Ceramics and digital design are worlds apart—practically a study in opposites. This presents a fascinating challenge when they have to be combined: how can you take the traditional materials and methods of producing ceramics and link them to modern 3D technologies?
It was during my Design degree studies at Liverpool Hope University in the U.K. that I first came across ceramics. Ceramics have always been a fun and interesting material to work with, almost like playing with play dough. But hand building or throwing traditional pots held little interest. Instead, I became captivated by the precision of using plaster molds and slip casting.
(Image Credit: Jens Steffen Galster.)
However, the process of creating the model for a mold felt rather old-fashioned and quite time consuming. Once the model for a mold was produced, there were then many ways that the mold might not work out. Models for molding are usually created from either plaster or clay, but this meant that the model could either break easily during the mold process, get stuck in the mold because of undercuts in the model or the precision and details I wanted were too difficult or even impossible to achieve.
I started to research the different ways of integrating the two, to achieve something which would otherwise be impossible to create in ceramics without the use of 3D technologies. This meant that I had to know the limitations of traditional ceramic production methods. When it comes to ceramics, plaster molds and slip casting are the most precise method of ceramic production.
(Image Credit: Jens Steffen Galster.)
Taking this into consideration, I began designing my ceramics in SOLIDWORKS. I use SOLIDWORKS like I use my sketchbook—I can design a whole range of pieces without going through the lengthy process of creating them in clay only to find that I’m unhappy with the design. Using SOLIDWORKS, I can create a whole range of pieces and play around with the composition of a collection. I can also render the designs with SOLIDWORKS Visualize and test out colors and finishes.
I used different projects throughout my degree to test out different designs, as well as to test different manufacturing processes, including laser cutting, 3D printing models for molds and even 3D printing the molds themselves. The first project was designed to incorporate laser cutting for a sculptural vessel collection inspired by layered rock formations and ice bubbles caused by volcanic gases. I revolved traditional vessel forms within SOLIDWORKS and within an assembly. I attached several different sized bubbles onto the vase. Once I was happy with the composition of the vase, I saved the assembly as a part and combined them into one solid body. Some designs were done in the opposite way, with the bubbles instead being taken away from the vessel body to produce craters in the body.
(Image Credit: Jade Wilson.)
The vase was then ‘split’ into 5mm layers using the SOLIDWORKS split tool. From here, I could select all the top faces of each vase layer and export them as DXF files for laser cutting. The layers were cut from 5mm thick sheets of Perspex (an engineering plastic) and reassembled into the vase shape. I used superglue to join sheets together, but also had to scrape away the melted edges created from the laser cutting process. If this edge had been left on, it would have caused an undercut on the model, which in turn would cause it to get stuck in the plaster mold or break edges within the mold.
There are many advantages to using the laser cut Perspex model. First, the model would stay intact throughout the whole molding process. Second, I could pre-plan the overall size I wanted the final casting to be out of the mold, and account for the tolerances within SOLIDWORKS to scale up the model. Another advantage is that I could laser cut multiple models and they would all be exactly the same. From the solid model, I could make multiple molds from one model and have the opportunity for mass production.
When it comes to the disadvantages of this method, I must say the design capabilities of this modeling style are limited. The design must be layered in some way. To achieve a smooth finish, I had to look at 3D printing. With 3D printing, the possibilities were endless.
Moving on to my next project, I wanted to create a tableware collection. While designing my collection, I decided to create something that would be impossible to do without the use of 3D modeling and printing. My work is usually inspired by nature and patterns found in nature, so for this collection I looked to crystal formations. Just like the previous collection, I took a similar approach by combining and subtracting crystal shapes in SOLIDWORKS from tableware forms. This was a feature I added to the drinking cups to not only add a decorative style to the tableware, but also add an ergonomic holding feature for the person using the cups.
(Image Credit: David. J. Colbran.)
The finished design was scaled up by 12 percent to account for clay shrinkage during firing. It was then saved as an STL file and 3D printed using a polyamide material. I discovered the hard way that the surface finish created by most 3D prints isn’t perfect, so it took some trial and error before the process was perfected. I realised that I needed to prep the print surface, so I used a car filler spray paint to fill in the print’s resolution lines. I would then seal the print using a layer of clear lacquer spray paint. Sealing the print ensured two things: less friction on the 3D print surface, making it easier to remove from the mold; and using the lacquer would protect the print from the water and heat created by the plaster while it sets.
Once I have the 3D printed model, I can use it to create multiple molds for slip casting. The 3D printed model is also robust enough to mold from without the model becoming impaired. I think the biggest benefit of designing my pieces in SOLIDWORKS first was that I could test out my mold within a mold to work out split lines. This helps speed up my production casting.
