The integrity of the items is the POF shrink film packaging plays a very good role

Everyone knows that vegetables are easy to rot during transportation, but now that we see that the vegetables are so intact and undamaged, our POF shrink film product packaging has played a good protective role. Broccoli has a high respiratory intensity, and its physiological and metabolic activities are very vigorous after harvest. It will lose water and turn yellow in a short time, which will affect the commodity value of the vegetable itself. Therefore, vegetables must be pre-cooled in time after harvest to quickly remove the field heat, reduce the center temperature and respiratory intensity of broccoli, so as to achieve the purpose of slowing down the metabolic activity of vegetables and extending the preservation period. At present, the pre-cooling link in domestic vegetable production areas is weak and lacks professional pre-cooling facilities; refrigerated transportation is rarely used during transportation. Retail links such as farmers' markets and supermarkets are mostly sold at room temperature without packaging. The facilities for selling fruits and vegetables are basically ordinary shelves and ordinary shelves. Humidification spray device (RH: 80%～90%) and refrigerated display cabinet (2～10℃). The corruption rate of vegetable circulation in China is 25% to 30%, which is the current situation of vegetable circulation in China. To do a simple experiment: choose fresh, clean, uniform size, no mechanical damage and pests, 15-20cm in diameter, about 15cm in length broccoli (a single weight is about 200 to study pressure difference pre-cooling and cold storage pre-cooling, poly The quality change of broccoli in styrene foam box with ice and 0℃ refrigerated transportation for 1 day, 4℃ and 20℃ with and without shrink film packaging, and 20℃ humidified sales for 2 days. The results show that: The pre-cooling speed is faster than the cold storage pre-cooling; the quality of broccoli sold at 4°C is better than the quality of broccoli sold at 20°C after 1 day of refrigerated transportation in polystyrene foam box with ice. PE heat shrinkable film replaces PVC shrinkable film The best choice. Because PVC contains low toxicity, it is generally not recommended to be used in food packaging, so the base material that replaces PVC is replaced by PE. PE is non-toxic and tasteless, and can be used whether it is industrial packaging or food packaging. Blowing crosslinking For film, we must first understand the orientation of shrinkage. Generally speaking, manual packaging uses finished films with large transverse shrinkage.