Precision injection molding. Reliable production. A partnership built around your success.

Founded in 1997 in Plain City, Ohio, Superior Plastics manufactures highly engineered, custom injection-molded components for customers around the globe. We combine advanced molding technology, quality engineering, and automation to support your supply chain from concept to mass production.

Our experience spans automotive, industrial adhesives, childcare safety, and office furniture manufacturing, along with medical and construction applications. In our October 2025 customer-success story, a team of 150 employees supported 24/7 production of over 207 million parts annually using 50 injection molding machines.

Machine counts, workforce, and annual production figures below reflect the October 2025 customer-success story.

Our operations in Plain City and Bellefontaine, Ohio, provide a combined 232,000 sq. ft. of manufacturing and warehouse space. Learn more about our locations and expansion.

Injection Molding

Superior Plastics has provided custom plastic injection molding solutions since 1997. We serve automotive, industrial adhesives, childcare safety, office furniture, medical, and construction customers with highly engineered components and solutions designed around your budget, production requirements, and timing.

All of our presses are equipped with three axis servo robots and press side automation to handle complicated processes. We also offer insert and over molding as well as pressurized water systems to handle highly engineered resins.

As documented in October 2025, 25 of our 50 injection molding machines were Milacron Roboshots. Those all-electric Roboshots ranged from a 33-ton model to a 550-ton model. FANUC-driven technology provides precise control of injection speed, pressure, and temperature to support consistent quality across demanding, high-volume applications.

All-electric precision, efficiency, and sustainability

• Repeatability and consistency: Precise electric servo control helps maintain consistent part quality across large production runs while reducing scrap.
• Faster response times: Rapid, accurate control supports optimized cycle times and increased throughput without sacrificing quality.
• Improved part quality: Consistent shot volume and pressure support tighter tolerances and better surface finishes.
• Reduced mechanical wear: An all-electric architecture avoids hydraulic components, supporting lower maintenance requirements and machine longevity.
• Greater process flexibility: Precise process control supports complex molding requirements and intricate, highly engineered parts.
• Environmental benefits: Reduced energy consumption and material waste, together with the elimination of hydraulic oil in the Roboshot platform, support more sustainable manufacturing.

View Common Materials

Assembly

Automation is a key for us to maximize our manufacturing capacity and overall productivity while keeping overhead manageable. We are able to improve our production outputs, part quality, and overall efficiency with automated assemblies and box fills. 

• Customized assembly solutions to meet customers’ needs
• Fully automatic assembly cells
• State of the art collaborative robots
• Integrated vision systems for quality control and inspection

Ultrasonic Welding

Superior Plastics is an industry leader in ultrasonic welding parts that are molded from a highly engineered resin to a metal component. This is an efficient and cost effective solution for many applications. It can be easily automated and in some cases, eliminate the need for adhesives and fasteners. It also cures very quickly and produces a clean and tight seal. Our ultrasonic welding is highly precise making it an ideal process for manufacturing parts used across many industries including automotive, consumer products, medical, and packaging.

Engineering

Superior Plastics’ Engineering provides full project management and tool building resources where our engineering team works hand in hand with a customer from concept to completion.  By allowing Superior Plastics to build your molds, this results in fewer mold modifications, reduced lead times, a preventative maintenance program, and lower overall costs. 

Our engineering team helps our customers in material selection, part design and automation processing.  Together we create a cost effective and high-quality product with the efficiency that makes working with us easier.

Quality

We work collaboratively with our customers to provide solutions to make plastics parts quicker while maintaining consistency and repeatability.

We offer vision measurement systems services for tight tolerance parts that deliver accuracy and repeatable measurement results. 

All of our tools have a personalized mold preventative maintenance program based upon tool design and material.  Our MoldTrax software is a comprehensive maintenance system database that allows us the means to track and analyze mold performance.  We are able to document shot count, repairs, and ultrasonic cleanings. 

Request a quote to discuss your next injection molding, assembly, or engineering project.