Master Guide to Compression Molding

Compression molding is a manufacturing process that involves compressing materials, such as rubber, into a specific shape or form. This process is typically the most common cost effective method to achieve different shapes and sizes of parts. This is because the cost per part decreases as more components are produced in a cycle, making it a dependable and affordable manufacturing method.

Elastomer Technologies, Inc. (ETI) is a top-notch company that offers exceptional compression molding and other manufacturing services. We take pride in producing intricate and visually appealing components and are dedicated to providing our customers with accessible, high-quality engineered parts.

This guide will explore the compression molding process, its benefits, its applications, and the key considerations when choosing a provider.

The Compression Molding Process

Compression molding is a great solution for producing parts requiring special materials or those with challenging inserts. Here’s how this process works:

Step 1: Preparing the Raw Materials

This step involves mixing a polymer or resin with other additives, like fillers or pigments, to create a specific blend of materials with desired properties.

Step 2: Loading the Material Into the Mold

The material is placed into the mold, made of  two or more metal plates heated to a specific temperature to soften the material and make it formable.

Step 3: Applying Heat and Pressure

After loading the mold, it is placed into a compression molding machine, which is heated to a specific temperature while the pressure is applied. Then, the temperature and pressure are carefully controlled to ensure that the material flows evenly and fills the mold completely.

Step 4: Curing and part removal

After the material has been molded, the mold is opened, and the part is ejected. The parts are then inspected and the flash is removed by hand or an alternate process.

Benefits of Compression Molding

The following are the advantages of compression molding:

Cost-Effective for Large Production Runs

Once the mold is created, it can be used repeatedly, making it an ideal option for manufacturers who need to produce many parts with the same specifications and tolerances.

Produces Consistent-Quality Components

Because compression molding uses a heated mold, the curing process is more controlled, resulting in high-quality uniform parts less prone to defects and deformations. Similarly, dimension uniformity ensures that all the parts meet the necessary tolerance requirements.

Flexible and Versatile

Compression molding can be used with thermosetting plastics, composites, and rubber. This flexibility in materials allows manufacturers to create parts with different properties and characteristics to meet specific application requirements. Likewise, compression molding versatility in part design enables the production of unique shapes and features that are impossible with other manufacturing processes.

Creates Minimal Manufacturing Waste

The compression molding process produces minimal waste because the material is preheated and compressed into the mold cavity, resulting in little to no excess material. Additionally, the materials used in compression molding are often recyclable, reducing their environmental impact.

Produces Durable Parts

This technique produces parts resistant to corrosion and wear, making them ideal for components intended for harsh environments. Also, compression molding allows manufacturers to easily incorporate metal or plastic inserts into the part during the process. This allows for creating components with intricate designs or those requiring additional strength.

Reduces Post-Processing Requirements

Compression molding produces parts with a high degree of finish, reducing the need for additional post-processing steps such as machining or painting. This saves time and money for manufacturers, making this technique a more cost-efficient option than other processes.

Applications of Compression Molding

The following are the most common applications of compression molding in different industries:


Compression molding is used in the automotive industry to manufacture engine covers, dashboards, bumpers, and other interior and exterior components.


The aerospace industry uses compression molding to produce components that must meet strict safety standards, including interior cabin parts, wings, and fuselages. The process is ideal for creating lightweight, high-strength parts that can withstand the rigors of flight.


In the electronics industry, compression molding is used to manufacture parts that require high precision, such as casings, buttons, and connectors.

Consumer Goods

Products such as phone cases, kitchenware, and toys can be manufactured using compression molding.


In the medical industry, compression molding is used to produce pacemakers, insulin pumps, and more. The process allows medical device manufacturers to create parts with high precision and consistency, which are crucial for ensuring the safety of hospital staff and patients.


The construction industry uses compression molding to produce parts such as pipe fittings, valve seals, and gaskets.

Sporting Goods

Compression molding is used to manufacture various sporting goods, including skateboard decks, snowboards, and bike seats.

Renewable Energy

The renewable energy industry uses compression molding to produce parts for solar panels, wind turbines, and other clean energy technologies.

Factors To Consider When Choosing a Compression Molding Provider

Choosing the right partner can make all the difference in the success of your project. Here are the key factors to consider when selecting a compression molding partner:

Expertise and Experience

Look for a company with a proven track record of delivering high-quality products that meet the needs of their customers. For instance, consider their experience in your specific industry or product niche. A provider with deep industry knowledge can offer valuable insights and help you optimize your design for maximum performance and cost-effectiveness.

Materials and Capabilities

Consider the materials and finishes that you require for your project, and ensure that your provider has the equipment, expertise, and resources to deliver.

Quality Control and Testing

Look for a provider with a robust quality control program with rigorous testing and inspection protocols. Ask about their evaluation procedures, and ensure they can provide documentation to back up their quality and performance claims.

Capacity and Lead Time

Consider the size and complexity of your order and your deadline. Additionally, make sure the provider you choose can meet your needs. Look for a provider with a flexible manufacturing process that can handle small and large orders and adjust to changing demands.

Communication and Customer Service

Seek a responsive and dedicated provider to work with you to achieve your goals. Good communication can prevent misunderstandings and ensure your project is completed on time and within budget.

Price and Value

While choosing the lowest-priced provider is tempting, remember that quality and expertise often come at a premium. Thus, select a manufacturer who offers competitive pricing without sacrificing quality or service.

Why Choose ETI’s Compression Molding Services

Elastomer Technologies offers a broad range of compression molding services using state-of-the-art equipment and technology. We specialize in creating complex parts with exceptional precision and accuracy. Moreover, our team of experts has decades of experience in manufacturing and can offer solutions for even the most challenging projects.

ETI’s commitment to quality is evident in every process step, from material selection to part delivery. We work closely with our customers to ensure that the final product meets their specifications. We also take great care to minimize waste and reduce costs, making our services an affordable option for businesses of all sizes.

Aside from compression molding, we also offer rubber and injection molding, die cutting, transfer molding, prototype molding, and other services. Visit our Services & Capabilities page to see more of our offerings!

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