Massivit3D’s New Solution for Large Composite Mould Making

Mould making in fibre-reinforced polymers, or simply composites, are undoubtedly the change that disrupted how we use and understand materials as the essential resource for manufacturing and design. This great remedy that materials science offers is not just another technology, but a new age in humanity, just as stone, bronze, and iron once did. But just as good news arrive, new challenges arise. Composite part manufacturing isn’t a simple matter at all! As material science develops, tool making processes are also in the middle of the 3D printing revolution. Please keep reading to find out how the upcoming Massivit 10000 (MTB) solution is taking giant steps in mould manufacturing and design processes for large composite parts by reducing exceedingly long and complex workflows into just a few steps!

Mould Making Composite Parts

In basic terms, composite materials combine very thin strands of materials (mainly fibreglass, carbon fibre, or kevlar) within a matrix of resins like epoxy, polyester, vinyl esters and polyamides. If done correctly, the mix will result in parts with high-performance properties (Stiffness, tensile and compressive strengths, elasticity, hardness, etc.).

Benefits

–Strength to weight ratio: Composite materials can deliver exceptional performance for structural applications while remaining lightweight. Considering how important this is for aerospace engineering, this advantage is gold!

–Versatility in design: Composites are anisotropic, meaning that their performance depends on how the fibres are placed within the resin. Every detail like fibre orientation, weaving pattern, number of layers, which resin is used, and the moulding process’s efficacy can make the design process a headache when determining your application’s best configuration. Looking at the bright side, the opportunity to experiment and optimise your design according to your requirements is priceless. The design freedom that manufacturing processes afford is an indispensable asset for achieving complex geometrical shapes, like aerofoils, with less effort than with other materials.

–Part consolidation: Composite manufacturing enables engineers to make seamless and continuous parts. For other, more traditional materials, integrating their separate elements into one and getting rid of undesirable failures between joints wouldn’t be possible, so the less, the better! The perfect example is, without a doubt, the continuous construction of big boat hulls.

–Insulation properties: It is typical for reinforced materials like fibreglass to provide exceptional insulation properties for heat, electricity or liquid.

–Very stable and durable: Composite materials are typically very resistant to environmental effects like chemicals, corrosion, biological and combustion, assuring a long life of usage. Another aspect to why it is the choice for precision engineering is their dimensional stability due to variability of temperature and other factors, which allows working with very tight tolerances.

–Shock resistance: Materials like kevlar have unique properties for dynamic impacts. Its use for ballistic and defence design is the best example.

Applications of Mould Making

Composite materials have become a must for high-end projects like military and aerospace. However, as production processes improve, composite materials are growing to become part of everyday consumers goods. Some of their main applications are:

–Aerospace: Perhaps the best example, current aerospace technology not only benefits from composites, but it also wouldn’t be possible. Reducing weight is one of the main concerns in the aerospace industry; every gram that can be taken out involves massive performance boosts. Please check out this article to read further into how important composite materials contribute substantially to cost reduction.

–Marine: Today, the use of composites in this sector is just another widespread phenomenon. Large and continuous boat structures are built to take the best advantages of these materials to achieve durable, resistant and buoyant solutions that allow these vessels to overcome the harshest environments.

–Automotive: Fibre reinforcement parts are quite popular when it comes to beautiful car panels, but there’re many other applications for inlet and outlet manifolds and insulators.

–Ducting and pipping: Optimal surface properties for fluids systems.

–Construction: Used as internal reinforcements for concrete structures, an outstanding alternative to conventional steel solutions.

–Consumer Goods: As time passes, these remarkable materials permeate into everyday-use goods. The main area of adoption has been sports equipment like golf clubs, racquets, surfboards, skis, and even bike frames! However, there are many other uses like luxury items with gorgeous surface finishes.

Mould Making Tools

It’s hard to think about succeeding in any manufacturing endeavour without the use of tools. The production of composite parts is not the exception at all; achieving the final shape heavily relies on mould making. Mould patterns come in many ways: male cores, female cavities, caul plates, mandrels, bladders. Still, the objectives are always the same: 

-Achieve the intended shape, surface finish and retaining dimensional accuracy by avoiding thermal expansion during the curing processes.

-To properly join the fibres within the matrix without leaving voids.

-Achieve strong enough structures to endure wide ranges of temperatures and pressures during the curing process.

-To have enough chemical, UV, degradation and moisture resistance.

-Being able of releasing the part after curing without damaging the surfaces in multiple cycles.

