Making connectivity work in plastic products: lessons from a real-world project

Connectivity is quickly becoming an expected feature of everyday products. From consumer devices to industrial sensors, adding wireless functionality is often seen as a logical next step in product innovation. But turning a concept into a market-ready connected plastic product is a process full of potential pitfalls. Navigating it successfully requires experience.

In this blog, we’ll explore some of the challenges involved and how to resolve them using a recent Rompa customer project as an illustrative real-world case study.

On paper, choosing a connectivity technology can look straightforward. Bluetooth Low Energy, Wi-Fi, cellular, RFID all are well understood, widely available, and supported by mature ecosystems. In practice, however, many connectivity projects run into trouble much later in the process. Not at the concept stage, and not in the electronics lab, but when the product needs to be manufactured, certified, and deployed in the real world.

Recently, Rompa worked with a leading US-based company developing a connected water leak detection system for residential use in the North American market. The electronics and backend software were already in place, and early prototypes appeared promising. But once the product moved toward production, problems started to emerge.

The device was designed to sit directly on the floor exactly where leaks are most likely to occur. In this position, wireless performance dropped significantly. Battery life was shorter than expected. And when the product was tested at scale, water ingress became a serious issue.

That’s when the customer approached Rompa’s plastics experts for their insights. They realized the problems weren’t with the connectivity technology itself. They were caused by the interaction between electronics, enclosure design, materials, antenna placement, and real-world conditions.

From a connectivity perspective, it’s tempting to focus on headline characteristics such as range, bandwidth, or data rate. But once connectivity is integrated into a plastic product, other factors quickly become just as important:

• Power consumption: Wireless technology choice and usage directly affect product size and shape because they affect battery size, lifetime, and replacement strategy.
• Firmware & configuration: Even once you’ve chosen your connectivity technology, the way firmware controls the radio — how often it wakes up, transmits, and checks in — can make or break battery life and real-world performance.
• Enclosure design: Plastic thickness, geometry, and material choice influence signal propagation and antenna efficiency.
• Product placement: A device mounted on a wall behaves very differently from one placed on the floor.
• Environmental exposure: Moisture, dust, and temperature variations demand robust mechanical solutions.
• Manufacturability: Designs that work in low-volume prototypes may fail during mass production.

In this project, the original approach relied on a connectivity solution that worked well in controlled lab conditions but struggled in the real world.

One of the most underestimated aspects of connected product design is the role of the plastic enclosure.

Antennas that are designed and tuned in isolation perform very differently when placed inside a plastic housing. Material properties, internal clearances, ribs, bosses, and even assembly methods can all affect signal strength and stability.

In this case, antenna placement and enclosure geometry had to be reconsidered together. Improving performance required a coordinated redesign that balanced:

• antenna size and position
• internal layout of the PCB
• enclosure geometry
• sealing strategy for waterproofing

These decisions can’t be made sequentially. They need to be addressed together, and early enough in the product design process to avoid costly rework later.

Another common pitfall in connected product development is underestimating the certification process. Wireless products must comply with regional regulations such as FCC rules in the US or ETSI requirements in Europe. Certification testing is performed on the final assembled product, not on individual components in isolation. That means enclosure design, antenna behavior, PCB layout, and firmware all influence whether a product passes or fails.

It’s also normal for products to require multiple iterations to pass certification. Small adjustments to hardware components, antenna matching, or internal layout are often needed to reduce unwanted emissions or improve stability.

Having experience with these testing cycles, and the ability to support testing, tuning, and revalidation, can make the difference between a smooth launch and months of delay. Rompa is equipped to run complete and speedy design, tuning, and validation cycles in-house, a skill set that’s not always offered by other contract manufacturers.

In this project, Rompa supported the transition from a working concept to a production-ready product by focusing on the areas where connectivity and plastics intersect:

• redesigning the enclosure to improve sealing and reliability and prevent leaks
• supporting antenna placement and performance within the plastic housing to optimize signal
• ensuring the product could be manufactured consistently at scale
• supporting the path toward certification and compliance

The result was not just a connected device, but a product designed to perform reliably in its intended environment. One that could be manufactured, certified, and deployed with confidence. And as a full-service contract manufacturing partner, Rompa covered every step of the process for our customer, from mold design and the phyiscal plastic injection molding to PCB design, firmware development, SMT, testing, assembly, packaging and logistics.

As connectivity becomes more widespread, more companies are finding themselves in a similar position: strong electronics and software capabilities, but limited experience turning those technologies into robust, manufacturable plastic products.

The lesson from this project is simple: Choosing between different methods of connectivity is only the starting point. Making them work inside a plastic product is where most of the real challenges begin.

Addressing those challenges early, with support from the right skilled partners, reduces risk, shortens time to market, and avoids expensive surprises at the final stage.

Thinking about connectivity in your next product?

If you’re developing a connected product and want to make sure connectivity, enclosure design, and manufacturability work together from the start, involving an experienced manufacturing partner early can make a significant difference.

Rompa supports customers from concept through to production, helping turn connected ideas into reliable, production-ready plastic products.

Want to get our expert insight into your next contract manufacturing project? Get in touch.