Polyethylene pipe production in Iran is one of the most stable and profitable branches of the polymer industry. By choosing the right grade such as HDPE100 and properly adjusting the extruder process, a high-quality and competitive product can be produced even on a medium scale.
How is polyethylene pipe production done?
The production of polyethylene pipes is an industrial process, but it is completely precise and calculated. Contrary to the simple appearance of the pipe, behind each meter of it lies a combination of materials science, precise temperature regulation and pressure uniformity control. In Iran, most polyethylene pipes are made of heavy grades such as HDPE PE100 and PE80, which have high strength and desirable flexibility.
The production process begins with the preparation of raw materials. At this stage, polyethylene granules are mixed in a mixer with a certain amount of color masterbatch and heat-stabilizing or UV-resistant additives. The quality of the mixture is of great importance at this step; Because the slightest unevenness in the mix will later cause lines in the pipe body or fluctuations in wall thickness.
In the next step, the prepared mixture enters the extruder; where the temperature is usually set between 180 and 230 degrees Celsius to melt the granules and form a uniform melt. This hot melt passes through a die (ring mold) under pressure and takes on the initial shape of the pipe. At the same time, the newly formed pipe enters a water cooling tank to stabilize its dimensions and prevent deformation.
Next, a calibrator accurately adjusts the outer diameter and wall thickness. The pipe is then cut into specified lengths, usually 6 or 12 meters, by an automatic cutter. In larger factories, there are online (Ultrasonic) thickness control systems that check the diameter and wall thickness at any time during production to ensure that no human error occurs.
After cutting, it is time for quality control tests; hydrostatic pressure test, tensile test, impact test and inspection of the inner surface of the pipe to ensure that there are no bubbles or cracks. Only after these tests are approved are the pipes packaged and transferred to the warehouse.
A point that most experienced manufacturers emphasize is the correct choice of polyethylene grade. For example, CRP100 or EX5 grade is one of the most popular options for the production of water and gas pipes; because in addition to high strength, it also has fluid processability. A supplier that can offer a standard and consistent grade plays a direct role in the stability of the final quality — a topic that is well covered in cooperation with brands such as Raja Plast.
Finally, it should be noted that the production of polyethylene pipes does not depend only on the machine; it is a combination of high-quality raw materials, precise adjustment of technical parameters and operator experience that creates the final product. A pipe that is resistant to pressure, impact and temperature changes is the result of these precise details in the production line.
Raw materials used in the production of polyethylene pipes
The main basis for the production of any type of polyethylene pipe is the careful selection of raw materials. All polyethylene pipes may look similar in appearance, but their real difference lies in the type of polymer, the quality of the grade and the ratio of additives. In Iran, as in other countries, professional manufacturers use a combination of several main polymer materials and specialized additives to achieve a durable product, both to meet technical standards and to keep the final cost low.
The main material in this industry is high-density polyethylene (HDPE). This polymer has high resistance to water pressure and impact due to its high density and excellent tensile strength. Various grades of heavy polyethylene are used to produce pipes; including PE63, PE80 and PE100, each of which has different technical characteristics.
For example, the PE100 grade, which is the most common option in the Iranian market today, in addition to its high molecular weight, has a uniform molecular distribution and is more resistant to stress cracks and high temperatures. For this reason, most factories use it to produce high-pressure pipes and water transmission lines.
Among domestic manufacturers, grades such as CRP100 Jam, EX5 Amirkabir, 7000F Miandoab and 100B Lorestan have the largest share. The difference between these materials is not only in the name of the factory; each has a different flowability behavior (MFI) and environmental resistance, and choosing the wrong grade can severely reduce the quality of the pipe.
But the raw materials are not limited to polyethylene. In addition to the base granule, additives play an important role in the stability and life of the pipe. The most important of them are:
Antioxidants: Prevent the destruction of polymer chains during extrusion.
UV Stabilizer: Protect the pipe from sunlight.
Color masterbatch: To create black, blue or yellow color based on the type of application.
Lubricants and antistatics: Help the melt flow better and reduce static electricity.
In many domestic production lines, to reduce costs, mixed masterbatches are used that contain several types of additives in a polymer base. Of course, the quality of these masterbatches is of great importance; because its cheap or non-standard type can cause the pipe to become brittle or change color in a short time.
Ultimately, what professional manufacturers know is that choosing a reliable raw material supplier is as important as the manufacturing formula. An HDPE granule with an accurate melt index, an additive with a reliable analysis and a standard color powder can make the difference between a regular pipe and a product with a 50-year useful life.
Brands like Raja Plast, by offering reliable domestic and foreign grades, respond to exactly this need; that is, providing materials that are both competitive in price and that pass pressure and strength tests.
