Uninvited!
As for the poster’s question, the second person in the testing machine believes that corporate users should pay attention to the following aspects when choosing a tensile testing machine:
1. First, the tensile range of the material to be tested should be considered< /p>
The different tensile force ranges determine the different sensors used, which also determines the structure of the tensile machine, but this has little impact on the price (except for the portal type). For general flexible packaging manufacturers, a pulling force range of 100 Newtons is sufficient. Therefore, it was decided to use the single-arm type. The corresponding structure to the single-arm type is the portal structure, which is suitable for relatively large pulling forces, such as one ton or more. Therefore, flexible packaging manufacturers basically do not need it.
2. The problem of test stroke
According to the performance and requirements of the flexible packaging film test, the stroke is 600-1500mm. If the material elongation exceeds 1000%, you can choose a stroke of 1000 or 1200mm.
3. Standard configuration issues
There are three basic configurations of intelligence: host, microcomputer, and printer. If the microcomputer is powerful, it can print directly. In addition, it can also be equipped with an ordinary computer. With a computer, you can perform complex data analysis, such as data editing, partial enlargement, adjustable report formats, and group-style statistical analysis. If it is equipped with a computer, the manufacturer should add the corresponding control system.
4. Output results
The test result output results can be set arbitrarily: maximum force value, elongation, tensile strength, constant force elongation, constant elongation force value, yield Strength, elastic modulus, maximum test force 8 items. This can be said to be the most comprehensive result output by a microcomputer when operating. Products from some foreign manufacturers can generally output these 8 items. Some domestic manufacturers can output 5-6 items, while others can only output three items: maximum force value, average value, and minimum value.
5. In terms of experimental projects
Soft packaging requires a tensile machine with multiple functions, that is, on the basis of being equipped with different fixtures, it can be used for stretching, compression, bending, and tearing. , shear, 180 degree peeling, 90 degree peeling test. In addition to the above items, there are some high-end tensile machines on the market that can also test the friction coefficient due to their high sensor accuracy (some reaching one part in 350,000).
6. The main configuration of the product machinery
Transmission includes screw transmission and rack transmission. The former is expensive and is used for high precision and test repeatability; the latter is cheap and is used for high test repeatability. Low accuracy and low test repeatability. The screw plays a decisive role in the precision measurement of tension. Generally, there are ball screws, trapezoidal screws, and ordinary screws. Among them, the ball screw has the highest accuracy, but its performance requires the operation of a computer servo system, and the entire set is relatively expensive. The accuracy required for flexible packaging can be achieved by using ordinary screws and trapezoidal screws, that is, 0.1-1% accuracy. Transmission includes gear transmission and chain transmission. The former is expensive and is used for high precision; the latter is cheap and is used for low precision. The main cost of sensors lies in their lifespan. Photoelectric induction is one of the more advanced technologies and can generally be used more than 100,000 times.
7. Test speed
Some of the equipment on the market are 10~500mm/min, and some are 0.001~500mm/min. The former generally uses ordinary speed control systems and has lower costs. Roughness affects accuracy; the latter uses a servo system, which is expensive and has high accuracy. For flexible packaging companies, it is enough to use a servo system with a speed range of 1~500mm/min. This does not affect the accuracy and the price is within a reasonable range. .
8. Measurement accuracy
Accuracy issues include force measurement accuracy, speed accuracy, deformation accuracy, and displacement accuracy. These precision values ??can be up to plus or minus 0.5. But for general manufacturers, reaching 1% accuracy is enough.
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