There are certain standards that must be carried out from the beginning till the end of production. A number of tests are applied in line with these standards.
These tests are carbon black content and dispersion, MFI, OIT, determination of the resistance to internal pressure, determination of tensile and determination of density.
CARBON BLACK CONTENT (ISO 6964)
It is made with the aim of determining the percentage of carbon that is homogeneously reinforced under refinery conditions in order to give the material resistance against UV rays. The amount of carbon, which is the unburned part in the sample burned in the blast furnace with nitrogen gas, is calculated as a percentage.
DETERMINATION OF DENSITY (EN ISO 1183-1)
It is carried out in order to calculate the weight of the pipe in unit volume. First, the density is found by weighing the air, then in the liquid whose density is known, with the calculations specified.
MFI (MELT FLOW INDEX) ( EN ISO 1133-1)
It is a test method to examine the behavior of the material against temperature before it is processed. The samples coming out of the test with the MFI device are weighed with an analytical balance and the values found are loaded into the device and calculated in gr/10 min.
DETERMINATION OF OXIDATION INDUCTION TIME (OIT)
(EN ISO 11357-6)
OIT is a relative measure of oxidative degradation of stabilized materials. The criterion oxidation time for PE100 pipes and fittings is minimum 20 minutes at 210 ºC.
DETERMINATION OF THE RESISTANCE TO INTERNAL PRESSURE (EN ISO 1167-1/2)
It is a test method in which the behavior of PE100 pipes and pipe fittings against pressure over time is examined under shortened ambient conditions. By applying high pressure conditions to PE100 pipes and pipe fittings, changes in the pipe are monitored over a 50-year period.
DETERMINATION OF TENSILE (ISO 13953)
It is the test of examining the surfaces of the ruptured points after PE100 pipes and pipe fittings are pulled and ruptured at a certain speed.
ASSESSMENT OF THE DEGREE OF PIGMENT OR CARBON BLACK DISPERSION (ISO 18553)
It is done with the aim of examining the homogeneous pigment distribution and possible gaps in the structure of the material. A microtome section taken with a thickness of 10-15 μm is examined under a microscope. As a result of the measurement, the degree of dispersion for PE pipes and fittings should be ≤3%.
Dökerler, which applies all these tests and manufactures HDPE pipe fittings with high quality, has become a pioneer and leader company in its field.