Filling machines are among the widely used equipment and tools in packaging lines, available in various types with different functionalities in the market. Liquid filling machines can be used for transferring various food liquids such as pastry creams, sesame oil, breakfast chocolate spreads, date syrup, honey, and various edible oils, as well as for transferring chemical liquids like grease and petroleum jelly, which change their properties after cooling. It is worth mentioning that these machines are designed with heaters and mixers. These machines are available in both hot and cold models, and in this guide, we aim to provide a better understanding of liquid filling machines and explain the differences between hot and cold filling machines.
Types of Liquid Filling Machines
Considering the difference in liquids in terms of viscosity, they can be categorized into the following types:
liquid filling machine for thin liquids
Thin liquids include water, doogh, various edible oils, herbal distillates, some medicinal syrups, perfumes, and more. For filling thin liquids, three types of filling machines are used: pump, gravity, and piston cylinder machines. The choice of each of these machines may vary depending on the concentration and viscosity of the liquids, as well as the required accuracy and speed of the operation.
Thick liquid filling machine
Before discussing the difference between hot and cold filling machines, it is important to note that thick liquids refer to liquids with high viscosity. Examples of thick liquids include high-concentration chemical oils, grease, medicinal materials or high-concentration medicinal syrups, honey, date syrup, jams, and generally any liquid with high viscosity. Since the sensitivity in the volume and quantity of these liquids is high, the best method for filling them is the piston cylinder mechanism.
The difference between hot and cold filling machines
In order to better understand the difference between hot and cold filling machines, let’s take the example of thick liquids. Grease is a high-concentration petroleum derivative that is in a liquid or semi-solid form, used for lubrication. In general, filling grease, whether by traditional or common methods, is labor-intensive and costly. Therefore, automatic and semi-automatic filling machines for thick liquids can be used. The filling mechanism for materials like grease is fundamentally different from those that are fluid and thin. One of the main differences is the material transfer drive to the feeding section in the thick liquid filling machine. The injection system for these materials is done by filling from the bottom of the container, as this ensures complete filling of the container and prevents the creation of bubbles inside.
Difference between hot and cold filling machines: Cold filling machine
Typically, heating grease and making it flow more easily simplifies the filling process. However, some greases are highly resistant to heat or lose their properties when exposed to heat. Therefore, to preserve the properties of these types of greases, they must be filled without altering their structure. The most suitable machine for filling thick liquids like grease is the cold filling machine. Thus, it can be said that the preservation of the material’s structure is one of the differences between hot and cold filling machines. Generally, the cold filling machine for thick liquids such as grease is produced semi-automatically, and the operator needs to place the container under the nozzle and start the process by pressing a pedal. After a specified period of time, the container is filled, and the process continues by switching containers.
Difference between hot and cold filling machines: Hot filling machine
The hot filling machine for grease is produced in both semi-automatic and fully automatic models. The operation of the semi-automatic model involves the operator placing the containers under the filling nozzle, and by pressing the button, the filling process is carried out. A load cell is installed beneath the containers, and when the pre-set weight is reached, the machine nozzle shuts off. In contrast, the fully automatic hot filling machine operates by automatically performing all of the mentioned steps. After the operation is completed, the hot filling machine is synchronized with a conveyor belt, passing the containers under the nozzle and moving them to another location.
The difference between hot and cold filling machines for grease
In the hot grease filling machine, the grease is heated within a double-walled tank to make it thinner and easier to fill. However, in the cold grease filling machine, the product is pumped and filled into containers without being exposed to heat. It is worth mentioning that both types of these machines can be manufactured and supplied depending on the customer’s needs, considering the difference between hot and cold filling machines.
Advantages of using hot and cold filling machines
✅ High accuracy in filling machines
If the volume or weight of materials is important in packaging lines, it is recommended to purchase automatic filling machines. In some cases, changes in the volume or weight of certain products can lead to reduced product quality and customer dissatisfaction.
✅ High filling speed
Using automatic liquid filling machines compared to manual models results in a multiple increase in the production line’s efficiency.
✅ Cost reduction
Since these machines are automatic and perform the filling process of containers automatically, the need for a large number of operators in the production line is minimized. As a result, the final production cost of the product is reduced.
✅ Ensuring hygiene
Using automatic filling machines, considering the difference between hot and cold filling machines, ensures better hygiene as the filling process is carried out without manual intervention. Packaging products with these machines is completely ideal from a hygiene perspective and, in addition to improving hygiene, also enhances the quality of the final product.
Final Words
The filling machine is a device used to fill a specific volume of solid, powdered, and granular products, as well as liquids with varying viscosities and densities, into glass, plastic, metal, and other types of containers. This machine has widespread applications in the food, chemical, pharmaceutical industries, and more. Liquids can generally be divided into two categories: thick and thin. The difference between hot and cold filling machines lies in the properties of the liquids and their resistance to heat. For example, some types of grease, which are derivatives of oil, have high resistance to heat or lose their properties when exposed to heat; therefore, cold filling machines are required for packaging and filling these substances into containers.
Frequently Asked Questions
✅ What is a Pump Filling Machine?
A pump filling machine is one of the mechanisms used in liquid filling machines, specifically designed for injecting liquids with high viscosity, such as grease, motor oil, and similar substances.
✅ What is a Piston Cylinder Liquid Filler?
A piston cylinder filler is one of the best choices for setting up a packaging line for thick liquids such as yogurt, honey, date syrup, dishwashing liquid, and more. This mechanism offers very high accuracy and is used in automatic machinery.