Why Use HDPE In Structural Foam Molding? HDPE Properties and Uses

When you are choosing a material for your structural foam molding project, it is important to understand the properties, uses, advantages, and disadvantages of each material. One of the most common materials used in structural foam molding is HDPE, however, it may not be the right material for your specific application. Our team has outlined HDPE properties, uses, and disadvantages to help you determine if this material is right for your project.

HDPE Properties

HDPE is a thermoplastic polymer whose molecules are packed closely together, giving it a higher density than other forms of polyethylene. This gives HDPE its name: high density polyethylene. The density of this material gives it many advantageous properties that may be ideal for structural foam molding projects. Some of the most beneficial HDPE properties include:

High Strength-to-Weight Ratio

HDPE in structural foam molding is lighter than straight injection molded parts and is often lighter than metal parts. However, despite its lightweight nature, it is remarkably strong. This allows HDPE to be used in applications where strength and light weight are needed. Its strength-to-weight ratio allows HDPE to efficiently resist loads and retain its shape when subjected to difficult loads.

Low Moisture Absorption

The low moisture absorption of HDPE means that the material does not absorb much water from the air. Low moisture absorption makes HDPE more dimensionally stable in environments where water is present, such as outdoor applications and chemical containers.

High Impact Strength and Durability

HDPE is an extremely durable material. It can withstand wear, breakage, and deterioration over time, giving it a long life. Additionally, it exhibits great impact strength, allowing it to withstand sudden forces.

Chemical Resistance

Since HDPE is resistant to many chemicals, it is able to be used in a wide range of applications without concern that it will break down. This material is resistant to water, solvents, acids, detergents, and cleaning fluids.


With so many beneficial properties, HDPE is a common material choice for a variety of industries and applications. Regarding structural foam molding projects, there are a few common uses for HDPE.

Chemical Containers

With HDPE’s chemical resistance, low moisture absorption, durability, and lightweight nature, it is a great choice for chemical containers. The plastic won’t break down in the presence of chemicals, won’t absorb too much water from the air around it, and these containers won’t be damaged with ordinary everyday use.

Pipe Systems

Pipes carry many materials, from water to chemicals to gasses and more. The chemical resistance of HDPE along with its durability and low moisture absorption ensure that HDPE pipes are able to withstand the constant flow of water, chemicals, or other materials.

Gardening Equipment

Again, the chemical resistance of HDPE allows it to be used in gardening equipment because it won’t break down in the presence of fertilizers, weed killer, grass killer, or other chemicals commonly used in the yard.

Disadvantageous HDPE Properties

While HDPE is a great material for many applications and has many advantageous properties, there are a few HDPE properties that may imply it is not the best option for your project.

Poor Weather Resistance

While HDPE is a durable material, it cannot withstand certain weather conditions. For example, HDPE may break down when exposed to UV light for extended periods of time, making it difficult to use in outdoor applications.


HDPE is a flammable material so you must be careful about what you use HDPE for. This material should not be used in applications where it will be around fire or other flammable materials.

Sensitive to Stress Cracking

Again, HDPE is a durable material, however, it is prone to stress cracking. This means that under too much constant pressure, products made from HDPE may crack.

Experience HDPE Properties with Port Erie’s Structural Foam Molding Services

If you are still unsure if HDPE is the right polymer for your structural foam molding projects, Port Erie is here to help. We will assign a plastics engineer to your project who helps you make sure your materials are ideal for your applications and continues to make sure the production runs smoothly. In addition to helping you with your material selection, our team can take on your large-tonnage structural foam molding projects with ease.

After production, we also offer secondary services such as assembly, decorating, and more to make sure your projects are exactly as you imagine them. Once your product is completed, we can warehouse it for you in our facilities.

If you are ready to get started on your HDPE structural foam molding project, contact our team today!

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