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Desenvolvimento de Formulações de Pastas de Gesso para Fabrico Aditivo
| Content Provider | Semantic Scholar |
|---|---|
| Author | Caetano, Daniel Esperança |
| Copyright Year | 2016 |
| Abstract | This paper reports a study on the effect of addition of accelerators and binders in plaster formulations as regards the variation of the setting time and mechanical resistance. The production of molds for ceramics is still held in an overwhelming majority by conventional processes leading to very high rate of material waste. Efficiency and cost are excellence factors with regard to industrial production processes. So, the additive manufacturing (AM) is the correct path for the optimization of waste material and for production of small series or single parts. The willingness to innovate provided the search for a new method for the production of plaster molds. Through the partnership between INEGI and CEI by Zippor, a new project emerged. Founded in AM, plaster extrusion can now become a reality. Then arises as a consequence of the aforesaid, the ADIMAQ project (“Fabrico ADItivo por extrusão e MAQuinagem para produção híbrida de modelos, moldes e moldações de grandes dimensões”). The main objective of this project is then passed by the development of a hybrid device that combines the AM technologies by extrusion deposition and subtractive manufacturing (SM) by machining, being the plaster a target of study. This work has as main objective the study of formulations of plaster for use in a hybrid process that combines the AM and the SM. The AM is currently an area with an immeasurable dimension and remains in constant expansion, although the use of plaster in these processes is still a gap to correct. The α hemihydrate and β hemihydrate without any additives have a very high setting time taking into account the concepts of AM and, therefore, the addition of supplements to the formulations in order to make this process faster is required. By adding setting accelerators, such as potassium sulphate, zinc sulphate or calcium carbonate, it is possible to reduce these setting times and thereby producing slurry that can achieve viscosity at a sufficiently fast speed to be extruded in an AM process. The low mechanical strength of plaster prevents their profitable use in machining processes, thereby leading the additive addition, in this case binders based on acrylic or vinyl, that allow increased mechanical strength and higher possibility of being machined. Were made and exposed in this work, the results of tests in order to control the setting time of the formulations, the flexural strength and viscosity of various formulations that in future will be tested at the level of AM and machinability. Desenvolvimento de formulações de pastas de gesso para fabrico aditivo |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://repositorio-aberto.up.pt/bitstream/10216/96868/2/125962.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
