MDOPE Heat Seal Performance
The essence of this issue is about the dimensional stability of the film at high temperatures.
LD PACK’s packaging with MDOPE is used high density polyethylene (HDPE) as the main raw material, which has good temperature resistance and good dimensional stability. Low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) are polymers with amorphous structure. Due to its low tensile strength and elastic modulus, high temperature will cause material creep, which can also be clearly shown from the basic properties of polyethylene.
Basic Properties of PE Film
| Performance | Unit | HDPE | LDPE | LLDPE |
| Density | 0.94-0.97 | 0.91-0.94 | 0.92-0.93 | |
| Softening Point | ℃ | 125~135 | 90~100 | 94~108 |
| Continuous heat resistance temperature | ℃ | 120 | 80~100 | 105 |
For the finished stretched PE film, the corresponding thermal performance index is the thermal shrinkage rate of the film. As the value of the hot-shrinkage rate of the product, one of the most obvious differences is that the casting MDOPE film with HDPE as the main raw material has a test temperature of 120°C.
Hot-shrinkage Performance
When printing, laminating, especially the heat sealing process of pouch-making, it puts forward higher requirements on the dimensional thermal stability of printing layer materials at high temperatures, which is related to the heat sealing strength of the product, the quality of the heat sealing surface, the production efficiency and many other aspects.
The greater the difference between the melting point of the printing layer and the heat sealing layer, the more beneficial to many aspects of the heat sealing link. The control and regulation of the production process is conducive to the stability of product quality and the improvement of production efficiency. The stretched PE film with HDPE as raw material has a natural advantage in terms of the high temperature thermal stability of the material.
Easy Peel Performance
Different from the branched molecular structure of low density polyethylene (LDPE), the polymer chain of high density polyethylene (HDPE) is a typical linear structure with few branched chains. Through the orientation, the mechanical properties of the anisotropy is obvious. When mechanical strength in machine direction(MD) increases significantly, that in the transverse direction(TD) is significantly reduced. Therefore, the casting MDO-HDPE film has excellent peeling performance.
Compared with the mature BOPET film, the stretched PE film used for the printing layer in flexible packaging is still in the initial stage, and the stretched PE film with the three production process paths has both advantages and disadvantages. During the continuous development and innovation, LD PACK has a deeper understanding and improvement of flexible packaging printing and laminating, and keep on launching new products in line with industry development to the market.
