Analysis of the common knowledge of several major processes of blowing blown film technology

Machine structure, taking 80 blown film machine as an example: (different models, different specifications)

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

Mast (6CM diameter), housing 8, 7CM, 11kw motor (host) drive. The heating zone is divided into one, two and three from the inlet.

The next turn is upward, which belongs to the four heating zone. The machine is called three-way, one-way three-zone, two-way change net exit, three-way five-zone

The fifth heating zone, that is, the discharge zone, is turned to the top through the 3-port, called the membrane head, which is the most critical part of the machine. The accessory is a blower.

The second part is the traction zone, which is blown up and compressed, and the total height is about 3 or 5 meters. The fitting is an air pump.

The third part is the winding area.

The main materials are: low-pressure polyethylene HPPE with high-pressure polyethylene LLDPE mixed materials, low-pressure materials mainly account for about 80%, the higher the pressure is added, the better the tension, the disadvantage is that there is no stiffness, too much will cause the film to blow back and forth Swing, so that the film that is blown out is not neat, and even can not be blown at the end.

The film blowing process begins:

First, after the first, second and third districts are preheated, the area should be lower, generally about 170 degrees, and the other areas should be about 200 degrees. If the temperature is high, the material cannot be sent from the screw or even burnt.

Next is the four districts, namely the three links. The three-way 160-mesh filter is designed to prevent impurities from entering the five zones. The larger the mesh, the finer the mesh, and the thinner the film, including the transparency of the film, the smoothness of the handle, the tension, etc. However, too much too much will prevent the passage of the material, and if it is too much, it will not blow out. Usually 3-5 pieces are suitable, and the thickness is determined according to the requirements.

After feeding to the five zones, the discharge port becomes a 7cm diameter round and sticky paste through the film head, and the temperature of the material is basically stable. The appropriate temperature of the heating process is controlled according to the discharge condition, and the film is too high. And charred discoloration, too low to pull the film. The film thickness unevenness must be adjusted by the film head twist.

Then there is the traction zone. After the air is blown into the air bubble of the film head, the gas is added to the middle of the round film, and the film is linearly upward. The size of the plastic bag is controlled by the blowing amount, and then the film is stabilized by the film stabilizer. The thickness is controlled by the main engine and the traction speed. It can be understood that the faster the main engine speed, the faster the feeding speed and the thicker the film; the traction is just the opposite. The faster the pulling, the thinner the film, which is the most important link.

In order to achieve a 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.

If the proportional misalignment will lead to a decrease in the transverse pulling force, if the existing die and the folding diameter are used, the bubble is stable, that is, there is no problem with the BUR, and 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, and reducing the BUR will only make the DDR bigger (Wang Wang, the objective point of the treasure)

If the film is unstable when the film is blown, it means that the film head is too small, and the fixing frame can be used to stabilize the film.

Finally, the winding is carried out. The film is taken down from a high-altitude angle and wound up by a winder. The speed of the winder can be adjusted according to the speed of the film. After winding, the film becomes the film roll of the required size and thickness. Next is the procedure for the bag making machine.

The film blowing machine can be divided into the upper blowing method (introduced type), the flat blowing method, the lower blowing method, and the like according to the direction of the blowing film.

Chemical formula:

H3PO4

Molecular weight:

172.09

Standard executed:

GB/T 28159-2011  GB3149-2004/FCC  GB/T 2091-2008

Properties:

Under normal temperature, Phosphoric acid is a colorless transparent viscous liquid, with a melting point of 21.1℃ and a boiling point of 158 ℃. As a tribasic acid with moderate acidity, it has all the common characteristics of an acid, including strong metal corrosion properties.

Usage:

1.Phosphoric acid Electronic Grade is widely used in the semiconductor industry in ultra large scale integrated circuits, electronic chips, liquid crystal display films and cleaning and etching of said products. It is also used in the preparation processes of high purity special phosphates and high purity organic phosphorus products.

2.Phosphoric Acid Food Grade is used as a clarifier in food and beverage industries, as an acid additive or a yeast nutrient, and in the production of food grade phosphates.

3.Mainly used as a metal surface treatment agent, as the phosphate in raw material products, as an organic reaction catalyst in the sugar industry and as a refractory additive or a activated carbon treatment agent in the compound fertilizer industry.

Packaging and storage:

Electronic Grade:Packaged in 200L HDPE drums(330Kg / drum), IBC ton barrels (1700 Kg /drum), or the ISO lorry lined in 316L stainless steel.

Food grade:1000L IBC (1700KG/tank,IBC),200L drum (330KG/drum),25L drum(35KG/drum) and ISO-TANK. Store in a cool, dry, well-ventilated area away from toxic and hazardous

Tech grade:1000L tank(1700KG/tank, IBC);200L plastic drum (330KG/drum);25L plastic drum(35KG/drum) and ISO-TANK.

Phosphoric Acid CAS NO.7664-38-2

wc-reiniger,EVITs,H3PO4,PHOS ACID,MFCD00011340,Phosphoric,Marphos,Phosphorous acid,U.N. 1805,( 1527873,R)-VAPOL phosphoric acid,VAPOL hydrogenphosphate

Jinan Forever Chemical Co., Ltd. , https://www.jinanforever.com