Researchers Evaluate 3D Printing for Headlight Lens Manufacturing – 3DPrint.com

When we hear about 3D printing lenses for optical applications, it’s often for eyewear. But a group of researchers from Tunghai University in Taiwan are looking into the technology for a different use case: headlight lenses. Their paper, published in the Optica Publishing Group journal Applied Optics, evaluates and compares headlight lenses produced with additive manufacturing to those made using more traditional manufacturing methods, like reverse engineering and CNC machining. The team reports that AM has several advantages over these other processes when it comes to fabricating headlight lenses, such as improved performance and flexibility.

As one of the first industries to produce rapid prototypes, the “automotive market is one of the longest-standing users of 3D printing technology,” according to a report by Additive Manufacturing Research. The report also states that multiple market, environmental, and technological trends are combining to transform the automotive industry, with many turning to 3D printing “as a critical tool to enable this transformation, from the transition to electric vehicles (EVs) to the drive towards making supply chains more sustainable.” Recently, we’ve seen examples of AM being used to make headlight tabs for auto repair, so why not 3D print the lenses as well, if the capability is there?

3D printed headlight tabs

“Traditional manufacturing methods come with limitations such as high costs, long delivery times, and low yield,” explained Chia-Hung Yeh, Study Team Leader and a professor at Tunghai University. “This study uses a headlight lens as a case study to explore the potential of 3D printing as an alternative to traditional manufacturing methods, aiming to create a faster product verification process for the industry.”

Replacing the traditional mass production model, decision-makers in the optical plastics industry are now focusing more on addressing specific customer needs. Traditional lens molds are fairly expensive, which means manufacturers have to carefully weight the benefits against the financial risks. This can lead to a much longer deliberation process before production even gets started. Additionally, according to Yeh, mold manufacturing can become more intricate when you’re dealing with complex product designs, which also slows things down.

“To stay competitive in a rapidly changing market, manufacturing design capabilities must meet these demands quickly,” he explained.

In this study, the researchers compared 3D printing with CNC machining and reverse engineering, which have traditionally been used to manufacture optical components.

“3D-printing technology holds significant promise for producing optical components by allowing rapid prototyping of product designs, enabling designers and engineers to quickly validate the aesthetic, structural, and functional aspects of their creations,” said Wei-Min Chen, a doctoral student at Tunghai University. “Additionally, it makes it possible to bring intricate and innovative designs to life, shortening the development cycle for new vehicle models and boosting overall market competitiveness.”

The research, led by PI Chia-Hung Yeh (left) and doctoral candidate Wei-Min Chen (right), was conducted at the Digital Design Engineering Laboratory, Department of Industrial Engineering and Enterprise Information, Tunghai University. Credit: Chia-Hung Yeh, Tunghai University

The researchers used a headlight lens as their case study. They used a fairly inexpensive resin material to 3D print 14 lenses in one 8-hour print cycle, which means that the technology can improve operational efficiency, support one-off prototype design manufacturing, and speed up production for small-batch manufacturing of varied designs.

In evaluating the production results of their 3D printed headlight lenses, the team also found that the technology offers excellent surface quality and precision. The researchers analyzed several important aspects of the lenses, such as surface profile and roughness, height and diameter, light transmittance, and radius of curvature. They reported a minimal curvature radius error, and a 93% transmittance, which exceeds that of a commercially available polycarbonate (PC) lens with a 90% transmittance. The 3D printed lenses were comparable, though not better, than CNC machined ones with a 94% transmittance and reverse engineered samples with 91% and 94% transmittance. Finally, they determined that the 3D printed headlight lenses were more cost-effective than traditionally manufactured versions.

A new study demonstrated the benefits of 3D printing for manufacturing, using a headlight lens as an example. 3D printing achieved exceptional precision and surface quality while also outperforming traditional methods in production efficiency and cost-effectiveness. The image shows the Luce Memorial Chapel in Taichung, Taiwan, viewed through one of the 3D printed headlight lenses. Image Credit: Chia-Hung Yeh, Tunghai University

“3D printing offers key advantages, such as consolidating multiple components into a single structure, reducing manufacturing costs, and simplifying assembly,” Yeh concluded. “Overall, 3D printing in optical applications improves design flexibility, cost efficiency, and sustainability, positioning it as a transformative force in the industry as technology continues to advance.”

To asses the performance of 3D printed headlight lenses in more practical settings, the researchers now plan to look into particular headlamp module combinations and evaluate the internal elements, like structural design, fixture temperature, and operational environment.

At our Additive Manufacturing Strategies (AMS) this week in New York City, there were several panel discussions and presentations focusing on themes that are related to this research, such as “The Polymer Toolbelt,” and a session focused on Transportation, with talks including “AM for Mobility” and “Integrate to Scale – How Additive Manufacturing Works for the BMW Group.”