KP8118 wires hot stretching device, heat distortion device
Test standard: meet the requirements of UL - 1581 heat deformation test. Need to aging box. This device is equipped with a tray, can according to need to add the corresponding weight in weight. (weight configuration according to customer's request)
Main parameters: pressure stick the upper diameter: ¢19 mm
Pressure rod bottom diameter: ¢9.5 MM
The pressure bar: the total weight is 250 grams
Heat insulation and sheath extending, heat deformation test
A, the purpose of the test
Hot stretch is assessment of rubber insulation and sheath insulation materials in plastic deformation under the action of heat load and permanent deformation of a testing method, much higher than the applicable temperature test under the condition of temperature and a certain weight, after a short time of thermal aging of elongation change to plastic deformation and permanent deformation of a test. If under the action of heat and load deformation, mechanical properties, can be lost to cause short circuit, cable can't normal use.
Second, the scope of application
This test method is suitable for rated voltage up to and including 450/750 rubber insulated cables of the national standard and rated voltage up to and including 450/750 rubber insulated flexible wire and cable industry standards for all products in the insulation and sheath of hot ductility test.
Three, inspection basis
ICEA_T - 27-581-581-4.3
4, test equipment and instruments
1, hot stretch tester, Jordan farmar
2, steel rule
Five, sampling and sample preparation
1, test samples cut from each take two sample insulation and sheath sample.
2, dumbbell specimens should be remove all ridges and/or from the insulation and sheath after the inner semiconductive layer.
3, press dumbbell specimens and taking two tubular specimen preparation methods of the insulation and sheath sample.
4, calculate cross-sectional area.
Six, test steps
1, to extend heat meter heated to 200 + / - 3 ℃.
2, the two specimens and ruler clamping in the test frame, hang up on the lower end of the specimen according to the mechanical stress is 0.20 N/mm squared weight is calculated.
3, with chuck fixed tubular specimens, should not be tightly sealed on both ends of the specimen. As in the specimen side insert a small piece of metal needles, the inner diameter slightly smaller than the size specimen.
4, after the specimens in the oven at temperature specified start time, 15 minutes immediately after measuring the distance between marker, if there is no observation window and oven must open the door to run measurement, the completion of measurement shall be within 30 seconds after opening the door. (in case of dispute, the test shall be carried out within the oven with observation Windows, and do not open the box measure).
5, measured immediately after lifting heavy objects from the specimen (the chuck to snip the sample), and restore the specimen under the specified temperature for 5 minutes. Then remove the specimen from the oven and cooled slowly to room temperature, measure the distance between the tag line again.
6, calculate elongation and intermediate values.
Elongation calculation formula is as follows:
Stretching after mark — the distance between the distance between the original markup
elongation = X 100%
The distance between the original markup
7, evaluation of test results
1, under specified temperature load after 15 minutes, the elongation of the intermediate values is not greater than 175%.
2, specimens taken from the oven after cooling tag line distance between the increase in the middle of the values of the percentage of the specimens in the oven before the distance should be not greater than 25%.