3D Printing with WELDPLAST 600 for Milan Polytechnic

Success Stories1 Sept 2023
Scientists from Milan Polytechnic and Leister engineers have used their synergy to produce architectural elements in impressive dimensions via 3D printing with the WELDPLAST 600-i. Read more about this and how the Leister extruder was used in the process in this blog post.

Author: Mariateresa Pirozzi, Marketing Specialist, Leister Technologies AG, Italy

The synergy was born of an idea that matured within the “Cultura Meccanica” project of the Department of Mechanics at Milan Polytechnic. The goal was to develop knowledge and skills for creating and reproducing architectural elements in impressive dimensions. These elements were to be produced in a 3D printing process using the Leister WELDPLAST 600-i extruder.

Integration of the WELDPLAST 600-i into Fanuc Anthropomorphic Robots

The science side of the project was managed by Prof. Francesco Braghin, Department of Mechanics, and coordinated by engineer Pierpaolo Ruttico, Department of ABC. The work site was located in the INDEXLAB laboratory of the Territorial Center of Lecco under the operational direction of engineer Carlo Beltracchi with the support of engineer Gabriele Viscardi and computational designer Khalid Alabdula.

The core of the research was the development of techniques for integrating the Leister WELDPLAST 600-i extruder module into an anthropomorphic Fanuc robot. This is because the extruder, attached to the robot arm, was to produce exceptionally large plastic elements via 3D printing. These elements were designed as independent, easy to assemble blocks of a modular architectural system.

Careful Placement and Perfect Matching of Components

Polypropylene reinforced with glass fibers is completely recyclable and was developed and supplied by the Dutch company. With the integration of the extruder into the robot, the various components were carefully placed and perfectly matched. The WELDPLAST’s control computer, power supply and connections were installed directly on the robot's “wrist” to create a compact, functional and user-friendly plug-and-play system. This arrangement allows the maximum flexibility of the robot on several axes. It also significantly reduces the risk of cable tangling and possible interference due to the distance between components.

Control via PLC for Precise Control of the Extrusion Process

The system is controlled by a programmable logic controller (PLC). This ensures precise control of the extrusion process and is triggered when the critical temperature for extrusion of the selected material is reached. The WELDPLAST 600-i proved its worth here with its printing speed of 50 to 75 mm per second, allowing the extrusion of up to 3 kg of material per hour. The extrusion material was fed into the extruder in 2.5 kg coils of 4 mm in diameter.

Creating Elements with Free Forms, both Flowing and Broken

One of the most striking results of this project was to create elements with free forms, both flowing and broken. The ability to create structures with significant overhangs is a significant advance achieved through a specific cutting strategy. This cutting strategy, developed by engineer Carlo Beltracchi and computational designer Khalid Alabdula, made it possible to overcome the traditional limitations of 3D printing, increasing the range of possible shapes and pushing the boundaries of innovation in additive manufacturing.

“Virtù Principesche” by Luigi Vanvitelli, 3D Printed

The video demonstrates how the “Virtù Principesche” by Luigi Vanvitelli (Italian architect, born May 12, 1700 in Naples, died March 1, 1773 in Caserta) is realized using an innovative 3D printing process. To do this, the Department of Mechanics of Milan Polytechnic collaborated with the Milan-based art studio Cracking Art.


An anthropomorphic robotic arm with six mechanical joints uses an extruder to deposit a polymer material layer by layer. An algorithm is used that converts the 3D models into motion commands. This additive manufacturing process is repeatable, but each piece is unique and combines art with advanced technology.

Discrete Architecture

At the INDEXLAB laboratory of Milan Polytechnic, Khalid Alabdula has been researching “discrete architecture”: his research focuses on components that are 3D printed to configure architectural structures. This innovative approach uses polypropylene reinforced with glass fibers and offers new possibilities in the field of architectural design.

According to engineer Carlo Beltracchi, Alabdula’s work could make an important contribution towards connecting the digital world with real life through the concept of the metaverse. He is exploring the use of discrete architectures printed in 3D form that feature modularity and flexibility. This enables the creation of an adaptable model that opens up endless possibilities for an architecture in which robotics acts as a link between the digital and real worlds.


The picture shows a series of elements created in the course of research on “discrete architecture”.