We recently acquired a new blow moulding machine that can produce HDPE bottles. So, to continue our All About series, we’re talking about HDPE this month. Similar to PET, HDPE is a safe-to-use plastic that is mostly used for containers, bottles, and pipes.
Let’s take a closer look at HDPE.
What is HDPE?
HDPE stands for High-Density Polyethylene. HDPE is also known as “alkathene” or “polythene”, but these terms are mostly used for when HDPE is made into pipes.
Polyethylene, the base ingredient used to make HDPE, is a thermoplastic that is both lightweight and durable. The process to make polyethylene was developed by Karl Ziegler and Giulio Natta back in the 1950s. HDPE is a super versatile plastic and is the most commonly recycled form of plastic.
Advantages of HDPE
Due to its higher density compared to other plastics, HDPE is highly crack resistant, has a high impact point, and an impressive melting point of 130.8 °C. This means that while it is strong and stiff, it is also able to resist warping from high temperatures. HDPE is also water-proof and is resistant against solvents such as gentle oxidants, reducing agents, strong acids, and strong bases.
HDPE does not contain Bisphenol A (better known as BPA) phthalates, heavy metals, or allergens. This is why it can be used for containing consumables such as milk or margarine. This also makes HDPE an ideal material for pharmaceutical plastic bottles.
Recycling and environmental impact
HDPE’s SPI (Society of Plastics Industry, now known as the Plastics Industry Association) Resin Identification code is 2. Did you know that just because an item has the triangular arrow symbol does not mean the item is recyclable? It’s actually the number inside the chasing arrows triangle, in this case, number 2, that dictates what type of plastic the bottle or container is and if it is recyclable. There are 7 identifying numbers in total, but we’ll cover that in another blog post.
HDPE is the most recycled type of plastic due to its versatility and durability. When recycled, it is commonly used for plastic lumber, which has a multitude of benefits over traditional wood when used for the correct circumstances. Recycled HDPE can also go through the same process to become a new container or bottle once again. At B&I, we mainly use virgin plastic to manufacture our HDPE bottles due to pharmaceutical industry compliance regulations, but we do use non-virgin material upon request or for plastic use outside of typical human consumption.
Disadvantages of HDPE
HDPE is highly flammable, making it unsuitable for environments where an open flame is present or where there is a high chance that the container will catch alight.
HDPE has little to no UV resistance, and therefore containers should be stored out of the sun to protect the contents from UV damage. This makes HDPE bottles unsuitable for prolonged outdoor exposure.
Chances are if you’ve used a hair product, ordered tablets from the pharmacy or even sat on a plastic piece of furniture, you’ve encountered HDPE.
HDPE is commonly used to make shampoo bottles, motor oil containers, margarine tubs, milk jugs, and water pipes. Due to the various moulding techniques, HDPE’s physical properties do vary. The most common physical appearance of HDPE is a matte, opaque white, with an almost wax-like texture.
Find out more
B&I Polycontainers is a Proudly South African plastic bottle manufacturer and has decades of experience working with HDPE.
Have you decided that HDPE is the best material for your bottling needs? Or are you still searching? Contact us for a personalised material and mould showcase, and we’ll be happy to help you find the perfect material for your packaging needs.