3D Printing Composite Tooling vs. Traditional Composite Tooling: What are the Differences?
3D printing composite tooling is a method that is rapidly growing in popularity, and has many applications in different industries. It allows for a shortened production time, and improves the possibilities for design customization and flexibility, while being overall very cost-effective.
Composite tooling refers to the production of molds and tools which are then used to manufacture a composite part. A typical composite part is made out of carbon or glass fiber. Composite products respond to the need for parts that are strong, durable and lightweight at the same time. Composite parts are used in many different fields, such as the automotive, aerospace and medical industries, and even in the production of consumer goods, such as tennis rackets.
Traditional composite tooling is mainly produced by CNC milling machines. A CNC milling machine is capable of carving a shape out of a larger block of material; the shape can be a mold or it can have the same shape and dimensions as the final part (i.e. a plug). The material that is used can be PU foam, metal or a tooling block. This process creates a lot of waste materials, especially when dealing with large scale composite tooling (1 meter or larger).
3D printing (i.e. additive manufacturing) composite tooling uses 3D printers to create tools and molds, which are then used in the production of parts, and has a number of differences to traditional composite tooling, as well as a number of advantages when the two are compared. More and more companies turn to 3D printing composite tooling because of its relative ease of use and its cost-effectiveness, as well as the improved design flexibility that is possible with it.
3D printing composite tooling begins with the design of the tooling part in a CAD program, where the design is laid out. After that, it is printed out with a 3D printer. This allows for having fewer seams, and for managing complex designs that prove to be challenging when using traditional composite tooling methods. You can even 3D print with materials that can be dissolved in a liquid: once the part is produced and cured, the tooling can be dissolved in a solution, allowing for the production of extremely complex parts with a single tool.
We’ll now look into the main differences between using 3D printing for the production of composite tooling and traditional composite tooling.
3D printing composite tooling significantly reduces production time
With 3D printing, the production process is significantly shortened, allowing for companies to accommodate to accelerating composite tooling production cycles. Projects that are particularly time-sensitive can benefit enormously from the flexibility and swiftness that 3D printing provides, as designs can be rapidly modified.
This proves to be an important advantage especially for large format composite tooling.
Example: Composite boat mold
Let’s consider an example: producing a boat mold by using traditional composite tooling methods. There are a number of production steps to follow. Firstly, a very large CNC machine will carve out the rough shape of the final part out of polystyrene foam. After the rough carving, a worker has to cover the surface with a PU foam paste. This PU foam paste will harden, which this allows for a more detailed milling operation with the CNC machine. The finished product is a foam representation of the finished product. The technical jargon for this foam representation is “a plug”.
Finalizing the plug, the production of the mold can start. Most often, this process starts with applying a gel coat at the surface of the plug. After that, several layers of fiberglass and epoxy are applied. This process is done manually and can take days (or weeks) of work. The next step is the manufacturing of a steel frame which is applied to the outside of the mold, after curing the fiberglass. This provides additional strength for the final mold, so that it can maintain its shape. After that, the negative mold can finally be removed from the plug. The final mold can be used to make the composite boat, as intended. As you see in this example, the traditional way of making large format composite tooling is very labor-intensive and time-consuming.
With large format 3D printing, the composite tooling production process can be shortened to days instead of weeks. Firstly, a near net shape of the neagtive (and final) mold is printed. With pellet extrusion 3D printing machines this can be done in a matter of several hours or days. After 3D printing the large format composite tool, a CNC machine will smoothen the surface and bring the part within the required tolerances. The machining process is only used as a finishing operation, which saves a lot of machining time. After the machining process, the mold can be used directly. There is no need to make a plug, and then a negative mold – the negative mold is printed directly. A separate steel frame is also not needed – the frame can be printed together with the mold itself.
As you can see, with 3D printing, the composite tooling production process can be shortened to days instead of the weeks or months needed for traditional composite tooling.
3D printing composite tooling can be very cost-effective
Using 3D printing technology allows for a much more cost-effective production process, as the production time is significantly shortened, and the multi-step process needed for traditional composite tooling is simplified.
3D printing can be used for the production of a low volume of composite parts, and provides engineers with the possibility to quickly alter and adapt the tooling design, as necessary, and produce a number of variations for a fraction of the cost of traditional composite tooling techniques.
Large format 3D printing of composite tools saves on material costs, since the mold can be printed in a near net shape.
3D printers are versatile and can be used for a number of possible applications, such as to produce tools, fixtures, jigs and molds, thus justifying their initial cost and bringing down total production costs over time. Because of this, composite tooling manufacturers who use 3D printing can be more versatile and provide a multitude of possible solutions to their clients, while keeping costs down.
Design flexibility is improved with 3D printed composite tooling
Freedom of design can be extremely valuable for some projects, and the possibility to rapidly create and introduce new designs into the production of parts is sometimes crucial.
Design customization is significantly easier with 3D printing, as designs are quickly modified and a few iterations can be created, without significantly increasing neither the time that is necessary for their development, nor the production costs.
Additionally, more complex tooling designs are possible, as 3D printing allows designers to work effectively with inner surfaces and parts that are difficult to access. Designing complex parts with intricate geometry is not an issue with 3D printing.
This is why trapped tool designs are made significantly easier when using 3D printing for making composite tooling: it is possible to manufacture complex parts that completely enclose the tools in a much simpler way, compared to multi-piece tools required in traditional composite tooling. This allows for an unparalleled design flexibility when dealing with complex designs.
This leads us to the next point:
3D printing allows for washing out of the tooling, leaving only the finished part
Removing the tools after the production and the curing process of complex, hollow parts has been a challenge for traditional composite tooling for a long time, and 3D printing provides an efficient solution to this problem. Overall, the removal of the tooling from the composite part is made much easier with 3D printing.
3D printing allows for sacrificial composite tooling, where the tool material can be dissolved in a solvent (or even in water, depending on the materials that are used) after curing, leaving only the cured composite part. After that, the part can be used as necessary on the assembly line. For this reason, using 3D printed composite tooling is particularly useful when the part fully covers the tool, where removing the tool is problematic or requires complex solutions.
In this article, we have outlined the main differences between 3D printed composite tooling and traditional composite tooling. In short, 3D printing allows for a faster & easier production process, where improved design flexibility is possible – designs can be easily modified and adapted to engineers’ needs. Cost efficiency is another important element for 3D printing composite tooling, as 3D printers are versatile and have a number of possible applications.
Additionally, sacrificial composite tooling is made possible with 3D printing, where the tooling can be washed out after production & curing of the parts.
Overall, 3D printing gives composite tooling manufacturers the possibility to be more flexible and adapt to the demand of shorter production cycles, while growing their portfolio and guaranteeing that application needs can be successfully met, and won’t be restricted by the limitations of the production process.
CEAD is a developer and manufacturer of large scale 3D printing equipment. The development of the AM Flexbot has a focus on 3D printing of large format composite tooling, combining the power of pellet extrusion 3D printing and 5-axis CNC machining. More information regarding the AM Flexbot can be found here: www.ceadgroup.com
Would you like to learn what 3D prinitng of composite tooling can bring to your production process? Get in touch!