Senior Plastics Engineer

Role details

About Sigma International

Sigma International is a global Tier-1 automotive supplier specializing in decorative trim, illuminated components, plastic injection-molded products, and integrated electronic systems.

We partner with leading automotive OEMs to develop innovative interior and exterior components that combine design, functionality, and advanced manufacturing technologies.

Position Overview

Sigma International is seeking an experienced Senior Plastics Engineer with deep technical expertise in plastic injection molding, product design, tooling, and automotive manufacturing.

This is a senior, hands-on engineering position for someone who understands plastics inside and out. The ideal candidate has extensive experience working with injection-molded components, plastic materials, mold design, manufacturing processes, and complex technical challenges.

The Senior Plastics Engineer will take ownership of product engineering activities, provide technical direction, resolve complex design and manufacturing issues, and support projects from initial concept through production.

We are looking for someone who can work independently, make sound engineering decisions, and serve as a technical resource across engineering, manufacturing, quality, and suppliers.

Senior Product Engineering & Technical Leadership

• Lead the design, development, and optimization of automotive plastic components and assemblies.
• Serve as the primary technical expert for plastic product design, materials, injection molding, and tooling.
• Evaluate product designs for functionality, manufacturability, dimensional accuracy, quality, and cost.
• Apply advanced Design for Manufacturability (DFM) principles to improve product performance and manufacturing efficiency.
• Review and approve engineering designs, GD&T, material specifications, tolerances, and technical documentation.
• Develop and modify complex 3D CAD models, assemblies, and engineering drawings.
• Provide technical guidance to engineering, quality, manufacturing, and program teams.
• Independently manage engineering priorities and make technical recommendations.

Plastic Injection Molding, Materials & Tooling

• Lead technical evaluations of injection-molded plastic components and tooling designs.
• Work directly with mold makers and tooling suppliers to review mold concepts, identify risks, and resolve technical challenges.
• Provide expert-level troubleshooting of injection molding defects, including warpage, sink marks, shrinkage, flow lines, dimensional variation, and cosmetic defects.
• Evaluate and recommend plastic resins based on mechanical, thermal, optical, dimensional, and manufacturing requirements.
• Lead mold trials, tooling modifications, engineering validation, and production readiness activities.
• Identify opportunities to improve mold performance, cycle times, part quality, and manufacturing costs.
• Resolve complex tooling and molding issues with practical, cost-effective solutions.

Engineering & Manufacturing Support

• Act as a senior technical resource for daily engineering and production challenges.
• Lead root cause investigations involving product design, tooling, materials, dimensional issues, and assembly failures.
• Develop and implement permanent corrective actions to prevent recurring manufacturing problems.
• Support prototype development, product testing, engineering validation, and design improvements.
• Design or modify checking fixtures, prototype tooling, and assembly stations when required.
• Collaborate closely with manufacturing and quality teams to improve existing products and processes.
• Support continuous improvement initiatives focused on product quality, manufacturability, and cost reduction.

Automotive Program & Customer Support

• Lead technical feasibility reviews and engineering evaluations for new RFQs and customer programs.
• Provide engineering input for tooling costs, product development, manufacturing feasibility, and technical risks.
• Take ownership of engineering deliverables throughout product development and launch.
• Support APQP, PPAP, design validation, tooling approval, and production launch activities.
• Work directly with customers, suppliers, and internal teams to resolve complex engineering issues.
• Ensure engineering documentation and technical requirements are maintained throughout the product lifecycle.

Required Qualifications

• Bachelor's degree in Plastics Engineering, Mechanical Engineering, Polymer Engineering, or a related technical field.
• 8–10+ years of hands-on engineering experience with plastic injection-molded components, preferably in the automotive industry.
• Extensive, demonstrated expertise in plastics engineering, injection molding processes, mold tooling, and plastic material selection is essential.
• Proven ability to independently troubleshoot and resolve complex plastic molding, tooling, and product design problems.
• Strong understanding of plastic resin properties, shrinkage, warpage, mold flow behavior, dimensional stability, and manufacturing limitations.
• Advanced proficiency in at least one professional 3D CAD platform: Siemens NX, CATIA, or SolidWorks.
• Experience creating and modifying complex 3D models, assemblies, and 2D engineering drawings.
• Strong knowledge of DFM, GD&T, dimensional tolerances, and automotive engineering specifications.
• Significant experience working directly with mold makers, tooling suppliers, and injection molding operations.
• Experience leading engineering activities from product development through tooling validation and production launch.
• Working knowledge of automotive APQP and PPAP requirements.
• Demonstrated ability to take technical ownership, make independent engineering decisions, and manage multiple priorities.
• Strong analytical, troubleshooting, communication, and cross-functional collaboration skills.

Important: Candidates must have substantial, practical experience in plastics engineering. General mechanical design experience without significant injection molding, tooling, and plastic materials expertise will not meet the requirements of this position.

Preferred Qualifications

• Experience designing or developing automotive plastic optical lenses, light guides, and illuminated components.
• Knowledge of optical-grade plastics, particularly polycarbonate (PC) and PMMA.
• Experience integrating plastic lenses and light guides with LEDs, PCBAs, and electronic assemblies.
• Experience with automotive interior and exterior decorative components.
• Knowledge of Class-A surfaces, painting, plating, coatings, and decorative finishes.
• Experience with Moldflow analysis and injection molding simulation.
• Experience designing checking fixtures, prototype tooling, and assembly stations.
• Knowledge of IATF 16949 automotive quality requirements.
• Previous experience serving as a senior technical expert or mentoring other engineers.

What Success Looks Like

• Complex plastic design, tooling, and manufacturing problems are resolved independently and effectively.
• Plastic components consistently meet customer specifications, dimensional requirements, and manufacturing expectations.
• Tooling and injection molding issues are identified early, minimizing delays, scrap, and production disruptions.
• Engineering projects move efficiently from concept through tooling development, validation, and production. Manufacturing, quality, and program teams receive strong technical guidance and practical solutions. Product quality, manufacturability, and cost are continuously improved.

Pay: $95,100.00 - $115,000.00 per year

Benefits:

• 401(k)
• 401(k) matching
• Dental insurance
• Health insurance
• Health savings account
• Life insurance
• Paid time off
• Vision insurance

Work Location: In person