Six factors affecting plastic tensile test results

The six major factors influencing the plastic tensile test results the six major factors affecting plastic tensile test results

' What to watch for 】 Each kind of plastic before, have to be strict on its various performance test and confirmation. Clarify from test Angle, there are many factors influencing the plastic tensile test results, in addition to the internal factors, and some external factors. This article from the test environment, test instrument, sample preparation and processing three aspects to analyze their effects on plastic tensile test results.

test environment's influence on the plastic tensile test

there are many: the factors influencing the plastic tensile test data such as vibration, temperature, humidity, personnel, etc. , one of the most important factor is the temperature and humidity. Specified in GB/T1040, lab environment temperature for ( 23±2） ℃, relative humidity for ( 50±10） %。

the tensile properties of the thermoplastic test is affected by temperature is bigger, often temperature on the high side, low tensile strength, elongation slants big, on the other hand, on the other hand. With the rising of the temperature, the tensile properties of the thermoplastic will also gradually from the hard brittle to glue is strong, the tensile strength and tensile modulus of elasticity with smaller, and elongation at break will be synchronized.

the relative humidity of the bibulous rate is compared commonly big influence on plastic. After part of plastic water absorption increases, the water molecules in the plastic played a coupling agent and the effect of toughening agent, thus affecting the plastic rigidity and toughness. Through the above practice, the tensile properties of the plastic test should be carried out under the condition of constant temperature and humidity.

material testing machine for plastic tensile test

the influence of material testing machine ( Also known as tensile machine) Is specially for the material mechanics performance testing instrument. Sells on the market is mainly suitable for plastic plate, pipe, profiles, plastic and rubber, wire and cable, waterproof coil, wire and other materials of various physical and mechanical properties test.

tensile machine used for metal materials and nonmetal materials for tensile, compression, bending, shear, peel the mechanics performance test of mechanical strength, tensile machine fixture as an important part of the instrument, different material need different jig. It is also testing can go smoothly and the accuracy of test data are an important factor. By tensile, bending, stripping, compression, tearing test, tensile test is the use of material testing machine, using standard specified in the sample, the determination of material under the standards stipulated by the state tensile force, tensile strength, elongation at break, parameters such as fracture strength.

force sensor measurement precision, the speed control precision, fixtures, alignment and data acquisition frequency is the main factors affecting tensile test data of material testing machine. Force transducer is the key component of material testing machine, its accuracy directly affect the test data and the size deviation. Smooth uniform tensile speed requirements, speed is high or low will affect the tensile results.

in the process of test, the tester jig separation speed, to the mm/Austin as the unit. Fixture design is mainly two kinds of manual and pneumatic. Testing machine alignment is not good, tensile displacement is larger, the tensile strength will be affected, sometimes small. Test data acquisition frequency also wants moderate, otherwise will affect the test data, a small peak.

sample preparation and processing of plastic tensile testing of the influence of the

when do all kinds of plastic test, sample is made according to standard ( According to GB/T1040 part related to the tested material sample preparation) 。 Sample preparation method has two kinds: one is the use of raw materials, sample preparation, another is from sampling directly on products. Made with raw material samples there are several ways, including mold, injection molding, calendering forming or blown film forming, etc. , each sample preparation process has to comply with relevant standards.

but I don't think you can compare the different party legal sample test data. The same kind of sample preparation methods for process parameters ( Such as mold structure, molding temperature, molding pressure, cooling speed, etc. ) Processes and also to be the same, otherwise the microstructure in the process of plastic molding such as crystallinity, molecular orientation would be a big change, directly affect the test data. After the raw material

the blown film, reoccupy sampling machine and cutter made of standard sample. A sharp knife to specification, sample preparation or sample will have defects such as burrs or scratched. The thickness and width of the sample had a great influence on the result, if the same type of plastic the size of the sample is different, its tensile strength test results will have certain difference. Therefore, when processing sample, measuring the sample size, paying special attention to be the size and tolerance of the test sample is within the scope stipulated in the standard, the size of sample is to be consistent. The specimen thickness is different, the thickness of the different test data of samples, generally small test data. That is to say, the defect of the thicker the higher the probability of the sample.

from the plastic products, direct sampling to representative sampling position, sampling should be far away from the edge and corner area, change and transformation of different perspectives and different position. Contraction after injection molding samples tend to be larger, if measured parts appear light miniature mark influence smoothness must pay attention to the measurement points, to obtain the real size. Sample preparation, to be placed under the condition of constant temperature sex wet processing, the standard of GB/T1040. In the process of placing, will cause the molecular weight, molecular configuration and the change of physical state, and can eliminate the residual stress of the specimen of memory.

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