Wet layup is a common manufacturing method employed in the composite industry across many sectors where the strength to weight ratio is important. Some examples of components manufactured using the wet layup process are, wind turbine blades, sailboat masts or even the performance bicycles and high-end skateboards.
Conventional wet layup processes (i.e. vacuum infusion, hand layup, compression molding, etc.) carry many challenges that need to be addressed. These processes involve placing composites fibers in a mold of the required shape and impregnating it with two-part epoxy. The processes are often labor intensive and quality consistency of components is heavily dependent on the workers’ skills. This increases waste and cost for quality control. Additionally, the processes expose the workers to toxic epoxy and its fumes, thereby raising health and safety concerns. When working with epoxy, it is essential to avoid contact without the proper personal protective equipment (PPE), as severe skin irritation and/or headaches can occur.
Addcomposites has developed the Automated Wet Layup (AWL) tool to address these concerns. The AWL tool is an attachment that can be mounted on a pre-existing industrial robot. The tool is delivered with external control systems and software packages needed to integrate it with the industrial robot. The software packages consist of necessary libraries and configurations for integration with the robot controller, and an offline programming software with robot simulation.
As shown in the picture below, the AWL tool takes the dry composites fibers in tape form and two parts of the epoxy separately as input. The tool deposits the composite tape on the mold while impregnating it with the 2 part mixed epoxy as the robot moves along the shape of the mold. The 2 part epoxy is mixed in-situ and in real time during the layup process.
The video below demonstrates the Addcomposites AWL tool in action
Advantages of the Addcomposites AWL tool are:
The AWL tool eliminates human error during layup, while keeping workers safe from epoxy exposure during the layup process.
Since wet layup epoxies can cure at room temperatures, this process can also be used with low-temperature molds that are 3D printed, form or wood. Thereby reducing the mold cost.
The need for expensive autoclaves (pressurized ovens) also becomes optional.
Since the epoxy is mixed in real time when needed, AWL tool eliminates the need of expensive cold storage facilities that are typically required for prepregs in Automated Tape Laying (ATL) machines.
The AWL tool ensures consistent consolidation and impregnation of the fibers and epoxy. This reduces the overall quantity of epoxy needed to produce the part. Note that the epoxy content in the cured part will still depend on the vacuuming process.
The AWL tool by Addcomposites addresses a concern in the composites industry, which is affordable and accessible automation. The demand for composite parts has drastically increased in recent years, and the current hand layup processes are becoming outdated and costly. Addcomposites created the AWL tool for small to medium volume production runs to bring automation and manufacturability to everyone in order to meet production goals.