Melt Flow Index (MFR)

This test is performed according to ISO 1133 standard. In this test, the flow rate of molten raw materials is measured at a constant temperature and time to check the results of how the materials behave inside the extruder in order to create a suitable process. This test is performed for raw materials to confirm the quality and viscosity of materials and also to check the product to control the quality of the production process and compare it with the results of raw materials, which according to the standard , Otherwise the production process will require new settings.

3 to 5 grams of the sample of pipe or raw materials are poured into the MFR device with a temperature of 190 degrees and the test time is 10 minutes. After the test, the output parts of the device are weighed. It is 10 minutes.

Carbon Black Content

This test is performed according to ISO 6964 standard. The purpose of this test is to calculate the percentage of carbon in the pipe, which according to the product characteristics standard should be between 2 to 2.5 percent. In order to increase the resistance of the pipe to the sun’s rays, it is necessary to add soot to the raw materials during a proper process. If the amount of soot in the final product is less than necessary, the polymer will not have sufficient resistance to sunlight. If the amount of soot is too much, the concentration of stress is created and makes the pipe brittle and the pipe becomes vulnerable.

In this test, 1 gram of sample is placed at 550 ° C for 45 minutes in the presence of pure nitrogen gas. At the end of the test, the available hydrocarbons are burned and only the amount of carbon present in the sample remains. Obtained.

Investigation of soot distribution (Carbon Black Dispersion)

This test is performed according to ISO 18553 standard. The required moisture to protect polyethylene pipes from UV rays is the appropriate amount of soot in the final product, but this amount alone is not enough. Due to their special chemical structure, soot particles tend to cluster and so-called stick together, so the masterbatch mixing process should be such that the particles, in addition to dispersion and dispersion, are properly distributed on the polyethylene surface to be effective. Optimal in full protection of polyethylene.

Recent research has shown that cracking in pressurized pipes begins at the site of soot accumulation, especially when carbon accumulation is linear; Because the accumulation of soot in the pipe acts like a foreign object in the wall of the pipe and causes failure.

Examines how carbon is distributed in the pipe. Since soot particles, due to their special chemical structure, tend to cluster and so-called stick together, so the masterbatch mixing process should be such that the particles, in addition to being crushed and dispersed evenly and evenly on the poly surface. Ethylene should be distributed so that it can have a favorable effect in the complete protection of polyethylene.

In this test, 6 samples with a weight of 0.25 05 0.05 mg were cut and prepared with the help of a sharp blade and the test samples should be separated from different parts. The samples are placed on the slide regularly and at the same distance. Another clean slide is placed on the slide and the 2 slides are connected with a tight metal clamp.

The prepared slide is placed in the oven at a temperature between 150 and 210 degrees (preferably 180 degrees) for at least 10 minutes to melt the sample and be ready to be placed under a microscope, then magnified 100 times by microscope and grid software And its rate is calculated that its rate must be less than 3.

Ring Stiffness (SN)

This test is performed according to ISO 9969 standard. To determine the short-term ring strength of corrugated pipes, 3 pipe samples with a length of 30 cm are selected and the desired force is applied to the pipe according to the formula according to the relevant standard, and the deformation of the pipe should not be more than 3% of the pipe diameter. The speed of each size is according to the table below. Each sample is tested at an angle of 0 ° 120 ° and 240 °.

Long Ring Stiffness (SR24)

This test is performed according to DIN 16961-2. To determine the long-term ring strength according to the relevant standard, a sample with a length of twice the inner diameter of the pipe and a maximum of 1 meter is selected and the sample should be placed in a laboratory at 23 2 2 ° C for 24 hours to relieve production stresses. According to the pipe series, the desired force of that series is applied to it for 24 at a temperature of 23 2 2 (usually the pipes used in the sewage collection system are 31.5 kN / m2 of series 5) and the deformation of the pipe In 1, 6 and 24 hours it should not be more than 3% of the inner diameter of the pipe.

Ring Flexibility

This test is performed according to EN 1446 standard. For this test, 3 samples of 300 mm long tubes are prepared and the samples should be placed in a laboratory environment for 24 hours at a temperature of 23 2 2 degrees to relieve production stresses.

Samples are subjected to pressure at angles of zero, 120 and 240 degrees, respectively, up to 30% of the outer diameter of the pipe. The inner layers of the outer layers are separated from each other.

Water Tightness

This test is performed according to EN 1053 standard. In this test, first, using EPDM sealing washers for each size, the pipes are connected from the coupler and spigat part and both ends of the pipe are closed using a suitable drip and water flows into the pipe and Using a suitable gauge, the water pressure inside the pipe is controlled to reach 0.5, then for 1 minute under the applied pressure, no water leakage should be observed from the coupler connection.

Impact or TIR (Falling weight)

This test is performed according to EN 744 standard. In this test, the resistance of the pipe to external shocks is measured and this test is performed at a temperature of zero degrees. % Be.

The length of the prepared sample should be 10 ± 200 mm and should be placed in a tank containing zero degree water for 1 hour before the test.

We have two types of weights, which are named d25 and d90 based on the diameter of the surface hitting the pipe

Number of lines that must be drawn longitudinally inside the pipe according to different instruments:

The number of samples prepared should be such that according to the number of lines drawn in the pipe, at least 25 strokes should be applied in order to calculate the TIR.

The weights used in this test are of type d90, which are specified in the table below in terms of height and weight of the weight according to the size of the pipe: