In the early morning packaging workshop, freeze-dried strawberries on the assembly line are completing the last process through fully automatic nitrogen filling equipment. Operator Master Li touched the control screen lightly, watching the light blue nitrogen accurately injected into the packaging bag, and the corners of his mouth unconsciously raised a smile-this set of third-generation nitrogen-filled fresh-locking packaging equipment developed by ply-pack is quietly changing the preservation pattern of freeze-dried food in China.
At this year's National Food Packaging Technology Forum, the nitrogen-filled fresh-locking packaging technology of the ply-pack packaging machine factory became the focus. This technology replaces oxygen with 98.5% pure food-grade nitrogen to control the residual oxygen content in the packaging bag below 0.8%. "It's like putting invisible protective clothing on food," said Wang Mingyang, technical director. Compared with traditional vacuum packaging, the nitrogen filling process can not only avoid physical squeezing of food ingredients, but also extend the shelf life of freeze-dried food to more than 18 months through a continuous antibacterial environment.
"The 5 tons of freeze-dried mango cubes shipped to Northern Europe last month were reported by customers to have the same aroma when they opened the bag as when they left the factory half a year ago." Zhang Li, purchasing manager of a freeze-dried food company, showed the overseas inspection report. Since the introduction of ply-pack's nitrogen filling and fresh-keeping system, the product shelf complaint rate has dropped by 62%, which has enabled their freeze-dried okra to successfully enter high-end supermarkets in Japan. More and more customers are beginning to require that packaging equipment must be equipped with an intelligent oxygen content monitoring module, which has become a new industry standard.
On the supply chain side, the popularization of nitrogen filling and fresh-keeping technology has driven the development of supporting industries. A valve supplier in Zhejiang recently set up a food-grade gas control device R&D team. "In the past, we mainly made industrial valves, but now we have to hold technical docking meetings with ply-pack engineers every week." The person in charge, Mr. Chen, admitted that this cross-domain collaboration has forced the company to improve its precision manufacturing capabilities. At the same time, packaging material suppliers are also developing multi-layer composite films, which have increased nitrogen barrier performance by 3 times.
"Next year we will launch a mobile nitrogen filling workstation." Zhou Jianhua, general manager of ply-pack, revealed at an internal strategic meeting. This equipment, which can be flexibly adapted to small and medium-sized production lines, targets the emerging freeze-dried pet food market. According to industry associations, as consumers pay attention to the nutritional retention of freeze-dried foods, the market size of nitrogen-filled fresh-keeping packaging equipment is expected to exceed 1.2 billion yuan in 2024, and the technology iteration cycle has been shortened from three years to eighteen months.
The industrial park is brightly lit in the twilight, and engineers are debugging a new pulse nitrogen filling device in the ply-pack laboratory. Outside the glass window, a few sycamore leaves fall with the wind, just like the freeze-dried ingredients gently supported by nitrogen in the packaging bag. This fresh-keeping revolution that began on the workshop assembly line is injecting new vitality into China's food packaging industry through continuous technical development. When more companies master the core code of nitrogen-filled fresh-keeping packaging technology, the "time preservation technique" of freeze-dried food will eventually fly into the homes of ordinary people.
