Safety operation specifications for ribbon slitting machine: cut protection and emergency stop logic

The ribbon slitting machine is a key equipment in the production process of thermal transfer ribbon, with sharp knife sets, fast running speed, high tension control accuracy, and improper operation is very easy to cause cutting accidents. Formulating and strictly implementing safety operation specifications, especially the core requirements around cut protection and emergency stop logic, is the basis for ensuring the personal safety of operators and the stable operation of equipment.

1. Key points of cut protection

Cuts are the most common operational risk, and protective measures should run through the whole process of equipment operation.

1. Physical protection of the knife group area

• Forced closure of the protective cover: All rotating blades, slitting knife sets and retraction reels must be equipped with transparent impact protection when the equipment is in operation. The device should not start or stop automatically when the shield is not fully closed.

• Anti-cut device: A finger guard plate or grating sensing area is set between the blade and the pressure roller to prevent the hand from accidentally entering the cut-off point.

• Tool change and debugging protection: When replacing or adjusting the blade, the locking system (LOTO) must be implemented to cut off the power source and release the residual energy before operation. Operators must wear cut-resistant gloves.

2. Code of Conduct

• Do not handle running materials with gloves: Ordinary gloves can be caught in the shaft roller, causing more serious injuries. When the hand is in direct contact with the ribbon in operation or close to the knife area, remove the gloves or use special tools.

• Avoid cleaning chips by hand: Use a vacuum cleaner or a special brush to clean up the ribbon debris (dust) near the knife area after the machine is stopped, and it is strictly forbidden to sweep it by hand when the equipment is running.

• Maintain a safe distance: maintain a natural working distance of at least 30cm between the operating position and the cutting point of the blade, and the operation interface should be set on the side away from the tool area.

3. Auxiliary safety device

• Two-Hand Start Button: When resetting or restarting the device, both hands must be pressed at the same time to ensure that the operator's hands are not in the knife area.

• Foot switch anti-accidental touch: If the foot switch is used to control the feeding or operation, a protective arch cover should be installed to prevent unexpected stepping.

2. Emergency stop logic design

The emergency stop system is the last line of defense in the safety chain, and its logic must be clear, reliable and easy to operate.

1. E-stop button layout requirements

• Multiple locations: The device is equipped with at least 3 emergency stop buttons - 1 operation panel, 1 at each end of the device (or 1 near the protective cover on each side).

• Easy to slap: The button should be a red mushroom head, yellow backing, and installed at a height of 1.0–1.2 meters from the ground, making it easy to hit with elbow or knee.

• Self-locking function: The emergency stop button must be mechanically self-locked after pressing, and the reset must be pulled out by manual rotation to avoid the second start caused by automatic reset.

2. Equipment response logic after emergency stop

After the emergency stop signal is triggered, the equipment must be executed in the following order:

1. Instantaneously cut off all power sources: the main motor, rewinding motor, tension motor, hydraulic/pneumatic system, etc. are all powered off and degassed.

2. Brake locking: The main drive shaft and retracting reel should stop rotating within 0.5 seconds through the electromagnetic brake to avoid inertial sliding.

3. Separation or retraction of the tool group: If the equipment is equipped with a movable tool holder, the tool should be automatically retracted during emergency stop, so that the blade is separated from the bottom roller and the risk of continuous cutting is reduced.

4. Alarm signal output: buzzer and indicator light (flashing red) are activated, and an emergency stop event code is sent to the control system at the same time.

3. Unacceptable emergency stops

• It is forbidden to use PLC software to slow down instead of hardware emergency stop.

• Do not include timers or delay relays in the emergency stop loop.

• It is forbidden to automatically restart the equipment by the program when the emergency stop is resumed, and the operator must manually release the emergency stop, confirm the status, and press the start button to reset.

3. Safety treatment under special working conditions

Working condition scenario	Safe operation requirements
The ribbon is broken and wrapped around the knife shaft	Immediately press the emergency stop→ cut off the power supply→ use a cutting knife to clean the winding material belt from the inside out, and do not pull it by hand
The blade is slightly chipped	Shutdown → listing→ disassembly of the tool set→ uniform grinding or replacement, and it is forbidden to use sand strips on the machine
Slitting electrostatic ignition	Install an anti-static elimination stick, and the operator uses an anti-static bracelet to avoid static electricity causing instinctive hand retraction and accidental touch of the knife area
Night shift or fatigue work	It is mandatory to rotate every 2 hours, and set a voice prompt to confirm the boot "The knife area protection is closed"

4. Daily inspection and periodic verification

Daily checklist

• Whether the protective cover closes smoothly and whether the induction switch is effective

• Whether the emergency stop button is pressed to return to the position feels clear

• The light grating or safety relay indicator is in good condition

• The knife set cover is not missing or deformed

Monthly security verification (at least once)

• Simulate hand entry into the knife area (using a test rod) to confirm that the device stops immediately

• Press each emergency stop button one by one to measure the time from triggering to complete stop of the spindle (no more than 0.8 seconds)

• Check that the drawings of the emergency stop circuit are consistent with the on-site wiring, and there is no short connection or modification

Mandatory testing every year

• Safety loop integrity testing by a qualified third party and filing a report

5. Accident emergency treatment process

Even with protection in place, cuts can still occur. Clear emergency process cards must be posted on site:

1. Press the nearest emergency stop button as soon as possible (operated by the injured person or a companion)

2. Do not try to pull the cut out of the blade, but observe the cut first

3. Cut off the main power supply and have the second person call the emergency number

4. Apply pressure and bandage to the bleeding area, elevate the injured limb, and do not use a tourniquet for more than 15 minutes

5. Keep the state after the emergency stop button is pressed, and do not reset it until the accident is investigated

Epilogue

The safe operation of the ribbon slitting machine is not a "constraint", but a protection of life. The closing of every protective cover, every active press of the emergency stop button, and every round of standardized spot inspections are all about transforming uncertain risks into definite safety. Enterprises should incorporate the above specifications into the post SOP (standard operating procedures), and ensure that every operator moves from "knowing" to "doing" through practical assessments and irregular spot checks. The cost of cuts is irreversible, and the logic of emergency stops must be zero delay.