Packaging accuracy control of transparent film three-dimensional packaging machine

Control methods and key points of Packaging Accuracy for Transparent Film three-dimensional Packaging machines

The packaging accuracy of the transparent film three-dimensional packaging machine directly affects the appearance quality, sealing performance and production efficiency of the product. It needs to be controlled from multiple dimensions such as equipment adjustment, process optimization and process monitoring. The following analysis is conducted from four aspects: factors influencing accuracy, control methods, solutions to common problems, and maintenance suggestions:

First, the key factors affecting packaging accuracy

Mechanical structure accuracy

Forming mold: The dimensional accuracy and surface finish of the mold determine the fit of the film material wrapping. If the mold is worn or the design is unreasonable, it may cause the membrane material to wrinkle or not be tightly wrapped.

The wear of transmission components such as chains, synchronous belts, and gears can cause speed fluctuations, affecting the accuracy of membrane material conveying and sealing and cutting positions.

Guiding and deviation correction device: The parallelism of the guiding roller and the sensitivity of the deviation correction sensor directly affect the stability of membrane material transportation.

Membrane material characteristics

Uniformity of thickness: A deviation of more than ±5% in the thickness of the membrane material may result in loose sealing or offset at the cutting position.

Thermal shrinkage: Some membrane materials will shrink after heating. If not pre-treated in advance, it may cause dimensional changes after packaging.

Surface friction coefficient: A friction coefficient that is too high or too low will affect the smoothness of membrane material transportation. It needs to be optimized by adding an anti-static coating or adjusting the tension control.

Process parameter matching

Temperature and time: Excessively high sealing temperature or overly long heat sealing time may cause deformation of the film material, affecting the dimensional accuracy of the packaging.

Tension control: If the tension of the membrane material fluctuates by more than ±10%, it will cause the membrane material to stretch or relax, thereby affecting the sealing and cutting position and the tightness of the packaging.

Speed stability: Fluctuations in the main drive speed exceeding ±2% May cause asynchronous membrane material conveying and sealing and cutting.

Second, methods for controlling packaging accuracy

Equipment adjustment and calibration

Calibration of forming molds: Regularly inspect the mold dimensions, use a micrometer to measure key parts, and ensure that the deviation is within ±0.1mm. If the mold is worn out, it needs to be repaired or replaced in time.

Maintenance of transmission components: Check the tightness of the chain and synchronous belt every month and adjust it to the specified range (for example, the chain sagging is 10-15mm). The meshing clearance of gears needs to be controlled within 0.1-0.2mm.

Optimization of the guiding and deviation correction device: Adjust the parallelism of the guiding roller and calibrate it with a laser level to ensure that the deviation is less than 0.05mm. Regularly clean the deviation correction sensor to avoid dust interference.

Membrane material pretreatment and selection

Thickness inspection: Use a film thickness gauge to measure the thickness of the film material and remove the rolls with excessive thickness deviations.

Heat shrinkage compensation: For heat shrinkable membrane materials, the impact of shrinkage can be reduced by pre-stretching or adjusting the heat sealing temperature and time. For instance, reduce the heat sealing temperature by 5 to 10 degrees Celsius while extending the cooling time.

Surface treatment: Apply anti-static agent on the surface of the membrane material to reduce the coefficient of friction and ensure smooth transportation.

Process parameter optimization

Temperature and time control: Determine the optimal sealing temperature and time through experiments. For instance, for BOPP film, the sealing temperature can be set at 160-170℃, and the heat sealing time is 0.8-1.0 seconds.

Tension closed-loop control: Tension sensors and magnetic powder brakes/clutches are adopted to achieve tension closed-loop control, ensuring that tension fluctuations are less than ±5%.

Speed stability improvement: Use high-precision frequency converters or servo controllers to control speed fluctuations within ±1%.

Process monitoring and feedback

Sealing quality inspection: Install infrared sensors or visual inspection systems to monitor the sealing temperature, pressure and time in real time to ensure the integrity of the seal.

Cutting position detection: Use photoelectric sensors or encoders to locate the cutting position. When the deviation exceeds 0.5mm, an automatic alarm will be triggered and adjustments will be made.

Dimensional measurement: Regularly spot-check the dimensions of the packaged finished products. Use a vernier caliper or laser rangefinder for measurement to ensure that the deviation is within ±1mm.

Third, common problems and solutions

The membrane material is wrinkled or shifted

Reasons: The guide rollers are not parallel, the tension is uneven, and the thickness of the membrane material is uneven.

Solution: Adjust the parallelism of the guide rollers, optimize the tension control, and replace the membrane material with uniform thickness.

The seal is not tight or there is air leakage

Reasons: too low temperature, insufficient pressure, and surface contamination of the membrane material.

Solution: Increase the sealing temperature and pressure, clean the surface of the film material to ensure there is no oil stain or dust.

Cutting position deviation

Reasons: Wear of the cutting knife, loose transmission chain, encoder failure.

Solution: Replace the cutting knife, tighten the transmission chain, and inspect and repair the encoder.

The packaging sizes are inconsistent

Reasons: Mold wear, thermal shrinkage of the membrane material, speed fluctuation.

Solution: Repair or replace the mold, optimize the heat sealing parameters, and stabilize the main drive speed.

Fourth, equipment maintenance and precision retention

Daily maintenance

Cleaning: After the end of daily production, clean the equipment, especially the heat sealing knife, cutting knife and guide roller, to prevent the accumulation of glue residue or film debris.

Lubrication: Lubricate the transmission components (such as chains and gears) weekly using high-temperature resistant grease.

Inspection: Check the membrane material conveying path daily to ensure there is no jamming or wear.

Regular calibration

Mold calibration: Use a micrometer to check the mold dimensions every month. Make adjustments when the deviation exceeds 0.1mm.

Sensor calibration: Calibrate the temperature sensor, tension sensor and deviation correction sensor every quarter to ensure measurement accuracy.

Speed calibration: Use a speedometer to check the main drive speed every six months. When the deviation exceeds ±1%, adjust the parameters of the frequency converter.

Spare parts Management

Key spare parts reserve: Stock commonly used spare parts (such as cutting knives, heat sealing knives, chains) to ensure timely replacement in case of failure.

Spare parts quality: Select spare parts that match the original equipment to avoid accuracy being affected by spare parts quality issues.

Fifth, suggestions for optimizing precision control

Data recording and analysis

Record parameters: For each production, record parameters such as the thickness of the membrane material, sealing temperature, tension, and speed, and establish a process database.

Analyze trends: Identify the key factors affecting accuracy through data analysis and optimize process parameters.

Personnel training

Operation training: Regularly train operators to master the skills of equipment adjustment, parameter setting and troubleshooting.

Quality awareness: Strengthen the quality awareness of operators to ensure that operations are carried out in accordance with standards.

Technological upgrade

Automation control: The introduction of PLC and touch screen enables automatic parameter adjustment and self-diagnosis of faults.

Visual inspection: Install a visual inspection system to monitor packaging quality in real time and automatically remove non-conforming products.

Summary

The packaging accuracy control of the transparent film three-dimensional packaging machine needs to be approached from multiple aspects such as equipment, film materials, processes, and monitoring. Through regular calibration, parameter optimization, strengthened maintenance, and data analysis, the stability of packaging quality can be ensured. Operators must strictly abide by the operating procedures, promptly identify and solve problems, and continuously improve the level of precision control in combination with technological upgrades.