The process of making silicone molds usually includes the following steps:
1. Preliminary preparation
Prepare tools and materials:
Acrylic sheet (or smooth materials such as plastic sheet, glass sheet, etc.)
Hot melt glue gun and glue strip
Two-component silicone (including silicone and curing agent)
Mold release agent
Measuring cup, electronic scale
Stirring rod (or glass rod)
Scissors, knife
Brush
Vacuum equipment (optional, used to remove bubbles)
Master mold processing:
Remove the processing burrs and supports on the master mold, and be careful not to damage the surface details.
Fix the master mold according to the requirements of the drawing to ensure dimensional accuracy.
Wash and brush the master mold with detergent water or vaseline to ensure a clean surface.
2. Build the mold frame and fix the master mold
Build the mold frame:
Build a suitable mold frame with acrylic sheet according to the size of the master mold.
Seal the joints with glue strips to prevent silicone from leaking out.
Fix the master mold:
Fix the master mold in the middle of the mold frame with glue strips to ensure that there will be no displacement or floating after pouring liquid silicone.
3. Prepare and mix silicone
Prepare silicone:
Prepare the right amount of silicone according to the correct ratio of silicone and curing agent (usually by weight) according to the size of the master mold.
The amount of curing agent added needs to be adjusted according to the ambient temperature to ensure a moderate curing speed.
Mixing and stirring:
Pour the weighed silicone and curing agent into the same container and mix them.
Use a stirring rod to stir thoroughly to avoid partial curing or non-curing.
4. Remove bubbles and pour silicone
Exhaust bubbles:
If conditions permit, put the evenly stirred silicone into a vacuum machine to evacuate and remove bubbles.
The vacuuming time should not be too long, generally not more than 10 minutes, to avoid cross-linking and curing reaction of silicone.
Pouring silicone:
Pour a small amount of silicone and brush it on the surface of the master mold with a brush to make the silicone and the gaps of the surface texture of the master mold in close contact.
Slowly pour the remaining silicone at one point to allow the liquid silicone to flow naturally in the mold frame.
The silicone should cover a certain distance (such as 2 cm to 5 cm) above the highest point of the master mold to ensure the integrity of the mold.
5. Waiting for curing and removing from mold
Waiting for curing:
Place the mold frame filled with glue on a flat surface and wait for curing.
The curing time depends on the ambient temperature and the amount of curing agent added. Generally, the higher the temperature, the faster the curing. When the temperature is below 0℃, the curing agent will lose its activity and it will be difficult to cure.
Removing from mold:
After the silicone is completely cured (usually 6 to 8 hours or longer), find the parting line mark and cut the mold frame.
Carefully remove the silicone mold from the mold frame to avoid damaging the mold surface.
6. Subsequent processing and optimization
Trimming edges:
Use scissors to trim excess silicone on the edges to make the mold neater.
Placement and testing:
It is recommended to place the prepared silicone mold for 24 hours before putting it into use to ensure stable performance in all aspects.
Perform necessary tests before use to ensure the applicability and durability of the mold.
In summary, the process of making silicone molds includes multiple steps such as preliminary preparation, building mold frames and fixing mother molds, configuring and mixing silicone, venting bubbles and pouring silicone, waiting for curing and removing from molds, and subsequent processing and optimization. Each step needs to be carefully performed to ensure that the final silicone mold quality meets the requirements.