#  Molding 

 



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  expand\_more  

 
  

 

## Materials

- Ecoflex 00-30, Ecoflex 00-35 2-part silicone rubber
- Smooth-On Sil-Poxy
- Acrylic sheets for laser cutting (1/4" and 1/8" think)
- Silicon mold release
- Pneumatic tubing
- Smooth-On Skin Tite
- Syringe, mixing cups, lab gloves, stir stick, pump

 ![molding](/sites/g/files/omnuum4601/files/srtsandbox/files/2_04.png)

 


## Fabrication Process

1\. Laser cut the molds from acrylic sheets, one for top layer and one for bottom layer. Assemble and glue the parts.

2\. Mix Ecoflex 00-30 part A and B and pour it into the molds. Mold release and vacuum de-bubble are not necessary here because of the materiality of the acrylic mold and silicon rubber. Keep them on a completely flat surface; otherwise the thickness would be uneven. Evenly distribute the silicone and rub off the excess silicone.

3\. Leave the silicone to set and cure in about 2 hours. Use a heat lamp to accelerate the process.

4\. Peel off the cured silicone carefully.

5\. Assemble the tube into the reserved channels. Use a little amount of uncured Ecoflex 00-30 to glue the top and bottom parts together. Apply some mold release on the thin air channels to prevent them from clogging together. Carefully squeeze out all the air bubbles; otherwise they become the weak point during inflation. Use Ecoflex 00-35 if this process can be done in 2 mins. Wait for the silicon to cure.

6\. Actuate and check for clog and openings. Use a thin rod to pierce clogs and Ecoflex 00-35 to seal openings as needed.


## Material Test

A series of silicone from Smooth-On was tested: Ecoflex 00-20, Ecoflex 00-30, Ecoflex 00-35, Dragon Skin 10 FAST, Dragon Skin FX Pro. The table below compares their key properties. Among them, Ecoflex 00-30 has a low shore hardness which makes it a very stretchable and flexible material. It’s tensile strength and elongation at break is higher than Ecoflex 00-20 so that it’s harder to break while inflated. Its low mixed viscosity comparing to Dragon Skin series makes it easier to mix and pour. From a series of experiments, Ecoflex 00-30 turns out to be the most suitable one for making this mask. Ecoflex 00-35 has the same properties as Ecoflex 00-30, but with very short cure time and an off-white color. This makes it a better candidate for gluing and repairing holes.

 ![The table compares key properties](/sites/g/files/omnuum4601/files/2025-05/n.png)