Rendering using SOLIDWORKS Visualize. (Image Credit: Jade Wilson)
3D printing has also allowed me to see my final product “in the flesh” before committing to making the mold. I can test functionality and size, which has been particularly helpful while designing a tableware collection. I have been able to test the grip of my cups – an important feature, as they were all designed without handles. The lack of handles meant that I needed to add a double-walled feature to allow the cup to be functional. I used the SOLIDWORKS intersection tool to create a body within the cup’s cavity, and the evaluate tool to test out my cup models for their volume capabilities. This allowed me to see how much liquid each cup could hold, and I could modify the model to account for this. By doing this, I could create and print a perfectly-sized model for molding in plaster.
Another benefit of using SOLIDWORKS for my designs was the undercut analysis found within SOLIDWORKS. This tool was invaluable to test out the models before 3D printing them. It was especially useful for designs that I wanted to create as one-part molds, also known as drop out molds. Single part molds can often be seen as simple molds but I could create extremely detailed designs by using SOLIDWORKS.
(Image Credit: Jade Wilson.)
I used SOLIDWORKS from start to finish for my ceramic designs. I used it to design my pieces, scale up parts to account for shrinkages, test models for undercuts, work out how many mold parts were needed to create the final mold, prepare models for laser cutting or 3D printing and render final models to predict the outcomes of my designs.
Once I knew using a 3D print was successful in mold making, I wondered if I could further speed up the whole molding process by just 3D printing the mold. However, it is not yet possible to 3D print with plaster absorbent enough to slip cast from, as the plaster is fused with glue. Instead, I decided to 3D print parts that I could fill with plaster to create the mold parts. In the ceramic industry, this is known as a master mold. A master mold is usually made with a much tougher and a more resilient plaster that you can mass produce molds from. Using this technique, I was able to carry out my ‘Mold of a Mold’ project which enables you to mass produce a ceramic piece.
Rendering using SOLIDWORKS Visualize. (Image Credit: Jade Wilson.)
This project ran alongside my tableware collection and was purely experimental, allowing me to really push the boundaries and discover the possibilities of 3D printing and ceramics. For this project, I had to start by designing the final piece I wanted to get out of the molds. Initially, this involved modeling a geometric mini vase in SOLIDWORKS. From here, I needed to model the mold of the vase, which I could do in SOLIDWORKS very quickly using the combine and split features. From this point, I needed to create molds of each mold part. The casting mold was in three parts, with each mold part needing a two-part mold to create it. Once I had these, I saved them all as STL files and 3D printed them using a similar Polyamide material to the one I used in previous projects.
The molds consisted of three, two-part molds. These had to be tied together and filled with plaster to create the mold parts of the final casting vase mold. Once the plaster mold parts were dry enough, they could be cast in liquid clay, known as slip. The slip I used was a Parian slip, which has a shrinkage rate of 15 percent. With this being a purely conceptual/research project, I didn’t account for the shrinkages in my modeling process. I designed the vase to be miniature for two reasons: the project was an experiment and its always best to start small, but also for cost reasons. At this point in time, I was a university student and the project involved printing six parts to create one design, which would have been costly.
(Image Credit: Jade Wilson.)
Apart from those limitations, this project was successful for a number of reasons. I could make several molds from the 3D printed master mold, which allowed me to cast multiples of the miniature vase at once, again creating a mass production opportunity. Another plus was the speed in which I could produce the casting mold from the print. Creating molds in the traditional method could take me one to two days, whereas this way, I could pour a mold every one to two hours.
The overall advantage of creating a design in a 3D software such as SOLIDWORKS is that you always have a backup of your model. Depending on my design, if a laser cut or 3D printed model is lost, damaged or more molds are needed, the file can be used to laser cut or 3D print another at any point. It is always ready to go!
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About the Author
Jade Wilson is a product designer, SOLIDWORKS blog contributor, CSWP and SOLIDWORKS Champion from the U.K. In 2015, she became a Queen Elizabeth Scholar for her degree specializing in ceramics and digital design. She is a self-taught SOLIDWORKS user with 10 years’ experience, and has been using it to inform and create her designs since her university days, up to now as a freelance product designer with her own company. She holds bachelor’s and master’s degrees in Design and specializes in the design and production of ceramics, homeware accessories and wooden toys. She has worked with a range of companies, including the BBC, Bigjigs, Great Little Trading Company and Granby Workshop. She has exhibited her own work and held workshops across the U.K. and Europe as well as working in several U.K. universities as a technician and guest tutor. She now creates fun and informative tutorials and blogs for SOLIDWORKS as a blog contributor, sharing her knowledge and ideas with others.