Today, we see that as much as possible, plastic containers are used to package and store drinks and food. This makes us less worried about breaking products when buying or using them.
One of the materials used in the industry to make plastic bottles is called PET. Molds called PET molds are used to shape these materials.
Introducing the PET mold
The word PET actually stands for polyethylene terephthalate. This plastic material is used for injection or blow molding. The mold into which the PET material is poured to take the shape of the desired product is called the PET mold.
Products made using PET are resistant to pressure, impact and deformation. They also have a clear and radiant appearance and do not have any bad smell. To increase the quality of these products, the cooling system behind the PET mold is usually used.
They also polish the mold itself as a mirror to increase its lifespan. The material of these molds is often steel or aluminum. PET mold is mainly used in food and beverage storage industry.
Pet mold performance
Because PET molds are flexible and produce strong products for us, they are widely used in the food and beverage industry. Some of these are:
- Production of bottles for storing water, juices, dairy products and beverages;Storage and
- transportation of beverages and food;
- Production of products for storage of various grains;
- Packaging and storage of foods such as honey, jams and… instead of using glass containers.
Advantages of PET mold
1. low weight
Products made with PET molds are about 90% lighter than glass products. This has made PET popular in the food industry in terms of transportation. It is interesting to know that using PET mold in injection molding, no raw material is wasted.
2. Beauty and efficiency
The transparency and radiance of the products made using PET mold have made these products attract customers. Usually, by labeling and printing advertising designs on these products, their beauty is doubled. You can also make a variety of creative bottles using a variety of PET molds.
3. Product security
The product is made using PET mold and has useful mechanical properties such as impact and heat resistance. The unbreakability of these products has made them very popular in the food industry for storage, transportation and consumption of beverages.
Types of pet molds
Pet molds can be categorized in terms of weight, opening, how to use, how to make and various other options; But the most important classification is based on the temperature of the plastic used in them and how the product is shaped. In this classification, we divide the PET molds into two categories: hot pass molding and cold pass molding.
1 . hot pass molding
These molds direct the PET-type plastic material from the injector nozzle to the product formation site. The mold should be such that the PET material has the least temperature drop and the pressure drop is minimized.
2 . cold pass molding
In this type of mold, the path of conducting the PET material to the place of product formation is shaved so that the material flows in this direction. This process is accompanied by a drop in the temperature of the plastic material, because it uses a stream of cold water to cool the product. Separating the product from this type of mold is very simple and has the least waste. This has led to the widespread use of this type of PET mold in the industry.
Of course, these two types of PET molds are used in injection molding. Another type of PET mold widely used in the industry is pneumatic mold. Blowing machines are used in blow molding or pneumatic casting and other plastic materials are not injected in the mold.
The air mold is made in such a way that by applying pressure in it, the PET material quickly takes the shape of the mold. Usually the amount of pressure applied in this type of mold is about 30 times.
Disadvantages of PET mold
1. Need different methods and tools to make the mold
While the use of professional techniques and tools can improve the quality of the mold, this can be one of the disadvantages of PET molds. Using these methods requires a variety of resources and costs. Also, many engineers and designers have to work together to make these molds to achieve the desired quality.
۲. Many restrictions during production
To make plastic parts such as bottles, it is necessary to work very carefully. Avoiding scratches or sharp edges, maintaining the same thickness throughout the wall of the product and taking great care of the product when cooling it are some of the points that should be considered when using PET molds.
How to make a PET mold
Factors such as the quality of the final product, the life of the mold, the time of the product forming cycle and the stability of the injection mold are very important in making PET molds. In this section, we have explained how to create a quality and ideal template by considering the necessary points.
1 . Preparation of raw materials
Choosing a quality raw material is very important in making a PET mold. This material, which is usually made of steel or alloy, must have a high durability and strength so that the mold is not eroded during production and molding.
Also, these materials must be corrosion resistant and well polished; Because the transparency of the final product largely depends on these factors. In addition, the bottom of the mold should use materials that have a long life. To do this, the bottom of the mold is usually selected from the standard LKM type.
2 . Template design
The structure of the mold should be designed as simple as possible so that the PET material flows well in it and after production, cleaning and maintenance is done easily. Also, in designing and manufacturing PET mold, attention should be paid to the installation of the cooling system.
It is better to design this system with a large diameter as much as possible so that more cold water flows in it and increases the product production and the life of the mold. The system should also be as close to the mold surface as possible.
3 . Designing or preparing a hot passage system
This system ensures that the balance and stability of the injected material in the mold is maintained. Temperature and pressure drops are also controlled by this system. Husky is one of the most famous brands of hot passage system production.
4 . Making molds in the factory
Once the design work is completed and the digital or physical 3D design of the design is approved, it is time to implement the design. Pet molds are manufactured in plastics mold-making factories. Engineers make these molds using special tools and taking into account the conditions set by the designer.