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Polyethylene Production with Blow Molding Technology
HDPE Polyethylene blow molding machines are machines that heat and plasticize high-density linear polyethylene raw materials, inflate them in a suitable mold by blowing method and produce hollow plastic containers. In general, the blow molding technologies of the machines that have a say in production are as follows: Extrusion blow molding (continuous, accumulative and co-extrusion) Injection blow molding Injection stretching blow molding.
Extrusion Blow Molding Machines
Extrusion blow molding technology is one of the most widely used methods in the blow molding industry. It is a technique similar to the method applied in glass bottle production. From 2 milliliters to 9000 liters in volume, it is a molding method that enables the production of bottles, drums and similar plastic goods of various sizes. This method is based on the principle of inflating the parts (also called parison) obtained from the mold in the form of pipes and cut to the desired dimensions in a hot mold by blowing air into it until it takes the shape of the surrounding mold without allowing it to cool.
The material in a closed compartment is forced to flow through a mold opening by applying pressure. In the process, the material forms a continuous product with a fixed cross-section as determined by the mold cavity. In this way, a hose (parison) is formed from thermoplastic materials. By means of a deflection head, the hose is brought into the vertical flow position. The extrusion process is a continuous process, after the hose is cut, the hose is given to another mold or the hose (parison) in the first mold is moved away from the extruder with the mold, while the other mold comes in front of the extruder and the hose is taken into it. Then the hot plastic hose in the mold is inflated in the mold cavity with air pressure between 5 – 10 bar and the finished product is formed. The picture below shows the hose formation in the extruder.
Advantages of Extrusion Blow Molding
The pressure used in blow molding is much lower than the pressure used in injection molding, another method of shaping the same material. It is therefore economical. The required extrusion blow molding machine park is cheaper compared to injection blow molding machines. It is possible to produce the screw areas on the produced part, which usually form the cover part of the product, in a single mold. Products in different geometric shapes and desired dimensions can be obtained. The throat area and body of the polyethylene water tank always have a good appearance. There is no burr problem in production and the product always comes out in the same weight.
In extrusion blow molding, the part (parison) is placed in the appropriate position on the mold as shown in the figure. The plastic remaining in the mold is separated from the flowing raw material by cutting with a hot knife. Air is then blown into the mold at the appropriate pressure (0.4-1.0 MN/m2). Following swelling, the part is cooled and removed
Basic Stages of Extrusion Blow Molding Process
Plasticizing and preparing the thermoplastic raw material in an extruder Directing the molten plastic with a vertical flow Directing the molten raw material into a fluid hose called parison and flowing it out of the head (The head where the parison flows is also called just the head, extrusion head, inflation head and parison head). The parison flowing from the head is clamped between a mold with the help of a vice. The inflation pins or inflation needles (or valve) enter the closed mold. The parison between the mold walls cooled with cooling water is inflated with compressed air by means of inflation pins. inflating and de-burring the throat at the end of the inflation process Opening the mold and suspending the inflated product on the inflation pin De-burring the inflated product in the edge areas Accumulative head extrusion inflation, especially high volume products, is an ideal solution for the production of polyethylene water tanks. The specially designed head ensures fast raw material delivery and prevents ripple marks on the product. The water-cooled inflation pin is hydraulically controlled. The inflation group can move up and down. The movement feature of the inflation group helps the parison to have a stronger structure and increase its durability during molding and mold opening. The difference of the machines we use from other extrusion blow molding machines is that thanks to the changeable head, it enables the formation of a second and third color product as a strip on the hose to be inflated. In this way, we are working with the machine that has the largest liter product production capacity in Turkey with a hygienic and drinkable inner layer in white color, a dark gray middle layer that prevents the harmful rays of the sun (UV) and prevents the formation of algae and odor, and an outer layer in blue color that provides decotative and durability. Polyethylene Products We Can Buy with Blow Molding Technology
500 liter horizontal 3-layer polyethylene water tank 1000 liter horizontal 3-layer polyethylene water tank
| CAPACITY | HORIZONTAL POLYETHYLENE TANK DIMENSIONS (CM) | ||
| PRODUCT | EN (DIAMETER) | HEIGHT (LENGTH) | HEIGHT |
| 500 Liter Horizontal Polyethylene Water Tank | 80 | 110 | 85 |
| 1000 Liter Horizontal Polyethylene Water Tank | 104 | 138 | 107 |
500 liter vertical 3-layer polyethylene water tank 750 liter vertical 3-layer polyethylene water tank 1000 liter vertical 3-layer polyethylene water tank 1500 liter vertical 3-layer polyethylene water tank 2000 liter vertical 3-layer polyethylene water tank 3000 liter vertical 3-layer polyethylene water tank
| CAPACITY | VERTICAL POLYETHYLENE WAREHOUSE DIMENSIONS (CM) | ||
| PRODUCT | EN (DIAMETER) | HEIGHT (LENGTH) | HEIGHT |
| 500 Liter Vertical Polyethylene Water Tank | 90 | 92 | |
| 750 Liter Vertical Polyethylene Water Tank | 102 | 114 | |
| 1000 Liter Vertical Polyethylene Water Tank | 110 | 125 | |
| 1500 Liter Vertical Polyethylene Water Tank | 125 | 140 | |
| 2000 Liter Vertical Polyethylene Water Tank | 136 | 165 | |
| 3000 Liters Vertical Polyethylene Water Tank | 153 | 190 | |
