar flow of an incompressible viscous fluid; Due to the viscosity of fluids, they are inevitably subjected to forces from the pipe wall that are opposite in direction to the fluid. By deriving the principles of fluid mechanics processes such as equilibrium between viscous resistance and driving force, the relationship between shear stress and shear rate at the pipe wall, pressure, and melt flow rate can be obtained as follows:

The shear stress of the material flowing through the capillary is:

τ=R·⊿P/2L                                    

（1）

Among them, R - the inner radius of the capillary tube, here R=0.635 mm          

Δ P - pressure difference of material flowing through capillary tube kg/cm2

L - the length of the capillary tube, for example, selecting a capillary tube with a length to diameter ratio of 30:1, L=38.1mm

Shear rate:=4Q/π R3

(2)

Where Q - extrusion flow rate cm3/s

Therefore, under the condition of constant temperature and capillary length to diameter ratio (L/2R), the flow rate Q of plastic melt through the capillary tube under different pressures can be measured. By calculating the corresponding shear stress and shear rate from the flow rate and the pressure difference Δ P at both ends of the capillary tube, a set of corresponding τ and can be plotted on logarithmic coordinate paper to obtain the non Newtonian index (n) and the apparent viscosity of the melt (η a); By changing the temperature or altering the aspect ratio of the capillary, the viscous flow activation energy representing the temperature dependence of viscosity can be obtained; And physical parameters that characterize rheological properties, such as the modulus expansion ratio.

A capillary rheometer is a device used to measure shear stress rate under high stress. It can measure the flowability and curing speed of thermosetting materials, draw stress-strain curves and plasticization curves of thermoplastic materials, and determine the temperature of softening point, melting point, and flow point. Measuring the viscosity and viscous flow activation of polymer melts, as well as studying the process conditions of melt spinning.

Used to measure the relationship between shear stress and shear rate of polymer melts in capillaries, directly observe the appearance of extruded materials, study the elasticity and instability of melts by changing the aspect ratio, and determine changes in the state of polymers. The study of polymer rheological properties can not only provide optimal processing conditions and data for plastic machinery design parameters, but also obtain useful data on structure and molecular parameters in material selection and raw material modification. There are more simulation processing modes and a wider range of shear rates.

The material is heated and melted in an electrically heated barrel, and a certain specification of capillary tube mouth mold (with different diameters of 0.25-2mm and lengths of 0.25-40mm) is installed at the lower part of the barrel. After the temperature stabilizes, the material rod at the upper part of the barrel is driven by a driving motor to extrude the material from the capillary tube mouth mold at a certain speed or at a certain regular speed. During the extrusion process, the pressure at the entrance of the capillary die can be measured, and the shear viscosity of the melt at different shear rates can be calculated by combining known velocity parameters, die and barrel parameters, and rheological models.

System composition of capillary rheometer

Capillary rheometer is a material rheological property testing equipment based on plasticization analysis research. Its outstanding feature is that it can study the rheological behavior of materials under close to real processing conditions. The capillary rheometer is mainly composed of a driving system, a temperature control system, a software system, and various accessories.

driving system

The driving system of the capillary rheometer mainly provides power and control functions for various functional units, and its chamber is a cylindrical plasticizer, which is an important component of the rheometer. In the processing of polymer materials, different molds are usually selected based on the shear strength requirements of the test material. By recording the changes in temperature, apparent shear stress, and viscosity of materials with shear rate during the testing process. Can study the dispersion performance, flow behavior, and thermal stability of materials during processing. And obtain the rheological curve. Objectively present the processing and plasticization process of materials.

Temperature control system

The temperature control system of a capillary rheometer mainly measures the temperature value of the chamber through sensors, converts it into a signal, and then inputs it into a temperature display and adjustment instrument. Compared with the set signal, after calculation, the output operating variable of the actuator is changed, thereby changing the heat output of the national heat chamber and achieving the purpose of temperature control. When the temperature inside the chamber is greater than the limited range, the temperature control system will automatically lower the temperature. When the temperature inside the chamber is less than this range, the temperature control system will automatically increase the temperature to ensure the normal connection of the system hardware equipment and sensors.

售后内容：

一、我公司派工程师负责安装调试及培训。

二、产品自客户验收之日起，免费保修 2 年，终身维修。

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