Optimization of The Packaging Forming Effect of The Transparent Film Three-dimensional Packaging Machine

Optimization methods and strategies for the packaging forming effect of transparent film three-dimensional packaging machines

The forming effect of the transparent film three-dimensional packaging machine directly affects the appearance quality, anti-counterfeiting performance and market competitiveness of the product. It needs to be improved through multi-dimensional collaborative efforts such as film material adaptation, equipment precision enhancement, process parameter optimization and process monitoring. The following analysis is conducted from four aspects: the influencing factors of molding effect, optimization methods, solutions to common problems, and long-term stability maintenance.

First, the key factors influencing the packaging forming effect

Characteristics of membrane materials

Flexibility and stiffness: Excessive flexibility of the membrane material (such as some PE films) can easily lead to wrinkles or collapse after molding, while insufficient stiffness (such as thin BOPP films) makes it difficult to fit complex contusions.

Thermoforming performance: The thermal shrinkage rate, thermal softening point and forming temperature window of the membrane material directly affect the forming accuracy. If the thermal shrinkage rate is too high (such as >5%), it may cause deformation after packaging.

Surface friction coefficient: If the friction coefficient is too high (such as >0.5), it will increase the frictional resistance between the film material and the mold, resulting in incomplete molding. If it is too low (such as <0.2), it may cause the membrane material to slip.

Equipment structure and precision

Forming mold: The surface roughness, dimensional accuracy and Angle design of the mold directly affect the adhesion of the film material. If the surface of the mold is rough (Ra>1.6μm), it may cause scratches on the film material or poor adhesion.

Tension control: Tension fluctuations exceeding ±5% will cause uneven stretching of the membrane material, resulting in local wrinkles or relaxation.

Heat sealing and cutting: Uneven temperature of the heat sealing knife or wear of the cutting knife will cause the edge of the film material to be uneven, affecting the aesthetic appearance of the formed product.

Process parameter matching

Temperature and speed: If the temperature is too high (such as >180℃) or the speed is too fast (such as >120 pieces per minute), the membrane material will be cut before it is fully adhered, resulting in bubbles or wrinkles.

Cooling efficiency: Insufficient cooling will cause the membrane material to continue to shrink during subsequent processing, damaging the molding effect.

Second, methods for optimizing packaging forming effects

Membrane material selection and adaptation

Balance of flexibility and stiffness: Prioritize the selection of membrane materials with moderate flexibility (elongation at break 150-250%) and high stiffness (such as BOPP/CPP composite films), and the thickness is recommended to be ≥35μm.

Optimization of thermoforming performance: Select film materials with a thermal shrinkage rate of ≤3% and a thermal softening point of 140-160℃ to ensure dimensional stability after forming.

Surface friction coefficient regulation: By corona treatment or adding anti-adhesive agents, the friction coefficient of the film material can be controlled at 0.3-0.4 to reduce frictional resistance and the risk of slipping.

Equipment adjustment and improvement

Optimization of forming molds

High-precision CNC machining molds are adopted to ensure dimensional accuracy within ±0.05mm and surface roughness Ra≤0.8μm.

The mold Angle design should match the product contour. For instance, R2-R3 transition fillets should be used at the fillets to reduce the risk of film material tearing.

Tension control system upgrade

Closed-loop tension control is introduced, and the tension is adjusted in real time through tension sensors and servo motors, with fluctuations controlled within ±2%.

Floating rollers and buffer devices are added to the membrane material conveying path to absorb tension fluctuations and prevent local over-tightness or relaxation.

Improvement of heat sealing and cutting processes

The segmented heating technology is adopted. The temperature at the front end is slightly higher (such as 165℃) to ensure the softening of the membrane material, while the temperature at the back end is slightly lower (such as 160℃) to avoid excessive stretching.

Regularly replace the cutting knife to ensure the sharpness of the blade (with a cutting edge Angle of 30°-45°) and reduce burrs on the edge of the film material.

Refinement of process parameters

Temperature and speed matching

Reduce the packaging speed by 10-15% (such as adjusting to 80-100 pieces per minute) to ensure that the film material has sufficient time to adhere to the products.

