Shuangli Machinery tells you how to improve the film blowing technology of the film blowing machine

Shuangli Machinery tells you how to improveBlowing MachineThe blown film technology is as follows:

Machine structure, take 80 film blowing machine as an example: (different models have different specifications)

The first part of the feed heating zone is divided into 5 zones:

Rod (diameter 6CM), shell 8, 7CM, 11kw motor (host) drive. It is divided into one, two and three heating zones from the feed inlet.

The next turn is upwards, it belongs to four heating zones, the machine is called three links, 1 link three zones, 2 links net changer outlet , 3 links five zones

The fifth heating zone is the discharging zone, which is turned upward through the 3-port, called the film head, and is the most critical part of the machine. The accessory is a blower.

The second part is the traction area, which blows up and compresses the edges, the total height is about 3 to 5 meters, and the accessory is the air pump.

The third part is the winding area.

The main materials are: low pressure polyethylene HPPE& nbsp; with high pressure polyethylene LLDPE mixed materials, low pressure materials mainly account for about 80%, the more high pressure is added, the better the tension, the disadvantage is that there is no stiffness, too much As a result, the blown-out film swings back and forth, and the blown-out film has uneven edges, and even cannot be blown at the end.

Next is to start the film blowing process:

After preheating in the first, second, and third zones, the first zone should be lower, generally around 170 degrees, and the other zones around 200 degrees. If the temperature is high, it will not be able to be sent through the rod, and it will even be burnt and discolored.

Next is the four-zone or three-way zone. Put a 60 mesh-160 filter screen in the tee to prevent impurities from entering the five zones. The larger the mesh, the finer the screen, and it can blow thinner and more demanding films, including film transparency, smoothness, tension, etc. , But too much and too fine will prevent the material from passing through, and too much will not be blown out. Generally 3-5 sheets are suitable, and the thickness is determined according to the requirements.

When the material reaches the fifth zone, the discharging port becomes a 7cm diameter round sticky paste through the film head, and the temperature of the material is basically stable. The suitability of the entire heating process should be controlled according to the discharging mouth. If it is too high, the film is unstable. , And scorched and discolored, too low to pull the film. The unevenness of the membrane thickness must be adjusted by the membrane head thread.

Then there is the traction zone, through the air blowing hole on the film head, air is added to the middle of the round film, the film is straight up, the size of the plastic bag is controlled by the amount of air blowing, and then the film stabilizer is used to stabilize the film. The thickness is controlled by the main engine and the traction speed. This can be understood. The faster the main engine speed, the faster the feeding speed, and the thicker the film; the opposite is true for the traction. The faster the pull, the thinner the film. This is the most important link.

In order to achieve good horizontal and vertical tensile force of the blown film, it is necessary to achieve a certain ratio of blow up ratio BUR and traction ratio DDR. Blowing Machine

If the ratio is not adjusted, the transverse tension will be reduced. If the bubble is stable under the existing die head and folding diameter, then there is no problem with the BUR. If the bubble is unstable, the BUR is too large;

DDR=Die gap/(film thickness×BUR)

Solution: To reduce the DDR, you need to reduce the die gap. Reducing the BUR will only make the DDR bigger.

If the film swings unstable during film blowing, it means that the film head is too small. You can use a fixing frame to stabilize the film.

Finally, the film is reeled from a high-altitude angle. The reel is reeled by the winder. The speed of the reel can be adjusted and controlled according to the speed of the film. After rewinding, the film becomes a film roll of the size and thickness we require. Next is the procedure of the bag making machine.

Plastic film blowing machine can be divided into up-blowing method (the kind introduced), down-blowing method, etc. according to different film blowing directions.