Update README.md

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.