1. What are the differences? between HDPE, LDPE, and LLDPE?
Performance comparison | HDPE | LDPE | LLDPE |
Low pressure | High pressure | ||
Odor | Odorless | Odorless | Odorless |
Color | Natural milky white, semi-translucent | Natural milky white, translucent | Natural milky white, translucent |
Toxicity | Non-toxic | Non-toxic | Non-toxic |
Density | 0.940～0.976g/cm3 | 0.910～0.940g/cm3 | 0.915～0.935g/cm3 |
Degree of crystallinity | 65-85% | 45-65% | 55-65% |
Molecular structure | It only contains carbon-carbon and carbon-hydrogen bonds, which require more energy to break. | Polymers have small molecular weight and require less energy to break. | Linear structure, branched chain, short chain less, need less energy to break. |
Softening point | 125-135℃ | 90-100℃ | 94-108℃ |
Mechanical property | High strength, good toughness, strong rigidity
| Poor mechanical strength | High strength, good toughness, strong rigidity
|
Tensile strength | High | Low | Medium-high |
Elongation at break | Medium-high | Low | High |
Impact strength | Medium-high | Low | High |
Moisture-proof & water-proof performance | Good permeability to water, water vapor, air, low water absorption, with good permeability. | Poor humidity and air insulation. | Good permeability to water, water vapor, air, low water absorption, with good permeability. |
Resistance to acid, alkali, corrosion, organic solvent performance | Strong oxidant corrosion resistance; Acid, alkali and salt corrosion resistance; Insoluble in any organic solvent, etc. | Acid, alkali, salt solution corrosion, but poor solvent resistance
| Resistant to acid, alkali and organic solvents |
Heat&Cold-resistant performance | Good heat and cold resistance, at room temperature and even at -40F low temperature, excellent impact resistance, low temperature brittle temperature < -90℃ | Low heat resistance, low temperature brittle temperature <-70℃
| Good heat and cold resistance low temperature brittle temperature < -90℃
|
Environmental stress crack resistance | Good | Less good | Good |
2. How can I distinguish HDPE, LDPE, and LLDPE?
① HDPE
The processing temperature of LDPE is lower, about 160 degrees Celsius, and the density is 0.918-0.932 grams/cubic centimeters. HDPE processing temperature is higher, about 180 degrees Celsius, the density is also higher.
② LDPE
Sensory detecting method: feel soft; White transparent, but average transparency.
Burn method: the burning flame is yellow on top and blue on the bottom; Smokeless when burning, smell of paraffin wax, melting dripping, easy to draw wire.
③ LLDPE
LLDPE can swell with benzene for a long time, and become brittle with HCL for a long time.
3. Summary
In conclusion, the above three materials play important roles in different types of seepage control projects. HDPE, LDPE and LLDPE three material has good insulation and moisture, impervious performance, non-toxic, tasteless, odourless performance make it in farming, aquaculture, and the application of artificial lakes, reservoirs, river is extremely widespread, and get the fisheries bureau, Shanghai fisheries research institute, China's ministry of agriculture fishery machinery and instrument research institute vigorously promote and popularize application.
In the medium environment of strong acid, strong alkali, strong oxidant and organic solvent, the material properties of HDPE and LLDPE can be well played and utilized. In particular, HDPE is far higher than the other two materials in terms of resistance to strong acid, strong alkali, strong oxidation and resistance to organic solvent. So HDPE impermeable and anticorrosive coil has been fully used in the chemical and environmental protection industries.
LDPE also has good resistance to acid, alkali and salt solutions, and has good extensibility, electrical insulation, chemical stability, processing performance and low temperature resistance, so it is widely used in agriculture, water storage and breeding, packaging, especially low temperature packaging and cable materials.
4. About us
Luoyang Dema Import & Export Co., Ltd. aims to provide high-quality, cost-effective products for global factories, plastic product manufacturers, and material distributors. Luoyang Dema Import & Export Co., Ltd. provides the best PP, PE, PVC, AVE, ABS material solutions for plastic product manufacturers, wholesalers, distributors, distributors, factory owners, processing workshops, etc.
If you are looking for general plastic materials, please feel free to get the latest prices and quotations from Luoyang Dema Import & Export Co., Ltd. The sales team will reply within 48 hours.