# Automated Cold Embossing for the Integration of Optical Lenses onto the Surface of Acrylonitrile Butadiene Styrene (ABS) 3D-Printed Parts

## TL;DR

This paper introduces an automated cold embossing method to add optical lenses onto 3D-printed ABS parts, improving manufacturing efficiency and precision.

## Contribution

The novel automated cold embossing process enables high-speed integration of micro-lenses onto 3D-printed ABS components.

## Key findings

- Precise embossing time (0.1 s) produced high-quality lens features on ABS surfaces.
- Insufficient embossing time or excessive duration hindered successful feature replication.
- Vapour smoothing effectively softened the surface for embossing, and a KUKA robot enabled rapid automation.

## Abstract

This paper presents an experimental study of a novel automated manufacturing process that integrates cold embossing to add complex features, such as micro-Fresnel lens designs, onto a 3D-printed ABS polymer component. The research demonstrates that precise control over process parameters, including embossing time (Et) and velocity (Ev), is critical for successful feature replication. Gloss analysis confirmed that surface softening as a crucial prerequisite for embossing was successfully achieved using a vapour smoothing (VS) chamber that was developed and optimised for the process. High-speed automation using a 6-axis KUKA robot allowed 48 embosses to be completed in just over one minute, highlighting its efficiency over conventional hot embossing (HE) methods. Results showed that an Et (0.01 s) prevented feature replication as there was insufficient time to allow for polymer flow, while an optimal Et (0.1 s) produced high-quality embosses across all test segments. Additionally, this study identified that while insufficient cycle times hinder polymer flow, extended durations can lead to surface hardening, prohibiting replication. These findings pave the way for integrating Diffractive Optical Elements into 3D-printed parts, potentially enhancing precision, functionality, and productivity beyond the capabilities of standard 3D-printing processes.