Custom OEM Manufacturing and Quality Assurance for Engineers
Redline Plastics partners with OEM engineers to turn product requirements into dependable manufacturing solutions. From early design and engineering through production, testing, and assembly, our team works to understand your specifications, address project challenges, and build a process around your application.
In 2026, Redline ranked among the Top 5 custom rotational molders in the United States, based on the Plastics News ranking with proprietary product sales excluded from the comparison. Rotational molding is one part of our broader custom OEM capabilities, which also include thick-gauge thermoforming, compression molding, commercial sewing, prototyping, and value-added assembly.
Our Manitowoc, Wisconsin facility spans more than 200,000 square feet and houses our corporate office and manufacturing operations, including rotational molding, thermoforming, and commercial sewing. The facility is ISO 9001:2015 certified, supporting a documented quality management system focused on meeting customer requirements and continual improvement.
Engineering Support for Custom OEM Programs
With experience as a Tier 1 supplier, Redline understands the coordination and documentation involved in rigorous Production Part Approval Process (PPAP) requirements. Our engineers and quality specialists work with customers to support project requirements, production planning, and testing needs.
Our quality lab includes advanced testing and inspection tools to help evaluate materials, part characteristics, and dimensions. The right approach depends on your product specifications, manufacturing process, and application. For testing beyond our in-house capabilities, we work with qualified third-party laboratories.
A Manufacturing Partner Built Around Your Requirements
Redline’s quality commitment is grounded in clear communication, responsive service, and continuous improvement. We work to understand what matters to your team, follow the requirements established for your project, and identify opportunities to improve the process.
For OEM engineers seeking a custom manufacturing partner, Redline brings multiple processes, engineering collaboration, and quality support together under one roof—from concept through production.
Your standards. Our blueprint. Contact Redline Plastics to discuss your custom OEM project.
We Evaluate Our Suppliers to Deliver the Best in Class
Prior to becoming a Redline supplier, candidates undergo a rigorous evaluation to ensure alignment with our high-quality standards. Selection is based on criteria such as completing a Redline audit or having ISO certification. Successful candidates receive the Redline Supplier Quality Control Manual, effectively communicating our requirements.
To maintain quality standards, regular performance evaluations are conducted, with monthly scorecards assessing performance and identifying any concerns. This meticulous process reinforces Redline’s commitment to excellence in its supply chain.