Air-filled Food Leakage Squeeze-Type Detection Equipment: A Technological Tool for Protecting Package Integrity

Those bulging puffed food bags sitting on the shelves conceal a delicate battle between gas and seal.

On supermarket shelves, puffed foods in air-filled packaging always attract consumers with their plump appearance. This packaging not only prevents the food from breaking but also protects its quality through the internal gas. However, even the slightest leak in the bag can cause food spoilage, posing a food safety risk.

Squeeze-type detection equipment is a quality control tool designed for this purpose. It applies pressure to the bag and observes the reaction to determine its sealing performance. With technological advances, these devices have evolved from simple manual operations to fully automated intelligent systems.

1. Traditional Testing and Technological Evolution

In the early days of squeeze-type detection equipment, food manufacturers primarily relied on manual testing. Workers would manually squeeze each bag, relying on experience to determine if there was a leak. This method was inefficient, and the results were highly dependent on personal experience, resulting in a high rate of missed detections.

With advances in industrial technology, simple mechanical detection devices began to emerge. These devices use cylinders or counterweights to generate pressure, achieving uniform compression of the packaging bag. An early device described in [2] utilized natural compression from a counterweight, detecting leaks by observing the downward movement of a lever.

Traditional squeeze-type detection equipment has demonstrated greater accuracy than manual inspection, but still has significant limitations. They are often unable to detect minute leaks, are unable to quantify the extent of leaks, and still require manual interpretation of test results.

With the advancement of sensor and automation technologies, modern squeeze-type detection equipment has achieved high-precision, fully automated testing, providing more reliable assurance of food packaging quality.

2. Device Working Principle and Technical Classification

Squeeze-type detection equipment operates on a simple physical principle: when pressure is applied to an inflatable package, if there is a leak, the gas inside will escape, causing changes in the bag's shape or pressure. Modern equipment uses precision sensors to detect these subtle changes, enabling precise detection. Modern squeeze-type inspection equipment can be primarily categorized into the following types based on their operating principles:

Negative pressure suction inspection equipment

This type of equipment features multiple suction holes on the inspection table. During inspection, a pneumatic cylinder pushes a piston to generate negative pressure, which holds the bag in place. The device described here incorporates a piezoelectric plate and conductive spring mechanism to automatically adjust the suction force based on the bag's leak status.

When a bag leaks, the device increases suction force to prevent the food from spilling. After inspection, it automatically activates a pneumatic blow-off system to remove defective products.

Counterweight self-pressurization inspection equipment

This type of equipment utilizes a counterweight and a pressure plate, naturally squeezing the food bag with constant pressure. As mentioned above, the device detects leaks by observing the degree of depression of the pressure plate. This method offers the advantage of stable and controllable pressure without causing sudden impacts on the bag.

Counterweight self-pressurization equipment typically features a marking line and indicator needle to quantify the extent of leakage, providing more detailed data support for quality control. Infrared thermal imaging inspection equipment

This is a non-contact inspection technology that creates a temperature difference between the airflow exiting the leak and the surrounding environment by cooling the inspection environment. The system described above uses an infrared detector to capture this temperature difference and visually display the leak location on a display screen.

This method has the advantage of not physically contacting the packaging bag, making it particularly useful for inspecting fragile food packaging. Furthermore, it can precisely locate the leak, providing valuable information for improving production processes.

3. Core Technical Elements and Innovative Design

The accuracy of modern squeeze-type inspection equipment stems from the integration and innovation of multiple core technologies. These technical elements work together to ensure efficient inspection and reliable results.

The pressure control system is a key component of squeeze-type inspection equipment. Advanced equipment uses programmable pneumatic or hydraulic systems to precisely control the applied pressure based on the material and size of the packaging bag. For example, some equipment allows the operator to set multiple pressure curves to simulate the various pressure conditions encountered during actual transportation and storage.

Advances in sensor technology have significantly improved the performance of inspection equipment. Modern equipment integrates a variety of high-precision sensors, including pressure sensors, displacement sensors, and optical sensors. These sensors can capture minute changes in packaging bags during compression, converting physical signals into electrical signals for analysis and judgment by the control system. Some advanced equipment also uses infrared thermal imaging technology to detect gas leaks through temperature changes.

