diff --git a/README.md b/README.md index cb6339c4f5cc8354b5697e885c6e15dfdc3bb7a6..7790a3f5dc1b0e4929d3172379b8eefb5c5368ea 100644 --- a/README.md +++ b/README.md @@ -94,7 +94,53 @@ And get a finished face mask with a replaceable wood pulp based filter <img src="images/l1_3.jpg" width="400" > +## Molding +In order to advance into mass production of the mask, we have been developing a 3D printed wood pulp mold, based on [Startasys](https://www.stratasysdirect.com/technologies/fused-deposition-modeling/fdm-tools-paper-pulp-molding). + +### Wood Pulp Molds + +<img src="images/M_1.PNG" width="400" > + +In the image above [[3](https://onlinelibrary.wiley.com/doi/abs/10.1002/pts.2289)] you can see how Wood Pulp Molds work. +The first part, called the moving half, of the mold is made from a solid material, and is the one that press the second part. +The second part, called the fixed half, has two different layers, this allows the water to flow through the fiber network, into a porous material, to the drainage channels (as you can see in the image above); this allows the mold to release water and keep its final form. + +### First iteration + +#### The Mold for Pulp Molding +You can find the mold .stl files in the following [link](https://github.com/FabLabUTFSM/WoodPulp-Filter---COVID-19/tree/master/3D_Models). + +<img src="images/M_2.jpg" width="400" > +(Models M_1 correspond to the iteration) + +#### Material Formula + +We used the following foormula for the first test: + +- Pulverized unbleached wood pulp: 11.3 grams + +It has to have the following texture: + +<img src="images/M_3.jpg" width="400" > + +- Water: 269 grams +- Polyvinyl acetate: 66.3 grams. + +#### Results + + +In the following pictures you can see the first results we got: + +<img src="images/M_4.jpg" width="200" > <img src="images/M_5.jpg" width="400" > + +#### Conclusions + +- After 12 hours of drying, the material was wet. We will improve the geometry and introduce porosity that expells the water out. +- The porous material layer of the fixed half must have a 1 mm thickness. +- We must add drain channels to the fixed half. +- The material is getting a good resolution. +- The cylinders for the respiration holes must be extended.