Our recent webinar ‘How to Revolutionize Your Architecture and Construction Business with 3D Printed Formwork’ was an exciting opportunity for us to connect with other 3D printing, construction and architecture enthusiasts. We had a great group of attendees there on the line asking questions of our webinar hosts, Jörg Petri and Tobias Wallisser. Due to limited time, Petri and Wallisser were not able to answer all questions on the day, so we contacted each participant with answers to their questions afterwards.
Many of the questions were very topical and great opportunities to explain some more context behind the scenes of BigRep and NOWlab projects, and Petri’s view of construction in the future with additive manufacturing. So, we decided to publish the answers here below!
Remember, you can easily watch the webinar for free here.
Can you go over the purpose and type of sensors you are embedding? Are you embedding them in the concrete or the plastic part?
The sensors were embedded in the concrete using a 3D-printed protection ring. We used capacitive sensor technology, so the closer you get with your hand, the stronger the signal. The sensor itself can be printed as well, as we did in another project: The Modular Wall.
Can you address cost of 3D printing vs. milling at this scale? We have found machining to be a lot cheaper.
To do a proper calculation, you have to look at the whole process chain. As print times are increasing, this calculation is no longer valid anyway. One of the clear advantages of 3D printing the formwork is less material waste. If you are milling, you will always use a massive block of a low-quality material like styrofoam, the waste for which cannot be easily recycled. After on-site use, the casting element is declared as toxic waste that has to be disposed of at high cost to the producer. In addition to this, you generally have to cover the milled part with epoxy to achieve the necessary strength.
The advantage of 3D printing over milling is that you only use the material you need to form the concrete, and you can print using high-quality polymers that are recyclable. If the strength is sufficient, you can print PLA as a biopolymer – you do not need to recycle it, as it is biodegradable. It is also possible to produce undercuts with flexible materials like a TPU-based filament (Pro FLEX) or a water-soluble PVA.
For each company, the cost and time saved used 3D printing will vary. However, we have found that many customers manage to significantly reduce their time to market. Milling can be cheap, but then can also take up to
several weeks longer than 3D printing molds, for example. So, the saving in terms of resources, material and competitive advantage are substantial. Here is a video providing some examples of time and cost savings that some of our customers have experienced.
Furthermore, the advantage of 3D printing is that it can fit into the production process – it does not have to replace it all together. We find that sometimes customers use traditional milling methods for some parts, while they use 3D printing technology at other stages of the production chain.
Can you also address direct 3D printing of concrete without molds vs with molds?
As mentioned briefly in the webinar, both technologies will play their part on the future building site. The current resolutions for 3D printing do not allow for the production of a visible concrete wall with the necessary surface quality demands.
Furthermore, speed will be an issue. If you reduce the printing resolution,it will be too slow and thus the advantages of using 3D printing are somewhat diminished.
The issue of reinforcement of 3D printed concrete walls is still waiting be solved. That is the advantage of the molding – we are tapping into an existing method and simply changing it slightly. This way, we retain the standards and methods used on-site with in-building pipes, establishing reinforcement, etc. Eventually, this technology and requisite methods will have been developed, but for now, it’s a good start: we’re focused on how replace or optimize some parts in the process chain.
What are the UV properties of BigRep materials? Have you done any testing for outdoor end-use applications?
We are moving through this process currently, to put our latest materials through new tests. We are using modified PLA, which resists temperatures up to 115 degrees Celsius. This is enough for the concrete, which would likely be exposed to the heat from sunlight. Our material development continues, and we will be working on new ones to withstand high temperatures and retain their strength and surface quality. Stay tuned for the end of the year when we have a big announcement surrounding this topic!
Can you develop on formworks recycling process?
We are in the process of testing this right now, to understand the best ways to clean the prints, ensure the safety of any toxic materials etc. So, there is no firm guideline for recycling yet, but it certainly is an important factor in the construction process, as 3D printing moves forward to become an important part of the process.