16 Oct Manufacturing High-Performance Automotive Plastic Components: Engineering, Design, and Material Optimization
A relatively simple design change that saves the customer more than $450,000 per year in manufacturing costs… That’s the kind of advantage we’re referring to when we talk about the value that Quantum Plastics’ engineering team brings to the table.
And that’s exactly the result we delivered on a high-volume, multiple-OEM vehicle program by rethinking how a Totally Integrated Power Module (TIPM) fuse box cover is sealed.
As is often the case, the answer wasn’t switching to a new material or running a bigger press. We engineered a more efficient, more cost-effective production process simply through smarter design.
Of course, what seems like a simple design choice is backed by decades of combined engineering expertise and validated in a prototype. That’s all built into the Quantum Plastics process.
Case Study: Design and Manufacturing for Automotive Fuse Box Covers
The TIPM sits at the heart of a vehicle’s electrical distribution system, so its fuse box cover has one job it cannot fail at: keep water out. The customer required zero water ingress, and every design has to meet that standard across the vehicle’s life.
Saving $450k+ per Year via Design Improvement
The previous two generations of this cover used a formed-in-place gasket (FIPG).
With FIPG, a bead of liquid sealant is applied to the molded cover and then cured in an oven. It works, but it’s an expensive secondary process. Quantum Plastics injection molded the covers to the customer’s exact standards, then outsourced the bead application.
We devised a method that was much more cost-effective than the alternatives at the time. Even so, the extra handling, curing time, and added cost stayed in the program.
Value Analysis and Engineering
During a VA/VE (value analysis/value engineering) cost reduction session, our team proposed a different approach for the next model: eliminate FIPG and use an overmolded thermoplastic elastomer (TPE) gasket instead. The gasket is molded directly onto the premolded cover, so the sealing feature is created in the molding process rather than added afterward.
Swapping the gasket style alone would not meet a zero water ingress requirement. A molded TPE seal has to be designed around how it will be compressed, where water will try to travel, and how the mating parts will move. Our engineers designed three “wiping seals” into the gasket geometry.
- Wiping Seal 1: The primary sealing lip. This lip makes first contact with the mating surface. As the cover seats, it wipes across the surface and clears away moisture, and it forms the first barrier against water.
- Wiping Seal 2: The secondary sealing lip. It sits behind the first as a redundant barrier. Any water that gets past the first lip meets a second wiping contact instead of a clear path to the fuses.
- Wiping Seal 3: The final wiping barrier. This third seal adds another layer of protection where the cover and housing meet. It also allows for variation in the mating parts, so sealing does not depend on perfect alignment.
The three seals create a layered defense. Each one wipes and compresses on installation, and each backs up the others.
Prototyping, Validation, and Automation
We built the design into a prototype and tested it against the zero water ingress requirement before committing to production tooling. Validating early let us prove the concept and refine details when changes are far less costly.
Automation was the other half of the solution. With the premolded fuse box cover and overmolded TPE gasket approach, we used full robotic pick and place. Robots handle the covers between operations, which supports consistent quality, repeatable cycle times, and less manual handling across a high-volume program.
The Results
Moving from FIPG to an overmolded TPE gasket removed the secondary bead application and oven curing steps entirely. There is no outsourced sealing operation to schedule, ship to, or wait on. The cover comes off the molding process ready for assembly, with the seal already part of the design.
Because this program runs at high volume across multiple OEM vehicles, small per-part savings add up quickly. The redesigned cover saved the customer more than $450,000 per year, while still meeting the customer’s zero water ingress requirement.
Engineering is Built into the Quantum Plastics Process
This project shows the advantages that can be realized when your injection molder is involved in the design conversation, not just the production run.
In this case, rather than simply building to print, we revamped the design and manufacturing process, applied our knowledge of materials, tooling, and automation, and proposed a change that improved the product while lowering cost.
That’s the value of engineering support at every stage of a program. If your current design relies on a costly secondary process, a VA/VE review with the Quantum Plastics team may reveal similar opportunities.