Plastic film slitting is according to the packaging, printing, electronics and other industry requirements, large film cutting into a smaller width of the professional process. The process encompasses raw material preparation, equipment commissioning, slicing, quality inspection and product packaging. Parameters such as tension, speed and tool precision must be strictly controlled to ensure product quality. The specific processes and key control points are as follows:
1.Raw Material Preparation and Inspection
Raw material roller identification;
Inspection Items: Check thickness, width, roll diameter, surface quality (no scratches, no holes, no wrinkles) of thin film material (e.g. PE, PP, PET, BOPP, etc.).
Typical Issues: If the end of the raw material roll is uneven or the tension is uneven, the coiling machine must be adjusted before cutting. Otherwise, it may lead to deviation or breakage in the cutting process.
Pretreatment (Optional)
Static Dissipation: electrostatic treatment of vacuum-prone films (such as BOPP) to prevent surface impurities from affecting subsequent treatment after slitting. Preheat and soften: Preheat high-hardness films (such as thick PET) (usually controlled at 40-60°C) to reduce cutting resistance and minimize burrs.
ii. Equipment Commissioning and Parameter Settings
Slitter Type Selection
Circular Knife Slitter: suitable for thin films (thickness ≤ 50 microns), high accuracy but slow speed.
Flat Knife Slitter: suitable for thick film (thickness greater than 50 microns), high cutting efficiency, but prone to burr.
Laser Slitter: Suitable for ultra-thin or high precision films (such as electronic grade films), but expensive equipment.
Key Parameter Settings
Cutting width: Adjust blade spacing to order, error within ±0.1mm.
Tension control:
Expansive tension: Typically set at 30-50% of the yield strength of the film to avoid deformation due to overextension.
Coil tension: Taper tension control (tension decreases as the roll diameter increases) is used to prevent inner layer from collapsing or outer layer from loosening. Cutting speed: Adjusted to film material and thickness, usually between 50 and500 m/min. For example, PE films can be slit at high speeds (300-500 m/min), while PET films require lower speeds (100-200m/min) to reduce burrs.
Tool Installation and Adjustment
Roundknife: Check blade sharpness during installation to ensure blade parallelism ≤ 0.05 mm to avoid wavy edges.
Flat Knife: Adjust the angle of the blade (usually 15-20°) to ensure the cutting surface is perpendicular to the film, reducing burr.
III. Slitting Operation Process
Loading and Film Threading
Roll the stock onto the scroll. Before attaching the film to the drum, manually pass through the guide rail, tension rollers and cutting mechanism.
Key points: Make sure the film centerline is aligned with the device center line to prevent deviation during slitting. Trial Cutting and Parameter Optimization
Start the machine and perform a low-speed test cut (≤50m/min) to check cutting quality:
Burn: If the burr width is greater than 0.1mm wide, adjust the blade angle or replace it.
Warp: If the film is sliced, edge warps, increasing coil tension or adjusting roller pressure.
Dimension Deviation: If the actual width deviates from the set value by more than 0.2mm, recalibrate blade spacing or test equipment accuracy.
Official Slitting
After trying to cut, gradually increase the speed to the target speed for continuous slitting.
Monitoring Points:
Real-time observation of tension display ensures ≤ 5%.
Periodically check the flatness the scroll to avoid it being "conical" or "chrysanthemum shaped."
IV. INTRODUCTION Quality inspection and control of commonly used identifiers and prompts in English
Online access
Width Inspection: The laser width gauge monitors the cutting width in real time and automatically adjusts the blade spacing based on feedback.
Defect Detection: A CCD camera or infrared sensors detect defects such as burrs, holes and creases, triggering alarms or turning off machines. Offline Inspection
Dimension measurement: Measuring the width and length of a slit film with a cursor or projector. Tolerance must be standard (e.g. ±0.1mm).
Physical testing:
Tensile strength: The longitudinal tensile strength and transverse tensile strength of the slit film were tested according to GB/T1040.3 to ensure that tensile strength did not decrease significantly.
Thermal sealing performance: Test the heat seal strength of the packaging film to see if the seams affect the structure of the heat seal layer.
V. Packaging and storage of finished products
Reels and safety
After slicing, secure the scroll with paper or a plastic core and label the end of the scroll (indicating specification, batch number and date of production).
Prevention of loosening: For films such as PE castings, the air shaft and air pressure can be adjusted to maintain the reel diameter stable.
Packaging and protection
Packaging: Wrap the scroll in polyethylene film or foam to prevent scratches during transport.
Packaging: Wrap in wooden or cardboard boxes labeled "fragile" and "moisture-resistant." Storage conditions: 15-30°C with humidity ≤ 65%. Avoid direct sunlight or high temperature, so as not to cause film deformation.
VI. INTRODUCTION II. Introduction 1. Introduction. Frequently Asked Questions
Causes and solutions to problems
Tilt: The end is uneven and tension affects the material roll. Reverse adjusting end face and optimizing tension control system.
Blade: Blunt blade, cut too fast. Replace the blade and reduce speed to 50-100m/min.
Warp: Insufficient winding tension, uneven guide roller pressure. Increase winding tension and adjust guide roller parallelism.
Dimensional deviation: blade gap calibration error, equipment vibration. Recalibrate blade gap and inspect equipment mounting bolts.
VII. Process Optimization
Automation Upgrade: Introduction of artificial intelligence visual inspection system, automatic identification and classification of defects, reduce the proportion of manual spot checks.
Energy saving design: using frequency conversion drive technology, dynamically adjust motor power according to load, reduce energy consumption by 20%-30%.
Environmentally Friendly Materials: Development of biodegradable and biodegradable membrane separation processes, such as optimization of (polylactic acid) film separation parameters.
