The physical and mechanical properties of the food bag indicators mainly include the following aspects:
Tensile strength: refers to the maximum tensile force that the food bag can withstand in the process of stretching to rupture, the unit is megapascal (MPa). Tensile strength reflects the ability of the food bag to resist tensile damage, the higher the value, indicating that the food bag is more tough, can withstand greater tension without rupture, can ensure that in the process of loading and handling of food, the food bag will not be subject to tensile force and breakage.
Elongation at break: It refers to the percentage of the elongation of the food bag in stretching to break with the original length. It reflects the flexibility and ductility of the food bag, a higher elongation at break means that the food bag can withstand greater deformation when being stretched without breaking, to adapt to different shapes and sizes of food packaging, but also in the impact of external forces have a certain cushioning effect.
Tear strength: indicates the ability of food bags to resist tearing damage, usually measured by the tearing force per unit thickness, the unit is Niu / mm (N/mm). Tear strength for food bags in the process of opening and use of the performance is very important, a higher tear strength can prevent the food bag in the torn or by the sharp object scratching easily tear, to ensure the integrity of the food bag.
Puncture strength: refers to the ability of the food bag to resist puncture by sharp objects, the unit is Niu (N). Puncture strength of food bags can effectively prevent the food in the bones, fish spines and other sharp objects puncture, thus avoiding food leakage and packaging damage, to protect the health and safety of food.
Heat seal strength: is a measure of the sealing performance of the food bag seal, the unit is Niu / 15 mm (N / 15mm). Heat sealing strength reflects the firmness of the seal of the food bag, good heat sealing strength of the food bag can prevent the seal from cracking during storage and transportation, to ensure that the seal of the food bag, to prevent the food from moisture, contamination and deterioration.
Rub resistance: food bags in actual use may be subject to rubbing, extrusion and other external forces, rub resistance is to assess the food bag after a certain number of times of rubbing, its physical properties and appearance to maintain intact ability. Good rubbing resistance can ensure that the food bag in a variety of use scenarios, such as bagging, handling, storage, etc., will not be rubbed due to rupture, delamination or surface abrasion and other problems, so as to maintain its protective function of the food.
Pressure resistance: the ability of a food bag to withstand a certain pressure without deformation, rupture or leakage. For some need to stack storage or may be subject to extrusion of food bags, such as packaging of dry goods, rice and noodles, etc., the pressure resistance is an important indicator, which can ensure that the food bag can withstand a certain amount of pressure in the storage and transportation process, to protect the food from extrusion damage.