Application of ACI Frequency Converter in Film Blowing Machine
Film blowing machine is the mechanical equipment that melts plastic particles and blown into athe thin film.
1. Production process and principle
The dried polyethylene particles are added to the lower hopper, and the weight of the particles themselves enters the screw from the hopper. When the pellets touch the screw bevel, the rotating chamfer faces the plastic particles to produce a thrust perpendicular to the oblique facets, moving the plastic particles forward. In the process of moving, due to the friction between the plastic particles and the screw, the friction between the plastic particles and the barrel, and the collision friction between the particles, molten plastic by the nose filter to remove impurities from the die after the mouth, the wind ring cooling, inflation and then by the word plate, traction roller, winding the finished film rolled into a tube.
2. Film blowing machine main structure: extruder, head, die, cooling device, the word plate, traction roller, coiling device, etc.
(1) Extruder: Extruder is mainly composed by the screw, barrel hopper, gear box and drive motor. The motor driver uses the ACI G11 frequency converter, which drives the reducer through the belt drive to rotate the screw in the barrel. The molten plastic is extruded from the filter.
(2) Three Tong: is composed of the filter, filter plate, three-way gland.
(3) Film head.
(4) Cooling device: is composed of the cooling air ring, duct, blower and other components.
(5) Traction: is composed of the traction frame, the word plate, traction roller, coiling mechanism and traction motor and other major components.
(6) Electrical control part: is composed of the button, air switch, heating coil and temperature detection and automatic temperature control and so on. During normal production, the temperature can be automatically controlled to ensure that the production process is stable and reliable. Blown film machine is divided into a variety of PE, POF, PVC and so on
Use the new particle to blow new material. Color is called, clean, good stretch of the bag.
Some people use recycled plastic bags to make particles, this particle is generally called the old material, made of particles is usually gray, in the bag is usually added to the pigment, made of bag color uneven, crisp and easy to break , The price is cheap.
Although it is the recovery of plastic bags but are generally bagging process waste bags, compared with the usual sense of the garbage plastic is still very different.
Blown film production is suitable for a variety of high-grade film packaging. This film because of its good barrier, fresh, moisture, frost, oxygen, oil, can be widely used in a variety of packaging. Such as all kinds of fresh fruit, meat food, pickles, fresh milk, liquid beverages, medical supplies and so on.
B. Reforming blown film machine with ACI frequency converter
1. The requirements of inverter transformation for film blowing machine system:
(1) Can be within a certain range of smooth speed, by adjusting the main motor, traction motor speed to produce different products
(2) Start, stop smooth, because the plastic extruder is a constant torque load, start, stop smooth to avoid too much mechanical shock, on the other hand can also reduce the start of the process of substandard products.
(3) The motor only need to run in one direction.
(4) Stable performance, reliable work.
2. The advantages of ACI inverter after the transformation:
(1) Energy savings: according to the inverter running V / F curve shows that the inverter is constant torque output, compared with other speed control system, the average energy savings of more than 30% in the low-speed operation of energy- Significantly.
(2) Improve product quality: stability performance of frequency control.
(3) Reduce the impact of the start of the grid, the starting current can be controlled within the rated current does not constitute the impact on the power grid.
(4) Reduce the impact of mechanical shock when the start, smooth start to extend the service life of the machine.
(5) Meet the stepless speed, speed is simple and convenient.
(6) Protection is powerful.
3. Parameters of the inverter
D0.01 --- Frequency reference mode d0.03 - External start
D0.17 --- Acceleration time d0.18 --- Deceleration time