To fulfil these requirements, manufacturers come out with many ingenious ways. Bladder moulding, vacuum bagging, OOA (Out of autoclave), wet layup, and compression moulding (Which we’ve reviewed in another article) are some of the most common composite forming methods. For more details on these processes, click here.

Large Mould Making Process and Its Challenges

As intended parts get larger, the mould making workflow gets tougher. New limitations arise, completion times become endless and more skilled hands are needed to tackle every small detail which can become significant inaccuracies or even fatal errors in the final result.

Plug Phase

Every process must start with the plug creation, the base pattern from where the mould takes its form. Given its size, it becomes a real challenge to make large complex shapes in one continuous piece with a firm structural composition. In most cases, Styrofoam or polyurethane sections, along with a plywood frame support, are cut and glued together to get the initial shape. Obtaining the smooth and glossy surface can be an even more laborious task. The following videos briefly illustrate the patience, dedication, materials and expertise needed just to make the plug.

In a simplified manner, these are the steps of mould making:

1-Cut the foam and plywood sections either by hand or CNCd.

2-Place together the parts.

3-Stabilise borders.

4-Trimming, sanding, filling.

5-Employ fibreglass lamination to protect the foam from the filler putty.

6-Apply layers of sandable putty and sand it until it gets a smooth shape.

7-Spray primer and polish it to get the desired glossy surface.

8-Apply wax.

Making the Mould

Now, we can finally make the mould itself. These moulds are made of highly durable composite bodies with an epoxy tooling coating at the cavity surface. So, why this coating? Well, it ensures a smooth, polishable and durable surface that can resist multiple releasing cycles. Moulds can have as many parting lines as needed. But as you add them, would mean a more labour-intensive process. The following video shows more details on the construction.

Summarising the last steps of mould making:

1-Identify parting lines to apply separation flanges.

2-Coat with PVA releasing agent (By the way, the same material used for water-soluble supports in 3D printing).

3-Apply the tooling gel coating.

4-Apply layers of reinforcement fibres, which materials and how you apply them differs for each design. Some moulds are made entirely out of fibreglass, while others can also have layers of carbon fibre.

5-It’s a common practice to cover it with a vacuum bag for resin infusion.

6-Apply resin and leave for curing.

7-Release mould.

We took the effort of dissecting the whole process just to get to this point: The results are extraordinary, but going through the process might not be worth it. Unless there are other ways to achieve this…

Massivit 10000 (Massivit Tool Builder)

3D printing solutions for composite manufacturing is nothing new. Markforged, for instance, has been doing it for years! However, a solution that directly tackles the mould making headache, especially large moulds, is something never heard of before.

Massivit3D is a 3D printer company unlike any other. Since inception, their focus has been on making printers for huge parts based on their unique Gel Dispensing Printing (GDP) technology. Massivit3D understood that composite tooling challenges must be addressed, so they produced the upcoming Massivit 10000 (MTB) just for this issue.

How Does It Work?

By using the Cast-in-Motion (CIM) technique. This impressive machine prints a sacrificial pattern while simultaneously casting a part made out of a high-performance thermoset resin, for instance, their proprietary epoxy formula. The sacrificial pattern enables a high-speed and accurate printing of a water-soluble structure with a smooth surface finish. Just behind the printer head, the gel dispensing head pours the resin that will directly take the shape of the final composite mould without having to build the plug! The cured resin alone can satisfy all the requirements a mould design needs. Everything that, by traditional means, takes several steps, now you just need to follow only these five:

1-CAD design and slicing.

2-Print mould.

3-Remove the pattern by dissolving it in water.

4-Oven cure.

5-Sand and polish the surface.

So, What are the Benefits?

-Shorten production time of moulds by 80%.

-Save up to 90% of manual labour.

-Significantly reduce tool costs.

-Simplify production, achieve higher yield.

-Simplify the supply chain and reduce required stocks.

-Reduce the waste of expensive materials.

-It leaves space for experimental iterations and rapid prototypes.

CAD part to CAD mould design enables improved accuracy, consistency and higher reliability. Additionally, with the Massivit Smart Slicer, optimising print settings helps to meet the design requirements efficiently.

Wrapping up

We are excited for the future to come in regards to what large composite parts production will offer and how it will be more accessible in terms of costs reduction. What do you think we’ll get in terms of innovation and new design opportunities?

To get further information on 3D printers and 3D scanners, Solid Print3D is here to help you! For more information, call Solid Print3D at 01926 333 777 or email at info@solidprint3d.co.uk