Sealing Detection Methods and Operating Specifications for Containers
Sealing performance is one of the most important indicators for packaging containers in food, pharmaceutical, daily chemical and beverage industries. Unqualified sealing will lead to leakage, oxidation and contamination of products, so enterprises must carry out standardized sealing detection for daily produced packaging containers. This article elaborates on the operating specifications of multiple sealing detection technologies to help enterprises complete container tightness testing efficiently.
At present, the mainstream container tightness testing technologies in the industry include bubble immersion testing, colored water penetration testing and negative pressure vacuum testing. Different sealing detection technologies have unique operating processes and applicable scenarios, which can match diverse types of packaging containers.
1.1 Bubble Immersion Method
1.1.1 Detection Principle
The bubble immersion method is the most commonly used container tightness testing technology. This sealing detection technology relies on negative pressure equipment to change the internal air pressure of a closed tank. During sealing detection, testers place packaging containers filled with finished products into clean water, and use negative pressure equipment to form a pressure difference inside and outside the packaging containers. The leakage position of packaging containers can be judged according to the continuous overflow of bubbles.
1.1.2 Operating Procedures
Sample Pretreatment: Seal the openings of packaging containers tightly and wipe off surface stains to avoid affecting the result of sealing detection.
Sample Placement: Put the treated packaging containers into the closed tank and completely immerse all samples in water for container tightness testing.
Pressure Adjustment: Turn on the supporting negative pressure equipment, set reasonable vacuum degree and holding time according to the material of packaging containers.
Real-time Observation: Observe the water surface state carefully during sealing detection to check whether bubbles emerge from any position of packaging containers.
Result Confirmation: After the pressure inside the closed tank returns to normal, take out the packaging containers and record the final data of sealing detection.
1.1.3 Applicable Scope and Materials
This low-cost container tightness testing technology has simple operation steps and low threshold for sealing detection. It is suitable for hard-shell packaging containers such as glass bottles and plastic bottles, and also compatible with flexible packaging containers used in the medical device industry.
1.2 Colored Water Penetration Method
1.2.1 Detection Principle
The colored water penetration method is a destructive container tightness testing technology. This sealing detection technology takes special aqueous colorant as the detection medium. The aqueous colorant can penetrate into the tiny gaps of unqualified packaging containers based on capillary effect, so as to accurately screen defective products during sealing detection.
1.2.2 Operating Procedures
Medium Preparation: Prepare uniform aqueous colorant according to the standard formula for subsequent sealing detection.
Liquid Filling: Inject the configured aqueous colorant into qualified packaging containers and seal the bottle mouth tightly.
Static Placement: Place the filled packaging containers upside down to make the aqueous colorant fully contact the sealing position of packaging containers.
Defect Screening: Disassemble the packaging containers after standing, and judge the sealing performance by checking the permeation track of aqueous colorant.
1.2.3 Applicable Scope and Materials
Aqueous colorant has strong identification in sealing detection, which can intuitively find micro-leakage points of packaging containers. This container tightness testing technology is widely used for sampling inspection of small-batch packaging containers in pharmaceutical and daily chemical industries.
1.3 Negative Pressure Vacuum Sealing Method
1.3.1 Detection Principle
The negative pressure vacuum sealing method is a high-precision container tightness testing technology. This sealing detection technology uses professional vacuum equipment to build a simulated low-pressure environment inside a closed tank, simulating the extreme environment that packaging containers may encounter during transportation and storage, so as to complete rigorous sealing detection.
1.3.2 Operating Procedures
Preparatory Work: Inject clean water into the closed tank and debug the vacuum equipment to ensure the stability of the whole sealing detection system.
Sample Fixing: Put the sealed packaging containers into the closed tank to prevent sample displacement during container tightness testing.
Vacuumizing: Start the vacuum equipment to discharge air inside the closed tank, and maintain the specified negative pressure value for a period of time.
Sampling and Analysis: Stop the vacuum equipment to restore atmospheric pressure, take out packaging containers and summarize the sealing detection results.
1.3.3 Applicable Scope and Materials
Relying on stable vacuum equipment and a closed tank, this efficient sealing detection technology supports non-destructive testing of various packaging containers. It is the preferred container tightness testing technology for large-scale factories with high detection accuracy requirements.
