DIFFERENCE BETWEEN HDPE, LDPE AND LLDPE

Flexibility and thickness
The difference between different polyethylene backing sheets when someone specifies HDPE over LDPE or LLDPE over MDPE for example. In the simplest terms, each liner will be different according to its thickness and flexibility. The main difference between the various plastics is how their cellular structure, or molecules, bind together and how tightly they are formed.

Which is the most flexible?
Linear Low Density Polyethylene (LLDPE) is the most flexible of all plastic films. LLDPE is a composite form of LDPE where the film has much higher ductility, tensile strength and conformability. It is more pliable and softer. LLDPE is used for pond liners or blended into other films to give them greater flexibility and durability. LLDPE is used for films that require extreme strength to absorb impacts while not tearing or perforating. An example of this is the  carpet plastic film  adhesive to the carpet. It's sturdy enough to withstand foot traffic, even from pointy heels! All the molecules line up and hold together when the membrane is stretched. The most common thickness range is from 0.5 mil to 40 mil for flexible plastic sheet.

Which type is the most popular?
Low-density polyethylene (LDPE) is the most common type of plastic sheet. It is very flexible, typically 0.5 mil to about 40 mil thick in flexible sheet form. Due to its versatility, it is suitable for a wide range of surfaces. The downside is that this LDPE is not as strong or dense as some other types of plastic sheets. It is almost not puncture resistant. LDPE is quite widely used in construction, agriculture, surface protection applications, including types, canvas and more.

Which type is the least used?
Medium-density polyethylene (MDPE) is the least commonly used form of polyethylene for flexible sheeting. Its positive attributes are that it is stronger than LDPE and is slightly more resistant to chemicals. It has a tighter cell structure so it is more resistant to tearing and perforation. When manufacturing pond liners  they are usually made of MDPE and blended with LDPE or LLDPE to achieve a strong yet flexible pond liner.

Which type is the most durable?
High-density polyethylene (HDPE, aka HD), has the distinction of being the strongest, toughest, most chemically resistant and least flexible of the four types of flexible plastic sheets covered in this article. HDPE is also the best in UV protection - against the harsh rays of the sun without the need for UV additive packages. HDPE's strength comes from its tight cellular structure that makes it very difficult for other molecules to pass through its structure at the microscopic level. When applications require very large liners such as pond liners, HDPE is the easiest to join or "stitch" together. Used in industry, thickness from 12 mils to 100 mil. HDPE is used as secondary containment liners for oil tanks, and most industrial ponds and channel liners where chemical resistance   is required.

In the end, which has the most balance out of the 3 types of HDPE, LDPE, LLDPE? It all depends on your application! It's a blessing that there are so many other types of plastic sheeting products to make of all kinds to protect the surface or project it's intended for. Take a look at our website, and you'll see several options available to you. We haven't listed all of our products yet - because there are too many.