Consistent edge spacing of the filter ensures filter performance, seal integrity, and downstream assembly efficiency. Dahe’s intelligent four-welt filter screen production line uses fully automatic control, fully analog servo drive, and automatic product size adjustment technology, without manual intervention, to produce thousands of parts per hour with edge spacing tolerances within ±0.2 mm. The advantage of the complete servo drive system is that it can quickly provide feedback on how the cycle reduces volatility. At the same time, centralized PLC control can also synchronize all production lines and perform automatic size compensation to cope with material stretching, so that uniform edge spacing can be maintained on any four-sided filter production line.
The four-welt filter screen production line uses a whole analog servo drive to ensure accuracy.
The core of edge spacing consistency lies in our complete analog servo drive architecture, which replaces stepping or hydraulic systems with servo drive motor control. “First, each axis (web feed, trimming, and sealing) uses brushless servomotors with high-resolution encoders that deliver 4,000 pulses per revolution. Second, the analog drive loops run at 10 kHz, minimizing communication latency and eliminating the quantization steps inherent in digital drives. At the same time, we configured the torque and velocity loops to have sub-millisecond correction rates, maintaining web position within ±0.05 under dynamic load conditions, to within millimeters. In addition, the continuous analog signal ensures a perfectly smooth motion curve, preventing micro-jitters that cause edge deviation. This basic accuracy ensures that the four-edge filter line maintains uniform edge spacing at high production volumes without drift or jitter.
Centralized, fully automatic control
The fully automatic control system coordinates all process functions, eliminating manual adjustments and recipe errors. The control system automatically regulates web tension, line speed, die position, and PLC sealing parameters based on the active HMI-loaded production recipe. In addition, recipe-driven switching automatically adjusts edge spacing, edge depth, and sealing temperature within five minutes. I program the HMI to let operators select product templates, while the PLC calculates servo setpoints and press tonnage in real time for repeatable accuracy. This automated coordination means that every run of the four-edge filter line can replicate the same edge spacing, no matter what the product is. The system eliminates operator adjustments, significantly reducing both scrap rates and downtime.
Automatic product size compensation for four-welt filter screen production lines
Automatic size compensation is key to dealing with material stretching, temperature fluctuations, and batch-to-batch differences. The system can continuously measure the feed width through a laser micrometer with an accuracy of up to ±0.02 mm. Therefore, it applies dynamic correction factors to the feed axis and the sealing axis to maintain a constant edge distance during the entire operation. In addition, I implemented a closed-loop scaling algorithm that dynamically adjusts the servo encoder counts by up to ±1.5%, ensuring that the dimensional drift does not exceed the tolerance of ±0.2 mm. At the same time, the compensation function also takes into account the temperature-induced expansion of the metal web and the coating thickness changes, ensuring that the four-welt filter screen production line can provide uniform edge spacing even under extreme environmental conditions.
High-speed automatic feeding, four-sided sealing integration
Integrate the high-speed automatic feeding four-sided sealing machine into the production. Precise synchronization is required in the line to maintain edge spacing. In addition to a servo-synchronized web feed system, we use a cam-driven loading module that captures the screen frame and positions it within ±0.1 mm of the web edge before sealing. As a result, the four sealing heads engage precisely at the programmed offsets without slippage. On the other hand, I synchronize the sealing cycle time with the web feed encoder to coordinate die closing and web advancement within 5 milliseconds to prevent edge misalignment. This tight integration enables line speeds of up to 120 screens per minute while maintaining uniform edge spacing for each four-sided sealed screen line product.
Sensor Feedback and Real-Time Correction
The system uses real-time sensor feedback to immediately correct any edge spacing deviations. At the same time, high-resolution vision cameras check the web edges and sealed welt seams at 200 frames per second, detecting deviations of less than 0.05 mm. We configure the vision system to pass the correction command directly to the PLC, which adjusts the servo offset in the next cycle to maintain consistent spacing. Tension and position sensors continuously feed data to the control system, which issues warnings or initiates automatic stops when values exceed preset thresholds. This closed-loop vision and sensor control ensures that the four-welt filter screen production lines can correct errors in real time and remove out-of-tolerance parts before they accumulate.
Get Uniform Edge Spacing
To achieve consistent edge spacing on the four-welt filter screen production line, precision analog servo drives, recipe-based centralized PLC control, automatic size compensation, synchronous four-edge sealing integration, real-time sensor feedback, and strict maintenance procedures are required. Through fully automatic adjustment and closed-loop control, each production line is designed to maintain an edge tolerance of ±0.2 mm, ensuring that each filter meets strict standards.
