Boxing Machinery

Usage method of CNC slitting machine (taking the slitting of protective film and double-sided tape a

Boxing Machinery

2025-12-02

As the core equipment in the field of coil slitting, the CNC slitting machine occupies a key position in the processing of flexible materials such as protective films and double - sided tapes by virtue of its advantages of high precision and high stability. Both protective films and double - sided tapes have the characteristics of surface sensitivity, large differences in viscosity, and high requirements for thickness uniformity. Their slitting processes have strict requirements for the precise control of equipment operation. This article will combine the slitting requirements of these two typical materials to elaborate in detail on the complete usage process and key technical points of the CNC slitting machine.

I. Pre - startup preparation: Laying a solid foundation for safety and technology

The preparatory work before starting the machine directly determines the safety of the slitting process and the qualified rate of products. A comprehensive inspection should be carried out from three aspects: equipment, materials, and tools. In particular, special inspection contents should be formulated according to the characteristics of protective films and double - sided tapes.

(I) Equipment safety and status inspection

First, execute the safety confirmation process: Check whether the emergency stop button, protective fence, and photoelectric induction protection device of the equipment are in normal condition to ensure that the machine can be stopped quickly in case of an emergency; Confirm that the power supply and air source connections of the equipment are stable, without looseness or damage, and the compressed air pressure is maintained at 0.6 - 0.8 MPa to meet the requirements of the cutter shaft drive and the material pressing mechanism. Then, conduct an equipment status inspection: Manually rotate the cutter shaft to feel whether the rotation is smooth without jamming, and check whether the gap between the upper and lower cutters is uniform; Start the equipment to run idle for 3 - 5 minutes, observe whether the running sound of the motor is stable, whether the display of the control system is normal, and whether the parameter setting interface and alarm prompt function on the touch screen are sensitive. For protective film slitting, the surface finish of the material pressing roller needs to be specially checked to avoid scratches on the surface of the protective film caused by impurities on the roller surface; For double - sided tape slitting, it is necessary to confirm whether the tension control system of the unwinding mechanism is normal to prevent material stretching and deformation caused by tension fluctuations.

(II) Material pre - treatment and fixation

The material inspection should be carried out in combination with the characteristics: For the protective film, the focus should be on checking whether there are scratches, bubbles, and impurities on the surface, and whether the edges are neat to avoid the spread of defects after slitting; For double - sided tape, it is necessary to check whether the adhesive layer is uniform, whether there is glue overflow or wrinkling of the release paper, and measure the material thickness at the same time, and record the value for subsequent cutter gap adjustment. The material fixation operation is as follows: Hoist the coil to the unwinding rack to ensure that the center of the coil is aligned with the center of the unwinding shaft. Use an expansion sleeve to fix the coil, select the appropriate expansion specification according to the inner diameter of the coil to ensure firm fixation without shaking; For protective film coils with a large width, a lateral guiding device can be installed to prevent material deviation during the slitting process; Since double - sided tape coils have strong adhesiveness, before unwinding, a non - stick agent can be slightly sprayed on the surface of the release paper (if the process allows), or the surface of the unwinding roller can be wrapped with a Teflon coating to reduce adhesive residue.

(III) Preparation of cutters and auxiliary tools

The cutter selection should match the material characteristics: When slitting the protective film, it is preferable to use a carbide circular cutter with a blade angle of 30° - 45°. If the thickness of the protective film is less than 0.1 mm, a ceramic cutter can be used to improve the smoothness of the cut; When slitting double - sided tape, since the material contains an adhesive layer, special cutters with anti - adhesive treatment on the blade should be used, and the blade angle is 45° - 60° to avoid the adhesion of the adhesive layer to the blade. Before installing the cutter, clean the blade and cutter shaft with alcohol. When installing, ensure that the end face of the cutter is perpendicular to the cutter shaft. When tightening the fixing nut, use a torque wrench to prevent cutter loosening from causing slitting deviation. At the same time, prepare auxiliary tools: A thickness gauge is used to measure the material thickness, a caliper is used to detect the width of the slit product, a cleaning cloth is used to clean the adhesive residue on the blade and the pressing roller in time, as well as spare cutters and expansion sleeves.

II. Core parameter setting: Precisely match the material characteristics

The parameter setting of the CNC slitting machine is the core link determining the slitting quality. It is necessary to accurately set the slitting size, cutter shaft clearance, running speed, and tension parameters according to the characteristics such as the thickness, width, and viscosity of the protective film and double - sided tape. The following are the specific setting methods and reference values.

