Linear gluing · Ring dispensing · Metered injection · Stable speed = consistent bead · Wait segments control valve timing · Multiple glue paths per product · No PLC, no programming
The core of single-axis gluing is one sentence: bead width is set by "valve opening × travel speed" — any speed fluctuation becomes a bead-width fluctuation. In the traditional "PLC + driver" architecture, pulses forward through two layers of equipment, and speed stability is affected by scan cycles and command latency.
This solution is built on the SD6 integrated drive & control closed-loop stepper driver: the gluing path (position, speed, wait timing) is stored inside the driver, closed-loop feedback keeps the travel speed constant end to end — stable speed = uniform bead. Wait-before segments precisely control valve open/close timing: no glue starvation at the start, no blobbing at the end. No PLC, no programming; multiple glue paths are stored in the driver and recalled per product.
Applicable to linear gluing, frame sealing, ring dispensing (rotary axis), metered injection and other single-axis gluing scenarios.
Valve timing is set by wait-segment parameters — "when the valve opens and for how long" are parameters, not program code
A complete gluing cycle = motion segments (travel with glue) alternating with wait segments (valve timing). Example of a frame-sealing cycle with start/end blob control (example values):
| Seg | Type | Action | Notes |
|---|---|---|---|
| Seg 1 | Wait | Valve opens, dwell 80 ms | Glue flows first — no starvation at the start |
| Seg 2 | Motion | Traverse the gluing stroke at process speed | Closed-loop constant speed = uniform bead width |
| Seg 3 | Wait | Dwell 50 ms | End-of-line refill — full, rounded finish |
| Seg 4 | Motion | Rapid return to standby | Valve already closed — no stringing on the return |
The "open-early" and "end-refill" wait segments are what keep start and stop points full — both are parameters, not code
| Process | Path Characteristics |
|---|---|
| Continuous gluing / frame sealing | Single constant-speed travel; wait-before opens the valve, wait-after finishes the line |
| Interrupted dotting | Motion and wait segments alternate: step, dwell, dot |
| Metered injection | Revolution-counted dosing; segmented speed keeps pressure stable |
| Signal | Direction | Function |
|---|---|---|
| Cycle start | DI input | Triggers the gluing cycle (foot switch / button / upstream signal) |
| Cycle stop | DI input | Finishes the current segment then stops |
| Origin switch | DI input | Power-up homing, re-establishes the datum |
| ± Limits | DI inputs | Hard travel protection |
| Glue valve | DO output | Valve open/close controlled by wait segments |
| Out-of-glue / alarm | DO output | Stall (blocked tube) or fault — audible/visual alert |
Point count and terminal definitions per SD6 specification
| Item | Traditional (PLC + driver) | SD6 Integrated Solution |
|---|---|---|
| Control devices | PLC + pulse output + driver | One SD6 only |
| Valve timing | Written in PLC program | Wait-segment parameters, panel editable |
| Speed stability | Pulses forwarded through two layers | Closed-loop inside the driver, direct to motion |
| Glue path per product | PLC program changes | Recall stored paths, panel switching |
| Troubleshooting | PLC or driver? Check both | Status LEDs + software, one-step location |
Check speed first: closed-loop constant speed is the prerequisite for a uniform bead; then check valve response and glue temperature. On the SD6 side, lower the travel speed slightly and lengthen accel/decel so speed fluctuation converges.
Solved with wait segments: a 50–100 ms wait-before lets glue flow before moving (full start point), and a 30–50 ms dwell at the end refills the finish. Both delays are parameters — two trials set them for good.
High-viscosity glue needs more push and lower speed — the low-speed high-torque characteristic of steppers matches well. Lower the travel speed, raise the current limit, and check glue warming.
Each line is an independent path segment (or path program), recalled by segment number on the panel; for upstream selection, switch paths via Modbus RTU.
The path table is edited in the office; on site there is only the glue gun and the trial run