Developing Moulds by 3D Printing: Advantages and Limitations

3D printing offers an ideal option to create products that are traditionally made with moulds without the need to use one. But this does not mean that the creation of moulds will be set aside forever. On the contrary, the technology of 3D printing has been taken to the construction of moulds quickly, effectively and economically.

With the advances in the science and engineering of materials, you can already build 3D printed moulds with metallic or resin materials. One of the advantages of designing moulds that can be printed on a 3D printer is that you can quickly obtain finished moulds in less than a day, and designers can quickly test and validate a design, iterate several times and make rapid improvements to the design in each step.

The use of 3D printing for the manufacturing mould allows prototypes to be made quickly and with great precision. The objective of this system is to accelerate and perfect the design of the final piece before mass production. Let’s analyse the advantages and disadvantages of this revolutionary system:

Advantages

The use of 3D printing machines for the development of moulds accelerates the process of prototyping parts. These machines are capable of printing complex geometric shapes quickly. Thus, the moulds can be manufactured in just a few hours, while conventional methods require weeks or months.

When it comes to customisation in the creation of moulds, it can be as immediate and frequent as the team of engineers considers necessary, which makes this type of machines the perfect ally during the product development processes, in order to obtain greater guarantees and lower probability of error in the production phase. Also, a shorter and more flexible process results in a significant reduction in costs and times, with shorter delivery times.

Some moulds created with ABS material (with FDM 3d printing technology) can produce moulds with the precision and resolution of a microscopic layer (100 microns), with an accuracy of +/- 0.2 – 0.4 mm. This will be comparatively a low cost solution.

Moulds created with Nylon material (with SLS 3d printing technology) results in output with the precision and resolution of a microscopic layer (60 microns), with an accuracy of +/- 0.1 – 0.2 mm. This is comparatively high priced solution. However, the surface finish and accuracy is good.

Moulds created with resin material (with SLA 3d printing technology) can produce moulds with the precision and resolution of a microscopic layer (30 microns), with an accuracy of +/- 0.05. This method will cost you higher than the other 3d printing technologies discussed. However, results in product of great detail to the final piece.

Once the design files (CAD) are loaded, 3D printers start printing the part that does not require manual intervention on the machine. This technique minimises the risk of errors in the machining of a metal mould, if previously a test unit with 3D printing has been manufactured. In this way, we can perform one or several tests in the fuel transfer to undertake an initial series of parts. With these parts, the manufacturer can objectively verify if the design of the mould is adequate or if otherwise, it is necessary to make some modification before machining.

Limitations

Of course, as with all developing technology, there are limitations. One of them in the moulds printed in 3D is the texture, which can also be determined as the resolution of the material printed in 3D. The texture can be altered with quite varied finishing methods, but this must be balanced with the tolerance and the consequences of working with these methods.

If a wrong finishing method is used, the desired characteristics of the mould could be eliminated and its tolerance negatively affected, all without mentioning the cost that is added to the project.

There is still a size limitation to make moulds of very small dimensions in certain materials. Also, the mould industry believes that the compaction and the quality of the materials used is inferior to the injected moulds. The durability of the materials limits the use of these moulds to the prototyping of pieces. They are not suitable for series production, only for small runs and prototyping.

Some applications of 3D printed moulds in the industry

Automotive and aeronautics are the sectors that are mostly working these moulds to design their prototyping parts. On the other hand, we talk specifically about moulds made with 3D printers, we will find a trend in the sports shoe market. Recently few companies have presented models of shoes made with moulds made with 3D printers.

One of them is Peak, a Chinese company that has taken advantage of the technology of 3D printering in recent years to improve the quality of their products manufactured in mace, making molds for their shoes, originally on a personal level, with which they can accommodate the needs of each person’s foot, achieving as a final result a perfect shoe for the individual.

These moulds can be made in a matter of hours and represent a revolution for the world of footwear because you can take three-dimensional studies of a client’s foot and hence design printable inner soles, which is also ideal for patients podiatrists, who are suffering from pain to have to resign themselves from generic shoes.

The creation of the moulds with conventional injection machines entails greater cost and time lags before any re-adaptation of the developed design. In this sense, these 3d printing of moulds is ideal in sectors of great complexity that must constantly innovate in order to ensure their leadership in the market.

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