Adjust the forming temperature according to the type of membrane material. For example, the forming temperature for BOPP/CPP films is 160-165℃, and for PETG films, it is 140-150℃.

Improved cooling efficiency

Add a cooling air knife or water cooling device to ensure that the film material cools to room temperature within 1 second after sealing, reducing subsequent shrinkage.

Optimize the design of the cooling air duct to ensure uniform air velocity (≥6m/s) and avoid insufficient local cooling.

Process monitoring and feedback

Real-time molding quality inspection

Install a laser rangefinder or 3D vision sensor to monitor the adhesion between the film material and the product in real time. An automatic alarm will be triggered when the deviation exceeds 0.2mm.

Finished product spot check

Randomly inspect the packaged finished products and evaluate the molding effect through visual inspection (such as wrinkles and bubbles) and dimensional measurement (such as diagonal deviation ≤1mm).

Use a pressure tester to check the tightness of the packaging. It is required that the product has no obvious shaking or the film material is loose after packaging.

Third, Common Problems and Solutions

Wrinkles or bubbles in the membrane material

Reasons: Uneven tension, too low mold temperature, excessive friction between the membrane material and the mold.

Solution: Adjust the tension to within ±2%, increase the mold temperature by 5-10℃, and apply an anti-stick coating (such as Teflon) on the mold surface.

The membrane material is torn or damaged

Reasons: Excessive tension, overly sharp mold Angle, insufficient tensile strength of the membrane material.

Solution: Reduce the tension by 5-10%, increase the fillet of the mold to R2-R3, and replace the membrane material with a tensile strength of ≥35MPa.

After forming, the membrane material shrinks or deforms

Reason: The shrinkage rate of the heat shrink film is too high and the cooling is insufficient.

Solution: Reduce the shrinkage temperature of the heat shrink film by 5-10℃ and extend the cooling time to more than 2 seconds.

The edges of the membrane material are uneven or have burrs

Reasons: The cutting knife is worn out and the pressure of the heat sealing knife is insufficient.

Solution: Replace the cutting knife and increase the pressure of the heat sealing knife by 10-15%.

Fourth, equipment maintenance and long-term stability

Daily maintenance

Cleaning: Clean the mold, heat sealing knife, cutting knife and guide roller daily to prevent the accumulation of glue residue or film chips.

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 and fillets every month. Make adjustments when the deviation exceeds 0.05mm.

Sensor calibration: Calibrate the tension sensor, laser rangefinder and visual inspection system every quarter to ensure measurement accuracy.

Calibration of heat sealing knives: Check the parallelism and temperature uniformity of the heat sealing knives every six months. Repair should be carried out when the deviation exceeds 0.05mm.

Spare parts Management

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

Spare parts quality: Select spare parts that match the original equipment to avoid affecting the molding effect due to spare parts quality issues.

Fifth, suggestions for optimizing the molding effect

Technological upgrade

Automation control: Introduce PLC and touch screen to achieve automatic adjustment of parameters such as tension, temperature and speed, as well as self-diagnosis of faults.

Online inspection system: Install high-precision 3D vision inspection and laser rangefinders to monitor the molding effect in real time and automatically remove non-conforming products.

Process optimization

Negative pressure-assisted molding: Negative pressure adsorption holes are added inside the mold to ensure that the film material closely adheres to complex contours.

Segmented cooling technology: The cooling process is divided into three stages: pre-cooling, main cooling, and shaping, reducing the stress concentration of the membrane material.

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 and ensure that they operate in accordance with standards.

Summary

The optimization of the forming effect of the transparent film three-dimensional packaging machine requires comprehensive improvements from multiple aspects such as film materials, equipment, processes, monitoring and maintenance. By choosing highly adaptable membrane materials, optimizing tension and forming processes, upgrading equipment control systems, strengthening daily maintenance and real-time detection, the forming quality can be significantly improved. Operators must strictly abide by the operating procedures, promptly identify and address any issues, and continuously enhance the packaging effect in combination with technological upgrades.