(1) Parameter setting of slitting size

According to the requirements of the production order, enter the target slitting width on the "Size Setting" interface of the equipment control system. Taking the common slitting of mobile phone protective films as an example, if the width of the original coil is 1200mm and it needs to be slit into finished products with a width of 150mm, enter the slitting quantity of 8 pieces and the single - piece width of 150mm. A compensation amount of 0.1 - 0.2mm should be reserved during setting. Since the protective film may be slightly stretched during the slitting process and the double - sided tape will have a slight shrinkage due to the compression of the adhesive layer, the compensation amount can be adjusted according to the actual slitting test results. At the same time, set the positioning parameters of the cutting knife to ensure that the distance between the cutters on the cutter shaft is consistent with the set width. Manually move the cutter shaft and repeatedly measure the distance between the cutters with a caliper until the error is controlled within ±0.05mm.

(2) Adjustment of cutter shaft clearance and pressure

The cutter shaft clearance needs to be accurately adjusted according to the material thickness. If the clearance is too large, it is easy to cause burrs on the cut. If the clearance is too small, it will damage the material or the blade. Adjustment method: Enter the "Cutter Shaft Clearance Setting" interface in the control system and enter the material thickness value. The equipment will automatically make a preliminary adjustment to the clearance. Then manually fine - tune the height of the upper cutter shaft and use a feeler gauge to measure the clearance between the upper and lower cutters to ensure that the clearance is 0.8 - 1.2 times the material thickness. For example, when slitting a PET protective film with a thickness of 0.05mm, set the cutter shaft clearance to 0.04 - 0.06mm; when slitting double - sided tape with a thickness of 0.1mm, set the clearance to 0.08 - 0.12mm. The pressure adjustment of the pressure roller needs to be adapted to the material viscosity. The protective film has weak viscosity, so set the pressing pressure to 0.3 - 0.5MPa to prevent surface indentation caused by excessive pressure; the double - sided tape has strong viscosity, so set the pressure to 0.5 - 0.7MPa to ensure stable material conveyance without slipping.

(3) Control of running speed and tension

The running speed setting should follow the principle of "starting at a low speed and gradually increasing the speed". On the "Speed Setting" interface, first set the unwinding speed, slitting speed, and rewinding speed to the initial speed of 5 - 10m/min. After the trial slitting is normal, gradually increase the speed to a stable speed. The stable speed for slitting the protective film can be set to 20 - 30m/min. If the material thickness is less than 0.05mm, the speed needs to be reduced to 15 - 20m/min to avoid material jitter caused by high - speed operation; since the double - sided tape has high viscosity and is easy to stretch, set the stable speed to 15 - 25m/min, and the speed increase amplitude should not exceed 5m/min each time. Tension control is the key to double - sided tape slitting. Set the unwinding tension to 0.5 - 1.0N and the rewinding tension to 1.0 - 1.5N. Adopt segmented tension control. The tension at the initial stage of rewinding is slightly smaller, and gradually increase the tension as the coil diameter increases; set the unwinding tension of the protective film to 0.3 - 0.8N and the rewinding tension to 0.8 - 1.2N to prevent the material from being stretched and deformed due to excessive tension, which affects the product size accuracy.

3. Trial slitting and debugging: Verifying the rationality of the process

Trial slitting is a key step to find and solve parameter setting problems. Through small - batch trial slitting, detect indicators such as product size accuracy and cut quality, and make fine adjustments to the parameters until the requirements are met. The specific process is as follows.

(1) Small - batch trial slitting operation

Press the “Test Cut Start” button on the device control panel. The device will run according to the set parameters, and the test cut length should be controlled within 1 - 2 meters. During the test cut, closely observe the following: whether the material is conveyed smoothly without deviation or wrinkling; whether there is any abnormal noise when the cutter is cutting, and judge whether the clearance of the cutter shaft is reasonable; whether the coil is neatly wound without loose winding or over - tightening during the winding process. For the test cut of the protective film, focus on observing whether there are scratches on the surface and whether the cut is smooth without burrs; for the test cut of the double - sided tape, pay attention to whether there is glue overflow in the adhesive layer, whether the release paper is damaged, and whether the adhesive layer at the cut is closely attached to the release paper.

(2) Detection of test cut samples and parameter adjustment

After the test cut is completed, conduct a comprehensive inspection of the samples: measure the width at 10 different positions with a caliper with an accuracy of 0.01mm. If the error exceeds ±0.1mm, the cutter spacing and cutting size parameters need to be readjusted; observe the cross - section of the cut. If there are burrs on the protective film, it indicates that the clearance of the cutter shaft is too small, and the clearance needs to be increased by 0.01 - 0.02mm; if the adhesive layer of the double - sided tape sticks together, the cutter temperature can be appropriately increased (if the device supports it) or a cutter with better anti - sticking performance can be replaced. If the coil is loosely wound during winding, the winding tension needs to be increased; if the material is stretched, the operating speed needs to be reduced and the tension needs to be decreased. Repeat the process of test cut - detection - adjustment until the qualification rate of the samples reaches 100%, and then enter the formal cutting stage.

