application

Polyethylene pipe manufacturing process is extrusion method for granular materials that are imported into the extruder and heat

Production of polyethylene pipes

The material is then processed by the screw (spiral rod) to be pushed and then is discharged from the extruder into the mold. Food cooked after leaving the mold, the cross calibrator and vacuum tank pressure are appropriately shaped. Upon exiting the calibrator tube surface by layers of water flow is cooled.
The high temperature molten polyethylene tank after removal from the mold in vacuum and then gradually cooling tanks is reduced using cold water.
specific measurements and cut.
All production process is fully automated by devices that control and monitor the quality of the final product is acceptable and the company name and standards.
Routine tests polyethylene pipe production
PE pipe production test categories are as follows:
Melt flow index (INSO 6980-1)
Determining density (INSO 7090-1)
Determination of soot (ISO 6964)
The distribution of soot (ISO 18553)
Tensile test (ISO 6259-1,3)
Hydrostatic pressure test (ISIRI 12181-1,2)
Burst pressure test (ASTM D 1599)
Back to thermal test (INSO 17614)
Measurement and visual examination tube (INSO 2412)
Thermal stability test in the presence of oxygen O.I.T (ISIRI 7186-6)

Melt flow index (INSO 6980-1):
In this test, the material melt flow rate is measured at fixed time and temperature, to the results, how to handle the material inside the extruder should be considered.
The raw material test (to confirm the quality of materials) as well as on the product. MFI value of the product shall not be more than 20% ± the raw material is different MFI.
• Determining density (INSO 7090-1)
The density of raw materials and product density flotation methods using accurate fluid balance with a certain density is determined. The “number density of the product, the quality of the production process.
• determination of soot (ISO 6964) and the distribution of soot (ISO18553)
Soot in raw materials and the final product is determined.
The permitted percentage of carbon black in polyethylene pipe 2 to 5.2% weight which should be distributed evenly across it.

• Testing (ISO 6259-1,3)
Using specialized laboratory, the mechanical properties of polyethylene pipes, including maximum strength against the external load, the elongation at break, coefficient of elasticity and deflection under loads three-point can be measured and according to the results of the test, we can evaluate the performance of the product during the operation.
• Hydrostatic pressure test (ISIRI 12181-1,2)
In order to assess the product’s strength against hydrostatic pressure test is carried out. , placed under constant internal pressure.
Any defect in the samples (cracking, bulging, local swelling, leakage and fine cracks) to mean the product has failed.
• Burst pressure test (ASTM D 1599)
In this test, sample tube floating in a pond with a constant temperature of 23 ° C and then placed under increasing internal pressure, so that over time 60 to 70 seconds, swell and then cause cracking.

Tube without cracking or bulging with the longitudinal slot is unsafe for consumption.
• Back heating test (ISO 2505)
The approximate length of 20 cm samples into one, with hot air circulation (2 ± 110) ° C for one to three hours (according to the pipe wall thickness), and after cooling is such the length of the tube, will be less than the initial state at normal temperature, which can lead to changes in behavior pipes installed in the pipe round, so the above test limit longitudinal changes (up to 3%) in the laboratory.

• measurement and visual examination tube (INSO 2412)
Polyethylene pipes must be free of any roughness (inside and superficial) and deep pores. Slight dents if they do not reduce the thickness to less than the limit, is negligible.
Exact designation of pipe wall thickness using ultrasonic thickness gauge calibrated calipers at the cutting section during a trumpet.
The outer diameter of the tube using the graded metal bands (Sykrvmtr) and along a branch was measured and the average value is reported