What is Better Than Injection Molding for Large Tonnage Products? The Structural Foam Molding Process, Benefits, and Applications

Plastic injection molding is an efficient, cost-effective manufacturing process that is used to create products in many industries. This process can create products of various sizes, however, it may fall short when it comes to manufacturing large-tonnage products. So, what is better than injection molding for large-tonnage products? One of the best manufacturing processes for producing these large products is structural foam molding.

What is Structural Foam Molding?

Structural foam molding is commonly used to create large-tonnage products with a hard exterior and a honeycombed interior. The manufacturing process begins with mixing a melted polymer with nitrogen gas and/or a chemical blowing agent. Then, this mixture is injected into the structural foam mold under low pressure. The polymer mix will cool as it touches the walls of the mold, forming a product with a solid exterior and a honeycombed interior.

The structural foam molding process results in products that are large, complex, and durable. With their durable exterior layer and less dense inner layer, the weight of these products is also reduced compared to their injection molded counterparts.

What Plastics Are Used in Structural Foam Molding

Polyethylene is the most commonly used plastic in the structural foam molding process. This plastic exhibits many ideal properties including:

• Chemical resistance
• Water resistance
• Recyclability
• High strength-to-weight ratio
• Low moisture absorption
• High impact strength
• Durability

However, there are some disadvantages to polyethylene. It does have poor weather resistance, is flammable, and can be sensitive to stress cracking. Polyethylene is good for use in creating chemical containers, pipe systems, and gardening equipment.

Benefits of Structural Foam Molding

Easily Creates Large Parts While Minimizing Damage and Deformities

Structural foam molding is a low-pressure process that requires less clamping force, allowing you to create tooling and molds from more cost-effective materials, such as aluminum. The low-pressure process also allows manufacturers to create large-tonnage products with a reduced risk of damage and deformities during the manufacturing process. This reduces the cost and time spent on re-running projects.

Increased Design Flexibility and Reduced Risk of Warpage

Since structural foam molding is a low-pressure process, it puts less stress on the product during manufacturing. This reduces the risk of damage compared to straight injection molding. You will also reduce the risk of warpage, allowing you to create more complex molds that maintain the desired shape of the finished product.

A Highly Efficient Process

Multiple structural foam molds can be run at the same time. Again, the low-pressure process allows these molds to run simultaneously without putting stress on the machines and the molds. Since you can run multiple molds at once, you will save time and money on your manufacturing process by producing more parts in a shorter amount of time.

Yields Products With Desirable Physical Properties

Structural foam molded products have various desirable properties, including a high strength-to-weight ratio, good thermal stability, durability, chemical resistance, and more. With so many advantageous properties, your products can be created to your exact specifications to meet the needs of your application and industry.

Structural Foam Molding Applications

Many industries benefit from the use of the structural foam molding manufacturing process. Some of the industries we have worked with include:

• Construction by creating large HDPE trench drains
• Lawn and Garden through carts and other lawn equipment
• Material Handling by creating large pallets

To explore more industries and products that can benefit from structural foam molding, check out our blog.

Ready to Experience the Process That is Better Than Injection Molding? Contact Port Erie Today

At Port Erie Plastics, we have been providing high-quality injection molding and structural foam molding processes since 1953. In addition to our molding processes, we also perform secondary operations and we can help you with your distribution and warehousing needs.

To learn more about our processes or to get started, contact our team today.