IV. Formal Cutting: Standardized Operation and Process Monitoring

During the formal cutting stage, strict standardized operations should be followed, process monitoring should be strengthened, and unexpected problems should be handled in a timely manner to ensure stable production efficiency and product quality.

(1) Operation process of batch cutting

After confirming that the test cut parameters are correct, set the cutting length and quantity in the control system, and press the “Batch Start” button. The device will enter the continuous cutting state. The operator should stand in the safety area and is strictly prohibited from touching the running cutter, pressure roller, and materials with hands. After each roll of material is cut, a new coil needs to be replaced in a timely manner. When replacing, first press the “Pause” button. After the device stops, perform the hoisting and fixing operations. After the replacement is completed, press the “Continue” button to resume operation. For the cutting of double - sided tape, the blade should be wiped with a cleaning cloth dipped in alcohol every 30 minutes to remove the sticky residue and avoid affecting the cutting quality; during the cutting of the protective film, the surface of the pressure roller should be checked regularly, and if there are impurities, clean them in time.

(2) Key quality and safety monitoring

The quality monitoring adopts the “Timed Sampling + Random Inspection” mode. One sample is taken every 10 minutes to detect the width and cutting quality, and the winding flatness is detected every 30 minutes. If scratches are found on the surface of the protective film, check whether there are foreign objects or damage on the pressure roller; if the release paper of the double - sided tape is wrinkled, adjust the unwinding tension or check whether there are quality problems with the coil. The safety monitoring focuses on the following: whether there is abnormal noise during the operation of the device. If there is abnormal noise, stop the machine immediately and check the cutter shaft, bearings and other components; whether there are alarm prompts in the control system, such as abnormal tension or cutter shaft overload, and the cause of the fault needs to be investigated and solved in a timely manner. At the same time, keep the work site clean, place the coils and finished products in categories, keep the passages unobstructed, and eliminate potential safety hazards.

V. Shutdown and Winding - up: Equipment Maintenance and Site Cleaning

After the cutting operation is completed, the shutdown process should be carried out in a standardized manner, and the equipment maintenance and site cleaning work should be well - done to extend the service life of the equipment and ensure the smooth progress of subsequent production.

(3) Standardized shutdown operation

After completing all the slitting tasks, press the “Stop” button. After the equipment has completely stopped running, turn off the power and air source switches. Move the knife shaft to the initial position, release the pressure roller, remove the remaining coils and finished products, and clean the residual materials on the equipment. For the knives, they need to be disassembled for cleaning. Apply special knife oil to the blade to prevent rust, and then store them properly in the knife box. If the knives have nicks or wear, mark them and send them for repair or replacement.

(4) Equipment maintenance and on - site tidying up

Key points of equipment maintenance: Use compressed air to blow the dust and impurities on the surface and inside of the equipment, especially in key parts such as the knife shaft gap and the tension sensor; Add lubricating oil to moving parts such as the knife shaft bearings and the bushings of the unwinding and rewinding rollers to ensure good lubrication; Check whether the electrical circuits and air pipes are worn. If there are problems, report for repair in time. On - site tidying up work: Package the finished products according to specifications and quantities, and paste labels; Clean up the waste materials, cleaning cloths and other sundries at the work site and pour them into the designated trash can; Fill in the production record form, and record in detail the slitting materials, parameter settings, product quantity and quality conditions to provide a reference for subsequent production.

6. Common problems and solution skills

During the slitting process of the protective film and double - sided tape, problems such as rough edges at the cut, dimensional deviation, and material stretching are prone to occur. The following are the cause analysis and solution skills for common problems.

(1) Rough edges at the cut

The rough edges of the protective film are mostly due to the excessive gap of the knife shaft or the dullness of the knives. The solution is to reduce the knife shaft gap by 0.01 - 0.02mm or replace the knives with new ones; The rough edges of the double - sided tape are mostly due to the adhesion of the adhesive layer to the blade. You can wipe the blade and apply an anti - sticking agent. If it is ineffective, replace it with a special anti - sticking knife.

(2) Dimensional deviation

If the slitting width is too large, reduce the knife spacing and recalibrate; If it is too small, check whether the material is stretched due to excessive tension. Appropriately reduce the unwinding and rewinding tension and at the same time reduce the operating speed.

(3) Material stretching and deformation

To prevent the stretching of the protective film, reduce the tension and operating speed, and adjust the pressure of the pressure roller; In addition to adjusting the tension and speed for the stretching of the double - sided tape, check whether there is jamming in the unwinding mechanism to ensure smooth material conveyance.

In short, the use of the CNC slitting machine needs to follow the principle of “fully prepared, accurate parameters, trial cutting for verification, process monitoring, and standardized ending”. Optimize the process parameters according to the characteristics of the protective film and double - sided tape, strengthen equipment maintenance and quality control, so as to achieve efficient and high - precision slitting production.

(The above content is only a personal opinion and does not represent the industry's implementation standards.)

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