Projekt L2-50045

Kratko ime projekta: 2F-3D Print

Partnerji projekta in njihovi logotipi

Vodja projekta:
Lucija Hanžič

Vodja projekta na ZAG:
Lucija Hanžič

Link na SICRIS

Trajanje projekta: 01.10.2023-30.09.2026

Višina financiranja:

2294 ur cenovne kategorije B letno in 100 020 € od sofinancerja Tajfun Planina

2294 hours of cost category B annually and 100 020 € from co-financer ROCKWOOL

Povzetek projekta SI:

3D tiskanje je poljudni izraz za računalniško vodeno aditivno proizvodnjo, kjer oblikovanje izdelka poteka z dodajanjem, namesto z odvzemanjem materiala. Sam koncept aditivne proizvodnje ni nov, vendar pa razvoj računalnikov odpira nove možnosti. S tehnološkim razvojem se uporabnost 3D tiska širi tudi na področje gradbeništva, kjer je beton zaradi svojih lastnosti in široke uporabnosti v središču pozornosti. Poraba betona predstavlja ~80 % celotne porabe materialov, zato lahko tehnologija 3D tiskanja z betonom pomembno prispeva k digitalizaciji in avtomatizaciji na področju gradbene proizvodnje. Uvedba digitalnih metod pa bo spremenila tudi načine oblikovanja objektov, saj je topološko optimirane konstrukcije, kjer je poraba materiala minimizirana, geometrijska oblika pa kompleksna, možno načrtovati in proizvajati izključno z digitalnimi metodami.

Najobetavnejši način 3D tiska z betonom je ekstruzijsko tiskanje, kjer se beton črpa do tiskalne glave, na kateri je ekstruzijska šoba pravokotnega ali okroglega prereza. Premikanje tiskalne glave omogoča bodisi artikulirana robotska roka bodisi portalni žerjav. Obnašanje betonskega filamenta po ekstruziji je odvisno on njegovih reoloških lastnosti. Medtem ko trdoplastični beton omogoča nalaganje večjega števila slojev brez porušitve, pa je sprijemljivost med filamenti slaba. Mehkoplastični filamenti se dobro sprijemajo, vendar pa se pod težo naloženih slojev sesedejo. Sistemi za ekstruzijsko tiskanje z betonom se zato zanašajo na manipulacijo reoloških lastnosti in uporabo pospešil, kar pa zahteva specialna znanja in opremo za testiranje, oboje pa presega kapacitete gradbene industrije. V projektu torej predlagamo tiskanje z dvema filamentoma, kjer mehkoplastični filament poveže sloje trdoplastičnih filamentov, slednji pa ustvarjajo stabilnost tiskanega izdelka. Projektiranje tovrstnih filamentov je nezahtevno.

Za konstrukcijsko analizo tiskanih elementov so primernejše metode za zidane konstrukcije, kar je še toliko bolj očitno pri dvofilamentnem tisku. Zidane konstrukcije vzbudijo asociacije na opečne konstrukcije, oblikovanje opečnih zidakov pa poteka z ekstruzijo. To nas privede na idejo, da bi tehnologijo dvofilamentnega 3D tiska lahko uporabili tudi za izdelavo zgradb iz zemljine. Gradnja z nežgano zemljino, ki vsebuje ustrezni delež gline, je starodavna gradbena tehnika, ki v sodobnem času ponovno pridobiva na veljavi, predvsem zaradi okoljskih koristi in dostopnosti. Vendarle pa je za uspešno implementacijo nujno potreben razvoj digitalnih proizvodnih kapacitet, saj je pomanjkanje tehnologije za gradnjo z zemljino prepoznano kot tehnična ovira.

Cilji projekta so torej opredeljeni kot:
• razviti tiskalno glavo z dvema šobama in izdelati manjši prototip tiskalnika za dvofilamentni tisk, ki omogoča tiskanje z enostavnimi betonskimi in maltnimi mešanicami;
• opredeliti reološke parametre za oba filamanta, trdoplastični in mehkoplastični filament, tako za beton kot za zemljino, ter zastaviti sistem preprostih testnih metod, s katerimi je možno ugotoviti primernost filamentov;
• demonstrirati dvofilamantno 3D tiskanje z betonom in z zemljino na manjšem konstrukcijskem elementu, konstrukcijska elementa preizkusiti in rezultate primerjati s konstrukcijsko analizo izpeljano iz principov zidanih konstrukcij.

