About the role#
Flex is hiring a Plastic Molding Engineering Co-Op for our site in Libertyville, Illinois. You will join the Process and Automation Engineering team to support injection molding process development and validation for high-precision medical components. This is a full-time, paid position for the Winter 2027 term.
What you'll do#
- Assist with injection mold trials and process window development.
- Support startup optimization and parameter validation.
- Carry out short-shot and imbalance studies.
- Help with defect analysis and root cause investigations.
- Assist in preparing IQ, OQ, and PQ documentation.
- Support tooling preventative maintenance and assess mold performance.
- Participate in team meetings to support ongoing project work.
What you'll need#
- Enrollment in an accredited university pursuing a BS or MS degree in Plastics, Polymer, Mechanical Engineering, or Materials Science.
- A minimum GPA of 3.0.
- Understanding of injection molding fundamentals and mold tooling components.
- Basic knowledge of process validation in regulated environments.
- Experience with defect and root cause analysis.
- Ability to read basic mechanical drawings.
- Strong communication and documentation skills.
- Previous manufacturing floor internship experience is a plus.
Location & details#
- This role is based on-site in Libertyville, Illinois.
- You must be able to work 40 hours per week.
- Sponsorship is not available for this position.
About Flex
Flex is a manufacturing partner that provides design, build, and logistics services for various brands. The company operates across sectors including medical, automotive, and consumer digital electronics. It maintains a global presence with headquarters in Austin, Texas. The firm employs over 56,000 people and functions as a public company.
How to get in at Flex
Securing an internship at Flex requires speed because high-volume manufacturing firms often receive a large number of applications. Intern Insider sends an instant alert the moment a role matching your target is published, so you apply among the first. Early applicants get seen before the pile grows, which helps you stand out in a crowded field. You can also use Intern Insider to surface the recruiters behind these roles. Reaching out directly to ask about the position or a referral materially improves response rates compared to waiting in a queue.
