Why use Medium Density Polyethylene for plastic products?

May 2, 2019

polyethylene granules raw plastic material

Excelsior is now over 100 years old, so as you can imagine we’ve got considerable experience behind us in using our roto moulding processes to create the perfect plastic products for our clients. One of the key materials we use for that is MDPE, short for medium density polyethylene. Now, we understand that it’s not the most enlightening of names, so if you’re not from a plastic manufacturing background, you might not know the ins and outs of why it’s quite so useful. Here, we’ve explained everything you need to know!

What is Medium Density Polyethylene, and why is it so useful?

Medium Density Polyethylene is a type of polyethylene, one of the most widely used plastic materials in the UK. Polyethylene itself is a thermoplastic polymer with an extremely large range of applications, and it’s the core material we work with for our own roto-moulding processes here at Excelsior. There are two other types of polyethylene – the super pliable LDPE, and the stiff, tough HDPE.

As a highly versatile material, the uniquely specific denisty of MDPE allows it to strike a useful balance between those two. It has many of the same strength characteristics of HDPE, including a great impact resistance against drops and other shocks, but retains the excellent flexibility of LDPE. The combination of these attributes means that it can be used for applications not suited to either of the other two materials, such heavy cables (more on that in a moment).

As well as sharing the insulation resistance of most plastic materials, MDPE also has a high resistance to heat, and better stress cracking resistance, or notch sensitivity. (Basically, notch sensitivity is defined as how easily a single crack, scratch, or notch in a material can widen into a serious fracture, affecting its overall integrity. Ductile materials like LDPE tend to have low notch sensitivity, while brittle substances like HDPE will have a higher notch sensitivity.)

What is Medium Density Polyethylene used for?

As we touched on above, the qualities of MDPE means it can be used for a diverse range of applications. In the UK, it’s often used for water piping, plumbing and waste water plumbing. Another application is electrical cables, as the hardness of the MDPE sheathing protects it from sharp objects being dropped or loaded onto the cable, while still allowing enough give to actually move the cable around.

Its impressive shock resistance and low notch sensitivity also makes it highly practical for liquid containers, such as water and oil tanks. For similar reasons, it’s often put to good use for the materials handling products we often create for clients here at Excelsior. These durable products are often used and abused in indoor and outdoor conditions throughout the year – as is children’s play equipment, which is yet another common application.

These are far from the only possible applications though – the list is practically endless! In addition to the products you see right here on our website, our experts have decades of experience in creating bespoke plastic products for our customers using our rotomoulding processes. One of the most recent examples includes Bikebox, which you can find out more about by clicking on the link. Meanwhile, if you’ve got an idea in mind for your own plastic product, don’t hesitate to give us a call on 0161 745 2010, and we’ll be happy to see how we can help you bring it to life!