Another key feature of modern inspection equipment is intelligent judgment and automatic sorting systems. Using preset algorithms, the equipment can automatically determine whether a package is acceptable and control actuators to separate unacceptable products.

For example, upon detecting a leak, the device described in [1] automatically activates a pneumatic blow-off system to remove unacceptable bags from the inspection line, ensuring that only qualified products enter the next production stage.

Adaptive adjustment technology represents the latest development in extrusion inspection equipment. An intelligent inspection system described here automatically adjusts the parameters of the inflation and packaging machine based on inspection results, creating a closed-loop quality control system.

This system uses a camera to capture three-dimensional data of the package during compression, calculates the volume change ratio, and determines whether the seal meets standards, enabling precise control of the inflation volume. 4. Application Scenarios and Industry Value

Squeeze testing equipment is widely used in the food industry, particularly for production line quality control of inflatable packaged products such as puffed foods, potato chips, and shrimp crackers. These foods are typically packaged in nitrogen-filled containers to protect the fragile contents during transportation and distribution.

Seal integrity testing is also crucial in the pharmaceutical and medical device sectors. Leakage in pharmaceutical packaging can cause drug deterioration and ineffectiveness, and even pose a threat to patient health. Squeeze testing equipment can ensure the integrity of pharmaceutical packaging, ensuring the stability and safety of drugs throughout their shelf life.

The chemical industry is also a key application area for squeeze testing equipment. Many chemical products are corrosive or toxic, and packaging leaks can pose a serious safety hazard. Through squeeze testing, companies can ensure the seals of chemical product packaging and prevent leaks.

With the rapid development of e-commerce, the proportion of food and pharmaceutical sales online is increasing, and packaging is subjecting it to increased pressure and impact during logistics. Squeeze testing equipment can simulate various pressure conditions encountered during logistics, helping companies evaluate and improve packaging design and reduce damage during transportation. 5. Technological Development Trends and Challenges

Squeeze-type inspection equipment is developing towards intelligence, high precision, and integration. Future equipment will place greater emphasis on data collection and analysis capabilities, helping companies optimize production processes and quality control procedures by analyzing large amounts of inspection data.

Multi-technology integration is another important trend. Traditional squeeze-type inspection primarily relies on pressure changes to determine sealability. Emerging technologies such as infrared thermal imaging and ultrasonic testing are being combined with squeeze-type inspection to form multimodal inspection systems.

These technologies complement each other, enabling a more comprehensive assessment of packaging quality and improving inspection accuracy and reliability.

Miniaturization and modular design are also trends in squeeze-type inspection equipment. As manufacturers demand greater flexibility, equipment manufacturers are developing smaller and more easily integrated inspection modules.

These modules can be flexibly configured to suit production line layouts, meeting the needs of diverse production environments while reducing installation and maintenance costs.

Squeeze-type inspection equipment also faces some challenges. For example, achieving uniform pressure and accurate inspection of irregularly shaped packaging bags remains a technical challenge.

Furthermore, packaging bags made of different materials and structures may require different inspection parameters and methods, requiring equipment with strong adaptability and adjustability.

With the application of new materials and processes, food packaging formats are becoming increasingly diverse, placing higher demands on inspection equipment. Future squeeze-type inspection equipment will need to possess stronger learning capabilities and adaptability, able to adapt to new inspection requirements through software updates rather than hardware replacements.

With the continuous advancement of technology, inspection equipment manufacturers are integrating more cutting-edge technologies. The new equipment introduced in [and] already incorporates machine learning algorithms, which can continuously optimize judgment criteria by analyzing large amounts of inspection data, reducing false positives and missed detections.

These intelligent devices are no longer just tools for quality control; they are also a vital source of data for optimizing production processes, providing companies with unprecedented insights into production.

In the future, with the widespread adoption of the Internet of Things (IoT), squeeze-type inspection equipment for leaks in inflated foods will become even more intelligent and networked, becoming an integral part of Food Industry 4.0.