Structural Foam Injection Molding

Founded in 1953 in Erie, Pennsylvania, Port Erie Plastics began with a single injection molding machine in a small building. Since then, our company has grown significantly to accommodate increasing customer demand, particularly for structural foam injection molding. Today, Port Erie Plastics is a leading provider of injection molding and structural foam injection molding services to meet all of our customers’ needs.

The structural foam injection molding process involves injecting a liquid resin with an inert gas or a chemical blowing agent. This mixture is then injected into the mold cavity where the gas or blowing agent expands and forces the resin to fill all areas of the cavity. As the material comes into contact with the walls of the mold, the surface cells collapse, resulting in a smooth and solid surface on the outside molded component.

Port Erie’s Structural Foam Injection Molding Capabilities

Our structural foam injection molding equipment allows us to create large-tonnage products with various properties, including:

  • Produces parts up to 7.5 feet in length
  • Parts have a typical wall thickness of 0.200 inches to 0.500 inches
  • The machines’ platen size is 96 inches x 89 inches
  • The machines’ tie bar spacing is 58.5 inches x 67.5 inches
  • Shot sizes up to 150 lbs

The process also allows us to run more than one mold at a time in a single machine, making your production more efficient and cost-effective.

Structural Foam Injection Molding Materials

Polyethylene (PE) Foam

Polyethylene foam is a durable and lightweight closed-cell material. It is popular in structural foam injection molding because it offers excellent load-bearing, shock absorption, vibration-dampening properties, and resistance to chemicals, grease, moisture, and solvents.

Polypropylene (PP) Foam

Polypropylene is a rigid and lightweight closed-cell material. It is often chosen due to its excellent compression and impact resistance, and it offers resistance to chemicals and moisture across a wide range of temperatures.

Case Study: Process Redesign of Structural Foam Molded Trench Designs

With over 70 years of experience in injection molding and structural foam injection molding, our team has the knowledge and skills to create structural foam components for virtually any customer. This expertise allows us to help customers optimize existing structural foam molding processes to achieve better product quality. We used these skills to help a customer in the construction industry redesign an existing structural foam process for better results.

The client was using straight injection molding to manufacture a line of linear trench drains for use in industrial, commercial, and residential applications. However, the single-cavity molds utilized in the existing process resulted in long cycle times and produced parts with warping and low dimensional tolerances.

Our team redesigned the manufacturing process to use the low-pressure structural foam method, which resulted in a 20% part weight reduction and a 40% cycle time reduction over the original process. The new process also allowed for the creation of trenches in 17 different sizes. We built aluminum molds and designed tooling with interchangeable molds to allow the customer to run any two of the 17 sizes in a single machine at the same time.

Read more about this project here.

Benefits of Structural Foam Injection Molding

Excellent Moldability

Structural foam is highly amenable to molding. It can be used to create parts with walls and other elements in various thicknesses without the risk of warping or deformation due to the stress experienced during the molding process.

High Strength-to-Weight Ratio

Structural foam components are generally very lightweight, typically ranging from 2 lbs/ft3 to 55 lbs/ft3. However, they are also strong, durable, and rigid.

Great Thermal Stability

Structural foam exhibits little to no thermal expansion, which makes it ideal for products used in a wide range of temperature conditions.

Good Acoustic and Thermal Insulation Properties

The nature of structural foam makes it perfect for use in products that require acoustic or thermal insulation.

Exceptional Cost-Effectiveness

The structural foam molding process utilizes slower clamping forces and pressures than other molding methods, which allows it to use less durable tools made from less expensive materials, like aluminum.

Partner with Port Erie for Your Structural Foam Injection Molding Projects

When looking for a structural foam molding partner, turn to Port Erie. With decades of experience, we have the equipment, knowledge, and skills needed to complete your project with ease. Contact us today with your questions or request a quote.