About Granger Plastics Company
Globally recognized leader in rotomolding, rotational molding design, custom plastic manufacturing, and full-service production solutions.
For over three decades, Granger Plastics Company has helped manufacturers, OEMs, and innovators turn demanding product ideas into durable, high-performing rotationally molded solutions. Founded in 1994 by rotomolding veteran John Grimes, Granger Plastics grew from a specialized rotational molding company in Sharonville, Ohio into a full-service manufacturing partner headquartered in Middletown, Ohio. Today, Granger Plastics is recognized for custom rotomolding expertise, innovative product design, in-house mold capabilities, and a quality-driven approach that supports customers across industries ranging from aerospace and defense to water treatment, material handling, waste management, safety products, and more.
A Legacy Built on Rotomolding Expertise
Granger Plastics was built on a deep foundation of rotational molding experience. John Grimes brought decades of industry knowledge to the company, including a family connection to the early development of the rotomolding industry through his father, John Grimes Sr., who was noted as one of the original architects of the industry in the 1950s. That heritage shaped Granger Plastics from the beginning: practical manufacturing knowledge, inventive engineering, and a commitment to building products that perform in real-world conditions.
As demand for custom rotational molding grew, Granger Plastics expanded rapidly, moving to Middletown, Ohio in 1996 to increase manufacturing capacity. In 1998, Jim Cravens joined the leadership team, bringing mechanical engineering expertise, extensive metal fabrication experience, and a disciplined focus on quality, productivity, and innovation. Under his direction, Granger Plastics continued to develop industry-leading rotational molding solutions and expanded into multiple specialized product divisions.
Full-Service Rotational Molding Solutions
Granger Plastics is more than a custom rotomolding supplier. The company offers complete, turnkey rotational molding services designed to help customers streamline development, production, finishing, packaging, and fulfillment. From early concept development to finished product delivery, Granger Plastics provides the technical knowledge, production resources, and hands-on support needed to bring complex plastic products to market with confidence.
- Custom rotomolding for OEMs, manufacturers, and product innovators
- Rotational molding design support using 3D modeling and practical manufacturing insight
- In-house mold fabrication, maintenance, repair, and metal fabrication services
- Secondary trimming, assembly, packaging, warehousing, and drop-shipping support
- Experience with large, complex, thick-walled, and highly durable rotomolded products
Engineering, Design, and Manufacturing Innovation
Successful rotational molding starts long before production begins. Granger Plastics works closely with customers to evaluate product requirements, design intent, material performance, mold construction, wall thickness, part geometry, molded-in features, finishing needs, and long-term durability. This design-forward approach helps reduce risk, improve manufacturability, and create products that are built for dependable performance.
With in-house mold and tooling capabilities, Granger Plastics can support customers through one of the most critical stages of any rotomolding project. By combining engineering insight with hands-on fabrication expertise, the company helps customers develop molds that support consistent production, efficient maintenance, and high-quality finished parts.
Quality-Driven Rotomolding for Demanding Applications
Granger Plastics has earned its reputation by producing durable rotationally molded products for customers with demanding performance expectations. The company’s quality-focused manufacturing approach supports parts used in challenging environments, including aerospace and defense applications, storm safety products, industrial components, plastic tanks, material handling products, water quality solutions, and specialty OEM programs.
Rotomolding is especially well suited for producing strong, hollow, seamless, and impact-resistant plastic products. Granger Plastics leverages the advantages of rotational molding to manufacture parts with practical performance benefits, including durability, design flexibility, corrosion resistance, long service life, and the ability to create complex shapes that may be difficult or inefficient to produce with other plastics manufacturing processes.
Industries Served
Granger Plastics supports a broad range of industries and applications, making the company a trusted rotational molding partner for organizations that need more than basic production capacity. Customers turn to Granger Plastics for technical guidance, product development support, and manufacturing solutions that align with real-world use requirements.
- Aerospace and defense
- Water treatment and water quality
- Material handling and industrial products
- Waste management and environmental solutions
- Storm shelters and safety products
- Agricultural, commercial, and OEM plastic components
- Specialty product development and proprietary molded solutions
Why Choose Granger Plastics?
Choosing the right rotational molding partner can determine the success of a product program. Granger Plastics brings together proven rotomolding experience, engineering capability, in-house mold expertise, production knowledge, and a commitment to customer-focused solutions. Whether a project requires a new custom rotomolded part, a complex mold, secondary assembly, or a complete turnkey manufacturing program, Granger Plastics provides the capabilities and confidence customers need from concept through delivery.
- Over three decades of rotational molding experience
- International recognition for rotomolding innovation and design
- Full-service support from design and molds to production and fulfillment
- Experience producing large, complex, and highly durable plastic parts
- Quality-driven leadership rooted in engineering and continuous improvement
- Proven solutions for OEMs, manufacturers, and specialized industries
Built to Solve Complex Rotomolding Challenges
At Granger Plastics, rotational molding is not simply a manufacturing process. It is a platform for solving complex design, production, and performance challenges. The company’s history of innovation includes proprietary product divisions such as Granger Aerospace Products, ForeverSafe Products, the Sandsaver natural solution to beach erosion, and the Granger ISS underground tornado shelter. These products reflect the same approach Granger Plastics brings to customer projects: practical engineering, durable materials, thoughtful design, and dependable manufacturing.
Partner with Granger Plastics
If your organization needs a proven partner for rotomolding, rotational molding design, custom plastic manufacturing, mold fabrication, or turnkey production support, Granger Plastics is ready to help. With decades of experience and a strong reputation for quality, innovation, and customer-focused manufacturing, Granger Plastics delivers rotational molding solutions designed to perform.
Contact Granger Plastics to discuss your custom rotomolding project, request design support, or explore full-service rotational molding solutions for your next product program.
