Producing expanded polystyrene is important for different industries. This polystyrene is known as EPS in the markets. It is a lightweight, white, moisture-proof, and sound-insulating material. This substance was first used by the Germans in World War II. In general, expanded polystyrene has a variety of applications.
Production expanded polystyrene methods are very diverse and produce different types of EPS. These materials are used as building insulation in buildings and have various applications. In this PETROPROVIDERS article, join us to show you producing expanded polystyrene.
This material is a type of polystyrene grade that expands after it is made. It is used in various industries and is used to make various plastic and foam tools. This material, after expansion, enlarges 40 times its original volume! This makes the polymer insulated against impact, moisture, and sound.
This material is made of styrene monomers. In general, polystyrenes are large chains made of styrene monomers. These monomers have the structure C8H8 n; That is, in the composition, they have 8 carbon atoms and 8 oxygen atoms. This material is molded in different ways, which we will examine in the following.
The most important features of EPS are:
The foaming process is the first step in building EPS. At this stage, the chemical compounds combine and the color of the system becomes cloudy, then bubbles form. At this stage, the viscosity of the compound increases and the material has less flowability.
Then, the molten material must enter the mold. The compound is then continuously molded. Then, the liquid dissolves well and reaches the saturation stage.
Then the foam is formed. This foam moves upwards and produces gas. The smaller the gas, the higher the pressure and the more unstable the compound. This reduces the total number of cells and increases the volume of polystyrene.
These gas cells are initially spherical; But after a while, they turn into polygons. This shape is for having the least energy. To form a foam, there are 3 main steps, which we will examine in the following.
At this stage, the foam material in the first stage must be applied. At this stage, the foam polystyrene goes into a vertical tank with a stirrer. This tank is used to form larger foam granules and is considered an automatic system.
This tank has a controllable speed and agitator. So you can control this speed and adjust the amount of input foam. In addition, the foam can heat up to about 90 ° C in the tank, which in turn increases the vapor pressure of the molecules.
In general, at this stage, the process of expansion and increase in grain volume must be done carefully. At this stage, the density of the molecules is also determined; It depends on the amount of grain, the type of polystyrene, and the additives. As mentioned, at this stage, the volume of polystyrene will increase up to 40 times!
At this stage, the seeds enter special containers and are stored there. These materials have a higher pressure than atmospheric pressure; therefore, they are stored in these containers so that their pressure is equal to atmospheric pressure.
After this step, the foam grains enter the mold and are heated. These grains are then steamed and compressed into molds. It should be noted that if these steps are performed intermittently, the foam grains must be weighed in each step to enter the mold evenly.
To control the density, automatic systems inside the tank can be used. In addition, in these steps, we need a dryer with a mechanism that fits the polystyrene system.
After the foam material dries in the previous step, the foam cools to ambient temperature. This stage may take 3 to 4 days and the water vapor around the seeds condenses. This water vapor then enters the grains and stabilizes the EPS.
We know that the shape of the mold is the most important factor in determining the final product and its application. For example, if we use an aluminum mold, the final product must be converted to aluminum. In addition, there are molds made of wood and galvanized. If you use the same molds, you should know that using closed molds will make the final material denser.
Closed molds have 6 different walls that expand EPS polystyrene. These walls are covered with Teflon or steel. It is interesting to know that this wall has small holes that cause air to escape during the expansion phase.
In general, there are 3 types of molds for producing expanded polystyrene. These 3 types of molds are: pressure molds, complex molds, and transition molds
At this stage, the final shape of the expanded polystyrene is determined. It should be noted that the desired pressure and cutting operations are performed at this stage. In addition, this step can be used to correct polystyrene molding errors.
In this article, we saw the various methods for the production and molding of EPS polystyrene. EPS is a lightweight, white, soundproofing, and moisture insulating material. In general, expanded polystyrene has a variety of applications.
These materials are used as building insulation in buildings and have various applications in the construction industry. It is interesting to know that this substance was first used by the Germans in World War II.
There are several steps involved in producing and formatting EPS that we have seen in this article. It should be noted that in all stages, the necessary standards must be observed so as not to harm humans, the environment, and polystyrene. In addition, we need to know that the use of polystyrene is harmful to humans.
This material is easily recycled and produced and is used in various industries. Do you think the production of EPS polystyrene will be limited in the future? Is this material suitable for making various plastics and insulations?