A water-cooled down film blowing machine is a type of blown film line where the molten polymer is extruded downward and rapidly cooled using a water-based cooling system. This downward blown film process is commonly used for applications requiring fast cooling and stable film formation.
How a Water-Cooled Down Film Blowing Machine Works
- Add dry plastic granules into the lower hopper of the extruder. The plastic granules enter the screw from the hopper by their own weight.
- The friction of the plastic particles with the screw and the screw barrel generates heat. At the same time, the external heater of the barrel is continuously heated. The plastic granules gradually melt under the combined effect of internal and external heat.
- The molten plastic pellets pass through the screen changer to filter the impurities. It is then extruded from the die through the die opening. Then it flows out in a cylindrical shape.
- The cylindrical film is pulled downward. The film is quickly formed after passing through the water cooling device. The cooled and shaped film passes through herringbone boards, traction rollers and other devices, and is finally wound up into roll film by a winding device.
Key Advantages of Water-Cooled Downward Blown Film
- High transparency: Water cooling down blowing method can quickly take away the heat.So that the film molecules quickly crystallize.And it form a fine and uniform crystal structure.This improve the film transparency.This method is suitable for packaging products with high transparency requirements.
- Good physical properties: the film produced has good tensile strength, toughness and puncture resistance, which can effectively protect the contents of the package.
- Good thickness uniformity: The thickness of the film blank is uniform. Because during the cooling process it is affected by gravity and the homogeneity of the cooling medium. This guarantees consistent product quality.
- Wide range of production: it is suitable for a variety of PE, PP raw materials, and can produce films of different thicknesses, widths and uses to meet diversified market demands.
Main Components (Extruder, Die Head, Water Cooling System, Haul-Off, Winder)
1.Extruder: It consists of screw, barrel, hopper, deceleration and drive motor to extrude the molten plastic granules.
2.Die head: Distributes the molten plastic extruded by the extruder evenly to form tubular film blanks, commonly available in spiral mandrel type die head.
3.Cooling device: Including water cooling system and related pipes, nozzles, etc., For rapid cooling and shaping of the film blank.
4.Bubble Stabilizer: Stabilizes the shape of the bubble, prevents it from swinging and deformation, and ensures uniform film thickness.
5.Herringbone plate: Gradually flatten the round film bubble into a sheet, which is convenient for subsequent traction and winding.
6.Traction roller: Tracts the film forward, controls the traction speed and tension of the film.
7.Dryer:Further drying of residual moisture in the film.
8.Winding device: Adopting center winding or surface winding, the film is neatly wound into rolls.
Typical Applications (Food Packaging, Daily Necessities, Industrial Film)
Food Packaging:
Daily necessities packaging:
FAQ
What is a water-cooled down film blowing machine?
A water-cooled down film blowing machine is a blown film line that extrudes the film downward and uses a water-based cooling system to stabilize the bubble and cool the melt for continuous film production.
What materials can run on a water-cooled down film blowing machine?
Many lines are designed for PP and PE family materials such as HDPE, LDPE, and LLDPE, but the final suitability depends on screw design, die configuration, and target film properties.
Why do some factories choose water-cooled downward blown film instead of air cooling?
Factories often choose water-cooled downward blown film when they want stronger cooling control and stable film formation, especially in applications where process stability and thickness consistency are key priorities.
What are the main components of a water-cooled down film blowing line?
Typical components include the extruder, die head, water cooling system and related piping, bubble stabilizer, haul-off unit, and winding system, plus optional control and safety devices.
Does a water-cooled down film blowing machine improve film thickness uniformity?
It can help by improving cooling stability and bubble control, but thickness uniformity also depends heavily on die quality, melt temperature control, and correct operating settings.
What maintenance is important for water-cooled down film blowing machines?
Key maintenance includes keeping the water circuit clean, preventing scaling, checking filters and pumps, and monitoring cooling performance to avoid instability caused by temperature fluctuation.
What products are commonly made with water-cooled down blown film?
Common products include packaging films for food and daily necessities, liners, bags, and other general-purpose films where stable output and reliable forming are important.
Is water-cooled down film blowing suitable for high-output production?
It can be suitable when the cooling capacity, die size, and extruder configuration are matched to the target output, and when the line is tuned for stable continuous running.
How do I choose film width and thickness for this type of machine?
Choose based on your end product, required mechanical strength, sealing needs, and packaging standards, then confirm the configuration with the machine supplier to match your output targets.
What information should I provide to get an accurate quotation?
Provide target film width, thickness range, material type, required output, main products, power standards, and any optional functions such as automatic winding or upgraded controls.
