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Understanding SPI Plastics Rotational Molding Process

Understanding SPI Plastics Rotational Molding Process

At SPI Plastics, we specialize in transforming visions into reality. Our rotational molding process allows us to create many custom plastic products, ranging from vibrant playgrounds that spark children’s imaginations to durable livestock waterers designed to withstand the toughest conditions. This cutting-edge technology, often called rotational molding, is at the heart of our operations. It’s what enables us to craft functional and tailored products to our client’s specific needs. This blog post aims to shed light on our rotational molding process, offering you a behind-the-scenes look at how your favorite SPI Plastics products come to life.


What Is Rotational Molding?

Rotational molding, or rotomolding, is a manufacturing technique that creates hollow, seamless, one-piece items. The process involves heating a plastic material in a rotated mold to distribute the plastic around the interior of the mold evenly. This method is precious in crafting custom plastic products, and it’s at the heart of what we do at SPI Plastics.


SPI’s Rotational Molding Process

Our rotational molding process is a unique blend of creativity, precision, and innovation. Each product we create goes through a meticulous four-step process: concept, design, product development, and secondary processes.

#1. Concept

The journey of every SPI Plastics product starts with an idea. We sit down with our clients, discussing their vision and getting a full understanding of the project they have in mind. This includes everything from the desired colors and shapes to the specific type of plastic material to be used. We aim to transform these visions into tangible, functional products.

#2. Design

At SPI Plastics, design is more than just an aesthetic consideration; it’s an essential part of the product development process. We utilize Computer-Aided Design (CAD) technology to provide our customers and mold makers with an accurate and detailed 3D perspective of the product. This allows everyone involved to visualize the final product before it is even made, ensuring that each detail aligns with the client’s expectations.

#3. Product Development

The product development stage is where the magic happens. Utilizing our state-of-the-art rotational molding technology, we transform raw materials into vibrant playgrounds or your custom design. Every product we craft is not only functional but also tailored to the specific needs of our clients.

#4. Secondary Processes

Once your part has been rotationally molded, there are a variety of secondary operations that occur. For instance, parting lines can be trimmed to ensure a smooth finish, and your part can be flame polished to achieve a glossy shine. Rotational molded parts can also be drilled, milled, sawed, or spin-welded, depending on the product requirements. Additionally, cooling jigs or fixtures may be used to maintain the shape of the product as it cools. After all these processes are completed, the product is now finished and ready for use, embodying the perfect blend of your vision and our expertise.

Is Rotational Molding Right For Your Project?

Deciding if rotational molding is the right choice for your project depends on various factors. Does your product have a complex shape? Would it benefit from being a single piece rather than assembled from multiple parts? Does it need to be resistant to corrosion, water, or chemicals? Does it need to hold materials or require special embellishments like imprints, handles, or caps?


If you answered yes to any of these questions, rotational molding might be the ideal solution for your manufacturing needs. With its low tooling expenses, design flexibility, and ability to produce complex geometries, rotational molding offers numerous benefits over traditional molding techniques. However, it’s essential to assess your design requirements and part specifications to determine if this method is compatible with your project.

Discover The Possibilities Of SPI Plastics’ Rotational Molding

At SPI Plastics, we are passionate about bringing ideas to life through our rotational molding services. Our team is committed to delivering high-quality, custom plastic products that meet and exceed our client’s expectations. If you’re curious about how our services could benefit your next project or want to explore the possibilities of rotational molding, don’t hesitate to get in touch with us today. Let’s discover together if rotational molding is the perfect fit for your upcoming project.

SPI Plastics Inc.

165 Stoneman Drive, Box 100
(Shouldice Block Road & Joynt Street)
Shallow Lake, ON
N0H 2K0

T   519-935-2211
TF 800-269-6533
F   519-935-2174

Business Hours

Monday - Thursday: 8am to 4:30pm
Friday: 8am to 4pm
Saturday & Sunday: Closed

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