WATERPROOFING MEMBRANE MANUFACTURER
The pre-applied HDPE membrane manufacturer will take you to understand: the role of HDPE in membrane formulation design
The pre-applied HDPE membrane manufacturer tells you that HDPE (High Density Polyethylene) is a high-density polyethylene, which is obtained by polymerizing ethylene monomer in a low-pressure reactor through a metal catalyst. It contains very little or almost no other comonomers. It is commonly known as low-pressure material in the market. The characteristic of its molecule is that it has almost no branched structure, usually has a wide molecular weight distribution and high crystallinity. The manufacturer of pre-applied HDPE membrane tells you that it is called high-density polyethylene because its density is much higher than other polyethylene materials, usually in the range of 0.948-0.965 g/cm3. The physical properties it brings are excellent stiffness, certain barrier properties, and strong tensile deformation resistance. However, the impact resistance is poor, the tear resistance is not good, and the flexibility is poor. At the same time, the density is too high, resulting in poor heat sealing performance of the film. HDPE can be widely used in films, injection molding, pipes, etc.
1. Improve film stiffness/rigidity
The manufacturer of pre-applied HDPE membrane tells you that the stiffness of the film is related to the crystallinity of the material. For polyethylene, the higher the crystallinity, the higher the density, and the higher the stiffness. Stiffness can affect the feel, the appearance of the film, the printability of the film, the running effect of the packaging line, and so on. Especially now that film products are developing in the direction of thinning, it is more necessary to maintain the requirements of stiffness.
2. Improve the barrier properties of the film
The manufacturer of pre-applied HDPE membrane tells you that the polyethylene material is divided into crystal regions and amorphous regions. The crystals have a certain barrier effect. HDPE has a high degree of crystallinity, and its barrier properties are better than other polyethylene materials. But it is definitely not as good as traditional barrier materials, such as nylon, EVOH, etc., but it can play a certain auxiliary role.
3. Improve resistance to external force deformation
The manufacturer of pre-applied HDPE membrane tells you that HDPE has good resistance to deformation because the crystal cannot be stretched. It can be well reflected in some applications, such as shopping bags, garbage bags, heavy-duty packaging bags and other film applications that need to withstand a certain degree of gravity.
4. Improve heat resistance
HDPE has a higher density and a higher melting point, and has a higher softening temperature than other low-density polyethylenes, so it can improve the heat resistance of the film.
5. Other performance improvements
For example, the shrinkage of the shrink film in the wrapping force; the cutting ability of the packaging film in the bag making process, and so on. In addition, although the optical performance of HDPE pure use is not good, it can be well improved through process and formulation design. At the same time, for HDPE with a very low melt index, its physical properties can be improved through the high-foam blown film process.
Due to its special molecular structure, HDPE plays an indispensable role in the film formulation design. According to the specific application, it can be matched with other polymer materials to achieve the optimization of the formulation and the balance of performance/stiffness.