Osrednja rezultata projekta sta prototip tiskalnika in demonstracija tiskanja z dvojnim filamantom in sicer z betonom in zemljino, kar bomo predstavili v promocijskem videoposnetku. Rezultati v javni domeni bodo obsegali še poročilo o lastnostih filamentov iz betona in zemljine ter protokol in rezultate konstrukcijske analize. Zaupni rezultati bodo obsegali specifikacije lastnosti tiskalnika in načrte za izdelavo posameznih delov ter celotnega tiskalnika. Pričakujemo, da bodo javni rezultati objavljeni v vsaj dveh znanstvenih in vsaj dveh strokovnih publikacijah, tiskalnik pa bomo predstavili bodisi na javni delavnici ali sejmu. Zaupni rezultati bodo predvidoma predmet najmanj ene patentne prijave.

Povzetek projekta EN:

3D printing is a popular term for computer-controlled additive manufacturing where a product is shaped by adding rather than subtracting the material. While the concept of additive manufacturing is not new, it is the development of computers which opens up new possibilities. Technological advances are paving the way for 3D printing also in construction where concrete is in the spotlight due to its properties and wide applicability. Concrete consumption constitutes ~80 % of total material consumption and therefore 3D concrete printing has the potential to digitalize and automate the construction industry. Furthermore, digital fabrication methods will also shift the design approach since topologically optimized structures are material-minimized but geometrically complex elements which can only be designed and fabricated by digital means.

The most promising 3D printing method is an extrusion-based approach where concrete is pumped to the printhead and squeezed through a circular or square nozzle. The motion of the printhead is enabled by an articulated robotic arm or a gantry crane. The behaviour of the filament after the extrusion is governed by its rheological properties. While stiff concrete enables the deposition of a larger number of subsequent layers without collapse the bond between the layers is poor. Soft filaments, on the other hand, bond well but they are prone to collapse due to the weight of the subsequent layers. Extrusion-based 3D printing with concrete, therefore, relies on the manipulation of the rheological properties and the use of accelerators. Both requires expert knowledge and testing equipment not readily available in the construction industry. This project thus proposes printing with two filaments where the soft filament binds the layers of stiff filaments and where the latter provide the stability to the printed product. The mix design of such filaments is simple.

The 3D-printed structural elements are often assessed by adopting the principles of masonry construction. The aptness of such an approach is even more evident in two-filament printing. Masonry structures are associated with bricks and brick forming is done by extrusion. This leads us to the idea of using two-filament printing to fabricate earth buildings. Building with earth, which contains a sufficient amount of clay, is an ancient construction technique which is on the rise in modern construction due to sustainability benefits and accessibility. However, to facilitate the implementation, it is of paramount importance to develop digital fabrication methods since a lack of technology is recognized as a technical barrier in earth construction.

Project objectives are thus defined as:
• develop a double-nozzle printhead and build a small-size concrete printer prototype for two-filament printing which enables the usage of simple concrete and mortar compositions;
• determine the range of suitable rheological parameters for stiff and soft filaments for concrete and earth and establish a system of simple test methods to assess filament suitability;
• demonstrate the two-filament 3D printing technology by printing a small-scale structural element, test both elements and compare the results with structural analysis derived from masonry structures.

The main results of the project are a printer prototype and a showcase of two-filament printing with concrete and earth which will be presented in a promotional video. The results in the public domain will also include the report on filament properties for concrete and earth as well as the structural analysis protocol. Confidential results will comprise the printer specifications and design plans for the fabrication of the printer and its components. It is expected that results in the public domain will be published in at least two scientific and at least two technical journals, while the printer itself will be presented at a public workshop or a fair. Confidential results are expected to be the subject of at least one patent application.

Faze projekta in opis realizacije (delovni sklopi)