When we easily tear open a bag of fresh coffee or take out the intact medical equipment from the sealed bag, we seldom think about the technological mysteries hidden behind it.

It is precisely this seemingly simple process of heat sealing that silently safeguards the quality and safety of products. Whether it's the roaster's concern about the oxidative deterioration of coffee beans or the damage caused by moisture to items, the quality of heat sealing technology directly affects product loss and user experience.

As a professional service provider of customized flexible packaging solutions, MTPAK has been deeply involved in the research and application of heat sealing technology, providing tailored sealed bag solutions for different industry needs, and helping enterprises solve sealing problems.

Why is heat sealing technology the guardian of modern packaging?

Heat sealing technology involves heating plastic films to melt and bond the sealing area, forming an invisible protective barrier. This barrier not only ensures the integrity of the packaging but also maintains the quality characteristics of the internal products. According to statistics, product deterioration caused by poor packaging sealing accounts for 32% of quality issues, while excellent heat sealing processes can control the leakage rate to below 0.1%. In the food industry, heat sealing is directly related to preservation effectiveness; in the medical field, it affects sterility assurance; and in the industrial sector, it determines the protection level of products. It can be said that the quality of heat sealing directly affects the safety and reliability of products.

What are the common types of heat sealing technology? How can different types be adapted to different application scenarios?

Currently, mainstream heat sealing technologies primarily fall into three categories: pulse heat sealing, constant temperature heat sealing, and ultrasonic heat sealing. These technologies exhibit notable differences in their working principles and performance characteristics, and are suited for distinct application scenarios. When making a selection, enterprises must comprehensively consider their own product characteristics and production efficiency requirements.

Pulse heat sealing involves generating pulse heat through high-frequency current to instantly heat the heat-seal layer, which, coupled with pressure, achieves sealing, followed by rapid cooling and setting. Its core advantage lies in high heat-sealing precision, allowing for precise control over heat-sealing temperature and time, making it suitable for thin or heat-sensitive materials; the heat-sealed edges are smooth, ensuring stable sealing performance. It applies to food packaging requiring high sealing performance, such as coffee bags and tea bags, as well as vacuum packaging bags for electronic components. However, its disadvantage is relatively low production efficiency, making it unsuitable for large-scale continuous production; equipment costs are also high.

Constant temperature heat sealing refers to the process where the heat sealing knife continuously maintains a set temperature, heats the film material to a molten state, and then applies pressure to complete the sealing. Its advantages include simple operation, high production efficiency, suitability for continuous batch production, and low equipment maintenance costs. It is suitable for scenarios where the sealing accuracy is not highly required, such as snack packaging bags and daily necessities storage bags, and generally uses conventional films with a thickness of 50-150μm. Its limitations include the difficulty in controlling the heat sealing temperature, which can easily lead to material carbonization due to excessively high temperature or affect the sealing strength due to excessively low temperature, making it unsuitable for heat-sensitive materials.

Ultrasonic heat sealing utilizes the mechanical energy generated by ultrasonic vibration to cause high-speed friction and heat generation in the molecules of the heat sealing layer, achieving material fusion and sealing. Its advantages lie in the fact that no external heating source is required, the heat-affected zone is small, and heat-sensitive materials can be protected from damage due to heat; sealing is fast, and energy consumption is low. It is suitable for temperature-sensitive products such as biological reagent packaging and medical dressing packaging, as well as for thin films (thickness < 30μm). However, it has high requirements for material compatibility. Some non-polar films (such as polyethylene) have poor absorption of ultrasonic energy, resulting in poor sealing effects; the initial investment cost of the equipment is high.

What pitfalls are easy to fall into when choosing a heat sealing solution for sealing bags?

Misconception 1: Focusing solely on heat sealing strength while neglecting barrier properties. Typically, people tend to believe that higher heat sealing strength is better, yet they overlook the barrier effects of EVOH barrier layers and film materials on oxygen and water vapor, which can lead to rapid oxidation and moisture deterioration of the contents, such as loss of flavor in coffee beans and rusting of electronic components. Avoidance advice: Based on the product shelf life requirements, first determine barrier indicators such as WVTR and OTR, and then match the corresponding heat sealing technology and materials.

Misconception 2: Blindly choosing high-priced heat sealing technology. People believe that the higher the price of heat sealing technology, the better the effect, without considering their own production scale and product demand. Avoidance advice: Choose technology based on production volume. Enterprises with a production volume of >100,000 pieces/month can choose constant temperature heat sealing, while enterprises with a production volume of <10,000 pieces/month can choose pulse heat sealing

Misconception 3: Ignoring the compatibility between heat sealing and other processes. Focusing solely on the heat sealing process without considering the impact of subsequent processes, such as printing and bag making, on the heat sealing effect can lead to potential risks such as ink evaporation and seal strength issues. Avoidance suggestion: During the scheme design stage, incorporate processes such as printing and bag making into consideration, select high-temperature resistant ink (temperature resistance > 200℃), and adjust tension parameters simultaneously during the bag making process to ensure compatibility between all stages.

Conclusion

Behind the seemingly unassuming sealing bag lies the synergistic effect of heat sealing technology, material science, and process design. Whether it's preserving the freshness and flavor of food or ensuring the safe storage of electronic components, a high-quality heat sealing solution is a crucial part of the quality defense line. As a service provider of customized flexible packaging solutions, MTPAK always puts customer needs at the core. Relying on a professional technical team and strict compliance standards, we provide tailored heat sealing solutions for different industries, escorting the entire process from parameter customization, sample testing, to mass production.

If you are troubled by the heat sealing issues of sealed bags, whether it's to enhance the freshness of coffee bean packaging or to address the moisture-proof challenges of your products, you can reach out to MTPAK.

Email：account@mtpak.com

Contact us：https://mtpak.com/contact-mtpak

Uncover The Secret of Heat Sealing Technology For Sealed Bags