Characteristics and classification of polyester industrial yarn:
The yarn quality of polyester yarn is not more stable than rayon, but more elastic. You can cut off the rayon thread for testing, pull it hard, and then relax, and find that the embroidery thread will not shrink much;
On the contrary, once the polyester yarn is stretched, it will return to its original length once it is relaxed, which sometimes causes the flowers to wrinkle. Therefore, it is necessary to be more accurate in adjusting the tension of the yarn. Polyester yarn products are mainly used in covering yarn, socks, yarn, gloves, carpets, curtains and other fields.
According to product performance, polyester industrial filaments are divided into three categories: high strength, low shrinkage and high modulus low shrinkage.
The major product categories are broken down as follows:
1. High-strength products are subdivided into:
——Super high-strength polyester industrial filament;
——High-strength polyester industrial filament;
——High-report medium-shrinkable polyester butyl filament;
——High-strength and low-shrinkage polyester working filament,
2. Low shrinkage products are subdivided into.
——Middle and low shrinkage polyester industrial filament;
——Low-shrinkage polyester industrial filament:
——Ultra-low shrinkage polyester industrial filament,
3. High-modulus and low-shrinkage products are subdivided into;
——High-modulus low-shrinkage polyester industrial filament;
——High-strength, high-modulus, low-shrinkage polyester industrial filament.
Test of Polyester Industrial Yarn
When the average elongation at break of the sample is less than 50%, it is (500 ± 1.0) mm; when the average elongation at break of the sample is greater than or equal to 50%, it is (250 ± 1.0) mm.
Test steps for polyester industrial yarn
1. Pretension is active
For laboratory samples that have been conditioned and balanced, after removing tens of meters of the surface layer, insert one end into the jaws of the upper holder and tighten it, carefully preventing twist changes or accidental stretching of the wire. Insert the other end of the specimen into the mouth of the lower holder and apply a specified pretension by adding a pretension weight or dragging the end of the wire to the unscrewed end. Make sure the filament is centered in the jaws of the gripper and tighten the lower gripper. Note: In addition to using the static load loading method to add pre-tension weights one by one, pre-tension devices such as springs or pneumatic mechanisms can also be used.
2. Slack start
After removing tens of meters of the surface layer of the humidity-balanced laboratory sample, introduce one end of the sample into one jaw of the holder and tighten it, and then introduce the other end of the sample into the second jaw and keep it The sample is just in a relaxed state (tension is exactly zero). Make sure the filament is centered in the gripper jaws and tighten the gripper.
NOTE: When starting with slack, the starting length is not exactly 500mm, but when the gripper is tightened, it will always be slightly longer because the specimen is slack. If the elongation is calculated according to 8.1.2, this additional length does not affect the test results.
3. Automatic sample loading
After removing tens of meters of the surface layer of the laboratory sample that has been adjusted and balanced, put it on the creel of the automatic strength machine, and put the wire end into the holding device of the tensile tester to set the test program.
4. Test
Start the tensile machine and let it run under the specified conditions. The operator should verify that no spurious growth due to slippage will occur during the test. Discard all measured values due to slippage or fracture within 10mm from the edge of the holder. If the number of discards exceeds 10% of the total number of times, the holder should be overhauled or replaced, and the test should be repeated.
Tensile test equipment for polyester industrial yarn:
We recommend using a 1000N, that is, a tensile machine of about 100KG. Generally, the accuracy of the industrial polyester tensile machine shall not be lower than 1%, and the accuracy of the industrial polyester laboratory tensile machine shall not be lower than 1%. From the perspective of the sensor, the measuring range of the tensile machine can meet the requirement of 0.5% within the range of 1~100%. The main physical properties tested by the polyester tensile testing machine include: density tensile properties, tear properties, compression properties, wear resistance, low temperature properties, rebound properties, etc.
Supporting Fixtures for Polyester Industrial Yarn Tensing Machine
The jig used to hold the sample is connected to the tensile machine so that the long axis of the sample coincides with the direction of tension passing through the center line of the jig, for example, it can be achieved by the centering pin on the jig. The clamped sample should be prevented from sliding relative to the fixture as far as possible, and it is best to use this type of fixture; when the tensile force applied to the sample increases, it can maintain or increase the clamping force on the sample, and will not be in the fixture. cause premature failure of the specimen
