Differences between PE and PET blow molding

‌The main differences between PE and PET blow molding are reflected in three aspects: material properties, molding process and application fields. ‌‌

1. Differences in material properties
‌Temperature resistance and rigidity‌

Polyethylene (PE) has excellent low temperature resistance (-100°C to -70°C), but it is easy to soften at high temperatures and is suitable for normal or low temperature environments.
Polyethylene terephthalate (PET) has better high temperature resistance and stronger rigidity, which is suitable for scenes that require higher load-bearing and deformation resistance, such as carbonated beverage bottles.
‌Chemical stability and transparency‌

PE has good chemical stability and can resist acid and alkali erosion, but has low transparency (only low-density PE is transparent).
PET has high transparency and a smooth surface, which is suitable for fields with high aesthetic requirements such as cosmetic bottles and beverage packaging.
2. Differences in molding process
‌Processing temperature and energy consumption‌

PE blow molding has a low temperature (such as LDPE about 130°C), and the molding energy consumption is relatively low, which is suitable for rapid production of films, soft bottles, etc.
PET requires two moldings (injection molding + blow molding), with a higher processing temperature (about 260°C), high energy consumption, but stronger recyclability.
‌Process complexity‌

The PE blow molding process is simple and can be formed in one step by flat blowing, up blowing, down blowing, etc. It is widely used in food bags and daily necessities.
PET blow molding requires strict control of stretch ratio and orientation, and the preform design is more complex, prone to atomization defects, and is often used in high-transparency bottles.
3. Differences in application fields
‌Typical applications of PE‌

Films: agricultural films, packaging bags;
Hollow containers: medicine bottles, soft daily chemical bottles;
Industrial products: pipes, cable insulation layers.
‌Core scenarios of PET‌

Highly transparent packaging: beverage bottles (such as mineral water, carbonated beverages);
Cosmetic containers: toner bottles, essence bottles;
Fibers and films: clothing fabrics, electronic product insulation films.
‌Summary‌: The key difference between PE and PET blow molding comes from the characteristics of the material itself, and the appropriate process needs to be selected according to product requirements (such as transparency, temperature resistance, and environmental protection). If you need to know more about the specific process parameters, please refer to the blow molding process or plastic material properties.