Linear low-density polyethylene (LLDPE)

Description

Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethylene. It was the first grade of polyethylene, produced in 1933 by Imperial Chemical Industries (ICI) using a high pressure process via free radical polymerization. LDPE has the most excessive branching.

This causes the low density to have a less compact molecular structure which is what makes it less dense. It has a density of 0.91-0.925g/cm3. Linear Low Density Polyethylene (LLDPE) is the most flexible of the plastic sheeting films. LLDPE is blended form of LDPE where the film has much more flexibility, tensile strength, and more conformability. It is more pliable and softer.

LLDPE has a significant number of short branches. Because it has shorter and more branches its chains are able slide against each other upon elongation without becoming entangled like LPDE which has long branching chains that would get caught on each other. This gives LLDPE higher tensile strength and higher impact and puncture resistance than the LDPE. It has a density of 0.91-0.94g/cm3.

LLDPE is used for pond liners or blended into other films to give them more flexibility and extra strength. LLDPE is used for films that need a tremendous amount of strength to absorb impacts while not tearing or puncturing. An example of this is a carpet plastic film that adheres to the carpet.

It is strong enough to withstand foot traffic, even from stiletto high heels! The molecules all line up and strongly hold together as the film is stretched. The most common thickness range is from 0.5 mil to 40 mil in flexible plastic sheeting.

High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. Not only is it one of the most versatile of plastics—used in everything from hard hats to house wraps—it’s also widely recycled, in both its rigid form (e.g., containers) and flexible form (e.g., bags). Like many other plastics, HDPE often replaces heavier materials, in part because our society and many companies are pursuing sustainability goals, such as reducing the amount of material used in packaging and products.