ADT frequency inverter in textile sizing machine

i sizing machine techniques and requirements:

 

Techniques overview

The sizing process is performed after spinning machine and before weaving machine. It is to apply size material to reduce the chances of threads fraying and breaking due to the friction of the weaving process

The process starts from the unwinding of yarn. In this process the unwinding device is powerless but pulled by the traction motor. A friction is always applied to make sure the yarn will not get loose during the stop and deceleration. And then it goes to size tank for sizing and after this goes to drying room for drying. During this there are extension control, temperature control, moisture regain control, tension control and length control etc., so that the yarn has required specific temperature, wetness, elongation.

ii the sizing machine transformation hardware configuration plan:

Traction part

The traction motor power is 15KW. Considering the long-term low speed operation, the variable-frequency motor with independent cooling fan is adopted. The motor, rotary encoder PG and AD300 vector control inverter form a closed-loop vector control driving. There are two main functions of the tractor. The first is to drag the dryer to dry the sized yarn. The second is to pull the two layers of yarn for orderly arrangement.

Winding part

The winding motor power is 22KW. Considering the long-term low-speed operation when the roll is full, the variable-frequency motor with independent cooling fan is adopted. The motor, rotary encoder PG and the AD300 inverter form the tension open-loop torque control mode. The tension open-loop torque control mode does not require tension feedback, and the system structure is the simplest, enabling a smoother tension.

Control and display part

PLC is used as the control device. Synchronous reference, proportional reference, torque reference, torque compensation when the rolling diameter changes, start and stop signals, etc. are all provided by the PLC. At the same time, the upper shaft pressing part is also controlled by the PLC to improve the reliability of this part.

The display part uses the graphic operation terminal, the process and parameters are clear at a glance, and the shortcut key operation is very convenient.

iii the sizing machine transformation hardware configuration diagram:

iv the advantages of frequency inverter transformation:

The modified sizing machine has high degree of automation, good design control precision, strong adaptability to varieties, and can meet the sizing requirements for wide, fine and high density fabrics. It is matched to various shuttle and shuttle-less looms. The results of various tests show that the product indexes are as good as or even exceed that of the imported sizing machine. The weaving efficiency and quality of is obviously improved compared with the previous ones, which has created good economic benefits for the enterprise.

 

ADT inverter in textile winding machine

The old style textile winding machine normally use A/D and D/A modules of PLC or the special tension control device via a potentiometer pressure transducer installed on pendulum to control the unwinding speed. This way of constant tension control method easily gets signal distortion due to the signal cable of pressure transducer or the D/A modules analog cable too long. Further more, the rewinding wheel of different diameters requires different PID parameters. The wrongly set PID parameters might makes the unwinding wheel to be very unstable and thus affect the winding quality. Using ADT inverters can completely avoid the above shortcomings and get a good performance in constant tension winding machine.

i Control requirements:

 

The unwinding speed is decided by rewinding yarn take-up speed. During take-up wheel’s starting acceleration and deceleration before stop, the unwinding wheel will need varying speed. And even when the rewinding wheel speed is constant, the yarn speed is also changing when the yarn accumulates more and more on the spindle. In one word, the tension control of rewinding directly decides the yarn’s quality. If the tension is too large, the rewinding is too tight and the yarn is drawn to be out of shape or even break; while the tension is too small, the yarn on rewinding spindle will be out of position and caused unconformity yarn spindle. This requires that the unwinding speed is adjusted quickly responding to the tension pendulum position.

ii Techniques requirements:

a) The produced yarn need to be wound up neatly and orderly by the yarn winders;

b) During processing, the yarn speed is changing and the rewinding diameter is also changing. The rewinding speed should be kept the same as the speed of yarn production machinery.

c) The unwinding speed should follow the yarn production machinery speed and adjust the speed when the diameter changes, keeping the same speed as the yarn production speed. The unwinding wheel needs rotates reversely when the yarn is loose and keep the constant tension of the yarn.

d) Breakage protection. The winding stops when the yarn breaks. 

iii The unwinding and rewinding rack control principle

The working process of the equipment is as shown in the figure below. During the processing, the rewinding speed is the working line speed which is fed back to inverter via tension sensor and thus control the unwinding wheel speed, keeping the rewinding speed is the same as the yarn production speed.

iv the main parameters of the inverter and system features:

a) The system uses the AD300 series high-performance general-purpose vector control inverter (AD300-T47R5GB/011PB)

b) Parameters setting is as follows.

F0.02=1     Run command by terminal

F0.03=7     Take PID as frequency reference

F0.19=2.0   Acc. time

F0.20=2.0   Dec. time

F1.13=1     Use energy consuming braking

F6.01=1     X1 Forward running

F8.00=0     PID digital setting   

F8.01=0     Feedback via AI1 terminal

F8.02=50    Analog PID digital setting value (Pendulum height can be adjusted according to site actual conditions)

F8.05=0.6   PID proportional gain 1 (KP1) (Set value 0.4~0.6 according to site actual conditions)

8.06=5     PID integration time 1 (Set value 6~9 according to site actual conditions)

F8.16=50    PID forward limit

F8.17=50    PID reversed limit

c) System features:

(1) Simple commissioning: only need to correctly install the position of the detection potentiometer and the system automatically track the rewinding and unwinding speed. No other external control signal is needed.

(2) Automatically identify the speed and direction of the yarn winding, automatically track the line speed of the wound yarn to keep the constant tension;

(3) It can be turned on at any position of the tension pendulum bar;

(4) The mechanical structure is simple and the cost is low. Only the inverter, the tension potentiometer, the stroke switch, the fixed pulley, the movable pulley, the tension weight device and the braking resistor can form the complete control system.