Polyethylene (HDPE/LDPE/LLDPE)

 

Polyethylene

 

polyethylene-hdpe-ldpe-lldpe siso-int.com

 

Polyethylene is a widely used synthetic polymer or plastic that belongs to the family of polyolefins. It is a versatile material known for its simplicity, durability, and flexibility. Polyethylene is produced through the polymerization of ethylene, a gaseous hydrocarbon, under specific conditions.

 

Polyethylene, in general, has several key characteristics and features:

  • Chemical Resistance: Polyethylene is resistant to many chemicals, making it suitable for various applications where exposure to different substances is a concern.
  • Durability: It is a durable material that can withstand a wide range of temperatures, making it suitable for both indoor and outdoor applications.
  • Recyclability: Polyethylene is recyclable, and efforts have been made to increase recycling rates to reduce environmental impact.
  • Versatility: The versatility of polyethylene allows for its use in a broad range of products, including packaging materials, containers, toys, medical devices, and more.
  • Cost-Effective: Polyethylene is relatively inexpensive to produce, contributing to its widespread use in various industries.

 

 The primary types of polyethylene include:

 

  1. Low-Density Polyethylene (LDPE):

    • LDPE has a low density and is more flexible and translucent compared to other forms of polyethylene.
    • Applicable for plastic bags, films, packaging materials, squeeze bottles, and coatings.
    • LDPE has good resistance to chemicals but is not as rigid as high-density polyethylene.

  2. High-Density Polyethylene (HDPE):

    • HDPE has a higher density and is more rigid and durable than LDPE.
    • It is used for a wide range of applications, including bottles (milk jugs, shampoo bottles), pipes, containers, and various types of packaging.
    • HDPE is known for its strength, chemical resistance, and suitability for outdoor use.
  3. Medium-Density Polyethylene (MDPE):
    • MDPE falls between LDPE and HDPE in terms of density and properties.
    • Usable for gas pipes, packaging films, and certain types of containers.
  4. Linear Low-Density Polyethylene (LLDPE):
    • LLDPE has a linear molecular structure, which gives it enhanced flexibility and toughness compared to traditional LDPE.
    • Used in flexible films for packaging, agricultural films, and various molded products.

 

 

For more information on the product grades and data sheet, please feel free to contact us

 

Application of polymers

 

For film ,Pipe, Container, Caps and Closure, tubes, plastic parts, laminates, in several markets (packaging, automotive, electrical, Injection , Blow , Extrusion , Rotomolding ,…

  • Comparison between Main Types of Polyethylene
  LDPE LLDPE HDPE
Polymer Full Name Low Density Polyethylene Linear Low Density Polyethylene High Density Polyethylene
Structure High Degree of short chain branching + long chain branching High Degree of short chain branching Linear (or Low degree of short chain branching)
Catalyst and process Using radical polymerization using tubular method or auto clave method Using Ziegler-Natta catalyst or metallocene catalyst Ziegler-Natta catalyst in:
– Single-stage polymerization
– Multi-stage polymerization or a Cr or Phillips-type catalyst
Density 0.910-0.925 g/cm3 0.91-0.94 g/cm3 0.941-0.965 g/cm3
Crystallinity Low crystalline and high amorphous (less than 50-60% crystalline) Semi-crystalline, level between 35 to 60% High crystalline and low amorphous (>90% crystalline)
Characteristics Flexible and good transparencyGood moisture barrier propertiesHigh impact strength at low temperatureExcellent resistance to acids, bases and vegetable oils As compared to LDPE, it has:higher tensile strengthhigher impact and puncture resistance Excellent Chemical ResistanceHigh tensile strengthExcellent moisture barrier propertiesHard to semi-flexible
       
General Applications Shrink wrap, films, squeezable bottles garbage bags, extrusion moldings, and laminates High performance bags, cushioning films, tire separator films, industrial liners, elastic films, ice bags, bags for supplemental packaging and garbage bags Molecular weight distribution is relatively narrow, has applications in injection moldings or flat yarns, and the latter typeMolecular weight distribution is wide, is used to make film products, hollow plastic products and pipes