I. Professional Data and Explanation of PE Film Specific Gravity (Density)
The density of PE film (polyethylene film) is a key parameter in material selection and process design. According to international standards ISO 1183 and ASTM D792, the specific gravity range of PE film is as follows:
1. LDPE (Low-Density Polyethylene): Specific gravity 0.91-0.93 g/cm³, commonly used for packaging bags and agricultural films;
2. LLDPE (Linear Low-Density Polyethylene): Specific gravity 0.91-0.94 g/cm³, high toughness, suitable for stretch film;
3. HDPE (High-Density Polyethylene): Specific gravity 0.94-0.96 g/cm³, high hardness, mostly used for industrial packaging.
Data source: American Chemical Society (ACS) "Polymer Materials Handbook" and Dow Chemical technical documents. The density difference is due to the degree of molecular chain branching: LDPE has a loose structure due to its high branching, while HDPE molecules are tightly packed.
II. PE Film Weight Calculation Formula and Practical Examples
Weight calculation requires a combination of specific gravity and geometric dimensions. The general formula is:
Weight (kg) = Length (m) × Width (m) × Thickness (mm) × Density (g/cm³)
Example: Calculate the weight of a roll of LDPE film that is 1.5m wide, 1000m long, and 0.05mm thick.
- Density is 0.92 g/cm³ (the median value for LDPE).
- Weight = 1000 × 1.5 × (0.05 ÷ 1000) × 0.92 × 1000 = 69 kg (note the uniformity of units).
