Week 12
Molding and Casting
Group Assignment
- Review the safety data sheets for each of your molding and casting materials, then make and compare test casts with each of them
- Compare printing vs milling molds
Safety data sheets
The moulding and casting project the student made was a cake pop mould casted with cake. Since the cake recipe does not come with a safety data sheet the only safety data sheet for this project is for the silicone used.
The silicone used is from Zhermack industrial and product number is ZA13. See the Material Safety Data sheet here
| Zhermack ZA13 Silicone | Unit |
| Mix Ratio By Weight | 1A : 1B |
| Density | 1.07 g/cc |
| Viscosity Of Pre-Catalysed Mix | 4500 ± 500 cP |
| Mixing Time @ 23°C | 1 min |
| Working Time @ 23°C | 40 - 50 mins |
| Setting Time @ 23°C | 2.5 - 3 hrs |
| Shore A Hardness | A13 |
| Tensile Strength | 3.0 ± 0.2 N/mm² |
| Elongation At Break | 450 ± 20% |
| Tear Resistance Die B | 14 ± 1 N/mm |
| Tear Resistance Die C | 9 ± 1 N/mm |
| Cure Colour | Translucent |
Table borrowed from Andri Sæmundsson
Printing vs milling molds
This cycle in the Fab Academy is the first cycle where students were allowed to 3d print their moulds. However, the moulds can not be printed using a FDM printer as the layers are not smooth enough. Students can only use a resin printer to create moulds. Fab Lab Reykjavik does not have a readily available resin printer so students have to use the CNC mill to create their moulds.