In the field of plastic packaging, bags made of low density polyethylene (LDPE) and high density polyethylene (HDPE) occupy a pivotal position, although the two belong to the same polyethylene family, but due to internal structural differences, they show many different characteristics and application focuses.

From the perspective of molecular structure, LDPE molecular chain contains branch chains of different lengths, which are relatively loose in arrangement, giving it a soft texture and elastic touch. The HDPE molecular chain is tightly arranged and regular, and the crystallinity is high, which makes it have excellent rigidity and clarity. Appearance, LDPE packaging bag is often translucent, hazy vision is suitable for creating a soft packaging atmosphere, like bread, pastry food often choose to wrap it, both vaguely show the attractive appearance of products, but also deliver fresh texture; HDPE packaging bags are mostly opaque, the color is often white or milky, and the appearance is simple and simple, which meets the practical packaging needs.

At the level of physical properties, LDPE has limited tensile strength, but has excellent tensile ductility, which can be greatly deformed and not easily broken when stressed, play a good buffer protection for the contents, and reduce collision damage in the packaging of fragile food and small precision objects. HDPE stands out with high strength and high wear resistance, and can carry heavier items, such as large bags of rice grains, hardware tools, etc. with HDPE packaging bags, fear handling wear, stacking and extrusion, strong and reliable.

In terms of processing performance, LDPE is easy to blow molding, and can be made into thin and thin packaging bags that fit the outline of the product, and fit the packaging needs of food preservation and lightweight daily necessities. HDPE processing requires higher pressure and temperature conditions, the thickness and stiffness of the bag made after molding are highly controllable, and large capacity and durable packaging styles can be customized on demand, showing their skills in the field of industrial raw materials, building materials and other product packaging.

In terms of chemical stability, the two have good tolerance to most chemical substances, but HDPE is slightly better in corrosion resistance and moisture resistance due to tight crystallization, extending the storage cycle of contents, and highlighting its advantages in long-term storage scenarios. LDPE and HDPE packaging bags, with their unique advantages, accurately match multiple packaging scenes and shine in the daily and industrial packaging world.