In the quality inspection workshop of a nut processing factory in Qujing, Yunnan, bags of walnut kernels are passing through the transparent channel at a speed of 120 bags per minute. When a blue-purple light spot passes over the surface of the packaging bag, 12 detection indicators flash synchronously on the control screen-this is the role of the intelligent visual inspection system independently developed by ply-pack, which upgrades traditional manual sampling to millisecond-level fully automatic quality control.
Eye of the spectrum: seeing invisible defects
Traditional photoelectric sensors can only identify obvious appearance defects, while this system uses multispectral imaging technology to scan through three bands of visible light, near infrared, and ultraviolet:
·The visible light channel captures macro defects such as sealing wrinkles and printing misalignment with 50 million pixels
·Near infrared band penetrates the packaging film layer to detect internal condensation caused by moisture content deviation of nuts
·UV light curtain excites ink fluorescence and identifies missing breakpoints of production date coding within 0.05 seconds
"The most ingenious thing is the optical compensation algorithm," The head of ply-pack's visual technology pointed to the ring light source at the inspection station and explained, "Even in an environment where the dust concentration in the workshop reaches 8mg/m³, the system can still maintain 99.2% imaging clarity."
The Evolution of Deep Learning
The system's deep learning algorithm has established a model library containing 128 abnormal scenarios:
. For misjudgments caused by nut crumbs, the Generative Adversarial Network (GAN) is introduced to simulate 3,000 interference environments
. The sealing strength prediction module calculates mechanical parameters in real time through the three elements of heat sealing temperature, pressure, and duration
. When insufficient nitrogen filling is detected, the system automatically traces back to the previous process and accurately locates the specific filling valve
On the production line of a Qujing customer, this system once captured a rare defect: 0.3mm periodic bubbles appeared at the seal of a batch of almond packaging bags. After tracing the source, it was found that the silicone gasket of the heat sealing roller had a micro-protrusion of 0.02mm. Based on this, the technical team optimized the equipment preventive maintenance strategy and reduced the occurrence rate of similar failures by 87%.
Real-time quality control reconstructs production logic
Unlike traditional post-inspection, real-time quality control technology enables the production line to have autonomous decision-making capabilities:
·The processing time of each frame of image is controlled within 8ms, ensuring zero delay in 120 packages/minute inspection
·The defect classification results are immediately fed back to the PLC, triggering the self-adjustment of the parameters of the corresponding workstation
·Quality data generates quality control maps every hour to guide process engineers to optimize the production process
"This system is like installing a nervous system for the production line," The quality director of a Qujing customer exclaimed at the real-time fluctuation curve on the electronic signboard, "The standard deviation of the sealing strength has dropped from 1.8N before the transformation to 0.4N, which is a stability that we could not imagine in the era of manual inspection."
Currently, ply-pack is expanding this technology to more application scenarios:
·Developing polarized light detection modules suitable for transparent bags to solve the problem of reflective interference
·Integrating blockchain technology to make the detection data of each package traceable to specific equipment, shifts, and operators
·Testing remote diagnostic systems among Southeast Asian customers to analyze fault characteristics in real time through 5G transmission
Standing in the visiting corridor of the workshop, you can clearly see the flashing indicator lights at the inspection stations: green represents the continuous flow of qualified products, and the red warning light is only on less than 20 times a year. This vibrant green is redefining the quality benchmark of the food packaging industry-when the intelligent visual inspection system pushes the quality control accuracy to the micron level, every detail of the snack packaging becomes a footnote to the brand's reputation.
