Table of Contents
Low-density polyethylene (LDPE):
- Low-density polyethylene (LDPE) is a polymer of ethylene produced mostly by the addition polymerization. LDPE is prepared by a high-pressure process. The monomer for polyethylene was obtained largely from molasses, a by-product of the sugar industry. From molasses, ethyl alcohol (C2H5OH) is obtained, which upon dehydration yields ‘ethylene,’ a monomer for low-density polyethylene.
Low-density polyethylene properties:
- LDPE has more branching than HDPE.
- Intermolecular forces are weaker.
- Poor ultraviolet rays’ resistance.
- High gas permeability, particularly carbon dioxide
- Very low water absorption.
- Processing temperatures are low compared with other plastic materials.
- It is not reactive at room temperature.
- The density of LDPE is 0.910–0.930 g/cm³.
- Flow properties are dependent on molecular weight and amount of branching.
- J1005 FY20
- J1020 FA20
- 1070 LA17
- 22FA002
- 24FS040
1005 FY20–
Density | 0.915-0.935 g/cc |
Melt flow index (MFI) | 0.50 g/10 min |
Tensile strength at break (MD/TD) | 21 / 20 MPa |
Dart Impact Strength | 3.7 g/µm |
Elongation at break (MD/TD) | 95/705 % |
Hardness | D 45 – 60 |
Melting point | 105-115 °C |
1020FA20–
Density | 0.918-0.920 g/cc |
Melt flow index (MFI) | 1.998 g/10 min |
Tensile strength at break (MD/TD) | 21/ 20 MPa |
Dart Impact Strength | 3.6 g/µm |
Elongation at break (MD/TD) | 276/426 % |
Hardness | D 46 – 61 |
Melting point | 105 – 113 °C |
1070LA17–
Density | 0.917-0.919 g/cc |
Melt flow index (MFI) | 6.998 g/10 min |
Tensile strength at break (MD/TD) | 17 / 16 MPa |
Dart Impact Strength | 3.0 g/µm |
Elongation at break (MD/TD) | 249/401 % |
Hardness | D 45 – 60 |
Melting point | 106 – 112 °C |
1070 LA17 is mostly used in extrusion coating and makes easy-tear pouch-like coffee, tea, and masala.
22FA 002–
Density | 0.918-0.920 g/cc |
Melt flow index (MFI) | 0.201 g/10 min |
Tensile strength at break (MD/TD) | 26/24 MPa |
Dart Impact Strength | 5.5 g/µm |
Elongation at break (MD/TD) | 401/601 % |
Hardness | D 45 – 60 |
Melting point | 110-115 °C |
22FA002 can be used to make a heavy-duty bag, pouch, lamination film, shrink film, etc.
Note:
- Read more about LDPE Material
- Read more about HDPE Material
FAQ of LDPE:
What is LDPE?
- LDPE (Low-Density Polyethylene) is a thermoplastic polymer made from the monomer ethylene.
- It is characterized by its low density, flexibility, and transparency. It is widely used in packaging, films, and containers due to its excellent chemical resistance and ease of processing.
What are the key properties of LDPE?
- Low density: lightweight and flexible.
- Chemical resistance: resistant to acids, bases, and alcohols.
- Transparency: Can be made transparent or translucent.
- Flexibility: soft and pliable at room temperature.
- Moisture resistance: excellent barrier to moisture.
- Low melting point: easily melted and molded.
What are the common uses of LDPE?
- Packaging: Plastic bags, shrink wraps, and films.
Containers: Squeeze bottles, lids, and caps.
Household items: Food storage containers, trash bags, and disposable gloves.
Industrial applications: wire and cable insulation, coatings, and liners.
Medical devices: Tubing and sterile packaging.
How is LDPE different from HDPE?
- Density: LDPE has a lower density (0.910–0.940 g/cm³) compared to HDPE (0.941–0.965 g/cm³).
Flexibility: LDPE is more flexible and softer, while HDPE is more rigid and durable.
Strength: HDPE has higher tensile strength and is more resistant to impact.
Applications: LDPE is used for films and bags, while HDPE is used for bottles, pipes, and heavy-duty containers.
Is LDPE recyclable?
- Yes, LDPE is recyclable and is labeled with the resin identification code #4. However, its recycling rate is lower compared to other plastics like PET or HDPE due to its lightweight and contamination issues.
Is LDPE safe for food contact?
Yes, LDPE is considered food-safe and is commonly used for food packaging, such as plastic wraps, bags, and containers. It does not leach (extract) harmful chemicals into food.
What is the melting point of LDPE?
- LDPE has a melting point range of 105–115°C (221–239°F). It softens at lower temperatures, making it easy to process.
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