This month we said goodbye to a colleague who has quietly shaped decades of product design across the Rompa Group and its predecessors. After more than 30 years with Verhoeven, and ITB – which ultimately joined the Rompa Group, Design Engineer Loek Willemse is retiring from our Netherlands HQ.

With so much experience in his field, we took the opportunity to sit down with Loek to get his view on what good design engineering really means in practice. His perspective captures something at the heart of Rompa’s philosophy: good design isn’t just about moldability; it’s about the product’s entire lifecycle.

“As a product engineer, you look beyond the mold,” says Loek. “You think about how the customer will use the product, how it’s assembled, how it’s sold, and even how it’s disposed of. Great design is about the whole product.”

When Loek began his career in 1992, everything was done in 2D. Drawings were created by hand, not by CAD. Prototypes were crafted manually. Mistakes were common, and spotting design issues early was difficult. “Once everything moved to 3D, the number of errors dropped dramatically,” he recalls. “Prototyping became easier. Simulations helped us evaluate designs before we ever cut steel. It became much more ‘first time right’.”

Today, Rompa’s engineers use 3D CAD, Moldflow, and FEA simulations to predict behavior during molding, shrinkage, cooling, and warpage. These digital capabilities help customers accelerate development, minimize risk, and ensure designs move smoothly from concept to high-volume production.

While many injection molders focus strictly on tooling and production, Loek believes Rompa’s ability to engage earlier - during product definition - sets us apart.

“Most smaller injection molding companies don’t offer design support,” he says. “Rompa is unusual in that we have in-house design engineers who can really influence the quality of the final product.”

For customers, this early involvement translates into better product design, less pressure on internal teams, and a smoother path from concept to mold-ready production. “In my work I always tried to create a product that is optimal for the client,” Loek adds. “Not only easy to mold, but also practical for assembly, packaging and disposal.”

Product development is a series of trade-offs, and Loek’s experience shows how even small design decisions can have a major impact on cost, quality, and manufacturability.

“If a product has multiple parts, you must make assembly easy - whether it’s done by hand or by automation,” he explains. “Positioning tolerances, stacking sequences and part interfaces all need to be considered very early.”

That same thinking often affects mold design. “Sometimes you need a more complex mold to get a better overall product,” Loek says. “It’s not about the easiest mold, but the right result - something that usually only becomes clear with experience. There are design rules, of course,” Loek adds, “but a lot of decisions come down to experience and engineering instinct built over many years.”

Modern technology sometimes adds to rather than reducing – the number of design variables. “In high volumes, advances in 2K molding or over-molding mean you can now remove entire assembly steps,” Loek explains. “The mold is more complicated, but you earn that back by reducing variation and simplifying the production flow.”

Rompa’s design team applies this thinking every day across finished goods, consumer products, life sciences components and more – making recommendations to clients to help them balance cost, manufacturability and performance.

Across his career, Loek contributed to a wide range of applications. Three recent ones stand out as memorable – not for their size, but for the engineering challenges and customer impact involved.

1. Earplug Storage and Carrying Case

Working from an initial design provided by our customer, Loek and the Rompa team refined the casing and the in-ear piece that houses Alpine’s proprietary audio filters. They developed improvements to enhance usability, robustness, and manufacturability.  “We needed to carefully balance multiple elements of this project to make the product as effective as possible,” Loek recalls. “Some of the biggest challenges came in designing the casing that protects and stores the earplugs, and on making sure the in-ear fit was good.”

2. Reverse-Engineered Travel Case

In another project, the team was asked to replicate a protective travel case for a personal care device using only a 3D scan of a warped sample from another supplier. “We reverse-engineered the geometry, rebuilt the structure, and adapted the design to meet the customer’s tolerance, fit and production requirements,” says Loek. “We were able to develop a design that met all the functional and production requirements. This enabled the customer to establish Rompa as a second production source for their cases and diversify their supply chain.”

3. Precision Components for Life Sciences

Loek also worked on the redesign and optimization of highly precise components used in laboratory applications. For one product, he was tasked with creating a plastic alternative to laminated foil structures for controlled-thickness fluid analysis. “The slides are used in labs to count the number of cells in a sample of blood or other fluids,” Loek explains. “Tolerances are critical, because even a tiny variation in thickness of the plastic can completely change the measurement and affect the accuracy of the cell count. Injection molding allowed for more precise, consistent results, but we had to get the design within extremely precise parameters.”

Even after decades in the industry, Loek sees exciting developments ahead—particularly around sustainability and simulation. Here’s what he predicts will be the key trends that will influence design engineering in the next few years:

1. More Use of Recycled Materials. “The push to use recycled plastics will change product design,” he notes. “Thin-walled products often require special high-flow materials that recycled plastics cannot always match. To use recycled material, designs may need to take a step back—thicker walls, different geometries, more common material specs.”
2. Better Warpage Compensation. “Simulation software is improving rapidly,” says Loek. “We already simulate today, but translating predicted warpage into a corrected mold is still difficult. Software is on the way that will help mold makers to compensate more accurately, so the final part will be exactly what you intended, first time.”
3. More Automation and Energy Focus. “As robots and cobots become more flexible and intelligent, trends such as over-molding, automated handling, and energy-efficient systems will continue to shape production environments,” Loek predicts.

And what of the buzzword that’s everywhere in manufacturing – Artificial Intelligence?

“We’re using AI today, and it’s helpful,” says Loek. “Especially for supporting us in problem solving. AI tools can suggest alternative solutions to a problem, but in the end, you still need an engineer to decide what works in the real world.”

Even though Loek is leaving us to enjoy his well-earned retirement, he leaves behind a team of expert colleagues who are fully equipped to support our customers in bringing their new products to market in the most cost-effective way, without compromising on quality or time-to-market.

If you’re developing a new product or considering redesigning an existing one, Rompa’s design engineering team can support you from concept through production. Get in touch to learn how we can help.