Mechanical Engineer- Plastics Processing

Mechanical-Engineer,-Plastics Processing 485
About Helpful Engineering
Helpful Engineering is a global open engineering community and a registered US 501(c)(3) nonprofit. It began in March 2020 as a grassroots response to COVID-19 medical equipment shortages and, within ten days of launch, grew from 35 people to 2,700 active members in 92 countries. Today more than 20,000 community members contribute across healthcare, supply chain and manufacturing, agriculture, water, energy, and infrastructure, with every project aligned to the UN Sustainable Development Goals.
Helpful works as connective tissue, not the factory. Members propose ideas, form project teams, and receive the scaffolding most volunteer projects lack: mentorship, design review, build help, quality assurance, and routes to deployment. Of roughly 100 launched projects, ten reached prototype, five became buildable designs, and two, RespiraWorks and Project Tetra, grew into independent nonprofits. The organization is fully virtual and entirely volunteer run, coordinated through Slack, with Helpful Innovation Labs as its internal innovation team.
The Project: Open Melt-Blown Polypropylene Machine
The Role
The Mechanical Engineer with a background in plastics leads the design of the machine's melt, die, air, and collection hardware. You will bring hands-on knowledge of polymer processing equipment to a machine that has to be precise enough to make filter-grade fibers and simple enough for a maker space to build and run safely.
What You Will Do
• Lead the mechanical design of the feed and melt subsystem: hopper, screw or plunger extrusion, and banded heaters, sized for high melt-flow polypropylene.
• Design the metering die, with its single row of fine orifices and flanking air knives; specify tolerances, manufacturing methods, and inspection.
• Size the air attenuation system, including compressor, inline heater, and air-knife geometry, within the 120V, 15 to 20 amp power budget.
• Design the collector drum or belt, the die-to-collector distance adjustment, and the stepper-driven take-up that sets basis weight.
• Manage heat zones, insulation, thermal expansion, and guarding so that the machine is safe to operate in a shared maker space.
• Develop the test plan with the Chemical Engineer, covering fiber diameter, web uniformity, basis weight, and filtration performance.
• Document every design decision so the final build guide can be followed by non-experts.
What You Bring
Essential
• A degree in mechanical engineering or equivalent professional experience
• Hands-on experience with polymer processing equipment, such as extrusion, injection molding, melt-blown or spunbond nonwovens, or fiber spinning
• Working understanding of how melt temperature, throughput, and air flow affect polypropylene fiber formation
• Precision machining and design-for-manufacture experience, including GD&T
• Fundamentals of heat transfer and fluid flow
Helpful to have
• Nonwovens or filtration media industry experience
• Extrusion die or air-knife design experience
• Machinist skills or access to a well-equipped maker space, particularly in the Ann Arbor and University of Michigan region
• FreeCAD or other open source CAD experience
Volunteer Terms and OpenIP Recognition
• This is an unpaid, volunteer contributor opportunity on an open source project. It does not create an employment or contractor relationship.
• Designs, drawings, code, data, and documentation are published openly under Helpful Engineering's Contributor Agreement and licensing guidance, so anyone can build, adapt, and improve them.
• Your contribution is credited through OpenIP Recognition, recorded by name on the project's design documentation and repositories. It is a permanent, public record of your work that you can point to.
• Contribute only material you have the right to release openly. Please do not bring an employer's confidential or proprietary information into the project.
• You work remotely with a global team, at a pace that fits around your professional and personal commitments

Ready to Apply?
If you are excited to leverage your human resources expertise to create meaningful global impact, we want to hear from you! Even if you don’t meet every qualification, we encourage you
to apply—your perspective and passion may be exactly what we need.
This is an unpaid volunteer position at a nonprofit organization.
Join us in engineering the future of sustainability.
Apply now or learn more about us at:
helpfulengineering.org

Work arrangement
Yes