There’s a lot to learn about low-density polyethylene, as it’s an incredible material with applications in a variety of fields. One of the best uses for LDPE is plastic bags. These bags can be the standard plastic you encounter at the grocery store, or they can have additional properties to increase their usefulness. Read on to learn how standard and static dissipative LDPE are different.

What Is LDPE?

LDPE, or low-density polyethylene, is a thermoplastic made up of ethylene. Put simply, a thermoplastic is any plastic that softens when heated and becomes hard when cooled. LDPE is a semi-translucent plastic with great flexibility, which makes it perfect for use as film or bags. LDPE is a highly common form of polyethylene, along with high-density polyethylene.

Even though there are a variety of household uses for LDPE, you can also find LDPE in many other industries. LDPE is extremely important in the agricultural industry, as it helps keep all sorts of fruits and vegetables fresh and preserved.

Benefits of LDPE

There are a host of benefits that come with using LDPE for many different tasks. For instance, LDPE is highly flexible and has low tensile strength. That combination of factors means that LDPE can undergo a great deal of stretching before it snaps. That’s why you’ll see LDPE in so many plastic bags—there’s nothing worse than spilling groceries all over the parking lot.

In addition, LDPE is highly resistant to moisture. This natural moisture repulsion helps keep moisture in fruits and vegetables, which prevents them from drying out before they reach the consumer’s table.

LDPE is also surprisingly resistant to impacts. This high durability makes it good for use in water bottles and drink containers. When a child tosses their spill-proof cup on the floor, you don’t want juice going everywhere, and LDPE prevents this.

As if all of that wasn’t enough, LDPE additionally has great chemical and high temperature resistance. These factors make LDPE uniquely suited for food packaging and even hygienic work surfaces for offices.

What Is HDPE?

HDPE shares a lot of similarities with LDPE with a major difference: HDPE is high-density polyethylene. Created in the 1930s, HDPE was famously used for high-frequency radar cables in World War II. Shortly after, HDPE was introduced to the world market as a polyethylene with a wide range of flexibilities, depending on its density.

Benefits of HDPE

HDPE is very easy to melt and bold. It has strong rigidity right up to its high melting point—once it hits that point, it’s a simple process to get HDPE to form to whatever shape you need. HDPE is commonly shaped into bottles, jugs, piping, and plastic lumber.

Do you need plastic in an environment with mold or mildew? HDPE is on the job! With high corrosion resistance, HDPE can stand up to a vast majority of environmental factors. For this reason, many underground piping solutions utilize HDPE for water delivery without worrying about rot. This is also why HDPE is a commonly used material for transporting chemicals, acids, and detergents.

Many people also choose HDPE for its easy recyclability. This helps keep landfills from overflowing with non-biodegradable materials, and it also reduces the need to produce new plastic.

Finally, HDPE has an excellent strength-to-density ratio. That means lightweight HDPE containers can easily carry materials that exceed their weight.

Differences Between LDPE and HDPE

There are a great many shared characteristics between LDPE and HDPE, but the differences are essential to note. For instance, LDPE is more flexible than HDPE and is softer. Even though LDPE has more flexibility, it is also more likely to crack under heavy stress. HDPE, on the other hand, has higher resistance to chemicals and a higher melting point, which makes it better at higher temperatures.

While LDPE and HDPE are both recyclable, they cannot be recycled together. LDPE is recycling number four, while HDPE is recycling number two. LDPE tends to be a bit more difficult to recycle due to its soft nature.

Finally, the production processes are also different. While LDPE is made through compression of monomer ethylene gas in a tubular reactor or autoclave, HDPE is produced by superheating petroleum.

Standard Plastic Bags

Now that you have a better understanding of LDPE and its properties, let’s discuss its applications in bags. Standard LDPE plastic bags are not designed to protect products from electrostatic discharges. While standard LDPE plastic won’t cause static, they don’t have a significant impact on stopping it.

Static is a killer of technology, from cheap hard drives to expensive graphic cards, so it needs to be packed carefully.

Static Dissipative Bags

Static dissipative bags slowly drain the electrical charge from components. Because these bags don’t protect components from ESD shocks (unless they are protected with a faraday cage), you should not use these bags to store components susceptible to static shocks.

Anti-Static Bags

When in an ESD-safe environment, anti-static bags are the transportation method of choice for components susceptible to electrostatic discharge. Anti-static bags are designed to stop triboelectric charges from building up inside the bag. However, if an electrostatic discharge occurs close by outside the bag, the components stored within will not be protected.

Bags With Static Shielding

Static shielded bags are the safest all-around form of transportation for products susceptible to electrostatic discharges. They have full protection whether or not you are in an electrostatic protected area.

Are Static Dissipative Bags Conductive?

Some people wonder whether static dissipative bags are conductive, but they are not. Static shielding bags are conductive and are made from polyethylene terephthalate (PET). Thin, metalized layers of film line the static shielding bags to produce the faraday cage effect. The metal aluminum layer is what gives static shielding bags their conductive properties.

LDPE and HDPE Electrical Applications

Just because LDPE and HDPE are not commonly used in static shielding bags does not mean that they cannot be used for other electrical applications. Some electrical connector caps, for example, use these types of plastic to great effect.

Now that you know how standard and static dissipative LDPE are different, make sure you’re using the right materials for your products!