What is the best choice for the most popular unive

2022-07-25
  • Detail

What kind of universal testing machine to choose

nowadays, more and more plastic processing enterprises are purchasing the so-called "universal" testing machine to conduct tensile, bending, compression and shear tests, so as to evaluate the performance of materials, conduct application development research and quality control. Developed electronics have improved the performance of these devices, making them easier to operate and cheaper.

universal testing machine (UTM) The plastic material spline can be stretched, bent, compressed or pulled through the adjustment of different speed levels, which is the most common equipment in the plastic mixing laboratory. During the preparation of mixed ingredients, UTM test materials can be used to determine whether the materials are suitable for some specific processing applications or terminal applications. UTM can also be used for product quality control to ensure the consistency of product quality among batches

nowadays, UTM is more and more used in plastic molding and extrusion laboratories. On the one hand, they are more and more involved in the development process of new products and new processes. On the other hand, it is because of their accuracy in the quality control of raw materials and finished products. In some fields with a strong sense of society, such as medical devices or automobile industry, plastic processing equipment is required to test their products, and u is also required to significantly improve the test effectiveness TM to play a greater role. At the same time, the internal test can improve the quality of process control and reduce the scrap rate, thus realizing the real benefits

different tests

utm testing machine includes one or more vertical bearing columns, on which a fixed horizontal base is installed, and a movable horizontal crosshead (cross beam) is arranged on the top. In the current UTM testing machine, there is usually a ball screw on the column to fix the movable crosshead. The size of UTM is jointly characterized by the maximum bearing level of the frame and the dynamometer for measuring load/tension. The dynamometer is attached to a movable crosshead driven by an electric motor or hydraulic device. The series dynamometer with clamp measures the force, and the results can be displayed by digital display or PC. Many UTMS have interchangeable dynamometers, so they can match the different materials tested. The static test is conducted by standard electronic universal testing machine, and the loading speed range is usually 0.001~20in/min(1in.=2.54cm)。 Dynamic test or cyclic test, such as crack growth and fatigue test, are usually carried out by hydraulic servo system UTM testing machine, with a long time and low load

early UTM testing machines had similar electronic components and recorders. Now it has been replaced by CNC equipment and PC software. The new automatic control equipment can run tests, display data, and sometimes even record while running. In previous recorders, including the digital display era before PC software, the test information obtained by the user is the load/deformation curve. The Y axis represents the stress and the X axis represents the deformation. These curves also need to be calculated and interpreted. The latest system can still provide these curves, but it can also calculate the data, such as yield strength, failure strength and modulus

at present, the most common items tested by universal testing machine are tensile strength and tensile modulus, bending strength and modulus. When the tensile test is carried out according to a stmd638 and iso527, both ends of the spline are clamped with clamps under the support of irrigation technology. One clamp is stationary, the other is fixed on the crosshead, moves away from the fixed clamp, pulls the spline until the spline breaks, and the crosshead will automatically stop when it breaks. During the bending test (astmd790, d6272 and ISO178), the spline is placed on the two supports of the fixed machine tool of the testing machine. In this test, the moving direction of the crosshead is opposite to that in the tensile test, and the spline is pushed to an unsupported center rather than pulled until the spline is bent or even broken. Since most thermoplastic materials will not break in this test, it is not possible to calculate the breaking bending strength. Therefore, the standard test method requires the calculation of the bending stress at the strain of 5%

generally, UTM testing machine is rarely used in compression test, although it is a major test for rigid plastic foam in astmd1621 and iso844 standards. UTM testing machine can also be used for crushing test of injection molded products of any shape, such as bottles. The stress value required to break or deform the sample at a certain height is the compressive strength value

according to the statistics of UTM suppliers, shear tests are rare for plastic materials. The shear strength value is measured by placing the sample in a punch type shear device. Impact velocity is 0.005in/Min until the movable part of the sample completely exposes the fixed part. The shear strength value is the value of stress/shear area. This is very important in film materials and sheet products, because this type of damage is easy to occur in such products, but this is not the most considered factor in the design of other extruded and injection molded products. When testing according to astmd732 (there is no equivalent ISO standard), the commonly used samples are plastic sheets or 0.005~0.500in Thick injection molded disc

electronic mechanical UTM testing machine this is the reason why engineers now believe that the design is based on DuPont Nomex fiber. 1

the capacity of the commonly used electronic UTM testing machine is 100 ~ 135000lb. The larger the size, the higher the cost. Generally speaking, the vertical equipment is smaller and easier to operate, and the thorny samples such as films can be easily manipulated as heavy injection molded parts with the help of the gravity of the sample itself. The single column UTM testing machine has a lower force range and price, and its structural capacity is generally 1000lb. The structural capacity of the gantry type UTM testing machine can reach 1000~135000lb. The dynamometer is also classified based on a maximum force value applicable to the structure and sample of the UTM testing machine. For example, a 100lb dynamometer installed in a 1000lb mold frame can provide a 100lb test load. The capacity of the dynamometer shall not exceed the predicted breaking load of the sample too much, otherwise the accuracy of the test results will be affected

software development

the development of software technology has improved the testing speed of UTM equipment and made the operation of the equipment easier. The reading of test data, the whole process of the test, whether the specimen is stretched and deformed before fracture, and whether the deformation is proportional to the external force can help material engineers or product designers evaluate the performance of different materials, determine the safety margin, and better simulate the application of terminal users

the new software can automatically operate the test, collect data, analyze data, record output, store data and repair. The user can input a certain operating load speed, and the system will automatically adjust the operation of the crosshead. The new software also allows users to obtain the true strain value during the test through the displacement sensor, which can accurately measure the displacement of the crosshead. When the sensor is replaced, the new software can also enable the dynamometer to automatically identify and calibrate

the software of the new PC type UTM testing machine can now perform the whole operation, so the cost will also be reduced due to the elimination of the digital display and some electronic components. The dynamic test

is different from the electronic UTM testing machine used for static test. The hydraulic servo UTM testing machine can perform dynamic test and fatigue test. In this way, the stress must be applied repeatedly to carry out the load release cycle. For example, in the fatigue crack growth test, the user expects to know how many cycles the material to be tested will break the valve

the stress required for dynamic test is smaller than that required for static test of electronic universal testing machine. The frame capacity of the hydraulic servo system testing machine ranges from 100lb to several tons, and the price is usually 2~3 times that of the electronic mechanics testing machine. It is basically used for fatigue test of metal materials, but it is more and more widely used in automotive plastics, aerospace plastics, biomedical plastics and plastics for electronic components, because structural components with good fatigue resistance are required in these fields

Copyright © 2011 JIN SHI