Packaging tightness is one of the main factors affecting product packaging quality. For the traditional packaging sealing test method, flexible packaging has promulgated the corresponding test standards. Let's analyze it from a simple and professional perspective.
There are two main reasons for the quality problem of the packaging bag: first, the quality of the material of the packaging bag is poor, such as the bonding strength between layers is not enough to cause the layering of the packaging bag and the loss of protection, or the heat sealing material is not up to the standard, the heat sealing quality is unstable leading to the sealing strength is not enough or the sealing is not tight or the leakage seal; The second is that the heat sealing conditions are not suitable, and the heat sealing temperature, heat sealing time and heat sealing pressure are the three elements of heat sealing. In order to ensure the quality of the packaging bag, the most reliable and scientific means is detection, so that not only can we clearly understand the quality of the packaging bag and the broken bag rate, but also provide a strong guarantee for the sustainable control of product quality.
Simpler testing methods include pressure testing, bubble testing, and penetration testing.
Pressure test: Put the packaging material into the water, and then fill the packaging with a certain air pressure to observe whether the packaging has air leakage phenomenon. If there is air leakage in the packaging, it means that the sealing of the packaging material is not good.
Bubble test: Put the packaging material into the water, and then blow a certain amount of air into the package to observe whether there are bubbles in the package. If there are bubbles in the packaging, it means that the sealing of the packaging material is not good.
Penetration test: The packaging material is placed in water, and then the packaging is observed for water infiltration. If there is water infiltration in the packaging, it means that the packaging material is not well sealed.
More complex and sophisticated vacuum testing and non-destructive testing require specialized equipment.
Vacuum test: Put the packaging materials into the empty box, and then vacuum the package to observe whether the package has air leakage. If there is air leakage in the packaging, it means that the sealing of the packaging material is not good. This method is usually suitable for detecting composite bags with high gas content. The specific methods can be divided into the following two types: vacuum pump method and vacuum generator method. Because the vacuum formed by the vacuum pump method is a pulsating airflow, the vacuum of packaging and printing is unstable; Vacuum forming time is long; Difficult vacuum maintenance, poor sealing performance; Pointer pressure display, low accuracy. Therefore, it has been phased out. The vacuum generator method is usually suitable for detecting composite bags with high air content. The bubble method is to soak the sample in a liquid at a certain temperature, and observe whether there are bubbles on the surface of the sample in the soaking liquid with a low-power microscope or the naked eye. The soaking liquid is generally stable and has no damage to the product. The temperature used should be controlled within the tolerance range of the sample, otherwise it will lead to incorrect detection. Sometimes, in order to improve the detection results, the immersion solution is usually pressurized or depressurized.
Non-destructive testing: At present, the more advanced packaging sealing testing methods are mostly non-destructive, that is, non-destructive testing, that is, under the premise of not damaging the package, to check the macro defects of the package or measure the characteristics of the workpiece.
Most flexible and semi-rigid bag non-destructive leak detection systems are based on a stimulus-response technology: the stimulation of the package can be ultrasonic, pressure, tracer gases such as nitrogen, carbon dioxide or hydrogen, and the response can be a sonic/ray reaction, package expansion and contraction, pressure change or detection of the tracer gas.
The micro leakage sealing tester based on vacuum attenuation principle was used to detect the micro leakage of the finished packaging. The tester was suitable for micro leakage detection and the integrity detection of various packaging containers. It can be used in ampoules, Xylin bottles, HDPE bottles, pre-filled needles and other medical packaging, food packaging, chemical industry packaging leak detection. The sealing tester has the advantages of non-destructive, non-destructive, no sample preparation, etc. Compared with the traditional color water method and microbial challenge method, the vacuum attenuation method is a zero emission, high efficiency and non-destructive physical detection method.
It should be noted that the above method can help you detect the tightness of packaging materials, but it should be noted that different packaging materials may require different detection methods, so you need to understand the characteristics of packaging materials before testing.
