The factors affecting coating uniformity in the horizontal and vertical directions are different, so the control measures are also different accordingly. In the specific implementation, it is related to the design and manufacture of the machine, as well as the operation and process control. So what are the common faults that affect the coating process?
There are many factors that affect the coating quality, including people, machines, materials, methods, and environment, but the basic factors are several conditions directly related to the coating process: coating substrate, adhesive, coating steel roller/rubber roller and laminating machine, etc.
1) Coating substrate: mainly material, surface characteristics, thickness and uniformity, etc.
2) Adhesive: mainly its working viscosity, affinity and adhesion to the substrate surface, etc.
3) Coating steel roller: It is both the direct carrier of the adhesive and the support base of the coating substrate and rubber roller, so it is the core of the entire coating mechanism. Its geometric tolerance, rigidity, dynamic and static balance quality, surface quality, temperature uniformity and thermal deformation conditions all affect the uniformity of coating.
4) Coating rubber roller: The rubber roller refers to an important variable of coating quality. Its material (such as rubber layer life), hardness, shape and position tolerance, rigidity, dynamic and static balance quality, surface quality, thermal deformation condition, etc. also affect the uniformity of coating.
5) Laminating machine: It is the basic platform for coating. In addition to the accuracy and sensitivity of the coating steel roller and the rubber roller pressing mechanism, it also includes the maximum design speed and the overall stability of the machine.
The factors affecting coating uniformity in the horizontal and vertical directions are different, so the control measures are also different accordingly. In the specific implementation, it is related to the design and manufacture of the machine, as well as the operation and process control. So what are the common faults that affect the coating process?
Fault: Unwinding correction limit
Reason: Unwinding mechanism is not in center mode when threading
Solution: Adjust sensor position or adjust roll position in center position
Fault: Upper and lower limit fault of discharge floating roller
Reason: Discharge pressure roller is not pressed or winding tension is not open, potentiometer is abnormal
Solution: Press discharge pressure roller or open winding tension switch, recalibrate potentiometer
Fault: Traveling correction limit
Reason: Traveling correction is not centered or probe is abnormal
Solution: Re-center setting, check probe position and whether probe is damaged
Fault: Rewinding correction limit
Reason: Rewinding mechanism is not in center mode when threading
Solution: Adjust sensor position or adjust roll position in center position
Fault: Back roller has no opening and closing action
Reason: Back roller has not completed origin calibration or calibration sensor status is abnormal
Solution: Recalibrate origin or check whether origin sensor status and signal are abnormal
Fault: Back roller servo fault
Reason: Communication abnormality or loose wiring
Solution: Press the reset button to reset the fault or power on again, check the alarm code and query the manual
Fault: Intermittent coating on the second side
Reason: Fiber failure
Solution: Check whether the coating parameters or fiber signal are abnormal
Fault: Scraper servo failure
Reason: Alarm of the servo driver for adjusting the blade or abnormal sensor status, emergency stop of the equipment
Solution: Check the emergency stop button or press the reset button to eliminate the alarm, recalibrate the origin of the scraper roller and check whether the sensor status is abnormal
Fault: Scratches
Reason: Slurry particles or notched scraper
Solution: Clear particles with a feeler gauge and check the scraper
Fault: Powder loss
Reason: a. Powder loss caused by over-baking; b. High humidity in the workshop and water absorption of the electrode; c. Poor adhesion of the slurry; d. The slurry has not been stirred for a long time
Solution: Contact on-site quality technology
Fault: Insufficient surface density
Reason: a. Large height difference of the liquid level; b. Speed c. Blade
Solution: Check speed, blade parameters, and maintain a certain liquid level
Fault: Too many particles
Reason: a. Carried or precipitated by the slurry itself; b. Caused by the roller during single-sided coating; c. The slurry has not been stirred for a long time (static state)
Solution: Wipe the roller clean before coating. If the slurry has not been used for a long time, you need to consult the quality technology whether to stir it
Fault: Tailing
Reason: Slurry tailing, non-parallel gap between back roller or coating roller, back roller bounce speed
Solution: Adjust the gap parameter of inter-coating, increase the back roller bounce speed
Fault: Front misalignment
Reason: Alignment parameters are not corrected when there is an alignment error
Solution: Check whether the foil is slipping, clean the back roller, press the reference roller and press the roller, and correct the alignment parameters
Fault: The inter-coating on the back is parallel and tailing
Reason: The spacing between the coating back rollers is too small, too small, or the back roller bounce distance is too small
Solution: Adjust the spacing between the coating back rollers Increase the back roller bounce distance
Fault: Thick head and thin tail
Reason: Head and tail thinning parameters are not adjusted properly
Solution: Adjust the head and tail speed ratio and the head and tail starting point distance
Fault: Changes in coating length and intermittent process
Reason: There is slurry on the back roller surface, the traction rubber roller is not pressed, and the gap between the back roller and the coating roller is too small and too tight
Solution: Clean the back roller surface, adjust the inter-coating parameters, press the traction and rubber roller
Fault: Obvious cracks on the pole piece
Reason: Drying speed is too fast, oven temperature is too high, baking time is too long
Solution: Check whether the relevant coating parameters meet the process requirements
Fault: The pole piece is wrinkled during operation
Reason:
1. Parallelism between rollers;
2. Severe slurry or water on the surface of back roller and roller;
3. Poor joint of foil strip leads to unbalanced tension on both sides;
4. Abnormal deviation correction system or deviation correction is not turned on;
5. Too large or too small tension;
6. Inconsistent gap between back roller and travel;
7. Periodic elastic deformation of rubber surface of back roller after long-term use
Solution:
1. Adjust the parallelism of roller;
2. Deal with foreign matter between back roller and roller in time;
3. Adjust the tension adjustment roller of the machine head first, and adjust it to the original state after the foil is stable;
5. Check the tension setting value, the rotation of each transmission roller and the retracting roller to see if it is flexible , deal with the inflexible roller in time;
6. Expand the gap appropriately, and then slowly reduce it to the appropriate position;
7. When the elastic deformation is serious, replace the new rubber roller
Fault: edge bulging
Reason: The baffle board foam blocks it
Solution: When installing the baffle board, it can be in an outward eight shape or when moving the baffle board, it can be moved from the outside to the inside
Fault: Leakage
Reason: The baffle board foam or scraper board is not installed tightly
Solution: The scraper board gap is slightly larger than the layer thickness by 10-20 microns, and the baffle board foam is pressed tightly
Fault: Uneven winding
Reason: The winding shaft is not installed properly, not inflated, the deviation correction is not turned on, or the winding tension is not turned on
Solution: Install and fix the reel, inflate the air shaft, turn on the correction function, reel tension, etc.
Fault: Uneven white space on both sides
Reason: The installation position of the baffle plate, the unwinding correction is not turned on
Solution: Move the baffle plate, check the rewinding correction
Fault: The reverse side intercoating cannot be tracked
Reason: No sensing input of the optical fiber or no intercoating on the front
Solution: Check the detection distance of the optical fiber head, optical fiber parameters, and the coating effect on the front
Fault: Correction does not work
Reason: The optical fiber parameters are incorrect, the correction switch is not turned on
Solution: Check whether the optical fiber parameters are reasonable (whether the correction indicator light flashes left and right), and whether the correction switch is turned on.
